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 jdk.internal.loader.BootLoader;
29 import jdk.internal.vm.annotation.Stable;
30 import jdk.internal.org.objectweb.asm.ClassWriter;
31 import jdk.internal.org.objectweb.asm.FieldVisitor;
32 import jdk.internal.org.objectweb.asm.MethodVisitor;
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.Arrays;
40 import java.util.Map;
41 import java.util.concurrent.ConcurrentHashMap;
42 import java.util.concurrent.ConcurrentMap;
43 import java.util.function.Function;
44
45 import static java.lang.invoke.LambdaForm.BasicType;
46 import static java.lang.invoke.LambdaForm.BasicType.*;
47 import static java.lang.invoke.MethodHandleStatics.*;
48 import static jdk.internal.org.objectweb.asm.Opcodes.*;
49
50 /**
51 * The flavor of method handle which emulates an invoke instruction
52 * on a predetermined argument. The JVM dispatches to the correct method
53 * when the handle is created, not when it is invoked.
54 *
55 * All bound arguments are encapsulated in dedicated species.
56 */
57 /*non-public*/ abstract class BoundMethodHandle extends MethodHandle {
58
59 /*non-public*/ BoundMethodHandle(MethodType type, LambdaForm form) {
60 super(type, form);
61 assert(speciesData() == speciesData(form));
62 }
63
64 //
65 // BMH API and internals
66 //
67
68 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) {
69 // for some type signatures, there exist pre-defined concrete BMH classes
70 try {
71 switch (xtype) {
72 case L_TYPE:
73 return bindSingle(type, form, x); // Use known fast path.
74 case I_TYPE:
75 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x));
76 case J_TYPE:
77 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x);
78 case F_TYPE:
79 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x);
80 case D_TYPE:
81 return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x);
82 default : throw newInternalError("unexpected xtype: " + xtype);
83 }
84 } catch (Throwable t) {
85 throw newInternalError(t);
86 }
87 }
88
89 /*non-public*/
90 LambdaFormEditor editor() {
91 return form.editor();
92 }
93
94 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) {
95 return Species_L.make(type, form, x);
96 }
97
98 @Override // there is a default binder in the super class, for 'L' types only
99 /*non-public*/
100 BoundMethodHandle bindArgumentL(int pos, Object value) {
101 return editor().bindArgumentL(this, pos, value);
102 }
103 /*non-public*/
104 BoundMethodHandle bindArgumentI(int pos, int value) {
105 return editor().bindArgumentI(this, pos, value);
106 }
107 /*non-public*/
108 BoundMethodHandle bindArgumentJ(int pos, long value) {
109 return editor().bindArgumentJ(this, pos, value);
110 }
111 /*non-public*/
112 BoundMethodHandle bindArgumentF(int pos, float value) {
113 return editor().bindArgumentF(this, pos, value);
114 }
115 /*non-public*/
116 BoundMethodHandle bindArgumentD(int pos, double value) {
117 return editor().bindArgumentD(this, pos, value);
118 }
119
120 @Override
121 BoundMethodHandle rebind() {
122 if (!tooComplex()) {
123 return this;
124 }
125 return makeReinvoker(this);
126 }
127
128 private boolean tooComplex() {
129 return (fieldCount() > FIELD_COUNT_THRESHOLD ||
130 form.expressionCount() > FORM_EXPRESSION_THRESHOLD);
131 }
132 private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count
133 private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count
134
135 /**
136 * A reinvoker MH has this form:
137 * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }}
138 */
139 static BoundMethodHandle makeReinvoker(MethodHandle target) {
140 LambdaForm form = DelegatingMethodHandle.makeReinvokerForm(
141 target, MethodTypeForm.LF_REBIND,
142 Species_L.SPECIES_DATA, Species_L.SPECIES_DATA.getterFunction(0));
143 return Species_L.make(target.type(), form, target);
144 }
145
146 /**
147 * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a
148 * static field containing this value, and they must accordingly implement this method.
149 */
150 /*non-public*/ abstract SpeciesData speciesData();
151
152 /*non-public*/ static SpeciesData speciesData(LambdaForm form) {
153 Object c = form.names[0].constraint;
154 if (c instanceof SpeciesData)
155 return (SpeciesData) c;
156 // if there is no BMH constraint, then use the null constraint
157 return SpeciesData.EMPTY;
158 }
159
160 /**
161 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount().
162 */
163 /*non-public*/ abstract int fieldCount();
164
165 @Override
166 Object internalProperties() {
167 return "\n& BMH="+internalValues();
168 }
169
170 @Override
171 final Object internalValues() {
172 Object[] boundValues = new Object[speciesData().fieldCount()];
173 for (int i = 0; i < boundValues.length; ++i) {
174 boundValues[i] = arg(i);
175 }
176 return Arrays.asList(boundValues);
177 }
178
179 /*non-public*/ final Object arg(int i) {
180 try {
181 switch (speciesData().fieldType(i)) {
182 case L_TYPE: return speciesData().getters[i].invokeBasic(this);
183 case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this);
184 case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this);
185 case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this);
186 case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this);
187 }
188 } catch (Throwable ex) {
189 throw newInternalError(ex);
190 }
191 throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i);
192 }
193
194 //
195 // cloning API
196 //
197
198 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf);
199 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg);
200 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg);
201 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg);
202 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg);
203 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
204
205 //
206 // concrete BMH classes required to close bootstrap loops
207 //
208
209 private // make it private to force users to access the enclosing class first
210 static final class Species_L extends BoundMethodHandle {
211 final Object argL0;
212 private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
213 super(mt, lf);
214 this.argL0 = argL0;
215 }
216 @Override
217 /*non-public*/ SpeciesData speciesData() {
218 return SPECIES_DATA;
219 }
220 @Override
221 /*non-public*/ int fieldCount() {
222 return 1;
223 }
224 /*non-public*/ static final SpeciesData SPECIES_DATA = new SpeciesData("L", Species_L.class);
225 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) {
226 return new Species_L(mt, lf, argL0);
227 }
228 @Override
229 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
230 return new Species_L(mt, lf, argL0);
231 }
232 @Override
233 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
234 try {
235 return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
236 } catch (Throwable ex) {
237 throw uncaughtException(ex);
238 }
239 }
240 @Override
241 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
242 try {
243 return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
244 } catch (Throwable ex) {
245 throw uncaughtException(ex);
246 }
247 }
248 @Override
249 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
250 try {
251 return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
252 } catch (Throwable ex) {
253 throw uncaughtException(ex);
254 }
255 }
256 @Override
257 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
258 try {
259 return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
260 } catch (Throwable ex) {
261 throw uncaughtException(ex);
262 }
263 }
264 @Override
265 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
266 try {
267 return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
268 } catch (Throwable ex) {
269 throw uncaughtException(ex);
270 }
271 }
272 }
273
274 //
275 // BMH species meta-data
276 //
277
278 /**
279 * Meta-data wrapper for concrete BMH types.
280 * Each BMH type corresponds to a given sequence of basic field types (LIJFD).
281 * The fields are immutable; their values are fully specified at object construction.
282 * Each BMH type supplies an array of getter functions which may be used in lambda forms.
283 * A BMH is constructed by cloning a shorter BMH and adding one or more new field values.
284 * The shortest possible BMH has zero fields; its class is SimpleMethodHandle.
285 * BMH species are not interrelated by subtyping, even though it would appear that
286 * a shorter BMH could serve as a supertype of a longer one which extends it.
287 */
288 static class SpeciesData {
289 private final String typeChars;
290 private final BasicType[] typeCodes;
291 private final Class<? extends BoundMethodHandle> clazz;
292 // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH
293 // Therefore, we need a non-final link in the chain. Use array elements.
294 @Stable private final MethodHandle[] constructor;
295 @Stable private final MethodHandle[] getters;
296 @Stable private final NamedFunction[] nominalGetters;
297 @Stable private final SpeciesData[] extensions;
298
299 /*non-public*/ int fieldCount() {
300 return typeCodes.length;
301 }
302 /*non-public*/ BasicType fieldType(int i) {
303 return typeCodes[i];
304 }
305 /*non-public*/ char fieldTypeChar(int i) {
306 return typeChars.charAt(i);
307 }
308 Object fieldSignature() {
309 return typeChars;
310 }
311 public Class<? extends BoundMethodHandle> fieldHolder() {
312 return clazz;
313 }
314 public String toString() {
315 return "SpeciesData<"+fieldSignature()+">";
316 }
317
318 /**
319 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that
320 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding
321 * getter.
322 */
323 NamedFunction getterFunction(int i) {
324 NamedFunction nf = nominalGetters[i];
325 assert(nf.memberDeclaringClassOrNull() == fieldHolder());
326 assert(nf.returnType() == fieldType(i));
327 return nf;
328 }
329
330 NamedFunction[] getterFunctions() {
331 return nominalGetters;
332 }
333
334 MethodHandle[] getterHandles() { return getters; }
335
336 MethodHandle constructor() {
337 return constructor[0];
338 }
339
340 static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class);
341
342 SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) {
343 this.typeChars = types;
344 this.typeCodes = basicTypes(types);
345 this.clazz = clazz;
346 if (!INIT_DONE) {
347 this.constructor = new MethodHandle[1]; // only one ctor
348 this.getters = new MethodHandle[types.length()];
349 this.nominalGetters = new NamedFunction[types.length()];
350 } else {
351 this.constructor = Factory.makeCtors(clazz, types, null);
352 this.getters = Factory.makeGetters(clazz, types, null);
353 this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters);
354 }
355 this.extensions = new SpeciesData[ARG_TYPE_LIMIT];
356 }
357
358 private void initForBootstrap() {
359 assert(!INIT_DONE);
360 if (constructor() == null) {
361 String types = typeChars;
362 CACHE.put(types, this);
363 Factory.makeCtors(clazz, types, this.constructor);
364 Factory.makeGetters(clazz, types, this.getters);
365 Factory.makeNominalGetters(types, this.nominalGetters, this.getters);
366 }
367 }
368
369 private static final ConcurrentMap<String, SpeciesData> CACHE = new ConcurrentHashMap<>();
370 private static final boolean INIT_DONE; // set after <clinit> finishes...
371
372 SpeciesData extendWith(byte type) {
373 return extendWith(BasicType.basicType(type));
374 }
375
376 SpeciesData extendWith(BasicType type) {
377 int ord = type.ordinal();
378 SpeciesData d = extensions[ord];
379 if (d != null) return d;
380 extensions[ord] = d = get(typeChars+type.basicTypeChar());
381 return d;
382 }
383
384 private static SpeciesData get(String types) {
385 return CACHE.computeIfAbsent(types, new Function<String, SpeciesData>() {
386 @Override
387 public SpeciesData apply(String types) {
388 Class<? extends BoundMethodHandle> bmhcl = Factory.getConcreteBMHClass(types);
389 // SpeciesData instantiation may throw VirtualMachineError because of
390 // code cache overflow...
391 SpeciesData speciesData = new SpeciesData(types, bmhcl);
392 // CHM.computeIfAbsent ensures only one SpeciesData will be set
393 // successfully on the concrete BMH class if ever
394 Factory.setSpeciesDataToConcreteBMHClass(bmhcl, speciesData);
395 // the concrete BMH class is published via SpeciesData instance
396 // returned here only after it's SPECIES_DATA field is set
397 return speciesData;
398 }
399 });
400 }
401
402 /**
403 * This is to be called when assertions are enabled. It checks whether SpeciesData for all of the statically
404 * defined species subclasses of BoundMethodHandle has been added to the SpeciesData cache. See below in the
405 * static initializer for
406 */
407 static boolean speciesDataCachePopulated() {
408 Class<BoundMethodHandle> rootCls = BoundMethodHandle.class;
409 try {
410 for (Class<?> c : rootCls.getDeclaredClasses()) {
411 if (rootCls.isAssignableFrom(c)) {
412 final Class<? extends BoundMethodHandle> cbmh = c.asSubclass(BoundMethodHandle.class);
413 SpeciesData d = Factory.getSpeciesDataFromConcreteBMHClass(cbmh);
414 assert(d != null) : cbmh.getName();
415 assert(d.clazz == cbmh);
416 assert(CACHE.get(d.typeChars) == d);
417 }
418 }
419 } catch (Throwable e) {
420 throw newInternalError(e);
421 }
422 return true;
423 }
424
425 static {
426 // Pre-fill the BMH species-data cache with EMPTY and all BMH's inner subclasses.
427 EMPTY.initForBootstrap();
428 Species_L.SPECIES_DATA.initForBootstrap();
429 // check that all static SpeciesData instances have been initialized
430 assert speciesDataCachePopulated();
431 // Note: Do not simplify this, because INIT_DONE must not be
432 // a compile-time constant during bootstrapping.
433 INIT_DONE = Boolean.TRUE;
434 }
435 }
436
437 static SpeciesData getSpeciesData(String types) {
438 return SpeciesData.get(types);
439 }
440
441 /**
442 * Generation of concrete BMH classes.
443 *
444 * A concrete BMH species is fit for binding a number of values adhering to a
445 * given type pattern. Reference types are erased.
446 *
447 * BMH species are cached by type pattern.
448 *
449 * A BMH species has a number of fields with the concrete (possibly erased) types of
450 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs,
451 * which can be included as names in lambda forms.
452 */
453 static class Factory {
454
455 static final String JLO_SIG = "Ljava/lang/Object;";
456 static final String JLS_SIG = "Ljava/lang/String;";
457 static final String JLC_SIG = "Ljava/lang/Class;";
458 static final String MH = "java/lang/invoke/MethodHandle";
459 static final String MH_SIG = "L"+MH+";";
460 static final String BMH = "java/lang/invoke/BoundMethodHandle";
461 static final String BMH_SIG = "L"+BMH+";";
462 static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData";
463 static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";";
464 static final String STABLE_SIG = "Ljdk/internal/vm/annotation/Stable;";
465
466 static final String SPECIES_PREFIX_NAME = "Species_";
467 static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME;
468 static final String SPECIES_CLASS_PREFIX = SPECIES_PREFIX_PATH.replace('/', '.');
469
470 static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG;
471 static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG;
472 static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG;
473 static final String VOID_SIG = "()V";
474 static final String INT_SIG = "()I";
475
476 static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;";
477
478 static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
479
480 static final ConcurrentMap<String, Class<? extends BoundMethodHandle>> CLASS_CACHE = new ConcurrentHashMap<>();
481
482 /**
483 * Get a concrete subclass of BMH for a given combination of bound types.
484 *
485 * @param types the type signature, wherein reference types are erased to 'L'
486 * @return the concrete BMH class
487 */
488 static Class<? extends BoundMethodHandle> getConcreteBMHClass(String types) {
489 // CHM.computeIfAbsent ensures generateConcreteBMHClass is called
490 // only once per key.
491 return CLASS_CACHE.computeIfAbsent(
492 types, new Function<String, Class<? extends BoundMethodHandle>>() {
493 @Override
494 public Class<? extends BoundMethodHandle> apply(String types) {
495 String shortTypes = LambdaForm.shortenSignature(types);
496 String className = SPECIES_CLASS_PREFIX + shortTypes;
497 Class<?> c = BootLoader.loadClassOrNull(className);
498 if (c != null) {
499 return c.asSubclass(BoundMethodHandle.class);
500 } else {
501 // Not pregenerated, generate the class
502 return generateConcreteBMHClass(shortTypes, types);
503 }
504 }
505 });
506 }
507
508 /**
509 * Generate a concrete subclass of BMH for a given combination of bound types.
510 *
511 * A concrete BMH species adheres to the following schema:
512 *
513 * <pre>
514 * class Species_[[types]] extends BoundMethodHandle {
515 * [[fields]]
516 * final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); }
517 * }
518 * </pre>
519 *
520 * The {@code [[types]]} signature is precisely the string that is passed to this
521 * method.
522 *
523 * The {@code [[fields]]} section consists of one field definition per character in
524 * the type signature, adhering to the naming schema described in the definition of
525 * {@link #makeFieldName}.
526 *
527 * For example, a concrete BMH species for two reference and one integral bound values
528 * would have the following shape:
529 *
530 * <pre>
531 * class BoundMethodHandle { ... private static
532 * final class Species_LLI extends BoundMethodHandle {
533 * final Object argL0;
534 * final Object argL1;
535 * final int argI2;
536 * private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
537 * super(mt, lf);
538 * this.argL0 = argL0;
539 * this.argL1 = argL1;
540 * this.argI2 = argI2;
541 * }
542 * final SpeciesData speciesData() { return SPECIES_DATA; }
543 * final int fieldCount() { return 3; }
544 * @Stable static SpeciesData SPECIES_DATA; // injected afterwards
545 * static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
546 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
547 * }
548 * final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
549 * return new Species_LLI(mt, lf, argL0, argL1, argI2);
550 * }
551 * final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
552 * return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
553 * }
554 * final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
555 * return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
556 * }
557 * final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
558 * return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
559 * }
560 * final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
561 * return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
562 * }
563 * public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
564 * return SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
565 * }
566 * }
567 * </pre>
568 *
569 * @param types the type signature, wherein reference types are erased to 'L'
570 * @return the generated concrete BMH class
571 */
572 static Class<? extends BoundMethodHandle> generateConcreteBMHClass(String shortTypes,
573 String types) {
574 final String className = speciesInternalClassName(shortTypes);
575 byte[] classFile = generateConcreteBMHClassBytes(shortTypes, types, className);
576
577 // load class
578 InvokerBytecodeGenerator.maybeDump(className, classFile);
579 Class<? extends BoundMethodHandle> bmhClass =
580 UNSAFE.defineClass(className, classFile, 0, classFile.length,
581 BoundMethodHandle.class.getClassLoader(), null)
582 .asSubclass(BoundMethodHandle.class);
583
584 return bmhClass;
585 }
586
587 /**
588 * @implNote this method is used by GenerateBMHClassesPlugin to enable
589 * ahead-of-time generation of BMH classes at link time. It does
590 * added validation since this string may be user provided.
591 */
592 static Map.Entry<String, byte[]> generateConcreteBMHClassBytes(
593 final String types) {
594 for (char c : types.toCharArray()) {
595 if ("LIJFD".indexOf(c) < 0) {
596 throw new IllegalArgumentException("All characters must "
597 + "correspond to a basic field type: LIJFD");
598 }
599 }
600 String shortTypes = LambdaForm.shortenSignature(types);
601 final String className = speciesInternalClassName(shortTypes);
602 return Map.entry(className,
603 generateConcreteBMHClassBytes(shortTypes, types, className));
604 }
605
606 private static String speciesInternalClassName(String shortTypes) {
607 return SPECIES_PREFIX_PATH + shortTypes;
608 }
609
610 static byte[] generateConcreteBMHClassBytes(final String shortTypes,
611 final String types, final String className) {
612 final String sourceFile = SPECIES_PREFIX_NAME + shortTypes;
613
614 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
615 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
616 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null);
617 cw.visitSource(sourceFile, null);
618
619 // emit static types and SPECIES_DATA fields
620 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null);
621 fw.visitAnnotation(STABLE_SIG, true);
622 fw.visitEnd();
623
624 // emit bound argument fields
625 for (int i = 0; i < types.length(); ++i) {
626 final char t = types.charAt(i);
627 final String fieldName = makeFieldName(types, i);
628 final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t);
629 cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd();
630 }
631
632 MethodVisitor mv;
633
634 // emit constructor
635 mv = cw.visitMethod(ACC_PRIVATE, "<init>", makeSignature(types, true), null, null);
636 mv.visitCode();
637 mv.visitVarInsn(ALOAD, 0); // this
638 mv.visitVarInsn(ALOAD, 1); // type
639 mv.visitVarInsn(ALOAD, 2); // form
640
641 mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false);
642
643 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
644 // i counts the arguments, j counts corresponding argument slots
645 char t = types.charAt(i);
646 mv.visitVarInsn(ALOAD, 0);
647 mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3
648 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t));
649 if (t == 'J' || t == 'D') {
650 ++j; // adjust argument register access
651 }
652 }
653
654 mv.visitInsn(RETURN);
655 mv.visitMaxs(0, 0);
656 mv.visitEnd();
657
658 // emit implementation of speciesData()
659 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null);
660 mv.visitCode();
661 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
662 mv.visitInsn(ARETURN);
663 mv.visitMaxs(0, 0);
664 mv.visitEnd();
665
666 // emit implementation of fieldCount()
667 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null);
668 mv.visitCode();
669 int fc = types.length();
670 if (fc <= (ICONST_5 - ICONST_0)) {
671 mv.visitInsn(ICONST_0 + fc);
672 } else {
673 mv.visitIntInsn(SIPUSH, fc);
674 }
675 mv.visitInsn(IRETURN);
676 mv.visitMaxs(0, 0);
677 mv.visitEnd();
678 // emit make() ...factory method wrapping constructor
679 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null);
680 mv.visitCode();
681 // make instance
682 mv.visitTypeInsn(NEW, className);
683 mv.visitInsn(DUP);
684 // load mt, lf
685 mv.visitVarInsn(ALOAD, 0); // type
686 mv.visitVarInsn(ALOAD, 1); // form
687 // load factory method arguments
688 for (int i = 0, j = 0; i < types.length(); ++i, ++j) {
689 // i counts the arguments, j counts corresponding argument slots
690 char t = types.charAt(i);
691 mv.visitVarInsn(typeLoadOp(t), j + 2); // parameters start at 3
692 if (t == 'J' || t == 'D') {
693 ++j; // adjust argument register access
694 }
695 }
696
697 // finally, invoke the constructor and return
698 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
699 mv.visitInsn(ARETURN);
700 mv.visitMaxs(0, 0);
701 mv.visitEnd();
702
703 // emit copyWith()
704 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null);
705 mv.visitCode();
706 // make instance
707 mv.visitTypeInsn(NEW, className);
708 mv.visitInsn(DUP);
709 // load mt, lf
710 mv.visitVarInsn(ALOAD, 1);
711 mv.visitVarInsn(ALOAD, 2);
712 // put fields on the stack
713 emitPushFields(types, className, mv);
714 // finally, invoke the constructor and return
715 mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
716 mv.visitInsn(ARETURN);
717 mv.visitMaxs(0, 0);
718 mv.visitEnd();
719
720 // for each type, emit copyWithExtendT()
721 for (BasicType type : BasicType.ARG_TYPES) {
722 int ord = type.ordinal();
723 char btChar = type.basicTypeChar();
724 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE);
725 mv.visitCode();
726 // return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg)
727 // obtain constructor
728 mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
729 int iconstInsn = ICONST_0 + ord;
730 assert(iconstInsn <= ICONST_5);
731 mv.visitInsn(iconstInsn);
732 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false);
733 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false);
734 // load mt, lf
735 mv.visitVarInsn(ALOAD, 1);
736 mv.visitVarInsn(ALOAD, 2);
737 // put fields on the stack
738 emitPushFields(types, className, mv);
739 // put narg on stack
740 mv.visitVarInsn(typeLoadOp(btChar), 3);
741 // finally, invoke the constructor and return
742 mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false);
743 mv.visitInsn(ARETURN);
744 mv.visitMaxs(0, 0);
745 mv.visitEnd();
746 }
747
748 cw.visitEnd();
749
750 return cw.toByteArray();
751 }
752
753 private static int typeLoadOp(char t) {
754 switch (t) {
755 case 'L': return ALOAD;
756 case 'I': return ILOAD;
757 case 'J': return LLOAD;
758 case 'F': return FLOAD;
759 case 'D': return DLOAD;
760 default : throw newInternalError("unrecognized type " + t);
761 }
762 }
763
764 private static void emitPushFields(String types, String className, MethodVisitor mv) {
765 for (int i = 0; i < types.length(); ++i) {
766 char tc = types.charAt(i);
767 mv.visitVarInsn(ALOAD, 0);
768 mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc));
769 }
770 }
771
772 static String typeSig(char t) {
773 return t == 'L' ? JLO_SIG : String.valueOf(t);
774 }
775
776 //
777 // Getter MH generation.
778 //
779
780 private static MethodHandle makeGetter(Class<?> cbmhClass, String types, int index) {
781 String fieldName = makeFieldName(types, index);
782 Class<?> fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType();
783 try {
784 return LOOKUP.findGetter(cbmhClass, fieldName, fieldType);
785 } catch (NoSuchFieldException | IllegalAccessException e) {
786 throw newInternalError(e);
787 }
788 }
789
790 static MethodHandle[] makeGetters(Class<?> cbmhClass, String types, MethodHandle[] mhs) {
791 if (mhs == null) mhs = new MethodHandle[types.length()];
792 for (int i = 0; i < mhs.length; ++i) {
793 mhs[i] = makeGetter(cbmhClass, types, i);
794 assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass);
795 }
796 return mhs;
797 }
798
799 static MethodHandle[] makeCtors(Class<? extends BoundMethodHandle> cbmh, String types, MethodHandle mhs[]) {
800 if (mhs == null) mhs = new MethodHandle[1];
801 if (types.equals("")) return mhs; // hack for empty BMH species
802 mhs[0] = makeCbmhCtor(cbmh, types);
803 return mhs;
804 }
805
806 static NamedFunction[] makeNominalGetters(String types, NamedFunction[] nfs, MethodHandle[] getters) {
807 if (nfs == null) nfs = new NamedFunction[types.length()];
808 for (int i = 0; i < nfs.length; ++i) {
809 nfs[i] = new NamedFunction(getters[i]);
810 }
811 return nfs;
812 }
813
814 //
815 // Auxiliary methods.
816 //
817
818 static SpeciesData getSpeciesDataFromConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh) {
819 try {
820 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
821 return (SpeciesData) F_SPECIES_DATA.get(null);
822 } catch (ReflectiveOperationException ex) {
823 throw newInternalError(ex);
824 }
825 }
826
827 static void setSpeciesDataToConcreteBMHClass(Class<? extends BoundMethodHandle> cbmh, SpeciesData speciesData) {
828 try {
829 Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA");
830 // ## FIXME: annotation parser can't create proxy classes until module system is fully initialzed
831 // assert F_SPECIES_DATA.getDeclaredAnnotation(Stable.class) != null;
832 F_SPECIES_DATA.set(null, speciesData);
833 } catch (ReflectiveOperationException ex) {
834 throw newInternalError(ex);
835 }
836 }
837
838 /**
839 * Field names in concrete BMHs adhere to this pattern:
840 * arg + type + index
841 * where type is a single character (L, I, J, F, D).
842 */
843 private static String makeFieldName(String types, int index) {
844 assert index >= 0 && index < types.length();
845 return "arg" + types.charAt(index) + index;
846 }
847
848 private static String makeSignature(String types, boolean ctor) {
849 StringBuilder buf = new StringBuilder(SIG_INCIPIT);
850 for (char c : types.toCharArray()) {
851 buf.append(typeSig(c));
852 }
853 return buf.append(')').append(ctor ? "V" : BMH_SIG).toString();
854 }
855
856 static MethodHandle makeCbmhCtor(Class<? extends BoundMethodHandle> cbmh, String types) {
857 try {
858 return LOOKUP.findStatic(cbmh, "make", MethodType.fromDescriptor(makeSignature(types, false), null));
859 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) {
860 throw newInternalError(e);
861 }
862 }
863 }
864
865 private static final Lookup LOOKUP = Lookup.IMPL_LOOKUP;
866
867 /**
868 * All subclasses must provide such a value describing their type signature.
869 */
870 static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY;
871
872 private static final SpeciesData[] SPECIES_DATA_CACHE = new SpeciesData[5];
873 private static SpeciesData checkCache(int size, String types) {
874 int idx = size - 1;
875 SpeciesData data = SPECIES_DATA_CACHE[idx];
876 if (data != null) return data;
877 SPECIES_DATA_CACHE[idx] = data = getSpeciesData(types);
878 return data;
879 }
880 static SpeciesData speciesData_L() { return checkCache(1, "L"); }
881 static SpeciesData speciesData_LL() { return checkCache(2, "LL"); }
882 static SpeciesData speciesData_LLL() { return checkCache(3, "LLL"); }
883 static SpeciesData speciesData_LLLL() { return checkCache(4, "LLLL"); }
884 static SpeciesData speciesData_LLLLL() { return checkCache(5, "LLLLL"); }
885 }