1 /*
2 * Copyright (c) 2017, 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.BytecodeName;
34
35 import java.lang.reflect.Constructor;
36 import java.lang.reflect.Field;
37 import java.lang.reflect.Modifier;
38 import java.security.AccessController;
39 import java.security.PrivilegedAction;
40 import java.security.ProtectionDomain;
41 import java.util.ArrayList;
42 import java.util.Collections;
43 import java.util.List;
44 import java.util.Objects;
45 import java.util.concurrent.ConcurrentHashMap;
46 import java.util.function.Function;
47
48 import static java.lang.invoke.LambdaForm.*;
49 import static java.lang.invoke.MethodHandleNatives.Constants.REF_getStatic;
50 import static java.lang.invoke.MethodHandleNatives.Constants.REF_putStatic;
51 import static java.lang.invoke.MethodHandleStatics.*;
52 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
53 import static jdk.internal.org.objectweb.asm.Opcodes.*;
54
55 /**
56 * Class specialization code.
57 * @param <T> top class under which species classes are created.
58 * @param <K> key which identifies individual specializations.
59 * @param <S> species data type.
60 */
61 /*non-public*/
62 abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesData> {
63 private final Class<T> topClass;
64 private final Class<K> keyType;
65 private final Class<S> metaType;
66 private final MemberName sdAccessor;
67 private final String sdFieldName;
68 private final List<MemberName> transformMethods;
69 private final MethodType baseConstructorType;
70 private final S topSpecies;
71 private final ConcurrentHashMap<K, S> cache = new ConcurrentHashMap<>();
72 private final Factory factory;
73 private @Stable boolean topClassIsSuper;
74
75 /** Return the top type mirror, for type {@code T} */
76 public final Class<T> topClass() { return topClass; }
77
78 /** Return the key type mirror, for type {@code K} */
79 public final Class<K> keyType() { return keyType; }
80
81 /** Return the species metadata type mirror, for type {@code S} */
82 public final Class<S> metaType() { return metaType; }
83
84 /** Report the leading arguments (if any) required by every species factory.
85 * Every species factory adds its own field types as additional arguments,
86 * but these arguments always come first, in every factory method.
87 */
88 protected MethodType baseConstructorType() { return baseConstructorType; }
89
90 /** Return the trivial species for the null sequence of arguments. */
91 protected final S topSpecies() { return topSpecies; }
92
93 /** Return the list of transform methods originally given at creation of this specializer. */
94 protected final List<MemberName> transformMethods() { return transformMethods; }
95
96 /** Return the factory object used to build and load concrete species code. */
97 protected final Factory factory() { return factory; }
98
99 /**
100 * Constructor for this class specializer.
101 * @param topClass type mirror for T
102 * @param keyType type mirror for K
103 * @param metaType type mirror for S
104 * @param baseConstructorType principal constructor type
105 * @param sdAccessor the method used to get the speciesData
106 * @param sdFieldName the name of the species data field, inject the speciesData object
107 * @param transformMethods optional list of transformMethods
108 */
109 protected ClassSpecializer(Class<T> topClass,
110 Class<K> keyType,
111 Class<S> metaType,
112 MethodType baseConstructorType,
113 MemberName sdAccessor,
114 String sdFieldName,
115 List<MemberName> transformMethods) {
116 this.topClass = topClass;
117 this.keyType = keyType;
118 this.metaType = metaType;
119 this.sdAccessor = sdAccessor;
120 this.transformMethods = List.copyOf(transformMethods);
121 this.sdFieldName = sdFieldName;
122 this.baseConstructorType = baseConstructorType.changeReturnType(void.class);
123 this.factory = makeFactory();
124 K tsk = topSpeciesKey();
125 S topSpecies = null;
126 if (tsk != null && topSpecies == null) {
127 // if there is a key, build the top species if needed:
128 topSpecies = findSpecies(tsk);
129 }
130 this.topSpecies = topSpecies;
131 }
132
133 // Utilities for subclass constructors:
134 protected static <T> Constructor<T> reflectConstructor(Class<T> defc, Class<?>... ptypes) {
135 try {
136 return defc.getDeclaredConstructor(ptypes);
137 } catch (NoSuchMethodException ex) {
138 throw newIAE(defc.getName()+"("+MethodType.methodType(void.class, ptypes)+")", ex);
139 }
140 }
141
142 protected static Field reflectField(Class<?> defc, String name) {
143 try {
144 return defc.getDeclaredField(name);
145 } catch (NoSuchFieldException ex) {
146 throw newIAE(defc.getName()+"."+name, ex);
147 }
148 }
149
150 private static RuntimeException newIAE(String message, Throwable cause) {
151 return new IllegalArgumentException(message, cause);
152 }
153
154 public final S findSpecies(K key) {
155 // Note: Species instantiation may throw VirtualMachineError because of
156 // code cache overflow. If this happens the species bytecode may be
157 // loaded but not linked to its species metadata (with MH's etc).
158 // That will cause a throw out of CHM.computeIfAbsent,
159 // which will shut down the caller thread.
160 //
161 // In a latter attempt to get the same species, the already-loaded
162 // class will be present in the system dictionary, causing an
163 // error when the species generator tries to reload it.
164 // We try to detect this case and link the pre-existing code.
165 //
166 // Although it would be better to start fresh by loading a new
167 // copy, we have to salvage the previously loaded but broken code.
168 // (As an alternative, we might spin a new class with a new name,
169 // or use the anonymous class mechanism.)
170 //
171 // In the end, as long as everybody goes through the same CHM,
172 // CHM.computeIfAbsent will ensure only one SpeciesData will be set
173 // successfully on a concrete class if ever.
174 // The concrete class is published via SpeciesData instance
175 // returned here only after the class and species data are linked together.
176 S speciesData = cache.computeIfAbsent(key, new Function<>() {
177 @Override
178 public S apply(K key1) {
179 return newSpeciesData(key1);
180 }
181 });
182 // Separating the creation of a placeholder SpeciesData instance above
183 // from the loading and linking a real one below ensures we can never
184 // accidentally call computeIfAbsent recursively. Replacing rather than
185 // updating the placeholder is done to ensure safe publication.
186 if (!speciesData.isResolved()) {
187 synchronized (speciesData) {
188 S existingSpeciesData = cache.get(key);
189 if (existingSpeciesData == speciesData) { // won the race
190 // create a new SpeciesData...
191 speciesData = newSpeciesData(key);
192 // load and link it...
193 speciesData = factory.loadSpecies(speciesData);
194 if (!cache.replace(key, existingSpeciesData, speciesData)) {
195 throw newInternalError("Concurrent loadSpecies");
196 }
197 } else { // lost the race; the retrieved existingSpeciesData is the final
198 speciesData = existingSpeciesData;
199 }
200 }
201 }
202 assert(speciesData != null && speciesData.isResolved());
203 return speciesData;
204 }
205
206 /**
207 * Meta-data wrapper for concrete subtypes of the top class.
208 * Each concrete subtype corresponds to a given sequence of basic field types (LIJFD).
209 * The fields are immutable; their values are fully specified at object construction.
210 * Each species supplies an array of getter functions which may be used in lambda forms.
211 * A concrete value is always constructed from the full tuple of its field values,
212 * accompanied by the required constructor parameters.
213 * There *may* also be transforms which cloning a species instance and
214 * either replace a constructor parameter or add one or more new field values.
215 * The shortest possible species has zero fields.
216 * Subtypes are not interrelated among themselves by subtyping, even though
217 * it would appear that a shorter species could serve as a supertype of a
218 * longer one which extends it.
219 */
220 public abstract class SpeciesData {
221 // Bootstrapping requires circular relations Class -> SpeciesData -> Class
222 // Therefore, we need non-final links in the chain. Use @Stable fields.
223 private final K key;
224 private final List<Class<?>> fieldTypes;
225 @Stable private Class<? extends T> speciesCode;
226 @Stable private List<MethodHandle> factories;
227 @Stable private List<MethodHandle> getters;
228 @Stable private List<LambdaForm.NamedFunction> nominalGetters;
229 @Stable private final MethodHandle[] transformHelpers = new MethodHandle[transformMethods.size()];
230
231 protected SpeciesData(K key) {
232 this.key = keyType.cast(Objects.requireNonNull(key));
233 List<Class<?>> types = deriveFieldTypes(key);
234 this.fieldTypes = List.copyOf(types);
235 }
236
237 public final K key() {
238 return key;
239 }
240
241 protected final List<Class<?>> fieldTypes() {
242 return fieldTypes;
243 }
244
245 protected final int fieldCount() {
246 return fieldTypes.size();
247 }
248
249 protected ClassSpecializer<T,K,S> outer() {
250 return ClassSpecializer.this;
251 }
252
253 protected final boolean isResolved() {
254 return speciesCode != null && factories != null && !factories.isEmpty();
255 }
256
257 @Override public String toString() {
258 return metaType.getSimpleName() + "[" + key.toString() + " => " + (isResolved() ? speciesCode.getSimpleName() : "UNRESOLVED") + "]";
259 }
260
261 @Override
262 public int hashCode() {
263 return key.hashCode();
264 }
265
266 @Override
267 public boolean equals(Object obj) {
268 if (!(obj instanceof ClassSpecializer.SpeciesData)) {
269 return false;
270 }
271 @SuppressWarnings("rawtypes")
272 ClassSpecializer.SpeciesData that = (ClassSpecializer.SpeciesData) obj;
273 return this.outer() == that.outer() && this.key.equals(that.key);
274 }
275
276 /** Throws NPE if this species is not yet resolved. */
277 protected final Class<? extends T> speciesCode() {
278 return Objects.requireNonNull(speciesCode);
279 }
280
281 /**
282 * Return a {@link MethodHandle} which can get the indexed field of this species.
283 * The return type is the type of the species field it accesses.
284 * The argument type is the {@code fieldHolder} class of this species.
285 */
286 protected MethodHandle getter(int i) {
287 return getters.get(i);
288 }
289
290 /**
291 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that
292 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding
293 * getter.
294 */
295 protected LambdaForm.NamedFunction getterFunction(int i) {
296 LambdaForm.NamedFunction nf = nominalGetters.get(i);
297 assert(nf.memberDeclaringClassOrNull() == speciesCode());
298 assert(nf.returnType() == BasicType.basicType(fieldTypes.get(i)));
299 return nf;
300 }
301
302 protected List<LambdaForm.NamedFunction> getterFunctions() {
303 return nominalGetters;
304 }
305
306 protected List<MethodHandle> getters() {
307 return getters;
308 }
309
310 protected MethodHandle factory() {
311 return factories.get(0);
312 }
313
314 protected MethodHandle transformHelper(int whichtm) {
315 MethodHandle mh = transformHelpers[whichtm];
316 if (mh != null) return mh;
317 mh = deriveTransformHelper(transformMethods().get(whichtm), whichtm);
318 // Do a little type checking before we start using the MH.
319 // (It will be called with invokeBasic, so this is our only chance.)
320 final MethodType mt = transformHelperType(whichtm);
321 mh = mh.asType(mt);
322 return transformHelpers[whichtm] = mh;
323 }
324
325 private final MethodType transformHelperType(int whichtm) {
326 MemberName tm = transformMethods().get(whichtm);
327 ArrayList<Class<?>> args = new ArrayList<>();
328 ArrayList<Class<?>> fields = new ArrayList<>();
329 Collections.addAll(args, tm.getParameterTypes());
330 fields.addAll(fieldTypes());
331 List<Class<?>> helperArgs = deriveTransformHelperArguments(tm, whichtm, args, fields);
332 return MethodType.methodType(tm.getReturnType(), helperArgs);
333 }
334
335 // Hooks for subclasses:
336
337 /**
338 * Given a key, derive the list of field types, which all instances of this
339 * species must store.
340 */
341 protected abstract List<Class<?>> deriveFieldTypes(K key);
342
343 /**
344 * Given the index of a method in the transforms list, supply a factory
345 * method that takes the arguments of the transform, plus the local fields,
346 * and produce a value of the required type.
347 * You can override this to return null or throw if there are no transforms.
348 * This method exists so that the transforms can be "grown" lazily.
349 * This is necessary if the transform *adds* a field to an instance,
350 * which sometimtes requires the creation, on the fly, of an extended species.
351 * This method is only called once for any particular parameter.
352 * The species caches the result in a private array.
353 *
354 * @param transform the transform being implemented
355 * @param whichtm the index of that transform in the original list of transforms
356 * @return the method handle which creates a new result from a mix of transform
357 * arguments and field values
358 */
359 protected abstract MethodHandle deriveTransformHelper(MemberName transform, int whichtm);
360
361 /**
362 * During code generation, this method is called once per transform to determine
363 * what is the mix of arguments to hand to the transform-helper. The bytecode
364 * which marshals these arguments is open-coded in the species-specific transform.
365 * The two lists are of opaque objects, which you shouldn't do anything with besides
366 * reordering them into the output list. (They are both mutable, to make editing
367 * easier.) The imputed types of the args correspond to the transform's parameter
368 * list, while the imputed types of the fields correspond to the species field types.
369 * After code generation, this method may be called occasionally by error-checking code.
370 *
371 * @param transform the transform being implemented
372 * @param whichtm the index of that transform in the original list of transforms
373 * @param args a list of opaque objects representing the incoming transform arguments
374 * @param fields a list of opaque objects representing the field values of the receiver
375 * @param <X> the common element type of the various lists
376 * @return a new list
377 */
378 protected abstract <X> List<X> deriveTransformHelperArguments(MemberName transform, int whichtm,
379 List<X> args, List<X> fields);
380
381 /** Given a key, generate the name of the class which implements the species for that key.
382 * This algorithm must be stable.
383 *
384 * @return class name, which by default is {@code outer().topClass().getName() + "$Species_" + deriveTypeString(key)}
385 */
386 protected String deriveClassName() {
387 return outer().topClass().getName() + "$Species_" + deriveTypeString();
388 }
389
390 /**
391 * Default implementation collects basic type characters,
392 * plus possibly type names, if some types don't correspond
393 * to basic types.
394 *
395 * @return a string suitable for use in a class name
396 */
397 protected String deriveTypeString() {
398 List<Class<?>> types = fieldTypes();
399 StringBuilder buf = new StringBuilder();
400 StringBuilder end = new StringBuilder();
401 for (Class<?> type : types) {
402 BasicType basicType = BasicType.basicType(type);
403 if (basicType.basicTypeClass() == type) {
404 buf.append(basicType.basicTypeChar());
405 } else {
406 buf.append('V');
407 end.append(classSig(type));
408 }
409 }
410 String typeString;
411 if (end.length() > 0) {
412 typeString = BytecodeName.toBytecodeName(buf.append("_").append(end).toString());
413 } else {
414 typeString = buf.toString();
415 }
416 return LambdaForm.shortenSignature(typeString);
417 }
418
419 /**
420 * Report what immediate super-class to use for the concrete class of this species.
421 * Normally this is {@code topClass}, but if that is an interface, the factory must override.
422 * The super-class must provide a constructor which takes the {@code baseConstructorType} arguments, if any.
423 * This hook also allows the code generator to use more than one canned supertype for species.
424 *
425 * @return the super-class of the class to be generated
426 */
427 protected Class<? extends T> deriveSuperClass() {
428 final Class<T> topc = topClass();
429 if (!topClassIsSuper) {
430 try {
431 final Constructor<T> con = reflectConstructor(topc, baseConstructorType().parameterArray());
432 if (!topc.isInterface() && !Modifier.isPrivate(con.getModifiers())) {
433 topClassIsSuper = true;
434 }
435 } catch (Exception|InternalError ex) {
436 // fall through...
437 }
438 if (!topClassIsSuper) {
439 throw newInternalError("must override if the top class cannot serve as a super class");
440 }
441 }
442 return topc;
443 }
444 }
445
446 protected abstract S newSpeciesData(K key);
447
448 protected K topSpeciesKey() {
449 return null; // null means don't report a top species
450 }
451
452 /**
453 * Code generation support for instances.
454 * Subclasses can modify the behavior.
455 */
456 public class Factory {
457 /**
458 * Get a concrete subclass of the top class for a given combination of bound types.
459 *
460 * @param speciesData the species requiring the class, not yet linked
461 * @return a linked version of the same species
462 */
463 S loadSpecies(S speciesData) {
464 String className = speciesData.deriveClassName();
465 assert(className.indexOf('/') < 0) : className;
466 Class<?> salvage = null;
467 try {
468 salvage = BootLoader.loadClassOrNull(className);
469 if (TRACE_RESOLVE && salvage != null) {
470 // Used by jlink species pregeneration plugin, see
471 // jdk.tools.jlink.internal.plugins.GenerateJLIClassesPlugin
472 System.out.println("[SPECIES_RESOLVE] " + className + " (salvaged)");
473 }
474 } catch (Error ex) {
475 if (TRACE_RESOLVE) {
476 System.out.println("[SPECIES_FRESOLVE] " + className + " (Error) " + ex.getMessage());
477 }
478 }
479 final Class<? extends T> speciesCode;
480 if (salvage != null) {
481 speciesCode = salvage.asSubclass(topClass());
482 linkSpeciesDataToCode(speciesData, speciesCode);
483 linkCodeToSpeciesData(speciesCode, speciesData, true);
484 } else {
485 // Not pregenerated, generate the class
486 try {
487 speciesCode = generateConcreteSpeciesCode(className, speciesData);
488 if (TRACE_RESOLVE) {
489 // Used by jlink species pregeneration plugin, see
490 // jdk.tools.jlink.internal.plugins.GenerateJLIClassesPlugin
491 System.out.println("[SPECIES_RESOLVE] " + className + " (generated)");
492 }
493 // This operation causes a lot of churn:
494 linkSpeciesDataToCode(speciesData, speciesCode);
495 // This operation commits the relation, but causes little churn:
496 linkCodeToSpeciesData(speciesCode, speciesData, false);
497 } catch (Error ex) {
498 if (TRACE_RESOLVE) {
499 System.out.println("[SPECIES_RESOLVE] " + className + " (Error #2)" );
500 }
501 // We can get here if there is a race condition loading a class.
502 // Or maybe we are out of resources. Back out of the CHM.get and retry.
503 throw ex;
504 }
505 }
506
507 if (!speciesData.isResolved()) {
508 throw newInternalError("bad species class linkage for " + className + ": " + speciesData);
509 }
510 assert(speciesData == loadSpeciesDataFromCode(speciesCode));
511 return speciesData;
512 }
513
514 /**
515 * Generate a concrete subclass of the top class for a given combination of bound types.
516 *
517 * A concrete species subclass roughly matches the following schema:
518 *
519 * <pre>
520 * class Species_[[types]] extends [[T]] {
521 * final [[S]] speciesData() { return ... }
522 * static [[T]] make([[fields]]) { return ... }
523 * [[fields]]
524 * final [[T]] transform([[args]]) { return ... }
525 * }
526 * </pre>
527 *
528 * The {@code [[types]]} signature is precisely the key for the species.
529 *
530 * The {@code [[fields]]} section consists of one field definition per character in
531 * the type signature, adhering to the naming schema described in the definition of
532 * {@link #chooseFieldName}.
533 *
534 * For example, a concrete species for two references and one integral bound value
535 * has a shape like the following:
536 *
537 * <pre>
538 * class TopClass { ... private static
539 * final class Species_LLI extends TopClass {
540 * final Object argL0;
541 * final Object argL1;
542 * final int argI2;
543 * private Species_LLI(CT ctarg, ..., Object argL0, Object argL1, int argI2) {
544 * super(ctarg, ...);
545 * this.argL0 = argL0;
546 * this.argL1 = argL1;
547 * this.argI2 = argI2;
548 * }
549 * final SpeciesData speciesData() { return BMH_SPECIES; }
550 * @Stable static SpeciesData BMH_SPECIES; // injected afterwards
551 * static TopClass make(CT ctarg, ..., Object argL0, Object argL1, int argI2) {
552 * return new Species_LLI(ctarg, ..., argL0, argL1, argI2);
553 * }
554 * final TopClass copyWith(CT ctarg, ...) {
555 * return new Species_LLI(ctarg, ..., argL0, argL1, argI2);
556 * }
557 * // two transforms, for the sake of illustration:
558 * final TopClass copyWithExtendL(CT ctarg, ..., Object narg) {
559 * return BMH_SPECIES.transform(L_TYPE).invokeBasic(ctarg, ..., argL0, argL1, argI2, narg);
560 * }
561 * final TopClass copyWithExtendI(CT ctarg, ..., int narg) {
562 * return BMH_SPECIES.transform(I_TYPE).invokeBasic(ctarg, ..., argL0, argL1, argI2, narg);
563 * }
564 * }
565 * </pre>
566 *
567 * @param className of the species
568 * @param speciesData what species we are generating
569 * @return the generated concrete TopClass class
570 */
571 Class<? extends T> generateConcreteSpeciesCode(String className, ClassSpecializer<T,K,S>.SpeciesData speciesData) {
572 byte[] classFile = generateConcreteSpeciesCodeFile(className, speciesData);
573
574 // load class
575 InvokerBytecodeGenerator.maybeDump(classBCName(className), classFile);
576 Class<?> speciesCode;
577
578 ClassLoader cl = topClass().getClassLoader();
579 ProtectionDomain pd = null;
580 if (cl != null) {
581 pd = AccessController.doPrivileged(
582 new PrivilegedAction<>() {
583 @Override
584 public ProtectionDomain run() {
585 return topClass().getProtectionDomain();
586 }
587 });
588 }
589 try {
590 speciesCode = UNSAFE.defineClass(className, classFile, 0, classFile.length, cl, pd);
591 } catch (Exception ex) {
592 throw newInternalError(ex);
593 }
594
595 return speciesCode.asSubclass(topClass());
596 }
597
598 // These are named like constants because there is only one per specialization scheme:
599 private final String SPECIES_DATA = classBCName(metaType);
600 private final String SPECIES_DATA_SIG = classSig(SPECIES_DATA);
601 private final String SPECIES_DATA_NAME = sdAccessor.getName();
602 private final int SPECIES_DATA_MODS = sdAccessor.getModifiers();
603 private final List<String> TRANSFORM_NAMES; // derived from transformMethods
604 private final List<MethodType> TRANSFORM_TYPES;
605 private final List<Integer> TRANSFORM_MODS;
606 {
607 // Tear apart transformMethods to get the names, types, and modifiers.
608 List<String> tns = new ArrayList<>();
609 List<MethodType> tts = new ArrayList<>();
610 List<Integer> tms = new ArrayList<>();
611 for (int i = 0; i < transformMethods.size(); i++) {
612 MemberName tm = transformMethods.get(i);
613 tns.add(tm.getName());
614 final MethodType tt = tm.getMethodType();
615 tts.add(tt);
616 tms.add(tm.getModifiers());
617 }
618 TRANSFORM_NAMES = List.of(tns.toArray(new String[0]));
619 TRANSFORM_TYPES = List.of(tts.toArray(new MethodType[0]));
620 TRANSFORM_MODS = List.of(tms.toArray(new Integer[0]));
621 }
622 private static final int ACC_PPP = ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED;
623
624 /*non-public*/ byte[] generateConcreteSpeciesCodeFile(String className0, ClassSpecializer<T,K,S>.SpeciesData speciesData) {
625 final String className = classBCName(className0);
626 final String superClassName = classBCName(speciesData.deriveSuperClass());
627
628 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
629 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
630 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, superClassName, null);
631
632 final String sourceFile = className.substring(className.lastIndexOf('.')+1);
633 cw.visitSource(sourceFile, null);
634
635 // emit static types and BMH_SPECIES fields
636 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, sdFieldName, SPECIES_DATA_SIG, null, null);
637 fw.visitAnnotation(STABLE_SIG, true);
638 fw.visitEnd();
639
640 // handy holder for dealing with groups of typed values (ctor arguments and fields)
641 class Var {
642 final int index;
643 final String name;
644 final Class<?> type;
645 final String desc;
646 final BasicType basicType;
647 final int slotIndex;
648 Var(int index, int slotIndex) {
649 this.index = index;
650 this.slotIndex = slotIndex;
651 name = null; type = null; desc = null;
652 basicType = BasicType.V_TYPE;
653 }
654 Var(String name, Class<?> type, Var prev) {
655 int slotIndex = prev.nextSlotIndex();
656 int index = prev.nextIndex();
657 if (name == null) name = "x";
658 if (name.endsWith("#"))
659 name = name.substring(0, name.length()-1) + index;
660 assert(!type.equals(void.class));
661 String desc = classSig(type);
662 BasicType basicType = BasicType.basicType(type);
663 this.index = index;
664 this.name = name;
665 this.type = type;
666 this.desc = desc;
667 this.basicType = basicType;
668 this.slotIndex = slotIndex;
669 }
670 Var lastOf(List<Var> vars) {
671 int n = vars.size();
672 return (n == 0 ? this : vars.get(n-1));
673 }
674 <X> List<Var> fromTypes(List<X> types) {
675 Var prev = this;
676 ArrayList<Var> result = new ArrayList<>(types.size());
677 int i = 0;
678 for (X x : types) {
679 String vn = name;
680 Class<?> vt;
681 if (x instanceof Class) {
682 vt = (Class<?>) x;
683 // make the names friendlier if debugging
684 assert((vn = vn + "_" + (i++)) != null);
685 } else {
686 @SuppressWarnings("unchecked")
687 Var v = (Var) x;
688 vn = v.name;
689 vt = v.type;
690 }
691 prev = new Var(vn, vt, prev);
692 result.add(prev);
693 }
694 return result;
695 }
696
697 int slotSize() { return basicType.basicTypeSlots(); }
698 int nextIndex() { return index + (slotSize() == 0 ? 0 : 1); }
699 int nextSlotIndex() { return slotIndex >= 0 ? slotIndex + slotSize() : slotIndex; }
700 boolean isInHeap() { return slotIndex < 0; }
701 void emitVarInstruction(int asmop, MethodVisitor mv) {
702 if (asmop == ALOAD)
703 asmop = typeLoadOp(basicType.basicTypeChar());
704 else
705 throw new AssertionError("bad op="+asmop+" for desc="+desc);
706 mv.visitVarInsn(asmop, slotIndex);
707 }
708 public void emitFieldInsn(int asmop, MethodVisitor mv) {
709 mv.visitFieldInsn(asmop, className, name, desc);
710 }
711 }
712
713 final Var NO_THIS = new Var(0, 0),
714 AFTER_THIS = new Var(0, 1),
715 IN_HEAP = new Var(0, -1);
716
717 // figure out the field types
718 final List<Class<?>> fieldTypes = speciesData.fieldTypes();
719 final List<Var> fields = new ArrayList<>(fieldTypes.size());
720 {
721 Var nextF = IN_HEAP;
722 for (Class<?> ft : fieldTypes) {
723 String fn = chooseFieldName(ft, nextF.nextIndex());
724 nextF = new Var(fn, ft, nextF);
725 fields.add(nextF);
726 }
727 }
728
729 // emit bound argument fields
730 for (Var field : fields) {
731 cw.visitField(ACC_FINAL, field.name, field.desc, null, null).visitEnd();
732 }
733
734 MethodVisitor mv;
735
736 // emit implementation of speciesData()
737 mv = cw.visitMethod((SPECIES_DATA_MODS & ACC_PPP) + ACC_FINAL,
738 SPECIES_DATA_NAME, "()" + SPECIES_DATA_SIG, null, null);
739 mv.visitCode();
740 mv.visitFieldInsn(GETSTATIC, className, sdFieldName, SPECIES_DATA_SIG);
741 mv.visitInsn(ARETURN);
742 mv.visitMaxs(0, 0);
743 mv.visitEnd();
744
745 // figure out the constructor arguments
746 MethodType superCtorType = ClassSpecializer.this.baseConstructorType();
747 MethodType thisCtorType = superCtorType.appendParameterTypes(fieldTypes);
748
749 // emit constructor
750 {
751 mv = cw.visitMethod(ACC_PRIVATE,
752 "<init>", methodSig(thisCtorType), null, null);
753 mv.visitCode();
754 mv.visitVarInsn(ALOAD, 0); // this
755
756 final List<Var> ctorArgs = AFTER_THIS.fromTypes(superCtorType.parameterList());
757 for (Var ca : ctorArgs) {
758 ca.emitVarInstruction(ALOAD, mv);
759 }
760
761 // super(ca...)
762 mv.visitMethodInsn(INVOKESPECIAL, superClassName,
763 "<init>", methodSig(superCtorType), false);
764
765 // store down fields
766 Var lastFV = AFTER_THIS.lastOf(ctorArgs);
767 for (Var f : fields) {
768 // this.argL1 = argL1
769 mv.visitVarInsn(ALOAD, 0); // this
770 lastFV = new Var(f.name, f.type, lastFV);
771 lastFV.emitVarInstruction(ALOAD, mv);
772 f.emitFieldInsn(PUTFIELD, mv);
773 }
774
775 mv.visitInsn(RETURN);
776 mv.visitMaxs(0, 0);
777 mv.visitEnd();
778 }
779
780 // emit make() ...factory method wrapping constructor
781 {
782 MethodType ftryType = thisCtorType.changeReturnType(topClass());
783 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC,
784 "make", methodSig(ftryType), null, null);
785 mv.visitCode();
786 // make instance
787 mv.visitTypeInsn(NEW, className);
788 mv.visitInsn(DUP);
789 // load factory method arguments: ctarg... and arg...
790 for (Var v : NO_THIS.fromTypes(ftryType.parameterList())) {
791 v.emitVarInstruction(ALOAD, mv);
792 }
793
794 // finally, invoke the constructor and return
795 mv.visitMethodInsn(INVOKESPECIAL, className,
796 "<init>", methodSig(thisCtorType), false);
797 mv.visitInsn(ARETURN);
798 mv.visitMaxs(0, 0);
799 mv.visitEnd();
800 }
801
802 // For each transform, emit the customized override of the transform method.
803 // This method mixes together some incoming arguments (from the transform's
804 // static type signature) with the field types themselves, and passes
805 // the resulting mish-mosh of values to a method handle produced by
806 // the species itself. (Typically this method handle is the factory
807 // method of this species or a related one.)
808 for (int whichtm = 0; whichtm < TRANSFORM_NAMES.size(); whichtm++) {
809 final String TNAME = TRANSFORM_NAMES.get(whichtm);
810 final MethodType TTYPE = TRANSFORM_TYPES.get(whichtm);
811 final int TMODS = TRANSFORM_MODS.get(whichtm);
812 mv = cw.visitMethod((TMODS & ACC_PPP) | ACC_FINAL,
813 TNAME, TTYPE.toMethodDescriptorString(), null, E_THROWABLE);
814 mv.visitCode();
815 // return a call to the corresponding "transform helper", something like this:
816 // MY_SPECIES.transformHelper(whichtm).invokeBasic(ctarg, ..., argL0, ..., xarg)
817 mv.visitFieldInsn(GETSTATIC, className,
818 sdFieldName, SPECIES_DATA_SIG);
819 emitIntConstant(whichtm, mv);
820 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA,
821 "transformHelper", "(I)" + MH_SIG, false);
822
823 List<Var> targs = AFTER_THIS.fromTypes(TTYPE.parameterList());
824 List<Var> tfields = new ArrayList<>(fields);
825 // mix them up and load them for the transform helper:
826 List<Var> helperArgs = speciesData.deriveTransformHelperArguments(transformMethods.get(whichtm), whichtm, targs, tfields);
827 List<Class<?>> helperTypes = new ArrayList<>(helperArgs.size());
828 for (Var ha : helperArgs) {
829 helperTypes.add(ha.basicType.basicTypeClass());
830 if (ha.isInHeap()) {
831 assert(tfields.contains(ha));
832 mv.visitVarInsn(ALOAD, 0);
833 ha.emitFieldInsn(GETFIELD, mv);
834 } else {
835 assert(targs.contains(ha));
836 ha.emitVarInstruction(ALOAD, mv);
837 }
838 }
839
840 // jump into the helper (which is probably a factory method)
841 final Class<?> rtype = TTYPE.returnType();
842 final BasicType rbt = BasicType.basicType(rtype);
843 MethodType invokeBasicType = MethodType.methodType(rbt.basicTypeClass(), helperTypes);
844 mv.visitMethodInsn(INVOKEVIRTUAL, MH,
845 "invokeBasic", methodSig(invokeBasicType), false);
846 if (rbt == BasicType.L_TYPE) {
847 mv.visitTypeInsn(CHECKCAST, classBCName(rtype));
848 mv.visitInsn(ARETURN);
849 } else {
850 throw newInternalError("NYI: transform of type "+rtype);
851 }
852 mv.visitMaxs(0, 0);
853 mv.visitEnd();
854 }
855
856 cw.visitEnd();
857
858 return cw.toByteArray();
859 }
860
861 private int typeLoadOp(char t) {
862 switch (t) {
863 case 'L': return ALOAD;
864 case 'I': return ILOAD;
865 case 'J': return LLOAD;
866 case 'F': return FLOAD;
867 case 'D': return DLOAD;
868 default : throw newInternalError("unrecognized type " + t);
869 }
870 }
871
872 private void emitIntConstant(int con, MethodVisitor mv) {
873 if (ICONST_M1 - ICONST_0 <= con && con <= ICONST_5 - ICONST_0)
874 mv.visitInsn(ICONST_0 + con);
875 else if (con == (byte) con)
876 mv.visitIntInsn(BIPUSH, con);
877 else if (con == (short) con)
878 mv.visitIntInsn(SIPUSH, con);
879 else {
880 mv.visitLdcInsn(con);
881 }
882
883 }
884
885 //
886 // Getter MH generation.
887 //
888
889 private MethodHandle findGetter(Class<?> speciesCode, List<Class<?>> types, int index) {
890 Class<?> fieldType = types.get(index);
891 String fieldName = chooseFieldName(fieldType, index);
892 try {
893 return IMPL_LOOKUP.findGetter(speciesCode, fieldName, fieldType);
894 } catch (NoSuchFieldException | IllegalAccessException e) {
895 throw newInternalError(e);
896 }
897 }
898
899 private List<MethodHandle> findGetters(Class<?> speciesCode, List<Class<?>> types) {
900 MethodHandle[] mhs = new MethodHandle[types.size()];
901 for (int i = 0; i < mhs.length; ++i) {
902 mhs[i] = findGetter(speciesCode, types, i);
903 assert(mhs[i].internalMemberName().getDeclaringClass() == speciesCode);
904 }
905 return List.of(mhs);
906 }
907
908 private List<MethodHandle> findFactories(Class<? extends T> speciesCode, List<Class<?>> types) {
909 MethodHandle[] mhs = new MethodHandle[1];
910 mhs[0] = findFactory(speciesCode, types);
911 return List.of(mhs);
912 }
913
914 List<LambdaForm.NamedFunction> makeNominalGetters(List<Class<?>> types, List<MethodHandle> getters) {
915 LambdaForm.NamedFunction[] nfs = new LambdaForm.NamedFunction[types.size()];
916 for (int i = 0; i < nfs.length; ++i) {
917 nfs[i] = new LambdaForm.NamedFunction(getters.get(i));
918 }
919 return List.of(nfs);
920 }
921
922 //
923 // Auxiliary methods.
924 //
925
926 protected void linkSpeciesDataToCode(ClassSpecializer<T,K,S>.SpeciesData speciesData, Class<? extends T> speciesCode) {
927 speciesData.speciesCode = speciesCode.asSubclass(topClass);
928 final List<Class<?>> types = speciesData.fieldTypes;
929 speciesData.factories = this.findFactories(speciesCode, types);
930 speciesData.getters = this.findGetters(speciesCode, types);
931 speciesData.nominalGetters = this.makeNominalGetters(types, speciesData.getters);
932 }
933
934 private Field reflectSDField(Class<? extends T> speciesCode) {
935 final Field field = reflectField(speciesCode, sdFieldName);
936 assert(field.getType() == metaType);
937 assert(Modifier.isStatic(field.getModifiers()));
938 return field;
939 }
940
941 private S readSpeciesDataFromCode(Class<? extends T> speciesCode) {
942 try {
943 MemberName sdField = IMPL_LOOKUP.resolveOrFail(REF_getStatic, speciesCode, sdFieldName, metaType);
944 Object base = MethodHandleNatives.staticFieldBase(sdField);
945 long offset = MethodHandleNatives.staticFieldOffset(sdField);
946 UNSAFE.loadFence();
947 return metaType.cast(UNSAFE.getObject(base, offset));
948 } catch (Error err) {
949 throw err;
950 } catch (Exception ex) {
951 throw newInternalError("Failed to load speciesData from speciesCode: " + speciesCode.getName(), ex);
952 } catch (Throwable t) {
953 throw uncaughtException(t);
954 }
955 }
956
957 protected S loadSpeciesDataFromCode(Class<? extends T> speciesCode) {
958 if (speciesCode == topClass()) {
959 return topSpecies;
960 }
961 S result = readSpeciesDataFromCode(speciesCode);
962 if (result.outer() != ClassSpecializer.this) {
963 throw newInternalError("wrong class");
964 }
965 return result;
966 }
967
968 protected void linkCodeToSpeciesData(Class<? extends T> speciesCode, ClassSpecializer<T,K,S>.SpeciesData speciesData, boolean salvage) {
969 try {
970 assert(readSpeciesDataFromCode(speciesCode) == null ||
971 (salvage && readSpeciesDataFromCode(speciesCode).equals(speciesData)));
972
973 MemberName sdField = IMPL_LOOKUP.resolveOrFail(REF_putStatic, speciesCode, sdFieldName, metaType);
974 Object base = MethodHandleNatives.staticFieldBase(sdField);
975 long offset = MethodHandleNatives.staticFieldOffset(sdField);
976 UNSAFE.storeFence();
977 UNSAFE.putObject(base, offset, speciesData);
978 UNSAFE.storeFence();
979 } catch (Error err) {
980 throw err;
981 } catch (Exception ex) {
982 throw newInternalError("Failed to link speciesData to speciesCode: " + speciesCode.getName(), ex);
983 } catch (Throwable t) {
984 throw uncaughtException(t);
985 }
986 }
987
988 /**
989 * Field names in concrete species classes adhere to this pattern:
990 * type + index, where type is a single character (L, I, J, F, D).
991 * The factory subclass can customize this.
992 * The name is purely cosmetic, since it applies to a private field.
993 */
994 protected String chooseFieldName(Class<?> type, int index) {
995 BasicType bt = BasicType.basicType(type);
996 return "" + bt.basicTypeChar() + index;
997 }
998
999 MethodHandle findFactory(Class<? extends T> speciesCode, List<Class<?>> types) {
1000 final MethodType type = baseConstructorType().changeReturnType(topClass()).appendParameterTypes(types);
1001 try {
1002 return IMPL_LOOKUP.findStatic(speciesCode, "make", type);
1003 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) {
1004 throw newInternalError(e);
1005 }
1006 }
1007 }
1008
1009 /** Hook that virtualizes the Factory class, allowing subclasses to extend it. */
1010 protected Factory makeFactory() {
1011 return new Factory();
1012 }
1013
1014
1015 // Other misc helpers:
1016 private static final String MH = "java/lang/invoke/MethodHandle";
1017 private static final String MH_SIG = "L" + MH + ";";
1018 private static final String STABLE = "jdk/internal/vm/annotation/Stable";
1019 private static final String STABLE_SIG = "L" + STABLE + ";";
1020 private static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
1021 static {
1022 assert(MH_SIG.equals(classSig(MethodHandle.class)));
1023 assert(MH.equals(classBCName(MethodHandle.class)));
1024 }
1025
1026 static String methodSig(MethodType mt) {
1027 return mt.toMethodDescriptorString();
1028 }
1029 static String classSig(Class<?> cls) {
1030 if (cls.isPrimitive() || cls.isArray())
1031 return MethodType.methodType(cls).toMethodDescriptorString().substring(2);
1032 return classSig(classBCName(cls));
1033 }
1034 static String classSig(String bcName) {
1035 assert(bcName.indexOf('.') < 0);
1036 assert(!bcName.endsWith(";"));
1037 assert(!bcName.startsWith("["));
1038 return "L" + bcName + ";";
1039 }
1040 static String classBCName(Class<?> cls) {
1041 return classBCName(className(cls));
1042 }
1043 static String classBCName(String str) {
1044 assert(str.indexOf('/') < 0) : str;
1045 return str.replace('.', '/');
1046 }
1047 static String className(Class<?> cls) {
1048 assert(!cls.isArray() && !cls.isPrimitive());
1049 return cls.getName();
1050 }
1051 }