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.*;
36 import java.security.AccessController;
37 import java.security.PrivilegedAction;
38 import java.security.ProtectionDomain;
39 import java.util.*;
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.*;
45 import static java.lang.invoke.MethodHandleNatives.Constants.REF_getStatic;
46 import static java.lang.invoke.MethodHandleNatives.Constants.REF_putStatic;
47 import static java.lang.invoke.MethodHandleStatics.*;
48 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
49 import static jdk.internal.org.objectweb.asm.Opcodes.*;
50
51 /**
52 * Class specialization code.
53 * @param <T> top class under which species classes are created.
54 * @param <K> key which identifies individual specializations.
55 * @param <S> species data type.
56 */
57 /*non-public*/
58 abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesData> {
59 private final Class<T> topClass;
60 private final Class<K> keyType;
61 private final Class<S> metaType;
62 private final MemberName sdAccessor;
63 private final String sdFieldName;
64 private final List<MemberName> transformMethods;
65 private final MethodType baseConstructorType;
66 private final S topSpecies;
67 private final ConcurrentMap<K, S> cache = new ConcurrentHashMap<>();
68 private final Factory factory;
69 private @Stable boolean topClassIsSuper;
70
71 /** Return the top type mirror, for type {@code T} */
72 public final Class<T> topClass() { return topClass; }
73
74 /** Return the key type mirror, for type {@code K} */
75 public final Class<K> keyType() { return keyType; }
76
77 /** Return the species metadata type mirror, for type {@code S} */
78 public final Class<S> metaType() { return metaType; }
79
80 /** Report the leading arguments (if any) required by every species factory.
81 * Every species factory adds its own field types as additional arguments,
82 * but these arguments always come first, in every factory method.
83 */
84 protected MethodType baseConstructorType() { return baseConstructorType; }
85
86 /** Return the trivial species for the null sequence of arguments. */
87 protected final S topSpecies() { return topSpecies; }
88
89 /** Return the list of transform methods originally given at creation of this specializer. */
90 protected final List<MemberName> transformMethods() { return transformMethods; }
91
92 /** Return the factory object used to build and load concrete species code. */
93 protected final Factory factory() { return factory; }
94
95 /**
96 * Constructor for this class specializer.
97 * @param topClass type mirror for T
98 * @param keyType type mirror for K
99 * @param metaType type mirror for S
100 * @param baseConstructorType principal constructor type
101 * @param sdAccessor the method used to get the speciesData
102 * @param sdFieldName the name of the species data field, inject the speciesData object
103 * @param transformMethods optional list of transformMethods
104 */
105 protected ClassSpecializer(Class<T> topClass,
106 Class<K> keyType,
107 Class<S> metaType,
108 MethodType baseConstructorType,
109 MemberName sdAccessor,
110 String sdFieldName,
111 List<MemberName> transformMethods) {
112 this.topClass = topClass;
113 this.keyType = keyType;
114 this.metaType = metaType;
115 this.sdAccessor = sdAccessor;
116 // FIXME: use List.copyOf once 8177290 is in
117 this.transformMethods = List.of(transformMethods.toArray(new MemberName[transformMethods.size()]));
118 this.sdFieldName = sdFieldName;
119 this.baseConstructorType = baseConstructorType.changeReturnType(void.class);
120 this.factory = makeFactory();
121 K tsk = topSpeciesKey();
122 S topSpecies = null;
123 if (tsk != null && topSpecies == null) {
124 // if there is a key, build the top species if needed:
125 topSpecies = findSpecies(tsk);
126 }
127 this.topSpecies = topSpecies;
128 }
129
130 // Utilities for subclass constructors:
131 protected static <T> Constructor<T> reflectConstructor(Class<T> defc, Class<?>... ptypes) {
132 try {
133 return defc.getDeclaredConstructor(ptypes);
134 } catch (NoSuchMethodException ex) {
135 throw newIAE(defc.getName()+"("+MethodType.methodType(void.class, ptypes)+")", ex);
136 }
137 }
138
139 protected static Field reflectField(Class<?> defc, String name) {
140 try {
141 return defc.getDeclaredField(name);
142 } catch (NoSuchFieldException ex) {
143 throw newIAE(defc.getName()+"."+name, ex);
144 }
145 }
146
147 private static RuntimeException newIAE(String message, Throwable cause) {
148 return new IllegalArgumentException(message, cause);
149 }
150
151 public final S findSpecies(K key) {
152 if (TRACE_RESOLVE) {
153 System.out.println("[SPECIES_RESOLVE] findSpecies " + key);
154 }
155 S speciesData = cache.computeIfAbsent(key, new Function<>() {
156 @Override
157 public S apply(K key1) {
158 return factory.loadSpecies(newSpeciesData(key1));
159 }
160 });
161 if (TRACE_RESOLVE) {
162 System.out.println("[SPECIES_RESOLVE] findSpecies " + key + " => " + speciesData);
163 }
164 // Note: Species instantiation may throw VirtualMachineError because of
165 // code cache overflow. If this happens the species bytecode may be
166 // loaded but not linked to its species metadata (with MH's etc).
167 // That will cause a throw out of CHM.computeIfAbsent,
168 // which will shut down the caller thread.
169 //
170 // In a latter attempt to get the same species, the already-loaded
171 // class will be present in the system dictionary, causing an
172 // error when the species generator tries to reload it.
173 // We try to detect this case and link the pre-existing code.
174 //
175 // Although it would be better to start fresh by loading a new
176 // copy, we have to salvage the previously loaded but broken code.
177 // (As an alternative, we might spin a new class with a new name,
178 // or use the anonymous class mechanism.)
179 //
180 // In the end, as long as everybody goes through the same CHM,
181 // CHM.computeIfAbsent will ensure only one SpeciesData will be set
182 // successfully on a concrete class if ever.
183 // The concrete class is published via SpeciesData instance
184 // returned here only after the class and species data are linked together.
185 assert(speciesData != null);
186 return speciesData;
187 }
188
189 /**
190 * Meta-data wrapper for concrete subtypes of the top class.
191 * Each concrete subtype corresponds to a given sequence of basic field types (LIJFD).
192 * The fields are immutable; their values are fully specified at object construction.
193 * Each species supplies an array of getter functions which may be used in lambda forms.
194 * A concrete value is always constructed from the full tuple of its field values,
195 * accompanied by the required constructor parameters.
196 * There *may* also be transforms which cloning a species instance and
197 * either replace a constructor parameter or add one or more new field values.
198 * The shortest possible species has zero fields.
199 * Subtypes are not interrelated among themselves by subtyping, even though
200 * it would appear that a shorter species could serve as a supertype of a
201 * longer one which extends it.
202 */
203 public abstract class SpeciesData {
204 // Bootstrapping requires circular relations Class -> SpeciesData -> Class
205 // Therefore, we need non-final links in the chain. Use @Stable fields.
206 private final K key;
207 private final List<Class<?>> fieldTypes;
208 @Stable private Class<? extends T> speciesCode;
209 @Stable private List<MethodHandle> factories;
210 @Stable private List<MethodHandle> getters;
211 @Stable private List<LambdaForm.NamedFunction> nominalGetters;
212 @Stable private final MethodHandle[] transformHelpers = new MethodHandle[transformMethods.size()];
213
214 protected SpeciesData(K key) {
215 this.key = keyType.cast(Objects.requireNonNull(key));
216 List<Class<?>> types = deriveFieldTypes(key);
217 // TODO: List.copyOf
218 int arity = types.size();
219 this.fieldTypes = List.of(types.toArray(new Class<?>[arity]));
220 }
221
222 public final K key() {
223 return key;
224 }
225
226 protected final List<Class<?>> fieldTypes() {
227 return fieldTypes;
228 }
229
230 protected final int fieldCount() {
231 return fieldTypes.size();
232 }
233
234 protected ClassSpecializer<T,K,S> outer() {
235 return ClassSpecializer.this;
236 }
237
238 protected final boolean isResolved() {
239 return speciesCode != null && factories != null && !factories.isEmpty();
240 }
241
242 @Override public String toString() {
243 return metaType.getSimpleName() + "[" + key.toString() + " => " + (isResolved() ? speciesCode.getSimpleName() : "UNRESOLVED") + "]";
244 }
245
246 @Override
247 public int hashCode() {
248 return key.hashCode();
249 }
250
251 @Override
252 public boolean equals(Object obj) {
253 if (!(obj instanceof ClassSpecializer.SpeciesData)) {
254 return false;
255 }
256 @SuppressWarnings("rawtypes")
257 ClassSpecializer.SpeciesData that = (ClassSpecializer.SpeciesData) obj;
258 return this.outer() == that.outer() && this.key.equals(that.key);
259 }
260
261 /** Throws NPE if this species is not yet resolved. */
262 protected final Class<? extends T> speciesCode() {
263 return Objects.requireNonNull(speciesCode);
264 }
265
266 /**
267 * Return a {@link MethodHandle} which can get the indexed field of this species.
268 * The return type is the type of the species field it accesses.
269 * The argument type is the {@code fieldHolder} class of this species.
270 */
271 protected MethodHandle getter(int i) {
272 return getters.get(i);
273 }
274
275 /**
276 * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that
277 * represents a MH bound to a generic invoker, which in turn forwards to the corresponding
278 * getter.
279 */
280 protected LambdaForm.NamedFunction getterFunction(int i) {
281 LambdaForm.NamedFunction nf = nominalGetters.get(i);
282 assert(nf.memberDeclaringClassOrNull() == speciesCode());
283 assert(nf.returnType() == BasicType.basicType(fieldTypes.get(i)));
284 return nf;
285 }
286
287 protected List<LambdaForm.NamedFunction> getterFunctions() {
288 return nominalGetters;
289 }
290
291 protected List<MethodHandle> getters() {
292 return getters;
293 }
294
295 protected MethodHandle factory() {
296 return factories.get(0);
297 }
298
299 protected MethodHandle transformHelper(int whichtm) {
300 MethodHandle mh = transformHelpers[whichtm];
301 if (mh != null) return mh;
302 mh = deriveTransformHelper(transformMethods().get(whichtm), whichtm);
303 // Do a little type checking before we start using the MH.
304 // (It will be called with invokeBasic, so this is our only chance.)
305 final MethodType mt = transformHelperType(whichtm);
306 mh = mh.asType(mt);
307 return transformHelpers[whichtm] = mh;
308 }
309
310 private final MethodType transformHelperType(int whichtm) {
311 MemberName tm = transformMethods().get(whichtm);
312 ArrayList<Class<?>> args = new ArrayList<>();
313 ArrayList<Class<?>> fields = new ArrayList<>();
314 Collections.addAll(args, tm.getParameterTypes());
315 fields.addAll(fieldTypes());
316 List<Class<?>> helperArgs = deriveTransformHelperArguments(tm, whichtm, args, fields);
317 return MethodType.methodType(tm.getReturnType(), helperArgs);
318 }
319
320 // Hooks for subclasses:
321
322 /**
323 * Given a key, derive the list of field types, which all instances of this
324 * species must store.
325 */
326 protected abstract List<Class<?>> deriveFieldTypes(K key);
327
328 /**
329 * Given the index of a method in the transforms list, supply a factory
330 * method that takes the arguments of the transform, plus the local fields,
331 * and produce a value of the required type.
332 * You can override this to return null or throw if there are no transforms.
333 * This method exists so that the transforms can be "grown" lazily.
334 * This is necessary if the transform *adds* a field to an instance,
335 * which sometimtes requires the creation, on the fly, of an extended species.
336 * This method is only called once for any particular parameter.
337 * The species caches the result in a private array.
338 *
339 * @param transform the transform being implemented
340 * @param whichtm the index of that transform in the original list of transforms
341 * @return the method handle which creates a new result from a mix of transform
342 * arguments and field values
343 */
344 protected abstract MethodHandle deriveTransformHelper(MemberName transform, int whichtm);
345
346 /**
347 * During code generation, this method is called once per transform to determine
348 * what is the mix of arguments to hand to the transform-helper. The bytecode
349 * which marshals these arguments is open-coded in the species-specific transform.
350 * The two lists are of opaque objects, which you shouldn't do anything with besides
351 * reordering them into the output list. (They are both mutable, to make editing
352 * easier.) The imputed types of the args correspond to the transform's parameter
353 * list, while the imputed types of the fields correspond to the species field types.
354 * After code generation, this method may be called occasionally by error-checking code.
355 *
356 * @param transform the transform being implemented
357 * @param whichtm the index of that transform in the original list of transforms
358 * @param args a list of opaque objects representing the incoming transform arguments
359 * @param fields a list of opaque objects representing the field values of the receiver
360 * @param <X> the common element type of the various lists
361 * @return a new list
362 */
363 protected abstract <X> List<X> deriveTransformHelperArguments(MemberName transform, int whichtm,
364 List<X> args, List<X> fields);
365
366 /** Given a key, generate the name of the class which implements the species for that key.
367 * This algorithm must be stable.
368 *
369 * @return class name, which by default is {@code outer().topClass().getName() + "$Species_" + deriveTypeString(key)}
370 */
371 protected String deriveClassName() {
372 return outer().topClass().getName() + "$Species_" + deriveTypeString();
373 }
374
375 /**
376 * Default implementation collects basic type characters,
377 * plus possibly type names, if some types don't correspond
378 * to basic types.
379 *
380 * @return a string suitable for use in a class name
381 */
382 protected String deriveTypeString() {
383 List<Class<?>> types = fieldTypes();
384 StringBuilder buf = new StringBuilder();
385 StringBuilder end = new StringBuilder();
386 for (Class<?> type : types) {
387 BasicType basicType = BasicType.basicType(type);
388 if (basicType.basicTypeClass() == type) {
389 buf.append(basicType.basicTypeChar());
390 } else {
391 buf.append('V');
392 end.append(classSig(type));
393 }
394 }
395 String typeString;
396 if (end.length() > 0) {
397 typeString = BytecodeName.toBytecodeName(buf.append("_").append(end).toString());
398 } else {
399 typeString = buf.toString();
400 }
401 return LambdaForm.shortenSignature(typeString);
402 }
403
404 /**
405 * Report what immediate super-class to use for the concrete class of this species.
406 * Normally this is {@code topClass}, but if that is an interface, the factory must override.
407 * The super-class must provide a constructor which takes the {@code baseConstructorType} arguments, if any.
408 * This hook also allows the code generator to use more than one canned supertype for species.
409 *
410 * @return the super-class of the class to be generated
411 */
412 protected Class<? extends T> deriveSuperClass() {
413 final Class<T> topc = topClass();
414 if (!topClassIsSuper) {
415 try {
416 final Constructor<T> con = reflectConstructor(topc, baseConstructorType().parameterArray());
417 if (!topc.isInterface() && !Modifier.isPrivate(con.getModifiers())) {
418 topClassIsSuper = true;
419 }
420 } catch (Exception|InternalError ex) {
421 // fall through...
422 }
423 if (!topClassIsSuper) {
424 throw newInternalError("must override if the top class cannot serve as a super class");
425 }
426 }
427 return topc;
428 }
429 }
430
431 protected abstract S newSpeciesData(K key);
432
433 protected K topSpeciesKey() {
434 return null; // null means don't report a top species
435 }
436
437 /**
438 * Code generation support for instances.
439 * Subclasses can modify the behavior.
440 */
441 public class Factory {
442 /**
443 * Get a concrete subclass of the top class for a given combination of bound types.
444 *
445 * @param speciesData the species requiring the class, not yet linked
446 * @return a linked version of the same species
447 */
448 S loadSpecies(S speciesData) {
449 String className = speciesData.deriveClassName();
450 assert(className.indexOf('/') < 0) : className;
451 Class<?> salvage = null;
452 try {
453 salvage = BootLoader.loadClassOrNull(className);
454 if (TRACE_RESOLVE && salvage != null) {
455 // Used by jlink species pregeneration plugin, see
456 // jdk.tools.jlink.internal.plugins.GenerateJLIClassesPlugin
457 System.out.println("[SPECIES_RESOLVE] " + className + " (salvaged)");
458 }
459 } catch (Error ex) {
460 if (TRACE_RESOLVE) {
461 System.out.println("[SPECIES_FRESOLVE] " + className + " (Error) " + ex.getMessage());
462 }
463 }
464 final Class<? extends T> speciesCode;
465 if (salvage != null) {
466 speciesCode = salvage.asSubclass(topClass());
467 factory.linkSpeciesDataToCode(speciesData, speciesCode);
468 factory.linkCodeToSpeciesData(speciesCode, speciesData, true);
469 } else {
470 // Not pregenerated, generate the class
471 try {
472 speciesCode = generateConcreteSpeciesCode(className, speciesData);
473 if (TRACE_RESOLVE) {
474 // Used by jlink species pregeneration plugin, see
475 // jdk.tools.jlink.internal.plugins.GenerateJLIClassesPlugin
476 System.out.println("[SPECIES_RESOLVE] " + className + " (generated)");
477 }
478 // This operation causes a lot of churn:
479 linkSpeciesDataToCode(speciesData, speciesCode);
480 // This operation commits the relation, but causes little churn:
481 linkCodeToSpeciesData(speciesCode, speciesData, false);
482 } catch (Error ex) {
483 if (TRACE_RESOLVE) {
484 System.out.println("[SPECIES_RESOLVE] " + className + " (Error #2)" );
485 }
486 // We can get here if there is a race condition loading a class.
487 // Or maybe we are out of resources. Back out of the CHM.get and retry.
488 throw ex;
489 }
490 }
491
492 if (!speciesData.isResolved()) {
493 throw newInternalError("bad species class linkage for " + className + ": " + speciesData);
494 }
495 assert(speciesData == factory.loadSpeciesDataFromCode(speciesCode));
496 return speciesData;
497 }
498
499 /**
500 * Generate a concrete subclass of the top class for a given combination of bound types.
501 *
502 * A concrete species subclass roughly matches the following schema:
503 *
504 * <pre>
505 * class Species_[[types]] extends [[T]] {
506 * final [[S]] speciesData() { return ... }
507 * static [[T]] make([[fields]]) { return ... }
508 * [[fields]]
509 * final [[T]] transform([[args]]) { return ... }
510 * }
511 * </pre>
512 *
513 * The {@code [[types]]} signature is precisely the key for the species.
514 *
515 * The {@code [[fields]]} section consists of one field definition per character in
516 * the type signature, adhering to the naming schema described in the definition of
517 * {@link #chooseFieldName}.
518 *
519 * For example, a concrete species for two references and one integral bound value
520 * has a shape like the following:
521 *
522 * <pre>
523 * class TopClass { ... private static
524 * final class Species_LLI extends TopClass {
525 * final Object argL0;
526 * final Object argL1;
527 * final int argI2;
528 * private Species_LLI(CT ctarg, ..., Object argL0, Object argL1, int argI2) {
529 * super(ctarg, ...);
530 * this.argL0 = argL0;
531 * this.argL1 = argL1;
532 * this.argI2 = argI2;
533 * }
534 * final SpeciesData speciesData() { return BMH_SPECIES; }
535 * @Stable static SpeciesData BMH_SPECIES; // injected afterwards
536 * static TopClass make(CT ctarg, ..., Object argL0, Object argL1, int argI2) {
537 * return new Species_LLI(ctarg, ..., argL0, argL1, argI2);
538 * }
539 * final TopClass copyWith(CT ctarg, ...) {
540 * return new Species_LLI(ctarg, ..., argL0, argL1, argI2);
541 * }
542 * // two transforms, for the sake of illustration:
543 * final TopClass copyWithExtendL(CT ctarg, ..., Object narg) {
544 * return BMH_SPECIES.transform(L_TYPE).invokeBasic(ctarg, ..., argL0, argL1, argI2, narg);
545 * }
546 * final TopClass copyWithExtendI(CT ctarg, ..., int narg) {
547 * return BMH_SPECIES.transform(I_TYPE).invokeBasic(ctarg, ..., argL0, argL1, argI2, narg);
548 * }
549 * }
550 * </pre>
551 *
552 * @param className of the species
553 * @param speciesData what species we are generating
554 * @return the generated concrete TopClass class
555 */
556 Class<? extends T> generateConcreteSpeciesCode(String className, ClassSpecializer<T,K,S>.SpeciesData speciesData) {
557 byte[] classFile = generateConcreteSpeciesCodeFile(className, speciesData);
558
559 // load class
560 InvokerBytecodeGenerator.maybeDump(classBCName(className), classFile);
561 Class<?> speciesCode;
562
563 ClassLoader cl = topClass().getClassLoader();
564 ProtectionDomain pd = null;
565 if (cl != null) {
566 pd = AccessController.doPrivileged(
567 new PrivilegedAction<>() {
568 @Override
569 public ProtectionDomain run() {
570 return topClass().getProtectionDomain();
571 }
572 });
573 }
574 try {
575 speciesCode = UNSAFE.defineClass(className, classFile, 0, classFile.length, cl, pd);
576 } catch (Exception ex) {
577 throw newInternalError(ex);
578 }
579
580 return speciesCode.asSubclass(topClass());
581 }
582
583 // These are named like constants because there is only one per specialization scheme:
584 private final String SPECIES_DATA = classBCName(metaType);
585 private final String SPECIES_DATA_SIG = classSig(SPECIES_DATA);
586 private final String SPECIES_DATA_NAME = sdAccessor.getName();
587 private final int SPECIES_DATA_MODS = sdAccessor.getModifiers();
588 private final List<String> TRANSFORM_NAMES; // derived from transformMethods
589 private final List<MethodType> TRANSFORM_TYPES;
590 private final List<Integer> TRANSFORM_MODS;
591 {
592 // Tear apart transformMethods to get the names, types, and modifiers.
593 List<String> tns = new ArrayList<>();
594 List<MethodType> tts = new ArrayList<>();
595 List<Integer> tms = new ArrayList<>();
596 for (int i = 0; i < transformMethods.size(); i++) {
597 MemberName tm = transformMethods.get(i);
598 tns.add(tm.getName());
599 final MethodType tt = tm.getMethodType();
600 tts.add(tt);
601 tms.add(tm.getModifiers());
602 }
603 TRANSFORM_NAMES = List.of(tns.toArray(new String[0]));
604 TRANSFORM_TYPES = List.of(tts.toArray(new MethodType[0]));
605 TRANSFORM_MODS = List.of(tms.toArray(new Integer[0]));
606 }
607 private static final int ACC_PPP = ACC_PUBLIC | ACC_PRIVATE | ACC_PROTECTED;
608
609 /*non-public*/ byte[] generateConcreteSpeciesCodeFile(String className0, ClassSpecializer<T,K,S>.SpeciesData speciesData) {
610 final String className = classBCName(className0);
611 final String superClassName = classBCName(speciesData.deriveSuperClass());
612
613 final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
614 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
615 cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, superClassName, null);
616
617 final String sourceFile = className.substring(className.lastIndexOf('.')+1);
618 cw.visitSource(sourceFile, null);
619
620 // emit static types and BMH_SPECIES fields
621 FieldVisitor fw = cw.visitField(NOT_ACC_PUBLIC + ACC_STATIC, sdFieldName, SPECIES_DATA_SIG, null, null);
622 fw.visitAnnotation(STABLE_SIG, true);
623 fw.visitEnd();
624
625 // handy holder for dealing with groups of typed values (ctor arguments and fields)
626 class Var {
627 final int index;
628 final String name;
629 final Class<?> type;
630 final String desc;
631 final BasicType basicType;
632 final int slotIndex;
633 Var(int index, int slotIndex) {
634 this.index = index;
635 this.slotIndex = slotIndex;
636 name = null; type = null; desc = null;
637 basicType = BasicType.V_TYPE;
638 }
639 Var(String name, Class<?> type, Var prev) {
640 int slotIndex = prev.nextSlotIndex();
641 int index = prev.nextIndex();
642 if (name == null) name = "x";
643 if (name.endsWith("#"))
644 name = name.substring(0, name.length()-1) + index;
645 assert(!type.equals(void.class));
646 String desc = classSig(type);
647 BasicType basicType = BasicType.basicType(type);
648 this.index = index;
649 this.name = name;
650 this.type = type;
651 this.desc = desc;
652 this.basicType = basicType;
653 this.slotIndex = slotIndex;
654 }
655 Var lastOf(List<Var> vars) {
656 int n = vars.size();
657 return (n == 0 ? this : vars.get(n-1));
658 }
659 <X> List<Var> fromTypes(List<X> types) {
660 Var prev = this;
661 ArrayList<Var> result = new ArrayList<>(types.size());
662 int i = 0;
663 for (X x : types) {
664 String vn = name;
665 Class<?> vt;
666 if (x instanceof Class) {
667 vt = (Class<?>) x;
668 // make the names friendlier if debugging
669 assert((vn = vn + "_" + (i++)) != null);
670 } else {
671 @SuppressWarnings("unchecked")
672 Var v = (Var) x;
673 vn = v.name;
674 vt = v.type;
675 }
676 prev = new Var(vn, vt, prev);
677 result.add(prev);
678 }
679 return result;
680 }
681
682 int slotSize() { return basicType.basicTypeSlots(); }
683 int nextIndex() { return index + (slotSize() == 0 ? 0 : 1); }
684 int nextSlotIndex() { return slotIndex >= 0 ? slotIndex + slotSize() : slotIndex; }
685 boolean isInHeap() { return slotIndex < 0; }
686 void emitVarInstruction(int asmop, MethodVisitor mv) {
687 if (asmop == ALOAD)
688 asmop = typeLoadOp(basicType.basicTypeChar());
689 else
690 throw new AssertionError("bad op="+asmop+" for desc="+desc);
691 mv.visitVarInsn(asmop, slotIndex);
692 }
693 public void emitFieldInsn(int asmop, MethodVisitor mv) {
694 mv.visitFieldInsn(asmop, className, name, desc);
695 }
696 }
697
698 final Var NO_THIS = new Var(0, 0),
699 AFTER_THIS = new Var(0, 1),
700 IN_HEAP = new Var(0, -1);
701
702 // figure out the field types
703 final List<Class<?>> fieldTypes = speciesData.fieldTypes();
704 final List<Var> fields = new ArrayList<>(fieldTypes.size());
705 {
706 Var nextF = IN_HEAP;
707 for (Class<?> ft : fieldTypes) {
708 String fn = chooseFieldName(ft, nextF.nextIndex());
709 nextF = new Var(fn, ft, nextF);
710 fields.add(nextF);
711 }
712 }
713
714 // emit bound argument fields
715 for (Var field : fields) {
716 cw.visitField(ACC_FINAL, field.name, field.desc, null, null).visitEnd();
717 }
718
719 MethodVisitor mv;
720
721 // emit implementation of speciesData()
722 mv = cw.visitMethod((SPECIES_DATA_MODS & ACC_PPP) + ACC_FINAL,
723 SPECIES_DATA_NAME, "()" + SPECIES_DATA_SIG, null, null);
724 mv.visitCode();
725 mv.visitFieldInsn(GETSTATIC, className, sdFieldName, SPECIES_DATA_SIG);
726 mv.visitInsn(ARETURN);
727 mv.visitMaxs(0, 0);
728 mv.visitEnd();
729
730 // figure out the constructor arguments
731 MethodType superCtorType = ClassSpecializer.this.baseConstructorType();
732 MethodType thisCtorType = superCtorType.appendParameterTypes(fieldTypes);
733
734 // emit constructor
735 {
736 mv = cw.visitMethod(ACC_PRIVATE,
737 "<init>", methodSig(thisCtorType), null, null);
738 mv.visitCode();
739 mv.visitVarInsn(ALOAD, 0); // this
740
741 final List<Var> ctorArgs = AFTER_THIS.fromTypes(superCtorType.parameterList());
742 for (Var ca : ctorArgs) {
743 ca.emitVarInstruction(ALOAD, mv);
744 }
745
746 // super(ca...)
747 mv.visitMethodInsn(INVOKESPECIAL, superClassName,
748 "<init>", methodSig(superCtorType), false);
749
750 // store down fields
751 Var lastFV = AFTER_THIS.lastOf(ctorArgs);
752 for (Var f : fields) {
753 // this.argL1 = argL1
754 mv.visitVarInsn(ALOAD, 0); // this
755 lastFV = new Var(f.name, f.type, lastFV);
756 lastFV.emitVarInstruction(ALOAD, mv);
757 f.emitFieldInsn(PUTFIELD, mv);
758 }
759
760 mv.visitInsn(RETURN);
761 mv.visitMaxs(0, 0);
762 mv.visitEnd();
763 }
764
765 // emit make() ...factory method wrapping constructor
766 {
767 MethodType ftryType = thisCtorType.changeReturnType(topClass());
768 mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC,
769 "make", methodSig(ftryType), null, null);
770 mv.visitCode();
771 // make instance
772 mv.visitTypeInsn(NEW, className);
773 mv.visitInsn(DUP);
774 // load factory method arguments: ctarg... and arg...
775 for (Var v : NO_THIS.fromTypes(ftryType.parameterList())) {
776 v.emitVarInstruction(ALOAD, mv);
777 }
778
779 // finally, invoke the constructor and return
780 mv.visitMethodInsn(INVOKESPECIAL, className,
781 "<init>", methodSig(thisCtorType), false);
782 mv.visitInsn(ARETURN);
783 mv.visitMaxs(0, 0);
784 mv.visitEnd();
785 }
786
787 // For each transform, emit the customized override of the transform method.
788 // This method mixes together some incoming arguments (from the transform's
789 // static type signature) with the field types themselves, and passes
790 // the resulting mish-mosh of values to a method handle produced by
791 // the species itself. (Typically this method handle is the factory
792 // method of this species or a related one.)
793 for (int whichtm = 0; whichtm < TRANSFORM_NAMES.size(); whichtm++) {
794 final String TNAME = TRANSFORM_NAMES.get(whichtm);
795 final MethodType TTYPE = TRANSFORM_TYPES.get(whichtm);
796 final int TMODS = TRANSFORM_MODS.get(whichtm);
797 mv = cw.visitMethod((TMODS & ACC_PPP) | ACC_FINAL,
798 TNAME, TTYPE.toMethodDescriptorString(), null, E_THROWABLE);
799 mv.visitCode();
800 // return a call to the corresponding "transform helper", something like this:
801 // MY_SPECIES.transformHelper(whichtm).invokeBasic(ctarg, ..., argL0, ..., xarg)
802 mv.visitFieldInsn(GETSTATIC, className,
803 sdFieldName, SPECIES_DATA_SIG);
804 emitIntConstant(whichtm, mv);
805 mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA,
806 "transformHelper", "(I)" + MH_SIG, false);
807
808 List<Var> targs = AFTER_THIS.fromTypes(TTYPE.parameterList());
809 List<Var> tfields = new ArrayList<>(fields);
810 // mix them up and load them for the transform helper:
811 List<Var> helperArgs = speciesData.deriveTransformHelperArguments(transformMethods.get(whichtm), whichtm, targs, tfields);
812 List<Class<?>> helperTypes = new ArrayList<>(helperArgs.size());
813 for (Var ha : helperArgs) {
814 helperTypes.add(ha.basicType.basicTypeClass());
815 if (ha.isInHeap()) {
816 assert(tfields.contains(ha));
817 mv.visitVarInsn(ALOAD, 0);
818 ha.emitFieldInsn(GETFIELD, mv);
819 } else {
820 assert(targs.contains(ha));
821 ha.emitVarInstruction(ALOAD, mv);
822 }
823 }
824
825 // jump into the helper (which is probably a factory method)
826 final Class<?> rtype = TTYPE.returnType();
827 final BasicType rbt = BasicType.basicType(rtype);
828 MethodType invokeBasicType = MethodType.methodType(rbt.basicTypeClass(), helperTypes);
829 mv.visitMethodInsn(INVOKEVIRTUAL, MH,
830 "invokeBasic", methodSig(invokeBasicType), false);
831 if (rbt == BasicType.L_TYPE) {
832 mv.visitTypeInsn(CHECKCAST, classBCName(rtype));
833 mv.visitInsn(ARETURN);
834 } else {
835 throw newInternalError("NYI: transform of type "+rtype);
836 }
837 mv.visitMaxs(0, 0);
838 mv.visitEnd();
839 }
840
841 cw.visitEnd();
842
843 return cw.toByteArray();
844 }
845
846 private int typeLoadOp(char t) {
847 switch (t) {
848 case 'L': return ALOAD;
849 case 'I': return ILOAD;
850 case 'J': return LLOAD;
851 case 'F': return FLOAD;
852 case 'D': return DLOAD;
853 default : throw newInternalError("unrecognized type " + t);
854 }
855 }
856
857 private void emitIntConstant(int con, MethodVisitor mv) {
858 if (ICONST_M1 - ICONST_0 <= con && con <= ICONST_5 - ICONST_0)
859 mv.visitInsn(ICONST_0 + con);
860 else if (con == (byte) con)
861 mv.visitIntInsn(BIPUSH, con);
862 else if (con == (short) con)
863 mv.visitIntInsn(SIPUSH, con);
864 else {
865 mv.visitLdcInsn(con);
866 }
867
868 }
869
870 //
871 // Getter MH generation.
872 //
873
874 private MethodHandle findGetter(Class<?> speciesCode, List<Class<?>> types, int index) {
875 Class<?> fieldType = types.get(index);
876 String fieldName = chooseFieldName(fieldType, index);
877 try {
878 return IMPL_LOOKUP.findGetter(speciesCode, fieldName, fieldType);
879 } catch (NoSuchFieldException | IllegalAccessException e) {
880 throw newInternalError(e);
881 }
882 }
883
884 private List<MethodHandle> findGetters(Class<?> speciesCode, List<Class<?>> types) {
885 MethodHandle[] mhs = new MethodHandle[types.size()];
886 for (int i = 0; i < mhs.length; ++i) {
887 mhs[i] = findGetter(speciesCode, types, i);
888 assert(mhs[i].internalMemberName().getDeclaringClass() == speciesCode);
889 }
890 return List.of(mhs);
891 }
892
893 private List<MethodHandle> findFactories(Class<? extends T> speciesCode, List<Class<?>> types) {
894 MethodHandle[] mhs = new MethodHandle[1];
895 mhs[0] = findFactory(speciesCode, types);
896 return List.of(mhs);
897 }
898
899 List<LambdaForm.NamedFunction> makeNominalGetters(List<Class<?>> types, List<MethodHandle> getters) {
900 LambdaForm.NamedFunction[] nfs = new LambdaForm.NamedFunction[types.size()];
901 for (int i = 0; i < nfs.length; ++i) {
902 nfs[i] = new LambdaForm.NamedFunction(getters.get(i));
903 }
904 return List.of(nfs);
905 }
906
907 //
908 // Auxiliary methods.
909 //
910
911 protected void linkSpeciesDataToCode(ClassSpecializer<T,K,S>.SpeciesData speciesData, Class<? extends T> speciesCode) {
912 speciesData.speciesCode = speciesCode.asSubclass(topClass);
913 final List<Class<?>> types = speciesData.fieldTypes;
914 speciesData.factories = this.findFactories(speciesCode, types);
915 speciesData.getters = this.findGetters(speciesCode, types);
916 speciesData.nominalGetters = this.makeNominalGetters(types, speciesData.getters);
917 }
918
919 private Field reflectSDField(Class<? extends T> speciesCode) {
920 final Field field = reflectField(speciesCode, sdFieldName);
921 assert(field.getType() == metaType);
922 assert(Modifier.isStatic(field.getModifiers()));
923 return field;
924 }
925
926 private S readSpeciesDataFromCode(Class<? extends T> speciesCode) {
927 try {
928 MemberName sdField = IMPL_LOOKUP.resolveOrFail(REF_getStatic, speciesCode, sdFieldName, metaType);
929 Object base = MethodHandleNatives.staticFieldBase(sdField);
930 long offset = MethodHandleNatives.staticFieldOffset(sdField);
931 UNSAFE.loadFence();
932 return metaType.cast(UNSAFE.getObject(base, offset));
933 } catch (Error err) {
934 throw err;
935 } catch (Exception ex) {
936 throw newInternalError("Failed to load speciesData from speciesCode: " + speciesCode.getName(), ex);
937 } catch (Throwable t) {
938 throw uncaughtException(t);
939 }
940 }
941
942 protected S loadSpeciesDataFromCode(Class<? extends T> speciesCode) {
943 if (speciesCode == topClass()) {
944 return topSpecies;
945 }
946 S result = readSpeciesDataFromCode(speciesCode);
947 if (result.outer() != ClassSpecializer.this) {
948 throw newInternalError("wrong class");
949 }
950 return result;
951 }
952
953 protected void linkCodeToSpeciesData(Class<? extends T> speciesCode, ClassSpecializer<T,K,S>.SpeciesData speciesData, boolean salvage) {
954 try {
955 assert(readSpeciesDataFromCode(speciesCode) == null ||
956 (salvage && readSpeciesDataFromCode(speciesCode).equals(speciesData)));
957
958 MemberName sdField = IMPL_LOOKUP.resolveOrFail(REF_putStatic, speciesCode, sdFieldName, metaType);
959 Object base = MethodHandleNatives.staticFieldBase(sdField);
960 long offset = MethodHandleNatives.staticFieldOffset(sdField);
961 UNSAFE.storeFence();
962 UNSAFE.putObject(base, offset, speciesData);
963 UNSAFE.storeFence();
964 } catch (Error err) {
965 throw err;
966 } catch (Exception ex) {
967 throw newInternalError("Failed to link speciesData to speciesCode: " + speciesCode.getName(), ex);
968 } catch (Throwable t) {
969 throw uncaughtException(t);
970 }
971 }
972
973 /**
974 * Field names in concrete species classes adhere to this pattern:
975 * type + index, where type is a single character (L, I, J, F, D).
976 * The factory subclass can customize this.
977 * The name is purely cosmetic, since it applies to a private field.
978 */
979 protected String chooseFieldName(Class<?> type, int index) {
980 BasicType bt = BasicType.basicType(type);
981 return "" + bt.basicTypeChar() + index;
982 }
983
984 MethodHandle findFactory(Class<? extends T> speciesCode, List<Class<?>> types) {
985 final MethodType type = baseConstructorType().changeReturnType(topClass()).appendParameterTypes(types);
986 try {
987 return IMPL_LOOKUP.findStatic(speciesCode, "make", type);
988 } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) {
989 throw newInternalError(e);
990 }
991 }
992 }
993
994 /** Hook that virtualizes the Factory class, allowing subclasses to extend it. */
995 protected Factory makeFactory() {
996 return new Factory();
997 }
998
999
1000 // Other misc helpers:
1001 private static final String MH = "java/lang/invoke/MethodHandle";
1002 private static final String MH_SIG = "L" + MH + ";";
1003 private static final String STABLE = "jdk/internal/vm/annotation/Stable";
1004 private static final String STABLE_SIG = "L" + STABLE + ";";
1005 private static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" };
1006 static {
1007 assert(MH_SIG.equals(classSig(MethodHandle.class)));
1008 assert(MH.equals(classBCName(MethodHandle.class)));
1009 }
1010
1011 static String methodSig(MethodType mt) {
1012 return mt.toMethodDescriptorString();
1013 }
1014 static String classSig(Class<?> cls) {
1015 if (cls.isPrimitive() || cls.isArray())
1016 return MethodType.methodType(cls).toMethodDescriptorString().substring(2);
1017 return classSig(classBCName(cls));
1018 }
1019 static String classSig(String bcName) {
1020 assert(bcName.indexOf('.') < 0);
1021 assert(!bcName.endsWith(";"));
1022 assert(!bcName.startsWith("["));
1023 return "L" + bcName + ";";
1024 }
1025 static String classBCName(Class<?> cls) {
1026 return classBCName(className(cls));
1027 }
1028 static String classBCName(String str) {
1029 assert(str.indexOf('/') < 0) : str;
1030 return str.replace('.', '/');
1031 }
1032 static String className(Class<?> cls) {
1033 assert(!cls.isArray() && !cls.isPrimitive());
1034 return cls.getName();
1035 }
1036 }