1 /*
2 * Copyright (c) 2011, 2013, 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 java.lang.annotation.*;
29 import java.lang.reflect.Method;
30 import java.util.Map;
31 import java.util.List;
32 import java.util.Arrays;
33 import java.util.HashMap;
34 import java.util.concurrent.ConcurrentHashMap;
35 import sun.invoke.util.Wrapper;
36 import java.lang.reflect.Field;
37
38 import static java.lang.invoke.LambdaForm.BasicType.*;
39 import static java.lang.invoke.MethodHandleStatics.*;
40 import static java.lang.invoke.MethodHandleNatives.Constants.*;
41
42 /**
43 * The symbolic, non-executable form of a method handle's invocation semantics.
44 * It consists of a series of names.
45 * The first N (N=arity) names are parameters,
46 * while any remaining names are temporary values.
47 * Each temporary specifies the application of a function to some arguments.
48 * The functions are method handles, while the arguments are mixes of
49 * constant values and local names.
50 * The result of the lambda is defined as one of the names, often the last one.
51 * <p>
52 * Here is an approximate grammar:
53 * <blockquote><pre>{@code
54 * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
55 * ArgName = "a" N ":" T
56 * TempName = "t" N ":" T "=" Function "(" Argument* ");"
57 * Function = ConstantValue
58 * Argument = NameRef | ConstantValue
59 * Result = NameRef | "void"
60 * NameRef = "a" N | "t" N
61 * N = (any whole number)
62 * T = "L" | "I" | "J" | "F" | "D" | "V"
63 * }</pre></blockquote>
64 * Names are numbered consecutively from left to right starting at zero.
65 * (The letters are merely a taste of syntax sugar.)
66 * Thus, the first temporary (if any) is always numbered N (where N=arity).
67 * Every occurrence of a name reference in an argument list must refer to
68 * a name previously defined within the same lambda.
69 * A lambda has a void result if and only if its result index is -1.
70 * If a temporary has the type "V", it cannot be the subject of a NameRef,
71 * even though possesses a number.
72 * Note that all reference types are erased to "L", which stands for {@code Object}.
73 * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
74 * The other types stand for the usual primitive types.
75 * <p>
76 * Function invocation closely follows the static rules of the Java verifier.
77 * Arguments and return values must exactly match when their "Name" types are
78 * considered.
79 * Conversions are allowed only if they do not change the erased type.
80 * <ul>
81 * <li>L = Object: casts are used freely to convert into and out of reference types
82 * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
83 * <li>J = long: no implicit conversions
84 * <li>F = float: no implicit conversions
85 * <li>D = double: no implicit conversions
86 * <li>V = void: a function result may be void if and only if its Name is of type "V"
87 * </ul>
88 * Although implicit conversions are not allowed, explicit ones can easily be
89 * encoded by using temporary expressions which call type-transformed identity functions.
90 * <p>
91 * Examples:
92 * <blockquote><pre>{@code
93 * (a0:J)=>{ a0 }
94 * == identity(long)
95 * (a0:I)=>{ t1:V = System.out#println(a0); void }
96 * == System.out#println(int)
97 * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
98 * == identity, with printing side-effect
99 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
100 * t3:L = BoundMethodHandle#target(a0);
101 * t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
102 * == general invoker for unary insertArgument combination
103 * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
104 * t3:L = MethodHandle#invoke(t2, a1);
105 * t4:L = FilterMethodHandle#target(a0);
106 * t5:L = MethodHandle#invoke(t4, t3); t5 }
107 * == general invoker for unary filterArgument combination
108 * (a0:L, a1:L)=>{ ...(same as previous example)...
109 * t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
110 * == general invoker for unary/unary foldArgument combination
111 * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
112 * == invoker for identity method handle which performs i2l
113 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
114 * t3:L = Class#cast(t2,a1); t3 }
115 * == invoker for identity method handle which performs cast
116 * }</pre></blockquote>
117 * <p>
118 * @author John Rose, JSR 292 EG
119 */
120 class LambdaForm {
121 final int arity;
122 final int result;
123 @Stable final Name[] names;
124 final String debugName;
125 MemberName vmentry; // low-level behavior, or null if not yet prepared
126 private boolean isCompiled;
127
128 // Caches for common structural transforms:
129 LambdaForm[] bindCache;
130
131 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
132
133 enum BasicType {
134 L_TYPE('L', Object.class, Wrapper.OBJECT), // all reference types
135 I_TYPE('I', int.class, Wrapper.INT),
136 J_TYPE('J', long.class, Wrapper.LONG),
137 F_TYPE('F', float.class, Wrapper.FLOAT),
138 D_TYPE('D', double.class, Wrapper.DOUBLE), // all primitive types
139 V_TYPE('V', void.class, Wrapper.VOID); // not valid in all contexts
140
141 static final BasicType[] ALL_TYPES = BasicType.values();
142 static final BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
143
144 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
145 static final int TYPE_LIMIT = ALL_TYPES.length;
146
147 private final char btChar;
148 private final Class<?> btClass;
149 private final Wrapper btWrapper;
150
151 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper) {
152 this.btChar = btChar;
153 this.btClass = btClass;
154 this.btWrapper = wrapper;
155 }
156
157 char basicTypeChar() {
158 return btChar;
159 }
160 Class<?> basicTypeClass() {
161 return btClass;
162 }
163 Wrapper basicTypeWrapper() {
164 return btWrapper;
165 }
166 int basicTypeSlots() {
167 return btWrapper.stackSlots();
168 }
169
170 static BasicType basicType(byte type) {
171 return ALL_TYPES[type];
172 }
173 static BasicType basicType(char type) {
174 switch (type) {
175 case 'L': return L_TYPE;
176 case 'I': return I_TYPE;
177 case 'J': return J_TYPE;
178 case 'F': return F_TYPE;
179 case 'D': return D_TYPE;
180 case 'V': return V_TYPE;
181 // all subword types are represented as ints
182 case 'Z':
183 case 'B':
184 case 'S':
185 case 'C':
186 return I_TYPE;
187 default:
188 throw newInternalError("Unknown type char: '"+type+"'");
189 }
190 }
191 static BasicType basicType(Wrapper type) {
192 char c = type.basicTypeChar();
193 return basicType(c);
194 }
195 static BasicType basicType(Class<?> type) {
196 if (!type.isPrimitive()) return L_TYPE;
197 return basicType(Wrapper.forPrimitiveType(type));
198 }
199
200 static char basicTypeChar(Class<?> type) {
201 return basicType(type).btChar;
202 }
203 static BasicType[] basicTypes(List<Class<?>> types) {
204 BasicType[] btypes = new BasicType[types.size()];
205 for (int i = 0; i < btypes.length; i++) {
206 btypes[i] = basicType(types.get(i));
207 }
208 return btypes;
209 }
210 static BasicType[] basicTypes(String types) {
211 BasicType[] btypes = new BasicType[types.length()];
212 for (int i = 0; i < btypes.length; i++) {
213 btypes[i] = basicType(types.charAt(i));
214 }
215 return btypes;
216 }
217 static boolean isBasicTypeChar(char c) {
218 return "LIJFDV".indexOf(c) >= 0;
219 }
220 static boolean isArgBasicTypeChar(char c) {
221 return "LIJFD".indexOf(c) >= 0;
222 }
223
224 static { assert(checkBasicType()); }
225 private static boolean checkBasicType() {
226 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
227 assert ARG_TYPES[i].ordinal() == i;
228 assert ARG_TYPES[i] == ALL_TYPES[i];
229 }
230 for (int i = 0; i < TYPE_LIMIT; i++) {
231 assert ALL_TYPES[i].ordinal() == i;
232 }
233 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
234 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
235 return true;
236 }
237 }
238
239 LambdaForm(String debugName,
240 int arity, Name[] names, int result) {
241 assert(namesOK(arity, names));
242 this.arity = arity;
243 this.result = fixResult(result, names);
244 this.names = names.clone();
245 this.debugName = fixDebugName(debugName);
246 int maxOutArity = normalize();
247 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
248 // Cannot use LF interpreter on very high arity expressions.
249 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
250 compileToBytecode();
251 }
252 }
253
254 LambdaForm(String debugName,
255 int arity, Name[] names) {
256 this(debugName,
257 arity, names, LAST_RESULT);
258 }
259
260 LambdaForm(String debugName,
261 Name[] formals, Name[] temps, Name result) {
262 this(debugName,
263 formals.length, buildNames(formals, temps, result), LAST_RESULT);
264 }
265
266 private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
267 int arity = formals.length;
268 int length = arity + temps.length + (result == null ? 0 : 1);
269 Name[] names = Arrays.copyOf(formals, length);
270 System.arraycopy(temps, 0, names, arity, temps.length);
271 if (result != null)
272 names[length - 1] = result;
273 return names;
274 }
275
276 private LambdaForm(String sig) {
277 // Make a blank lambda form, which returns a constant zero or null.
278 // It is used as a template for managing the invocation of similar forms that are non-empty.
279 // Called only from getPreparedForm.
280 assert(isValidSignature(sig));
281 this.arity = signatureArity(sig);
282 this.result = (signatureReturn(sig) == V_TYPE ? -1 : arity);
283 this.names = buildEmptyNames(arity, sig);
284 this.debugName = "LF.zero";
285 assert(nameRefsAreLegal());
286 assert(isEmpty());
287 assert(sig.equals(basicTypeSignature())) : sig + " != " + basicTypeSignature();
288 }
289
290 private static Name[] buildEmptyNames(int arity, String basicTypeSignature) {
291 assert(isValidSignature(basicTypeSignature));
292 int resultPos = arity + 1; // skip '_'
293 if (arity < 0 || basicTypeSignature.length() != resultPos+1)
294 throw new IllegalArgumentException("bad arity for "+basicTypeSignature);
295 int numRes = (basicType(basicTypeSignature.charAt(resultPos)) == V_TYPE ? 0 : 1);
296 Name[] names = arguments(numRes, basicTypeSignature.substring(0, arity));
297 for (int i = 0; i < numRes; i++) {
298 Name zero = new Name(constantZero(basicType(basicTypeSignature.charAt(resultPos + i))));
299 names[arity + i] = zero.newIndex(arity + i);
300 }
301 return names;
302 }
303
304 private static int fixResult(int result, Name[] names) {
305 if (result == LAST_RESULT)
306 result = names.length - 1; // might still be void
307 if (result >= 0 && names[result].type == V_TYPE)
308 result = VOID_RESULT;
309 return result;
310 }
311
312 private static String fixDebugName(String debugName) {
313 if (DEBUG_NAME_COUNTERS != null) {
314 int under = debugName.indexOf('_');
315 int length = debugName.length();
316 if (under < 0) under = length;
317 String debugNameStem = debugName.substring(0, under);
318 Integer ctr;
319 synchronized (DEBUG_NAME_COUNTERS) {
320 ctr = DEBUG_NAME_COUNTERS.get(debugNameStem);
321 if (ctr == null) ctr = 0;
322 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr+1);
323 }
324 StringBuilder buf = new StringBuilder(debugNameStem);
325 buf.append('_');
326 int leadingZero = buf.length();
327 buf.append((int) ctr);
328 for (int i = buf.length() - leadingZero; i < 3; i++)
329 buf.insert(leadingZero, '0');
330 if (under < length) {
331 ++under; // skip "_"
332 while (under < length && Character.isDigit(debugName.charAt(under))) {
333 ++under;
334 }
335 if (under < length && debugName.charAt(under) == '_') ++under;
336 if (under < length)
337 buf.append('_').append(debugName, under, length);
338 }
339 return buf.toString();
340 }
341 return debugName;
342 }
343
344 private static boolean namesOK(int arity, Name[] names) {
345 for (int i = 0; i < names.length; i++) {
346 Name n = names[i];
347 assert(n != null) : "n is null";
348 if (i < arity)
349 assert( n.isParam()) : n + " is not param at " + i;
350 else
351 assert(!n.isParam()) : n + " is param at " + i;
352 }
353 return true;
354 }
355
356 /** Renumber and/or replace params so that they are interned and canonically numbered.
357 * @return maximum argument list length among the names (since we have to pass over them anyway)
358 */
359 private int normalize() {
360 Name[] oldNames = null;
361 int maxOutArity = 0;
362 int changesStart = 0;
363 for (int i = 0; i < names.length; i++) {
364 Name n = names[i];
365 if (!n.initIndex(i)) {
366 if (oldNames == null) {
367 oldNames = names.clone();
368 changesStart = i;
369 }
370 names[i] = n.cloneWithIndex(i);
371 }
372 if (n.arguments != null && maxOutArity < n.arguments.length)
373 maxOutArity = n.arguments.length;
374 }
375 if (oldNames != null) {
376 int startFixing = arity;
377 if (startFixing <= changesStart)
378 startFixing = changesStart+1;
379 for (int i = startFixing; i < names.length; i++) {
380 Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
381 names[i] = fixed.newIndex(i);
382 }
383 }
384 assert(nameRefsAreLegal());
385 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
386 boolean needIntern = false;
387 for (int i = 0; i < maxInterned; i++) {
388 Name n = names[i], n2 = internArgument(n);
389 if (n != n2) {
390 names[i] = n2;
391 needIntern = true;
392 }
393 }
394 if (needIntern) {
395 for (int i = arity; i < names.length; i++) {
396 names[i].internArguments();
397 }
398 assert(nameRefsAreLegal());
399 }
400 return maxOutArity;
401 }
402
403 /**
404 * Check that all embedded Name references are localizable to this lambda,
405 * and are properly ordered after their corresponding definitions.
406 * <p>
407 * Note that a Name can be local to multiple lambdas, as long as
408 * it possesses the same index in each use site.
409 * This allows Name references to be freely reused to construct
410 * fresh lambdas, without confusion.
411 */
412 private boolean nameRefsAreLegal() {
413 assert(arity >= 0 && arity <= names.length);
414 assert(result >= -1 && result < names.length);
415 // Do all names possess an index consistent with their local definition order?
416 for (int i = 0; i < arity; i++) {
417 Name n = names[i];
418 assert(n.index() == i) : Arrays.asList(n.index(), i);
419 assert(n.isParam());
420 }
421 // Also, do all local name references
422 for (int i = arity; i < names.length; i++) {
423 Name n = names[i];
424 assert(n.index() == i);
425 for (Object arg : n.arguments) {
426 if (arg instanceof Name) {
427 Name n2 = (Name) arg;
428 int i2 = n2.index;
429 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
430 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
431 assert(i2 < i); // ref must come after def!
432 }
433 }
434 }
435 return true;
436 }
437
438 /** Invoke this form on the given arguments. */
439 // final Object invoke(Object... args) throws Throwable {
440 // // NYI: fit this into the fast path?
441 // return interpretWithArguments(args);
442 // }
443
444 /** Report the return type. */
445 BasicType returnType() {
446 if (result < 0) return V_TYPE;
447 Name n = names[result];
448 return n.type;
449 }
450
451 /** Report the N-th argument type. */
452 BasicType parameterType(int n) {
453 assert(n < arity);
454 return names[n].type;
455 }
456
457 /** Report the arity. */
458 int arity() {
459 return arity;
460 }
461
462 /** Return the method type corresponding to my basic type signature. */
463 MethodType methodType() {
464 return signatureType(basicTypeSignature());
465 }
466 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
467 final String basicTypeSignature() {
468 StringBuilder buf = new StringBuilder(arity() + 3);
469 for (int i = 0, a = arity(); i < a; i++)
470 buf.append(parameterType(i).basicTypeChar());
471 return buf.append('_').append(returnType().basicTypeChar()).toString();
472 }
473 static int signatureArity(String sig) {
474 assert(isValidSignature(sig));
475 return sig.indexOf('_');
476 }
477 static BasicType signatureReturn(String sig) {
478 return basicType(sig.charAt(signatureArity(sig) + 1));
479 }
480 static boolean isValidSignature(String sig) {
481 int arity = sig.indexOf('_');
482 if (arity < 0) return false; // must be of the form *_*
483 int siglen = sig.length();
484 if (siglen != arity + 2) return false; // *_X
485 for (int i = 0; i < siglen; i++) {
486 if (i == arity) continue; // skip '_'
487 char c = sig.charAt(i);
488 if (c == 'V')
489 return (i == siglen - 1 && arity == siglen - 2);
490 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
491 }
492 return true; // [LIJFD]*_[LIJFDV]
493 }
494 static MethodType signatureType(String sig) {
495 Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
496 for (int i = 0; i < ptypes.length; i++)
497 ptypes[i] = basicType(sig.charAt(i)).btClass;
498 Class<?> rtype = signatureReturn(sig).btClass;
499 return MethodType.methodType(rtype, ptypes);
500 }
501
502 /*
503 * Code generation issues:
504 *
505 * Compiled LFs should be reusable in general.
506 * The biggest issue is how to decide when to pull a name into
507 * the bytecode, versus loading a reified form from the MH data.
508 *
509 * For example, an asType wrapper may require execution of a cast
510 * after a call to a MH. The target type of the cast can be placed
511 * as a constant in the LF itself. This will force the cast type
512 * to be compiled into the bytecodes and native code for the MH.
513 * Or, the target type of the cast can be erased in the LF, and
514 * loaded from the MH data. (Later on, if the MH as a whole is
515 * inlined, the data will flow into the inlined instance of the LF,
516 * as a constant, and the end result will be an optimal cast.)
517 *
518 * This erasure of cast types can be done with any use of
519 * reference types. It can also be done with whole method
520 * handles. Erasing a method handle might leave behind
521 * LF code that executes correctly for any MH of a given
522 * type, and load the required MH from the enclosing MH's data.
523 * Or, the erasure might even erase the expected MT.
524 *
525 * Also, for direct MHs, the MemberName of the target
526 * could be erased, and loaded from the containing direct MH.
527 * As a simple case, a LF for all int-valued non-static
528 * field getters would perform a cast on its input argument
529 * (to non-constant base type derived from the MemberName)
530 * and load an integer value from the input object
531 * (at a non-constant offset also derived from the MemberName).
532 * Such MN-erased LFs would be inlinable back to optimized
533 * code, whenever a constant enclosing DMH is available
534 * to supply a constant MN from its data.
535 *
536 * The main problem here is to keep LFs reasonably generic,
537 * while ensuring that hot spots will inline good instances.
538 * "Reasonably generic" means that we don't end up with
539 * repeated versions of bytecode or machine code that do
540 * not differ in their optimized form. Repeated versions
541 * of machine would have the undesirable overheads of
542 * (a) redundant compilation work and (b) extra I$ pressure.
543 * To control repeated versions, we need to be ready to
544 * erase details from LFs and move them into MH data,
545 * whevener those details are not relevant to significant
546 * optimization. "Significant" means optimization of
547 * code that is actually hot.
548 *
549 * Achieving this may require dynamic splitting of MHs, by replacing
550 * a generic LF with a more specialized one, on the same MH,
551 * if (a) the MH is frequently executed and (b) the MH cannot
552 * be inlined into a containing caller, such as an invokedynamic.
553 *
554 * Compiled LFs that are no longer used should be GC-able.
555 * If they contain non-BCP references, they should be properly
556 * interlinked with the class loader(s) that their embedded types
557 * depend on. This probably means that reusable compiled LFs
558 * will be tabulated (indexed) on relevant class loaders,
559 * or else that the tables that cache them will have weak links.
560 */
561
562 /**
563 * Make this LF directly executable, as part of a MethodHandle.
564 * Invariant: Every MH which is invoked must prepare its LF
565 * before invocation.
566 * (In principle, the JVM could do this very lazily,
567 * as a sort of pre-invocation linkage step.)
568 */
569 public void prepare() {
570 if (COMPILE_THRESHOLD == 0) {
571 compileToBytecode();
572 }
573 if (this.vmentry != null) {
574 // already prepared (e.g., a primitive DMH invoker form)
575 return;
576 }
577 LambdaForm prep = getPreparedForm(basicTypeSignature());
578 this.vmentry = prep.vmentry;
579 // TO DO: Maybe add invokeGeneric, invokeWithArguments
580 }
581
582 /** Generate optimizable bytecode for this form. */
583 MemberName compileToBytecode() {
584 MethodType invokerType = methodType();
585 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
586 if (vmentry != null && isCompiled) {
587 return vmentry; // already compiled somehow
588 }
589 try {
590 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
591 if (TRACE_INTERPRETER)
592 traceInterpreter("compileToBytecode", this);
593 isCompiled = true;
594 return vmentry;
595 } catch (Error | Exception ex) {
596 throw newInternalError(this.toString(), ex);
597 }
598 }
599
600 private static final ConcurrentHashMap<String,LambdaForm> PREPARED_FORMS;
601 static {
602 int capacity = 512; // expect many distinct signatures over time
603 float loadFactor = 0.75f; // normal default
604 int writers = 1;
605 PREPARED_FORMS = new ConcurrentHashMap<>(capacity, loadFactor, writers);
606 }
607
608 private static Map<String,LambdaForm> computeInitialPreparedForms() {
609 // Find all predefined invokers and associate them with canonical empty lambda forms.
610 HashMap<String,LambdaForm> forms = new HashMap<>();
611 for (MemberName m : MemberName.getFactory().getMethods(LambdaForm.class, false, null, null, null)) {
612 if (!m.isStatic() || !m.isPackage()) continue;
613 MethodType mt = m.getMethodType();
614 if (mt.parameterCount() > 0 &&
615 mt.parameterType(0) == MethodHandle.class &&
616 m.getName().startsWith("interpret_")) {
617 String sig = basicTypeSignature(mt);
618 assert(m.getName().equals("interpret" + sig.substring(sig.indexOf('_'))));
619 LambdaForm form = new LambdaForm(sig);
620 form.vmentry = m;
621 form = mt.form().setCachedLambdaForm(MethodTypeForm.LF_COUNTER, form);
622 // FIXME: get rid of PREPARED_FORMS; use MethodTypeForm cache only
623 forms.put(sig, form);
624 }
625 }
626 //System.out.println("computeInitialPreparedForms => "+forms);
627 return forms;
628 }
629
630 // Set this false to disable use of the interpret_L methods defined in this file.
631 private static final boolean USE_PREDEFINED_INTERPRET_METHODS = true;
632
633 // The following are predefined exact invokers. The system must build
634 // a separate invoker for each distinct signature.
635 static Object interpret_L(MethodHandle mh) throws Throwable {
636 Object[] av = {mh};
637 String sig = null;
638 assert(argumentTypesMatch(sig = "L_L", av));
639 Object res = mh.form.interpretWithArguments(av);
640 assert(returnTypesMatch(sig, av, res));
641 return res;
642 }
643 static Object interpret_L(MethodHandle mh, Object x1) throws Throwable {
644 Object[] av = {mh, x1};
645 String sig = null;
646 assert(argumentTypesMatch(sig = "LL_L", av));
647 Object res = mh.form.interpretWithArguments(av);
648 assert(returnTypesMatch(sig, av, res));
649 return res;
650 }
651 static Object interpret_L(MethodHandle mh, Object x1, Object x2) throws Throwable {
652 Object[] av = {mh, x1, x2};
653 String sig = null;
654 assert(argumentTypesMatch(sig = "LLL_L", av));
655 Object res = mh.form.interpretWithArguments(av);
656 assert(returnTypesMatch(sig, av, res));
657 return res;
658 }
659 private static LambdaForm getPreparedForm(String sig) {
660 MethodType mtype = signatureType(sig);
661 //LambdaForm prep = PREPARED_FORMS.get(sig);
662 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
663 if (prep != null) return prep;
664 assert(isValidSignature(sig));
665 prep = new LambdaForm(sig);
666 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(sig);
667 //LambdaForm prep2 = PREPARED_FORMS.putIfAbsent(sig.intern(), prep);
668 return mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
669 }
670
671 // The next few routines are called only from assert expressions
672 // They verify that the built-in invokers process the correct raw data types.
673 private static boolean argumentTypesMatch(String sig, Object[] av) {
674 int arity = signatureArity(sig);
675 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
676 assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
677 MethodHandle mh = (MethodHandle) av[0];
678 MethodType mt = mh.type();
679 assert(mt.parameterCount() == arity-1);
680 for (int i = 0; i < av.length; i++) {
681 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
682 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
683 }
684 return true;
685 }
686 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
687 // The following line is needed because (...)void method handles can use non-void invokers
688 if (type == void.class) tc = V_TYPE; // can drop any kind of value
689 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
690 switch (tc) {
691 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
692 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
693 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
694 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
695 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
696 case V_TYPE: break; // allow anything here; will be dropped
697 default: assert(false);
698 }
699 return true;
700 }
701 private static boolean returnTypesMatch(String sig, Object[] av, Object res) {
702 MethodHandle mh = (MethodHandle) av[0];
703 return valueMatches(signatureReturn(sig), mh.type().returnType(), res);
704 }
705 private static boolean checkInt(Class<?> type, Object x) {
706 assert(x instanceof Integer);
707 if (type == int.class) return true;
708 Wrapper w = Wrapper.forBasicType(type);
709 assert(w.isSubwordOrInt());
710 Object x1 = Wrapper.INT.wrap(w.wrap(x));
711 return x.equals(x1);
712 }
713 private static boolean checkRef(Class<?> type, Object x) {
714 assert(!type.isPrimitive());
715 if (x == null) return true;
716 if (type.isInterface()) return true;
717 return type.isInstance(x);
718 }
719
720 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
721 private static final int COMPILE_THRESHOLD;
722 static {
723 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
724 }
725 private int invocationCounter = 0;
726
727 @Hidden
728 @DontInline
729 /** Interpretively invoke this form on the given arguments. */
730 Object interpretWithArguments(Object... argumentValues) throws Throwable {
731 if (TRACE_INTERPRETER)
732 return interpretWithArgumentsTracing(argumentValues);
733 checkInvocationCounter();
734 assert(arityCheck(argumentValues));
735 Object[] values = Arrays.copyOf(argumentValues, names.length);
736 for (int i = argumentValues.length; i < values.length; i++) {
737 values[i] = interpretName(names[i], values);
738 }
739 Object rv = (result < 0) ? null : values[result];
740 assert(resultCheck(argumentValues, rv));
741 return rv;
742 }
743
744 @Hidden
745 @DontInline
746 /** Evaluate a single Name within this form, applying its function to its arguments. */
747 Object interpretName(Name name, Object[] values) throws Throwable {
748 if (TRACE_INTERPRETER)
749 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
750 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
751 for (int i = 0; i < arguments.length; i++) {
752 Object a = arguments[i];
753 if (a instanceof Name) {
754 int i2 = ((Name)a).index();
755 assert(names[i2] == a);
756 a = values[i2];
757 arguments[i] = a;
758 }
759 }
760 return name.function.invokeWithArguments(arguments);
761 }
762
763 private void checkInvocationCounter() {
764 if (COMPILE_THRESHOLD != 0 &&
765 invocationCounter < COMPILE_THRESHOLD) {
766 invocationCounter++; // benign race
767 if (invocationCounter >= COMPILE_THRESHOLD) {
768 // Replace vmentry with a bytecode version of this LF.
769 compileToBytecode();
770 }
771 }
772 }
773 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
774 traceInterpreter("[ interpretWithArguments", this, argumentValues);
775 if (invocationCounter < COMPILE_THRESHOLD) {
776 int ctr = invocationCounter++; // benign race
777 traceInterpreter("| invocationCounter", ctr);
778 if (invocationCounter >= COMPILE_THRESHOLD) {
779 compileToBytecode();
780 }
781 }
782 Object rval;
783 try {
784 assert(arityCheck(argumentValues));
785 Object[] values = Arrays.copyOf(argumentValues, names.length);
786 for (int i = argumentValues.length; i < values.length; i++) {
787 values[i] = interpretName(names[i], values);
788 }
789 rval = (result < 0) ? null : values[result];
790 } catch (Throwable ex) {
791 traceInterpreter("] throw =>", ex);
792 throw ex;
793 }
794 traceInterpreter("] return =>", rval);
795 return rval;
796 }
797
798 //** This transform is applied (statically) to every name.function. */
799 /*
800 private static MethodHandle eraseSubwordTypes(MethodHandle mh) {
801 MethodType mt = mh.type();
802 if (mt.hasPrimitives()) {
803 mt = mt.changeReturnType(eraseSubwordType(mt.returnType()));
804 for (int i = 0; i < mt.parameterCount(); i++) {
805 mt = mt.changeParameterType(i, eraseSubwordType(mt.parameterType(i)));
806 }
807 mh = MethodHandles.explicitCastArguments(mh, mt);
808 }
809 return mh;
810 }
811 private static Class<?> eraseSubwordType(Class<?> type) {
812 if (!type.isPrimitive()) return type;
813 if (type == int.class) return type;
814 Wrapper w = Wrapper.forPrimitiveType(type);
815 if (w.isSubwordOrInt()) return int.class;
816 return type;
817 }
818 */
819
820 static void traceInterpreter(String event, Object obj, Object... args) {
821 if (TRACE_INTERPRETER) {
822 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
823 }
824 }
825 static void traceInterpreter(String event, Object obj) {
826 traceInterpreter(event, obj, (Object[])null);
827 }
828 private boolean arityCheck(Object[] argumentValues) {
829 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
830 // also check that the leading (receiver) argument is somehow bound to this LF:
831 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
832 MethodHandle mh = (MethodHandle) argumentValues[0];
833 assert(mh.internalForm() == this);
834 // note: argument #0 could also be an interface wrapper, in the future
835 argumentTypesMatch(basicTypeSignature(), argumentValues);
836 return true;
837 }
838 private boolean resultCheck(Object[] argumentValues, Object result) {
839 MethodHandle mh = (MethodHandle) argumentValues[0];
840 MethodType mt = mh.type();
841 assert(valueMatches(returnType(), mt.returnType(), result));
842 return true;
843 }
844
845 private boolean isEmpty() {
846 if (result < 0)
847 return (names.length == arity);
848 else if (result == arity && names.length == arity + 1)
849 return names[arity].isConstantZero();
850 else
851 return false;
852 }
853
854 public String toString() {
855 StringBuilder buf = new StringBuilder(debugName+"=Lambda(");
856 for (int i = 0; i < names.length; i++) {
857 if (i == arity) buf.append(")=>{");
858 Name n = names[i];
859 if (i >= arity) buf.append("\n ");
860 buf.append(n);
861 if (i < arity) {
862 if (i+1 < arity) buf.append(",");
863 continue;
864 }
865 buf.append("=").append(n.exprString());
866 buf.append(";");
867 }
868 if (arity == names.length) buf.append(")=>{");
869 buf.append(result < 0 ? "void" : names[result]).append("}");
870 if (TRACE_INTERPRETER) {
871 // Extra verbosity:
872 buf.append(":").append(basicTypeSignature());
873 buf.append("/").append(vmentry);
874 }
875 return buf.toString();
876 }
877
878 LambdaForm bind(int namePos, BoundMethodHandle.SpeciesData oldData) {
879 Name name = names[namePos];
880 BoundMethodHandle.SpeciesData newData = oldData.extendWith(name.type);
881 return bind(name, new Name(newData.getterFunction(oldData.fieldCount()), names[0]), oldData, newData);
882 }
883 LambdaForm bind(Name name, Name binding,
884 BoundMethodHandle.SpeciesData oldData,
885 BoundMethodHandle.SpeciesData newData) {
886 int pos = name.index;
887 assert(name.isParam());
888 assert(!binding.isParam());
889 assert(name.type == binding.type);
890 assert(0 <= pos && pos < arity && names[pos] == name);
891 assert(binding.function.memberDeclaringClassOrNull() == newData.clazz);
892 assert(oldData.getters.length == newData.getters.length-1);
893 if (bindCache != null) {
894 LambdaForm form = bindCache[pos];
895 if (form != null) {
896 assert(form.contains(binding)) : "form << " + form + " >> does not contain binding << " + binding + " >>";
897 return form;
898 }
899 } else {
900 bindCache = new LambdaForm[arity];
901 }
902 assert(nameRefsAreLegal());
903 int arity2 = arity-1;
904 Name[] names2 = names.clone();
905 names2[pos] = binding; // we might move this in a moment
906
907 // The newly created LF will run with a different BMH.
908 // Switch over any pre-existing BMH field references to the new BMH class.
909 int firstOldRef = -1;
910 for (int i = 0; i < names2.length; i++) {
911 Name n = names[i];
912 if (n.function != null &&
913 n.function.memberDeclaringClassOrNull() == oldData.clazz) {
914 MethodHandle oldGetter = n.function.resolvedHandle;
915 MethodHandle newGetter = null;
916 for (int j = 0; j < oldData.getters.length; j++) {
917 if (oldGetter == oldData.getters[j])
918 newGetter = newData.getters[j];
919 }
920 if (newGetter != null) {
921 if (firstOldRef < 0) firstOldRef = i;
922 Name n2 = new Name(newGetter, n.arguments);
923 names2[i] = n2;
924 }
925 }
926 }
927
928 // Walk over the new list of names once, in forward order.
929 // Replace references to 'name' with 'binding'.
930 // Replace data structure references to the old BMH species with the new.
931 // This might cause a ripple effect, but it will settle in one pass.
932 assert(firstOldRef < 0 || firstOldRef > pos);
933 for (int i = pos+1; i < names2.length; i++) {
934 if (i <= arity2) continue;
935 names2[i] = names2[i].replaceNames(names, names2, pos, i);
936 }
937
938 // (a0, a1, name=a2, a3, a4) => (a0, a1, a3, a4, binding)
939 int insPos = pos;
940 for (; insPos+1 < names2.length; insPos++) {
941 Name n = names2[insPos+1];
942 if (n.isParam()) {
943 names2[insPos] = n;
944 } else {
945 break;
946 }
947 }
948 names2[insPos] = binding;
949
950 // Since we moved some stuff, maybe update the result reference:
951 int result2 = result;
952 if (result2 == pos)
953 result2 = insPos;
954 else if (result2 > pos && result2 <= insPos)
955 result2 -= 1;
956
957 return bindCache[pos] = new LambdaForm(debugName, arity2, names2, result2);
958 }
959
960 boolean contains(Name name) {
961 int pos = name.index();
962 if (pos >= 0) {
963 return pos < names.length && name.equals(names[pos]);
964 }
965 for (int i = arity; i < names.length; i++) {
966 if (name.equals(names[i]))
967 return true;
968 }
969 return false;
970 }
971
972 LambdaForm addArguments(int pos, BasicType... types) {
973 // names array has MH in slot 0; skip it.
974 int argpos = pos + 1;
975 assert(argpos <= arity);
976 int length = names.length;
977 int inTypes = types.length;
978 Name[] names2 = Arrays.copyOf(names, length + inTypes);
979 int arity2 = arity + inTypes;
980 int result2 = result;
981 if (result2 >= argpos)
982 result2 += inTypes;
983 // Note: The LF constructor will rename names2[argpos...].
984 // Make space for new arguments (shift temporaries).
985 System.arraycopy(names, argpos, names2, argpos + inTypes, length - argpos);
986 for (int i = 0; i < inTypes; i++) {
987 names2[argpos + i] = new Name(types[i]);
988 }
989 return new LambdaForm(debugName, arity2, names2, result2);
990 }
991
992 LambdaForm addArguments(int pos, List<Class<?>> types) {
993 return addArguments(pos, basicTypes(types));
994 }
995
996 LambdaForm permuteArguments(int skip, int[] reorder, BasicType[] types) {
997 // Note: When inArg = reorder[outArg], outArg is fed by a copy of inArg.
998 // The types are the types of the new (incoming) arguments.
999 int length = names.length;
1000 int inTypes = types.length;
1001 int outArgs = reorder.length;
1002 assert(skip+outArgs == arity);
1003 assert(permutedTypesMatch(reorder, types, names, skip));
1004 int pos = 0;
1005 // skip trivial first part of reordering:
1006 while (pos < outArgs && reorder[pos] == pos) pos += 1;
1007 Name[] names2 = new Name[length - outArgs + inTypes];
1008 System.arraycopy(names, 0, names2, 0, skip+pos);
1009 // copy the body:
1010 int bodyLength = length - arity;
1011 System.arraycopy(names, skip+outArgs, names2, skip+inTypes, bodyLength);
1012 int arity2 = names2.length - bodyLength;
1013 int result2 = result;
1014 if (result2 >= 0) {
1015 if (result2 < skip+outArgs) {
1016 // return the corresponding inArg
1017 result2 = reorder[result2-skip];
1018 } else {
1019 result2 = result2 - outArgs + inTypes;
1020 }
1021 }
1022 // rework names in the body:
1023 for (int j = pos; j < outArgs; j++) {
1024 Name n = names[skip+j];
1025 int i = reorder[j];
1026 // replace names[skip+j] by names2[skip+i]
1027 Name n2 = names2[skip+i];
1028 if (n2 == null)
1029 names2[skip+i] = n2 = new Name(types[i]);
1030 else
1031 assert(n2.type == types[i]);
1032 for (int k = arity2; k < names2.length; k++) {
1033 names2[k] = names2[k].replaceName(n, n2);
1034 }
1035 }
1036 // some names are unused, but must be filled in
1037 for (int i = skip+pos; i < arity2; i++) {
1038 if (names2[i] == null)
1039 names2[i] = argument(i, types[i - skip]);
1040 }
1041 for (int j = arity; j < names.length; j++) {
1042 int i = j - arity + arity2;
1043 // replace names2[i] by names[j]
1044 Name n = names[j];
1045 Name n2 = names2[i];
1046 if (n != n2) {
1047 for (int k = i+1; k < names2.length; k++) {
1048 names2[k] = names2[k].replaceName(n, n2);
1049 }
1050 }
1051 }
1052 return new LambdaForm(debugName, arity2, names2, result2);
1053 }
1054
1055 static boolean permutedTypesMatch(int[] reorder, BasicType[] types, Name[] names, int skip) {
1056 int inTypes = types.length;
1057 int outArgs = reorder.length;
1058 for (int i = 0; i < outArgs; i++) {
1059 assert(names[skip+i].isParam());
1060 assert(names[skip+i].type == types[reorder[i]]);
1061 }
1062 return true;
1063 }
1064
1065 static class NamedFunction {
1066 final MemberName member;
1067 @Stable MethodHandle resolvedHandle;
1068 @Stable MethodHandle invoker;
1069
1070 NamedFunction(MethodHandle resolvedHandle) {
1071 this(resolvedHandle.internalMemberName(), resolvedHandle);
1072 }
1073 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1074 this.member = member;
1075 this.resolvedHandle = resolvedHandle;
1076 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1077 //assert(!isInvokeBasic());
1078 }
1079 NamedFunction(MethodType basicInvokerType) {
1080 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1081 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1082 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1083 this.member = resolvedHandle.internalMemberName();
1084 } else {
1085 // necessary to pass BigArityTest
1086 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1087 }
1088 assert(isInvokeBasic());
1089 }
1090
1091 private boolean isInvokeBasic() {
1092 return member != null &&
1093 member.isMethodHandleInvoke() &&
1094 "invokeBasic".equals(member.getName());
1095 }
1096
1097 // The next 3 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1098 // Any LambdaForm containing such a member is not interpretable.
1099 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1100 // And even without the resolvedHandle, the name can still be compiled and optimized.
1101 NamedFunction(Method method) {
1102 this(new MemberName(method));
1103 }
1104 NamedFunction(Field field) {
1105 this(new MemberName(field));
1106 }
1107 NamedFunction(MemberName member) {
1108 this.member = member;
1109 this.resolvedHandle = null;
1110 }
1111
1112 MethodHandle resolvedHandle() {
1113 if (resolvedHandle == null) resolve();
1114 return resolvedHandle;
1115 }
1116
1117 void resolve() {
1118 resolvedHandle = DirectMethodHandle.make(member);
1119 }
1120
1121 @Override
1122 public boolean equals(Object other) {
1123 if (this == other) return true;
1124 if (other == null) return false;
1125 if (!(other instanceof NamedFunction)) return false;
1126 NamedFunction that = (NamedFunction) other;
1127 return this.member != null && this.member.equals(that.member);
1128 }
1129
1130 @Override
1131 public int hashCode() {
1132 if (member != null)
1133 return member.hashCode();
1134 return super.hashCode();
1135 }
1136
1137 // Put the predefined NamedFunction invokers into the table.
1138 static void initializeInvokers() {
1139 for (MemberName m : MemberName.getFactory().getMethods(NamedFunction.class, false, null, null, null)) {
1140 if (!m.isStatic() || !m.isPackage()) continue;
1141 MethodType type = m.getMethodType();
1142 if (type.equals(INVOKER_METHOD_TYPE) &&
1143 m.getName().startsWith("invoke_")) {
1144 String sig = m.getName().substring("invoke_".length());
1145 int arity = LambdaForm.signatureArity(sig);
1146 MethodType srcType = MethodType.genericMethodType(arity);
1147 if (LambdaForm.signatureReturn(sig) == V_TYPE)
1148 srcType = srcType.changeReturnType(void.class);
1149 MethodTypeForm typeForm = srcType.form();
1150 typeForm.namedFunctionInvoker = DirectMethodHandle.make(m);
1151 }
1152 }
1153 }
1154
1155 // The following are predefined NamedFunction invokers. The system must build
1156 // a separate invoker for each distinct signature.
1157 /** void return type invokers. */
1158 @Hidden
1159 static Object invoke__V(MethodHandle mh, Object[] a) throws Throwable {
1160 assert(arityCheck(0, void.class, mh, a));
1161 mh.invokeBasic();
1162 return null;
1163 }
1164 @Hidden
1165 static Object invoke_L_V(MethodHandle mh, Object[] a) throws Throwable {
1166 assert(arityCheck(1, void.class, mh, a));
1167 mh.invokeBasic(a[0]);
1168 return null;
1169 }
1170 @Hidden
1171 static Object invoke_LL_V(MethodHandle mh, Object[] a) throws Throwable {
1172 assert(arityCheck(2, void.class, mh, a));
1173 mh.invokeBasic(a[0], a[1]);
1174 return null;
1175 }
1176 @Hidden
1177 static Object invoke_LLL_V(MethodHandle mh, Object[] a) throws Throwable {
1178 assert(arityCheck(3, void.class, mh, a));
1179 mh.invokeBasic(a[0], a[1], a[2]);
1180 return null;
1181 }
1182 @Hidden
1183 static Object invoke_LLLL_V(MethodHandle mh, Object[] a) throws Throwable {
1184 assert(arityCheck(4, void.class, mh, a));
1185 mh.invokeBasic(a[0], a[1], a[2], a[3]);
1186 return null;
1187 }
1188 @Hidden
1189 static Object invoke_LLLLL_V(MethodHandle mh, Object[] a) throws Throwable {
1190 assert(arityCheck(5, void.class, mh, a));
1191 mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1192 return null;
1193 }
1194 /** Object return type invokers. */
1195 @Hidden
1196 static Object invoke__L(MethodHandle mh, Object[] a) throws Throwable {
1197 assert(arityCheck(0, mh, a));
1198 return mh.invokeBasic();
1199 }
1200 @Hidden
1201 static Object invoke_L_L(MethodHandle mh, Object[] a) throws Throwable {
1202 assert(arityCheck(1, mh, a));
1203 return mh.invokeBasic(a[0]);
1204 }
1205 @Hidden
1206 static Object invoke_LL_L(MethodHandle mh, Object[] a) throws Throwable {
1207 assert(arityCheck(2, mh, a));
1208 return mh.invokeBasic(a[0], a[1]);
1209 }
1210 @Hidden
1211 static Object invoke_LLL_L(MethodHandle mh, Object[] a) throws Throwable {
1212 assert(arityCheck(3, mh, a));
1213 return mh.invokeBasic(a[0], a[1], a[2]);
1214 }
1215 @Hidden
1216 static Object invoke_LLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1217 assert(arityCheck(4, mh, a));
1218 return mh.invokeBasic(a[0], a[1], a[2], a[3]);
1219 }
1220 @Hidden
1221 static Object invoke_LLLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1222 assert(arityCheck(5, mh, a));
1223 return mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1224 }
1225 private static boolean arityCheck(int arity, MethodHandle mh, Object[] a) {
1226 return arityCheck(arity, Object.class, mh, a);
1227 }
1228 private static boolean arityCheck(int arity, Class<?> rtype, MethodHandle mh, Object[] a) {
1229 assert(a.length == arity)
1230 : Arrays.asList(a.length, arity);
1231 assert(mh.type().basicType() == MethodType.genericMethodType(arity).changeReturnType(rtype))
1232 : Arrays.asList(mh, rtype, arity);
1233 MemberName member = mh.internalMemberName();
1234 if (member != null && member.getName().equals("invokeBasic") && member.isMethodHandleInvoke()) {
1235 assert(arity > 0);
1236 assert(a[0] instanceof MethodHandle);
1237 MethodHandle mh2 = (MethodHandle) a[0];
1238 assert(mh2.type().basicType() == MethodType.genericMethodType(arity-1).changeReturnType(rtype))
1239 : Arrays.asList(member, mh2, rtype, arity);
1240 }
1241 return true;
1242 }
1243
1244 static final MethodType INVOKER_METHOD_TYPE =
1245 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1246
1247 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1248 MethodHandle mh = typeForm.namedFunctionInvoker;
1249 if (mh != null) return mh;
1250 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1251 mh = DirectMethodHandle.make(invoker);
1252 MethodHandle mh2 = typeForm.namedFunctionInvoker;
1253 if (mh2 != null) return mh2; // benign race
1254 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1255 throw newInternalError(mh.debugString());
1256 return typeForm.namedFunctionInvoker = mh;
1257 }
1258
1259 @Hidden
1260 Object invokeWithArguments(Object... arguments) throws Throwable {
1261 // If we have a cached invoker, call it right away.
1262 // NOTE: The invoker always returns a reference value.
1263 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1264 assert(checkArgumentTypes(arguments, methodType()));
1265 return invoker().invokeBasic(resolvedHandle(), arguments);
1266 }
1267
1268 @Hidden
1269 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1270 Object rval;
1271 try {
1272 traceInterpreter("[ call", this, arguments);
1273 if (invoker == null) {
1274 traceInterpreter("| getInvoker", this);
1275 invoker();
1276 }
1277 if (resolvedHandle == null) {
1278 traceInterpreter("| resolve", this);
1279 resolvedHandle();
1280 }
1281 assert(checkArgumentTypes(arguments, methodType()));
1282 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1283 } catch (Throwable ex) {
1284 traceInterpreter("] throw =>", ex);
1285 throw ex;
1286 }
1287 traceInterpreter("] return =>", rval);
1288 return rval;
1289 }
1290
1291 private MethodHandle invoker() {
1292 if (invoker != null) return invoker;
1293 // Get an invoker and cache it.
1294 return invoker = computeInvoker(methodType().form());
1295 }
1296
1297 private static boolean checkArgumentTypes(Object[] arguments, MethodType methodType) {
1298 if (true) return true; // FIXME
1299 MethodType dstType = methodType.form().erasedType();
1300 MethodType srcType = dstType.basicType().wrap();
1301 Class<?>[] ptypes = new Class<?>[arguments.length];
1302 for (int i = 0; i < arguments.length; i++) {
1303 Object arg = arguments[i];
1304 Class<?> ptype = arg == null ? Object.class : arg.getClass();
1305 // If the dest. type is a primitive we keep the
1306 // argument type.
1307 ptypes[i] = dstType.parameterType(i).isPrimitive() ? ptype : Object.class;
1308 }
1309 MethodType argType = MethodType.methodType(srcType.returnType(), ptypes).wrap();
1310 assert(argType.isConvertibleTo(srcType)) : "wrong argument types: cannot convert " + argType + " to " + srcType;
1311 return true;
1312 }
1313
1314 MethodType methodType() {
1315 if (resolvedHandle != null)
1316 return resolvedHandle.type();
1317 else
1318 // only for certain internal LFs during bootstrapping
1319 return member.getInvocationType();
1320 }
1321
1322 MemberName member() {
1323 assert(assertMemberIsConsistent());
1324 return member;
1325 }
1326
1327 // Called only from assert.
1328 private boolean assertMemberIsConsistent() {
1329 if (resolvedHandle instanceof DirectMethodHandle) {
1330 MemberName m = resolvedHandle.internalMemberName();
1331 assert(m.equals(member));
1332 }
1333 return true;
1334 }
1335
1336 Class<?> memberDeclaringClassOrNull() {
1337 return (member == null) ? null : member.getDeclaringClass();
1338 }
1339
1340 BasicType returnType() {
1341 return basicType(methodType().returnType());
1342 }
1343
1344 BasicType parameterType(int n) {
1345 return basicType(methodType().parameterType(n));
1346 }
1347
1348 int arity() {
1349 return methodType().parameterCount();
1350 }
1351
1352 public String toString() {
1353 if (member == null) return String.valueOf(resolvedHandle);
1354 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1355 }
1356
1357 public boolean isIdentity() {
1358 return this.equals(identity(returnType()));
1359 }
1360
1361 public boolean isConstantZero() {
1362 return this.equals(constantZero(returnType()));
1363 }
1364 }
1365
1366 public static String basicTypeSignature(MethodType type) {
1367 char[] sig = new char[type.parameterCount() + 2];
1368 int sigp = 0;
1369 for (Class<?> pt : type.parameterList()) {
1370 sig[sigp++] = basicTypeChar(pt);
1371 }
1372 sig[sigp++] = '_';
1373 sig[sigp++] = basicTypeChar(type.returnType());
1374 assert(sigp == sig.length);
1375 return String.valueOf(sig);
1376 }
1377 public static String shortenSignature(String signature) {
1378 // Hack to make signatures more readable when they show up in method names.
1379 final int NO_CHAR = -1, MIN_RUN = 3;
1380 int c0, c1 = NO_CHAR, c1reps = 0;
1381 StringBuilder buf = null;
1382 int len = signature.length();
1383 if (len < MIN_RUN) return signature;
1384 for (int i = 0; i <= len; i++) {
1385 // shift in the next char:
1386 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1387 if (c1 == c0) { ++c1reps; continue; }
1388 // shift in the next count:
1389 int c0reps = c1reps; c1reps = 1;
1390 // end of a character run
1391 if (c0reps < MIN_RUN) {
1392 if (buf != null) {
1393 while (--c0reps >= 0)
1394 buf.append((char)c0);
1395 }
1396 continue;
1397 }
1398 // found three or more in a row
1399 if (buf == null)
1400 buf = new StringBuilder().append(signature, 0, i - c0reps);
1401 buf.append((char)c0).append(c0reps);
1402 }
1403 return (buf == null) ? signature : buf.toString();
1404 }
1405
1406 static final class Name {
1407 final BasicType type;
1408 private short index;
1409 final NamedFunction function;
1410 @Stable final Object[] arguments;
1411
1412 private Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1413 this.index = (short)index;
1414 this.type = type;
1415 this.function = function;
1416 this.arguments = arguments;
1417 assert(this.index == index);
1418 }
1419 Name(MethodHandle function, Object... arguments) {
1420 this(new NamedFunction(function), arguments);
1421 }
1422 Name(MethodType functionType, Object... arguments) {
1423 this(new NamedFunction(functionType), arguments);
1424 assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == L_TYPE);
1425 }
1426 Name(MemberName function, Object... arguments) {
1427 this(new NamedFunction(function), arguments);
1428 }
1429 Name(NamedFunction function, Object... arguments) {
1430 this(-1, function.returnType(), function, arguments = arguments.clone());
1431 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1432 for (int i = 0; i < arguments.length; i++)
1433 assert(typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1434 }
1435 /** Create a raw parameter of the given type, with an expected index. */
1436 Name(int index, BasicType type) {
1437 this(index, type, null, null);
1438 }
1439 /** Create a raw parameter of the given type. */
1440 Name(BasicType type) { this(-1, type); }
1441
1442 BasicType type() { return type; }
1443 int index() { return index; }
1444 boolean initIndex(int i) {
1445 if (index != i) {
1446 if (index != -1) return false;
1447 index = (short)i;
1448 }
1449 return true;
1450 }
1451 char typeChar() {
1452 return type.btChar;
1453 }
1454
1455 void resolve() {
1456 if (function != null)
1457 function.resolve();
1458 }
1459
1460 Name newIndex(int i) {
1461 if (initIndex(i)) return this;
1462 return cloneWithIndex(i);
1463 }
1464 Name cloneWithIndex(int i) {
1465 Object[] newArguments = (arguments == null) ? null : arguments.clone();
1466 return new Name(i, type, function, newArguments);
1467 }
1468 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1469 if (oldName == newName) return this;
1470 @SuppressWarnings("LocalVariableHidesMemberVariable")
1471 Object[] arguments = this.arguments;
1472 if (arguments == null) return this;
1473 boolean replaced = false;
1474 for (int j = 0; j < arguments.length; j++) {
1475 if (arguments[j] == oldName) {
1476 if (!replaced) {
1477 replaced = true;
1478 arguments = arguments.clone();
1479 }
1480 arguments[j] = newName;
1481 }
1482 }
1483 if (!replaced) return this;
1484 return new Name(function, arguments);
1485 }
1486 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1487 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1488 */
1489 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1490 if (start >= end) return this;
1491 @SuppressWarnings("LocalVariableHidesMemberVariable")
1492 Object[] arguments = this.arguments;
1493 boolean replaced = false;
1494 eachArg:
1495 for (int j = 0; j < arguments.length; j++) {
1496 if (arguments[j] instanceof Name) {
1497 Name n = (Name) arguments[j];
1498 int check = n.index;
1499 // harmless check to see if the thing is already in newNames:
1500 if (check >= 0 && check < newNames.length && n == newNames[check])
1501 continue eachArg;
1502 // n might not have the correct index: n != oldNames[n.index].
1503 for (int i = start; i < end; i++) {
1504 if (n == oldNames[i]) {
1505 if (n == newNames[i])
1506 continue eachArg;
1507 if (!replaced) {
1508 replaced = true;
1509 arguments = arguments.clone();
1510 }
1511 arguments[j] = newNames[i];
1512 continue eachArg;
1513 }
1514 }
1515 }
1516 }
1517 if (!replaced) return this;
1518 return new Name(function, arguments);
1519 }
1520 void internArguments() {
1521 @SuppressWarnings("LocalVariableHidesMemberVariable")
1522 Object[] arguments = this.arguments;
1523 for (int j = 0; j < arguments.length; j++) {
1524 if (arguments[j] instanceof Name) {
1525 Name n = (Name) arguments[j];
1526 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1527 arguments[j] = internArgument(n);
1528 }
1529 }
1530 }
1531 boolean isParam() {
1532 return function == null;
1533 }
1534 boolean isConstantZero() {
1535 return !isParam() && arguments.length == 0 && function.isConstantZero();
1536 }
1537
1538 public String toString() {
1539 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1540 }
1541 public String debugString() {
1542 String s = toString();
1543 return (function == null) ? s : s + "=" + exprString();
1544 }
1545 public String exprString() {
1546 if (function == null) return toString();
1547 StringBuilder buf = new StringBuilder(function.toString());
1548 buf.append("(");
1549 String cma = "";
1550 for (Object a : arguments) {
1551 buf.append(cma); cma = ",";
1552 if (a instanceof Name || a instanceof Integer)
1553 buf.append(a);
1554 else
1555 buf.append("(").append(a).append(")");
1556 }
1557 buf.append(")");
1558 return buf.toString();
1559 }
1560
1561 static boolean typesMatch(BasicType parameterType, Object object) {
1562 if (object instanceof Name) {
1563 return ((Name)object).type == parameterType;
1564 }
1565 switch (parameterType) {
1566 case I_TYPE: return object instanceof Integer;
1567 case J_TYPE: return object instanceof Long;
1568 case F_TYPE: return object instanceof Float;
1569 case D_TYPE: return object instanceof Double;
1570 }
1571 assert(parameterType == L_TYPE);
1572 return true;
1573 }
1574
1575 /** Return the index of the last occurrence of n in the argument array.
1576 * Return -1 if the name is not used.
1577 */
1578 int lastUseIndex(Name n) {
1579 if (arguments == null) return -1;
1580 for (int i = arguments.length; --i >= 0; ) {
1581 if (arguments[i] == n) return i;
1582 }
1583 return -1;
1584 }
1585
1586 /** Return the number of occurrences of n in the argument array.
1587 * Return 0 if the name is not used.
1588 */
1589 int useCount(Name n) {
1590 if (arguments == null) return 0;
1591 int count = 0;
1592 for (int i = arguments.length; --i >= 0; ) {
1593 if (arguments[i] == n) ++count;
1594 }
1595 return count;
1596 }
1597
1598 boolean contains(Name n) {
1599 return this == n || lastUseIndex(n) >= 0;
1600 }
1601
1602 public boolean equals(Name that) {
1603 if (this == that) return true;
1604 if (isParam())
1605 // each parameter is a unique atom
1606 return false; // this != that
1607 return
1608 //this.index == that.index &&
1609 this.type == that.type &&
1610 this.function.equals(that.function) &&
1611 Arrays.equals(this.arguments, that.arguments);
1612 }
1613 @Override
1614 public boolean equals(Object x) {
1615 return x instanceof Name && equals((Name)x);
1616 }
1617 @Override
1618 public int hashCode() {
1619 if (isParam())
1620 return index | (type.ordinal() << 8);
1621 return function.hashCode() ^ Arrays.hashCode(arguments);
1622 }
1623 }
1624
1625 /** Return the index of the last name which contains n as an argument.
1626 * Return -1 if the name is not used. Return names.length if it is the return value.
1627 */
1628 int lastUseIndex(Name n) {
1629 int ni = n.index, nmax = names.length;
1630 assert(names[ni] == n);
1631 if (result == ni) return nmax; // live all the way beyond the end
1632 for (int i = nmax; --i > ni; ) {
1633 if (names[i].lastUseIndex(n) >= 0)
1634 return i;
1635 }
1636 return -1;
1637 }
1638
1639 /** Return the number of times n is used as an argument or return value. */
1640 int useCount(Name n) {
1641 int ni = n.index, nmax = names.length;
1642 int end = lastUseIndex(n);
1643 if (end < 0) return 0;
1644 int count = 0;
1645 if (end == nmax) { count++; end--; }
1646 int beg = n.index() + 1;
1647 if (beg < arity) beg = arity;
1648 for (int i = beg; i <= end; i++) {
1649 count += names[i].useCount(n);
1650 }
1651 return count;
1652 }
1653
1654 static Name argument(int which, char type) {
1655 return argument(which, basicType(type));
1656 }
1657 static Name argument(int which, BasicType type) {
1658 if (which >= INTERNED_ARGUMENT_LIMIT)
1659 return new Name(which, type);
1660 return INTERNED_ARGUMENTS[type.ordinal()][which];
1661 }
1662 static Name internArgument(Name n) {
1663 assert(n.isParam()) : "not param: " + n;
1664 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1665 return argument(n.index, n.type);
1666 }
1667 static Name[] arguments(int extra, String types) {
1668 int length = types.length();
1669 Name[] names = new Name[length + extra];
1670 for (int i = 0; i < length; i++)
1671 names[i] = argument(i, types.charAt(i));
1672 return names;
1673 }
1674 static Name[] arguments(int extra, char... types) {
1675 int length = types.length;
1676 Name[] names = new Name[length + extra];
1677 for (int i = 0; i < length; i++)
1678 names[i] = argument(i, types[i]);
1679 return names;
1680 }
1681 static Name[] arguments(int extra, List<Class<?>> types) {
1682 int length = types.size();
1683 Name[] names = new Name[length + extra];
1684 for (int i = 0; i < length; i++)
1685 names[i] = argument(i, basicType(types.get(i)));
1686 return names;
1687 }
1688 static Name[] arguments(int extra, Class<?>... types) {
1689 int length = types.length;
1690 Name[] names = new Name[length + extra];
1691 for (int i = 0; i < length; i++)
1692 names[i] = argument(i, basicType(types[i]));
1693 return names;
1694 }
1695 static Name[] arguments(int extra, MethodType types) {
1696 int length = types.parameterCount();
1697 Name[] names = new Name[length + extra];
1698 for (int i = 0; i < length; i++)
1699 names[i] = argument(i, basicType(types.parameterType(i)));
1700 return names;
1701 }
1702 static final int INTERNED_ARGUMENT_LIMIT = 10;
1703 private static final Name[][] INTERNED_ARGUMENTS
1704 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1705 static {
1706 for (BasicType type : BasicType.ARG_TYPES) {
1707 int ord = type.ordinal();
1708 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1709 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1710 }
1711 }
1712 }
1713
1714 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1715
1716 static LambdaForm identityForm(BasicType type) {
1717 return LF_identityForm[type.ordinal()];
1718 }
1719 static LambdaForm zeroForm(BasicType type) {
1720 return LF_zeroForm[type.ordinal()];
1721 }
1722 static NamedFunction identity(BasicType type) {
1723 return NF_identity[type.ordinal()];
1724 }
1725 static NamedFunction constantZero(BasicType type) {
1726 return NF_zero[type.ordinal()];
1727 }
1728 private static final LambdaForm[] LF_identityForm = new LambdaForm[TYPE_LIMIT];
1729 private static final LambdaForm[] LF_zeroForm = new LambdaForm[TYPE_LIMIT];
1730 private static final NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1731 private static final NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1732 private static void createIdentityForms() {
1733 for (BasicType type : BasicType.ALL_TYPES) {
1734 int ord = type.ordinal();
1735 char btChar = type.basicTypeChar();
1736 boolean isVoid = (type == V_TYPE);
1737 Class<?> btClass = type.btClass;
1738 MethodType zeType = MethodType.methodType(btClass);
1739 MethodType idType = isVoid ? zeType : zeType.appendParameterTypes(btClass);
1740
1741 // Look up some symbolic names. It might not be necessary to have these,
1742 // but if we need to emit direct references to bytecodes, it helps.
1743 // Zero is built from a call to an identity function with a constant zero input.
1744 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1745 MemberName zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1746 try {
1747 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, NoSuchMethodException.class);
1748 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, NoSuchMethodException.class);
1749 } catch (IllegalAccessException|NoSuchMethodException ex) {
1750 throw newInternalError(ex);
1751 }
1752
1753 NamedFunction idFun = new NamedFunction(idMem);
1754 LambdaForm idForm;
1755 if (isVoid) {
1756 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1757 idForm = new LambdaForm(idMem.getName(), 1, idNames, VOID_RESULT);
1758 } else {
1759 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1760 idForm = new LambdaForm(idMem.getName(), 2, idNames, 1);
1761 }
1762 LF_identityForm[ord] = idForm;
1763 NF_identity[ord] = idFun;
1764
1765 NamedFunction zeFun = new NamedFunction(zeMem);
1766 LambdaForm zeForm;
1767 if (isVoid) {
1768 zeForm = idForm;
1769 } else {
1770 Object zeValue = Wrapper.forBasicType(btChar).zero();
1771 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1772 zeForm = new LambdaForm(zeMem.getName(), 1, zeNames, 1);
1773 }
1774 LF_zeroForm[ord] = zeForm;
1775 NF_zero[ord] = zeFun;
1776
1777 assert(idFun.isIdentity());
1778 assert(zeFun.isConstantZero());
1779 assert(new Name(zeFun).isConstantZero());
1780 }
1781
1782 // Do this in a separate pass, so that SimpleMethodHandle.make can see the tables.
1783 for (BasicType type : BasicType.ALL_TYPES) {
1784 int ord = type.ordinal();
1785 NamedFunction idFun = NF_identity[ord];
1786 LambdaForm idForm = LF_identityForm[ord];
1787 MemberName idMem = idFun.member;
1788 idFun.resolvedHandle = SimpleMethodHandle.make(idMem.getInvocationType(), idForm);
1789
1790 NamedFunction zeFun = NF_zero[ord];
1791 LambdaForm zeForm = LF_zeroForm[ord];
1792 MemberName zeMem = zeFun.member;
1793 zeFun.resolvedHandle = SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm);
1794
1795 assert(idFun.isIdentity());
1796 assert(zeFun.isConstantZero());
1797 assert(new Name(zeFun).isConstantZero());
1798 }
1799 }
1800
1801 // Avoid appealing to ValueConversions at bootstrap time:
1802 private static int identity_I(int x) { return x; }
1803 private static long identity_J(long x) { return x; }
1804 private static float identity_F(float x) { return x; }
1805 private static double identity_D(double x) { return x; }
1806 private static Object identity_L(Object x) { return x; }
1807 private static void identity_V() { return; } // same as zeroV, but that's OK
1808 private static int zero_I() { return 0; }
1809 private static long zero_J() { return 0; }
1810 private static float zero_F() { return 0; }
1811 private static double zero_D() { return 0; }
1812 private static Object zero_L() { return null; }
1813 private static void zero_V() { return; }
1814
1815 /**
1816 * Internal marker for byte-compiled LambdaForms.
1817 */
1818 /*non-public*/
1819 @Target(ElementType.METHOD)
1820 @Retention(RetentionPolicy.RUNTIME)
1821 @interface Compiled {
1822 }
1823
1824 /**
1825 * Internal marker for LambdaForm interpreter frames.
1826 */
1827 /*non-public*/
1828 @Target(ElementType.METHOD)
1829 @Retention(RetentionPolicy.RUNTIME)
1830 @interface Hidden {
1831 }
1832
1833 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1834 static {
1835 if (debugEnabled())
1836 DEBUG_NAME_COUNTERS = new HashMap<>();
1837 else
1838 DEBUG_NAME_COUNTERS = null;
1839 }
1840
1841 // Put this last, so that previous static inits can run before.
1842 static {
1843 createIdentityForms();
1844 if (USE_PREDEFINED_INTERPRET_METHODS)
1845 PREPARED_FORMS.putAll(computeInitialPreparedForms());
1846 NamedFunction.initializeInvokers();
1847 }
1848
1849 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1850 // during execution of the static initializes of this class.
1851 // Turning on TRACE_INTERPRETER too early will cause
1852 // stack overflows and other misbehavior during attempts to trace events
1853 // that occur during LambdaForm.<clinit>.
1854 // Therefore, do not move this line higher in this file, and do not remove.
1855 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1856 }