1 /*
2 * Copyright (c) 2011, 2023, 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.misc.CDS;
29 import java.lang.classfile.TypeKind;
30 import jdk.internal.perf.PerfCounter;
31 import jdk.internal.vm.annotation.DontInline;
32 import jdk.internal.vm.annotation.Hidden;
33 import jdk.internal.vm.annotation.Stable;
34 import sun.invoke.util.Wrapper;
35
36 import java.lang.annotation.ElementType;
37 import java.lang.annotation.Retention;
38 import java.lang.annotation.RetentionPolicy;
39 import java.lang.annotation.Target;
40 import java.lang.reflect.Method;
41 import java.util.Arrays;
42 import java.util.HashMap;
43
44 import static java.lang.invoke.LambdaForm.BasicType.*;
45 import static java.lang.invoke.MethodHandleNatives.Constants.*;
46 import static java.lang.invoke.MethodHandleStatics.*;
47
48 /**
49 * The symbolic, non-executable form of a method handle's invocation semantics.
50 * It consists of a series of names.
51 * The first N (N=arity) names are parameters,
52 * while any remaining names are temporary values.
53 * Each temporary specifies the application of a function to some arguments.
54 * The functions are method handles, while the arguments are mixes of
55 * constant values and local names.
56 * The result of the lambda is defined as one of the names, often the last one.
57 * <p>
58 * Here is an approximate grammar:
59 * <blockquote><pre>{@code
60 * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
61 * ArgName = "a" N ":" T
62 * TempName = "t" N ":" T "=" Function "(" Argument* ");"
63 * Function = ConstantValue
64 * Argument = NameRef | ConstantValue
65 * Result = NameRef | "void"
66 * NameRef = "a" N | "t" N
67 * N = (any whole number)
68 * T = "L" | "I" | "J" | "F" | "D" | "V"
69 * }</pre></blockquote>
70 * Names are numbered consecutively from left to right starting at zero.
71 * (The letters are merely a taste of syntax sugar.)
72 * Thus, the first temporary (if any) is always numbered N (where N=arity).
73 * Every occurrence of a name reference in an argument list must refer to
74 * a name previously defined within the same lambda.
75 * A lambda has a void result if and only if its result index is -1.
76 * If a temporary has the type "V", it cannot be the subject of a NameRef,
77 * even though possesses a number.
78 * Note that all reference types are erased to "L", which stands for {@code Object}.
79 * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
80 * The other types stand for the usual primitive types.
81 * <p>
82 * Function invocation closely follows the static rules of the Java verifier.
83 * Arguments and return values must exactly match when their "Name" types are
84 * considered.
85 * Conversions are allowed only if they do not change the erased type.
86 * <ul>
87 * <li>L = Object: casts are used freely to convert into and out of reference types
88 * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
89 * <li>J = long: no implicit conversions
90 * <li>F = float: no implicit conversions
91 * <li>D = double: no implicit conversions
92 * <li>V = void: a function result may be void if and only if its Name is of type "V"
93 * </ul>
94 * Although implicit conversions are not allowed, explicit ones can easily be
95 * encoded by using temporary expressions which call type-transformed identity functions.
96 * <p>
97 * Examples:
98 * <blockquote><pre>{@code
99 * (a0:J)=>{ a0 }
100 * == identity(long)
101 * (a0:I)=>{ t1:V = System.out#println(a0); void }
102 * == System.out#println(int)
103 * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
104 * == identity, with printing side-effect
105 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
106 * t3:L = BoundMethodHandle#target(a0);
107 * t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
108 * == general invoker for unary insertArgument combination
109 * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
110 * t3:L = MethodHandle#invoke(t2, a1);
111 * t4:L = FilterMethodHandle#target(a0);
112 * t5:L = MethodHandle#invoke(t4, t3); t5 }
113 * == general invoker for unary filterArgument combination
114 * (a0:L, a1:L)=>{ ...(same as previous example)...
115 * t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
116 * == general invoker for unary/unary foldArgument combination
117 * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
118 * == invoker for identity method handle which performs i2l
119 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
120 * t3:L = Class#cast(t2,a1); t3 }
121 * == invoker for identity method handle which performs cast
122 * }</pre></blockquote>
123 * <p>
124 * @author John Rose, JSR 292 EG
125 */
126 class LambdaForm {
127 final int arity;
128 final int result;
129 final boolean forceInline;
130 final MethodHandle customized;
131 @Stable final Name[] names;
132 final Kind kind;
133 MemberName vmentry; // low-level behavior, or null if not yet prepared
134 private boolean isCompiled;
135
136 // Either a LambdaForm cache (managed by LambdaFormEditor) or a link to uncustomized version (for customized LF)
137 volatile Object transformCache;
138
139 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
140
141 enum BasicType {
142 L_TYPE('L', Object.class, Wrapper.OBJECT, TypeKind.ReferenceType), // all reference types
143 I_TYPE('I', int.class, Wrapper.INT, TypeKind.IntType),
144 J_TYPE('J', long.class, Wrapper.LONG, TypeKind.LongType),
145 F_TYPE('F', float.class, Wrapper.FLOAT, TypeKind.FloatType),
146 D_TYPE('D', double.class, Wrapper.DOUBLE, TypeKind.DoubleType), // all primitive types
147 V_TYPE('V', void.class, Wrapper.VOID, TypeKind.VoidType); // not valid in all contexts
148
149 static final @Stable BasicType[] ALL_TYPES = BasicType.values();
150 static final @Stable BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
151
152 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
153 static final int TYPE_LIMIT = ALL_TYPES.length;
154
155 final char btChar;
156 final Class<?> btClass;
157 final Wrapper btWrapper;
158 final TypeKind btKind;
159
160 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper, TypeKind typeKind) {
161 this.btChar = btChar;
162 this.btClass = btClass;
163 this.btWrapper = wrapper;
164 this.btKind = typeKind;
165 }
166
167 char basicTypeChar() {
168 return btChar;
169 }
170 Class<?> basicTypeClass() {
171 return btClass;
172 }
173 Wrapper basicTypeWrapper() {
174 return btWrapper;
175 }
176 TypeKind basicTypeKind() {
177 return btKind;
178 }
179 int basicTypeSlots() {
180 return btWrapper.stackSlots();
181 }
182
183 static BasicType basicType(byte type) {
184 return ALL_TYPES[type];
185 }
186 static BasicType basicType(char type) {
187 return switch (type) {
188 case 'L' -> L_TYPE;
189 case 'I' -> I_TYPE;
190 case 'J' -> J_TYPE;
191 case 'F' -> F_TYPE;
192 case 'D' -> D_TYPE;
193 case 'V' -> V_TYPE;
194 // all subword types are represented as ints
195 case 'Z', 'B', 'S', 'C' -> I_TYPE;
196 default -> throw newInternalError("Unknown type char: '" + type + "'");
197 };
198 }
199 static BasicType basicType(Class<?> type) {
200 return basicType(Wrapper.basicTypeChar(type));
201 }
202 static int[] basicTypeOrds(BasicType[] types) {
203 if (types == null) {
204 return null;
205 }
206 int[] a = new int[types.length];
207 for(int i = 0; i < types.length; ++i) {
208 a[i] = types[i].ordinal();
209 }
210 return a;
211 }
212
213 static char basicTypeChar(Class<?> type) {
214 return basicType(type).btChar;
215 }
216
217 static int[] basicTypesOrd(Class<?>[] types) {
218 int[] ords = new int[types.length];
219 for (int i = 0; i < ords.length; i++) {
220 ords[i] = basicType(types[i]).ordinal();
221 }
222 return ords;
223 }
224
225 static boolean isBasicTypeChar(char c) {
226 return "LIJFDV".indexOf(c) >= 0;
227 }
228 static boolean isArgBasicTypeChar(char c) {
229 return "LIJFD".indexOf(c) >= 0;
230 }
231
232 static { assert(checkBasicType()); }
233 private static boolean checkBasicType() {
234 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
235 assert ARG_TYPES[i].ordinal() == i;
236 assert ARG_TYPES[i] == ALL_TYPES[i];
237 }
238 for (int i = 0; i < TYPE_LIMIT; i++) {
239 assert ALL_TYPES[i].ordinal() == i;
240 }
241 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
242 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
243 return true;
244 }
245 }
246
247 enum Kind {
248 GENERIC("invoke"),
249 ZERO("zero"),
250 IDENTITY("identity"),
251 BOUND_REINVOKER("BMH.reinvoke", "reinvoke"),
252 REINVOKER("MH.reinvoke", "reinvoke"),
253 DELEGATE("MH.delegate", "delegate"),
254 EXACT_LINKER("MH.invokeExact_MT", "invokeExact_MT"),
255 EXACT_INVOKER("MH.exactInvoker", "exactInvoker"),
256 GENERIC_LINKER("MH.invoke_MT", "invoke_MT"),
257 GENERIC_INVOKER("MH.invoker", "invoker"),
258 LINK_TO_TARGET_METHOD("linkToTargetMethod"),
259 LINK_TO_CALL_SITE("linkToCallSite"),
260 DIRECT_INVOKE_VIRTUAL("DMH.invokeVirtual", "invokeVirtual"),
261 DIRECT_INVOKE_SPECIAL("DMH.invokeSpecial", "invokeSpecial"),
262 DIRECT_INVOKE_SPECIAL_IFC("DMH.invokeSpecialIFC", "invokeSpecialIFC"),
263 DIRECT_INVOKE_STATIC("DMH.invokeStatic", "invokeStatic"),
264 DIRECT_NEW_INVOKE_SPECIAL("DMH.newInvokeSpecial", "newInvokeSpecial"),
265 DIRECT_INVOKE_INTERFACE("DMH.invokeInterface", "invokeInterface"),
266 DIRECT_INVOKE_STATIC_INIT("DMH.invokeStaticInit", "invokeStaticInit"),
267 GET_REFERENCE("getReference"),
268 PUT_REFERENCE("putReference"),
269 GET_REFERENCE_VOLATILE("getReferenceVolatile"),
270 PUT_REFERENCE_VOLATILE("putReferenceVolatile"),
271 GET_INT("getInt"),
272 PUT_INT("putInt"),
273 GET_INT_VOLATILE("getIntVolatile"),
274 PUT_INT_VOLATILE("putIntVolatile"),
275 GET_BOOLEAN("getBoolean"),
276 PUT_BOOLEAN("putBoolean"),
277 GET_BOOLEAN_VOLATILE("getBooleanVolatile"),
278 PUT_BOOLEAN_VOLATILE("putBooleanVolatile"),
279 GET_BYTE("getByte"),
280 PUT_BYTE("putByte"),
281 GET_BYTE_VOLATILE("getByteVolatile"),
282 PUT_BYTE_VOLATILE("putByteVolatile"),
283 GET_CHAR("getChar"),
284 PUT_CHAR("putChar"),
285 GET_CHAR_VOLATILE("getCharVolatile"),
286 PUT_CHAR_VOLATILE("putCharVolatile"),
287 GET_SHORT("getShort"),
288 PUT_SHORT("putShort"),
289 GET_SHORT_VOLATILE("getShortVolatile"),
290 PUT_SHORT_VOLATILE("putShortVolatile"),
291 GET_LONG("getLong"),
292 PUT_LONG("putLong"),
293 GET_LONG_VOLATILE("getLongVolatile"),
294 PUT_LONG_VOLATILE("putLongVolatile"),
295 GET_FLOAT("getFloat"),
296 PUT_FLOAT("putFloat"),
297 GET_FLOAT_VOLATILE("getFloatVolatile"),
298 PUT_FLOAT_VOLATILE("putFloatVolatile"),
299 GET_DOUBLE("getDouble"),
300 PUT_DOUBLE("putDouble"),
301 GET_DOUBLE_VOLATILE("getDoubleVolatile"),
302 PUT_DOUBLE_VOLATILE("putDoubleVolatile"),
303 TRY_FINALLY("tryFinally"),
304 TABLE_SWITCH("tableSwitch"),
305 COLLECT("collect"),
306 COLLECTOR("collector"),
307 CONVERT("convert"),
308 SPREAD("spread"),
309 LOOP("loop"),
310 FIELD("field"),
311 GUARD("guard"),
312 GUARD_WITH_CATCH("guardWithCatch"),
313 VARHANDLE_EXACT_INVOKER("VH.exactInvoker"),
314 VARHANDLE_INVOKER("VH.invoker", "invoker"),
315 VARHANDLE_LINKER("VH.invoke_MT", "invoke_MT");
316
317 final String defaultLambdaName;
318 final String methodName;
319
320 private Kind(String defaultLambdaName) {
321 this(defaultLambdaName, defaultLambdaName);
322 }
323
324 private Kind(String defaultLambdaName, String methodName) {
325 this.defaultLambdaName = defaultLambdaName;
326 this.methodName = methodName;
327 }
328 }
329
330 // private version that doesn't do checks or defensive copies
331 private LambdaForm(int arity, int result, boolean forceInline, MethodHandle customized, Name[] names, Kind kind) {
332 this.arity = arity;
333 this.result = result;
334 this.forceInline = forceInline;
335 this.customized = customized;
336 this.names = names;
337 this.kind = kind;
338 this.vmentry = null;
339 this.isCompiled = false;
340 }
341
342 // root factory pre/post processing and calls simple constructor
343 private static LambdaForm create(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
344 names = names.clone();
345 assert(namesOK(arity, names));
346 result = fixResult(result, names);
347
348 boolean canInterpret = normalizeNames(arity, names);
349 LambdaForm form = new LambdaForm(arity, result, forceInline, customized, names, kind);
350 assert(form.nameRefsAreLegal());
351 if (!canInterpret) {
352 form.compileToBytecode();
353 }
354 return form;
355 }
356
357 // derived factories with defaults
358 private static final int DEFAULT_RESULT = LAST_RESULT;
359 private static final boolean DEFAULT_FORCE_INLINE = true;
360 private static final MethodHandle DEFAULT_CUSTOMIZED = null;
361 private static final Kind DEFAULT_KIND = Kind.GENERIC;
362
363 static LambdaForm create(int arity, Name[] names, int result) {
364 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
365 }
366 static LambdaForm create(int arity, Name[] names, int result, Kind kind) {
367 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
368 }
369 static LambdaForm create(int arity, Name[] names) {
370 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
371 }
372 static LambdaForm create(int arity, Name[] names, Kind kind) {
373 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
374 }
375 static LambdaForm create(int arity, Name[] names, boolean forceInline, Kind kind) {
376 return create(arity, names, DEFAULT_RESULT, forceInline, DEFAULT_CUSTOMIZED, kind);
377 }
378
379 private static LambdaForm createBlankForType(MethodType mt) {
380 // Make a blank lambda form, which returns a constant zero or null.
381 // It is used as a template for managing the invocation of similar forms that are non-empty.
382 // Called only from getPreparedForm.
383 int arity = mt.parameterCount();
384 int result = (mt.returnType() == void.class || mt.returnType() == Void.class) ? VOID_RESULT : arity;
385 Name[] names = buildEmptyNames(arity, mt, result == VOID_RESULT);
386 boolean canInterpret = normalizeNames(arity, names);
387 LambdaForm form = new LambdaForm(arity, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, names, Kind.ZERO);
388 assert(form.nameRefsAreLegal() && form.isEmpty() && isValidSignature(form.basicTypeSignature()));
389 if (!canInterpret) {
390 form.compileToBytecode();
391 }
392 return form;
393 }
394
395 private static Name[] buildEmptyNames(int arity, MethodType mt, boolean isVoid) {
396 Name[] names = arguments(isVoid ? 0 : 1, mt);
397 if (!isVoid) {
398 Name zero = new Name(constantZero(basicType(mt.returnType())));
399 names[arity] = zero.newIndex(arity);
400 }
401 assert(namesOK(arity, names));
402 return names;
403 }
404
405 private static int fixResult(int result, Name[] names) {
406 if (result == LAST_RESULT)
407 result = names.length - 1; // might still be void
408 if (result >= 0 && names[result].type == V_TYPE)
409 result = VOID_RESULT;
410 return result;
411 }
412
413 static boolean debugNames() {
414 return DEBUG_NAME_COUNTERS != null;
415 }
416
417 static void associateWithDebugName(LambdaForm form, String name) {
418 assert (debugNames());
419 synchronized (DEBUG_NAMES) {
420 DEBUG_NAMES.put(form, name);
421 }
422 }
423
424 String lambdaName() {
425 if (DEBUG_NAMES != null) {
426 synchronized (DEBUG_NAMES) {
427 String name = DEBUG_NAMES.get(this);
428 if (name == null) {
429 name = generateDebugName();
430 }
431 return name;
432 }
433 }
434 return kind.defaultLambdaName;
435 }
436
437 private String generateDebugName() {
438 assert (debugNames());
439 String debugNameStem = kind.defaultLambdaName;
440 Integer ctr = DEBUG_NAME_COUNTERS.getOrDefault(debugNameStem, 0);
441 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr + 1);
442 StringBuilder buf = new StringBuilder(debugNameStem);
443 int leadingZero = buf.length();
444 buf.append((int) ctr);
445 for (int i = buf.length() - leadingZero; i < 3; i++) {
446 buf.insert(leadingZero, '0');
447 }
448 buf.append('_');
449 buf.append(basicTypeSignature());
450 String name = buf.toString();
451 associateWithDebugName(this, name);
452 return name;
453 }
454
455 private static boolean namesOK(int arity, Name[] names) {
456 for (int i = 0; i < names.length; i++) {
457 Name n = names[i];
458 assert(n != null) : "n is null";
459 if (i < arity)
460 assert( n.isParam()) : n + " is not param at " + i;
461 else
462 assert(!n.isParam()) : n + " is param at " + i;
463 }
464 return true;
465 }
466
467 /** Customize LambdaForm for a particular MethodHandle */
468 LambdaForm customize(MethodHandle mh) {
469 if (customized == mh) {
470 return this;
471 }
472 LambdaForm customForm = LambdaForm.create(arity, names, result, forceInline, mh, kind);
473 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
474 // If shared LambdaForm has been compiled, compile customized version as well.
475 customForm.compileToBytecode();
476 }
477 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
478 return customForm;
479 }
480
481 /** Get uncustomized flavor of the LambdaForm */
482 LambdaForm uncustomize() {
483 if (customized == null) {
484 return this;
485 }
486 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
487 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
488 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
489 // If customized LambdaForm has been compiled, compile uncustomized version as well.
490 uncustomizedForm.compileToBytecode();
491 }
492 return uncustomizedForm;
493 }
494
495 /** Renumber and/or replace params so that they are interned and canonically numbered.
496 * @return true if we can interpret
497 */
498 private static boolean normalizeNames(int arity, Name[] names) {
499 Name[] oldNames = null;
500 int maxOutArity = 0;
501 int changesStart = 0;
502 for (int i = 0; i < names.length; i++) {
503 Name n = names[i];
504 if (!n.initIndex(i)) {
505 if (oldNames == null) {
506 oldNames = names.clone();
507 changesStart = i;
508 }
509 names[i] = n.cloneWithIndex(i);
510 }
511 if (n.arguments != null && maxOutArity < n.arguments.length)
512 maxOutArity = n.arguments.length;
513 }
514 if (oldNames != null) {
515 int startFixing = arity;
516 if (startFixing <= changesStart)
517 startFixing = changesStart+1;
518 for (int i = startFixing; i < names.length; i++) {
519 Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
520 names[i] = fixed.newIndex(i);
521 }
522 }
523 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
524 boolean needIntern = false;
525 for (int i = 0; i < maxInterned; i++) {
526 Name n = names[i], n2 = internArgument(n);
527 if (n != n2) {
528 names[i] = n2;
529 needIntern = true;
530 }
531 }
532 if (needIntern) {
533 for (int i = arity; i < names.length; i++) {
534 names[i].internArguments();
535 }
536 }
537
538 // return true if we can interpret
539 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
540 // Cannot use LF interpreter on very high arity expressions.
541 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
542 return false;
543 }
544 return true;
545 }
546
547 /**
548 * Check that all embedded Name references are localizable to this lambda,
549 * and are properly ordered after their corresponding definitions.
550 * <p>
551 * Note that a Name can be local to multiple lambdas, as long as
552 * it possesses the same index in each use site.
553 * This allows Name references to be freely reused to construct
554 * fresh lambdas, without confusion.
555 */
556 boolean nameRefsAreLegal() {
557 assert(arity >= 0 && arity <= names.length);
558 assert(result >= -1 && result < names.length);
559 // Do all names possess an index consistent with their local definition order?
560 for (int i = 0; i < arity; i++) {
561 Name n = names[i];
562 assert(n.index() == i) : Arrays.asList(n.index(), i);
563 assert(n.isParam());
564 }
565 // Also, do all local name references
566 for (int i = arity; i < names.length; i++) {
567 Name n = names[i];
568 assert(n.index() == i);
569 for (Object arg : n.arguments) {
570 if (arg instanceof Name n2) {
571 int i2 = n2.index;
572 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
573 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
574 assert(i2 < i); // ref must come after def!
575 }
576 }
577 }
578 return true;
579 }
580
581 // /** Invoke this form on the given arguments. */
582 // final Object invoke(Object... args) throws Throwable {
583 // // NYI: fit this into the fast path?
584 // return interpretWithArguments(args);
585 // }
586
587 /** Report the return type. */
588 BasicType returnType() {
589 if (result < 0) return V_TYPE;
590 Name n = names[result];
591 return n.type;
592 }
593
594 /** Report the N-th argument type. */
595 BasicType parameterType(int n) {
596 return parameter(n).type;
597 }
598
599 /** Report the N-th argument name. */
600 Name parameter(int n) {
601 Name param = names[n];
602 assert(n < arity && param.isParam());
603 return param;
604 }
605
606 /** Report the N-th argument type constraint. */
607 Object parameterConstraint(int n) {
608 return parameter(n).constraint;
609 }
610
611 /** Report the arity. */
612 int arity() {
613 return arity;
614 }
615
616 /** Report the number of expressions (non-parameter names). */
617 int expressionCount() {
618 return names.length - arity;
619 }
620
621 /** Return the method type corresponding to my basic type signature. */
622 MethodType methodType() {
623 Class<?>[] ptypes = new Class<?>[arity];
624 for (int i = 0; i < arity; ++i) {
625 ptypes[i] = parameterType(i).btClass;
626 }
627 return MethodType.methodType(returnType().btClass, ptypes, true);
628 }
629
630 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
631 final String basicTypeSignature() {
632 StringBuilder buf = new StringBuilder(arity() + 3);
633 for (int i = 0, a = arity(); i < a; i++)
634 buf.append(parameterType(i).basicTypeChar());
635 return buf.append('_').append(returnType().basicTypeChar()).toString();
636 }
637 static int signatureArity(String sig) {
638 assert(isValidSignature(sig));
639 return sig.indexOf('_');
640 }
641 static boolean isValidSignature(String sig) {
642 int arity = sig.indexOf('_');
643 if (arity < 0) return false; // must be of the form *_*
644 int siglen = sig.length();
645 if (siglen != arity + 2) return false; // *_X
646 for (int i = 0; i < siglen; i++) {
647 if (i == arity) continue; // skip '_'
648 char c = sig.charAt(i);
649 if (c == 'V')
650 return (i == siglen - 1 && arity == siglen - 2);
651 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
652 }
653 return true; // [LIJFD]*_[LIJFDV]
654 }
655
656 /**
657 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
658 */
659 boolean isSelectAlternative(int pos) {
660 // selectAlternative idiom:
661 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
662 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
663 if (pos+1 >= names.length) return false;
664 Name name0 = names[pos];
665 Name name1 = names[pos+1];
666 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
667 name1.isInvokeBasic() &&
668 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
669 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
670 }
671
672 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
673 if (pos+2 >= names.length) return false;
674 Name name0 = names[pos];
675 Name name1 = names[pos+1];
676 Name name2 = names[pos+2];
677 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
678 name0.isInvokeBasic() &&
679 name2.isInvokeBasic() &&
680 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
681 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
682 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
683 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
684 }
685
686 /**
687 * Check if i-th name is a start of GuardWithCatch idiom.
688 */
689 boolean isGuardWithCatch(int pos) {
690 // GuardWithCatch idiom:
691 // t_{n}:L=MethodHandle.invokeBasic(...)
692 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
693 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
694 return isMatchingIdiom(pos, "guardWithCatch", 3);
695 }
696
697 /**
698 * Check if i-th name is a start of the tryFinally idiom.
699 */
700 boolean isTryFinally(int pos) {
701 // tryFinally idiom:
702 // t_{n}:L=MethodHandle.invokeBasic(...)
703 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
704 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
705 return isMatchingIdiom(pos, "tryFinally", 2);
706 }
707
708 /**
709 * Check if i-th name is a start of the tableSwitch idiom.
710 */
711 boolean isTableSwitch(int pos) {
712 // tableSwitch idiom:
713 // t_{n}:L=MethodHandle.invokeBasic(...) // args
714 // t_{n+1}:L=MethodHandleImpl.tableSwitch(*, *, *, t_{n})
715 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
716 if (pos + 2 >= names.length) return false;
717
718 final int POS_COLLECT_ARGS = pos;
719 final int POS_TABLE_SWITCH = pos + 1;
720 final int POS_UNBOX_RESULT = pos + 2;
721
722 Name collectArgs = names[POS_COLLECT_ARGS];
723 Name tableSwitch = names[POS_TABLE_SWITCH];
724 Name unboxResult = names[POS_UNBOX_RESULT];
725 return tableSwitch.refersTo(MethodHandleImpl.class, "tableSwitch") &&
726 collectArgs.isInvokeBasic() &&
727 unboxResult.isInvokeBasic() &&
728 tableSwitch.lastUseIndex(collectArgs) == 3 && // t_{n+1}:L=MethodHandleImpl.<invoker>(*, *, *, t_{n});
729 lastUseIndex(collectArgs) == POS_TABLE_SWITCH && // t_{n} is local: used only in t_{n+1}
730 unboxResult.lastUseIndex(tableSwitch) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
731 lastUseIndex(tableSwitch) == POS_UNBOX_RESULT; // t_{n+1} is local: used only in t_{n+2}
732 }
733
734 /**
735 * Check if i-th name is a start of the loop idiom.
736 */
737 boolean isLoop(int pos) {
738 // loop idiom:
739 // t_{n}:L=MethodHandle.invokeBasic(...)
740 // t_{n+1}:L=MethodHandleImpl.loop(types, *, t_{n})
741 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
742 return isMatchingIdiom(pos, "loop", 2);
743 }
744
745 /*
746 * Code generation issues:
747 *
748 * Compiled LFs should be reusable in general.
749 * The biggest issue is how to decide when to pull a name into
750 * the bytecode, versus loading a reified form from the MH data.
751 *
752 * For example, an asType wrapper may require execution of a cast
753 * after a call to a MH. The target type of the cast can be placed
754 * as a constant in the LF itself. This will force the cast type
755 * to be compiled into the bytecodes and native code for the MH.
756 * Or, the target type of the cast can be erased in the LF, and
757 * loaded from the MH data. (Later on, if the MH as a whole is
758 * inlined, the data will flow into the inlined instance of the LF,
759 * as a constant, and the end result will be an optimal cast.)
760 *
761 * This erasure of cast types can be done with any use of
762 * reference types. It can also be done with whole method
763 * handles. Erasing a method handle might leave behind
764 * LF code that executes correctly for any MH of a given
765 * type, and load the required MH from the enclosing MH's data.
766 * Or, the erasure might even erase the expected MT.
767 *
768 * Also, for direct MHs, the MemberName of the target
769 * could be erased, and loaded from the containing direct MH.
770 * As a simple case, a LF for all int-valued non-static
771 * field getters would perform a cast on its input argument
772 * (to non-constant base type derived from the MemberName)
773 * and load an integer value from the input object
774 * (at a non-constant offset also derived from the MemberName).
775 * Such MN-erased LFs would be inlinable back to optimized
776 * code, whenever a constant enclosing DMH is available
777 * to supply a constant MN from its data.
778 *
779 * The main problem here is to keep LFs reasonably generic,
780 * while ensuring that hot spots will inline good instances.
781 * "Reasonably generic" means that we don't end up with
782 * repeated versions of bytecode or machine code that do
783 * not differ in their optimized form. Repeated versions
784 * of machine would have the undesirable overheads of
785 * (a) redundant compilation work and (b) extra I$ pressure.
786 * To control repeated versions, we need to be ready to
787 * erase details from LFs and move them into MH data,
788 * whenever those details are not relevant to significant
789 * optimization. "Significant" means optimization of
790 * code that is actually hot.
791 *
792 * Achieving this may require dynamic splitting of MHs, by replacing
793 * a generic LF with a more specialized one, on the same MH,
794 * if (a) the MH is frequently executed and (b) the MH cannot
795 * be inlined into a containing caller, such as an invokedynamic.
796 *
797 * Compiled LFs that are no longer used should be GC-able.
798 * If they contain non-BCP references, they should be properly
799 * interlinked with the class loader(s) that their embedded types
800 * depend on. This probably means that reusable compiled LFs
801 * will be tabulated (indexed) on relevant class loaders,
802 * or else that the tables that cache them will have weak links.
803 */
804
805 /**
806 * Make this LF directly executable, as part of a MethodHandle.
807 * Invariant: Every MH which is invoked must prepare its LF
808 * before invocation.
809 * (In principle, the JVM could do this very lazily,
810 * as a sort of pre-invocation linkage step.)
811 */
812 public void prepare() {
813 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
814 compileToBytecode();
815 }
816 if (this.vmentry != null) {
817 // already prepared (e.g., a primitive DMH invoker form)
818 return;
819 }
820 MethodType mtype = methodType();
821 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
822 if (prep == null) {
823 assert (isValidSignature(basicTypeSignature()));
824 prep = LambdaForm.createBlankForType(mtype);
825 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
826 prep = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
827 }
828 this.vmentry = prep.vmentry;
829 // TO DO: Maybe add invokeGeneric, invokeWithArguments
830 }
831
832 private static @Stable PerfCounter LF_FAILED;
833
834 private static PerfCounter failedCompilationCounter() {
835 if (LF_FAILED == null) {
836 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
837 }
838 return LF_FAILED;
839 }
840
841 /** Generate optimizable bytecode for this form. */
842 void compileToBytecode() {
843 if (forceInterpretation()) {
844 return; // this should not be compiled
845 }
846 if (vmentry != null && isCompiled) {
847 return; // already compiled somehow
848 }
849
850 // Obtain the invoker MethodType outside of the following try block.
851 // This ensures that an IllegalArgumentException is directly thrown if the
852 // type would have 256 or more parameters
853 MethodType invokerType = methodType();
854 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
855 try {
856 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
857 if (TRACE_INTERPRETER)
858 traceInterpreter("compileToBytecode", this);
859 isCompiled = true;
860 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
861 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
862 invocationCounter = -1;
863 failedCompilationCounter().increment();
864 if (LOG_LF_COMPILATION_FAILURE) {
865 System.out.println("LambdaForm compilation failed: " + this);
866 bge.printStackTrace(System.out);
867 }
868 } catch (Error e) {
869 // Pass through any error
870 throw e;
871 } catch (Exception e) {
872 // Wrap any exception
873 throw newInternalError(this.toString(), e);
874 }
875 }
876
877 // The next few routines are called only from assert expressions
878 // They verify that the built-in invokers process the correct raw data types.
879 private static boolean argumentTypesMatch(String sig, Object[] av) {
880 int arity = signatureArity(sig);
881 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
882 assert(av[0] instanceof MethodHandle) : "av[0] not instance of MethodHandle: " + av[0];
883 MethodHandle mh = (MethodHandle) av[0];
884 MethodType mt = mh.type();
885 assert(mt.parameterCount() == arity-1);
886 for (int i = 0; i < av.length; i++) {
887 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
888 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
889 }
890 return true;
891 }
892 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
893 // The following line is needed because (...)void method handles can use non-void invokers
894 if (type == void.class) tc = V_TYPE; // can drop any kind of value
895 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
896 switch (tc) {
897 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
898 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
899 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
900 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
901 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
902 case V_TYPE: break; // allow anything here; will be dropped
903 default: assert(false);
904 }
905 return true;
906 }
907 private static boolean checkInt(Class<?> type, Object x) {
908 assert(x instanceof Integer);
909 if (type == int.class) return true;
910 Wrapper w = Wrapper.forBasicType(type);
911 assert(w.isSubwordOrInt());
912 Object x1 = Wrapper.INT.wrap(w.wrap(x));
913 return x.equals(x1);
914 }
915 private static boolean checkRef(Class<?> type, Object x) {
916 assert(!type.isPrimitive());
917 if (x == null) return true;
918 if (type.isInterface()) return true;
919 return type.isInstance(x);
920 }
921
922 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
923 private static final int COMPILE_THRESHOLD;
924 static {
925 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
926 }
927 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
928
929 private boolean forceInterpretation() {
930 return invocationCounter == -1;
931 }
932
933 /** Interpretively invoke this form on the given arguments. */
934 @Hidden
935 @DontInline
936 Object interpretWithArguments(Object... argumentValues) throws Throwable {
937 if (TRACE_INTERPRETER)
938 return interpretWithArgumentsTracing(argumentValues);
939 checkInvocationCounter();
940 assert(arityCheck(argumentValues));
941 Object[] values = Arrays.copyOf(argumentValues, names.length);
942 for (int i = argumentValues.length; i < values.length; i++) {
943 values[i] = interpretName(names[i], values);
944 }
945 Object rv = (result < 0) ? null : values[result];
946 assert(resultCheck(argumentValues, rv));
947 return rv;
948 }
949
950 /** Evaluate a single Name within this form, applying its function to its arguments. */
951 @Hidden
952 @DontInline
953 Object interpretName(Name name, Object[] values) throws Throwable {
954 if (TRACE_INTERPRETER)
955 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
956 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
957 for (int i = 0; i < arguments.length; i++) {
958 Object a = arguments[i];
959 if (a instanceof Name n) {
960 int i2 = n.index();
961 assert(names[i2] == a);
962 a = values[i2];
963 arguments[i] = a;
964 }
965 }
966 return name.function.invokeWithArguments(arguments);
967 }
968
969 private void checkInvocationCounter() {
970 if (COMPILE_THRESHOLD != 0 &&
971 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
972 invocationCounter++; // benign race
973 if (invocationCounter >= COMPILE_THRESHOLD) {
974 // Replace vmentry with a bytecode version of this LF.
975 compileToBytecode();
976 }
977 }
978 }
979 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
980 traceInterpreter("[ interpretWithArguments", this, argumentValues);
981 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
982 int ctr = invocationCounter++; // benign race
983 traceInterpreter("| invocationCounter", ctr);
984 if (invocationCounter >= COMPILE_THRESHOLD) {
985 compileToBytecode();
986 }
987 }
988 Object rval;
989 try {
990 assert(arityCheck(argumentValues));
991 Object[] values = Arrays.copyOf(argumentValues, names.length);
992 for (int i = argumentValues.length; i < values.length; i++) {
993 values[i] = interpretName(names[i], values);
994 }
995 rval = (result < 0) ? null : values[result];
996 } catch (Throwable ex) {
997 traceInterpreter("] throw =>", ex);
998 throw ex;
999 }
1000 traceInterpreter("] return =>", rval);
1001 return rval;
1002 }
1003
1004 static void traceInterpreter(String event, Object obj, Object... args) {
1005 if (TRACE_INTERPRETER) {
1006 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
1007 }
1008 }
1009 static void traceInterpreter(String event, Object obj) {
1010 traceInterpreter(event, obj, (Object[])null);
1011 }
1012 private boolean arityCheck(Object[] argumentValues) {
1013 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
1014 // also check that the leading (receiver) argument is somehow bound to this LF:
1015 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
1016 MethodHandle mh = (MethodHandle) argumentValues[0];
1017 assert(mh.internalForm() == this);
1018 // note: argument #0 could also be an interface wrapper, in the future
1019 argumentTypesMatch(basicTypeSignature(), argumentValues);
1020 return true;
1021 }
1022 private boolean resultCheck(Object[] argumentValues, Object result) {
1023 MethodHandle mh = (MethodHandle) argumentValues[0];
1024 MethodType mt = mh.type();
1025 assert(valueMatches(returnType(), mt.returnType(), result));
1026 return true;
1027 }
1028
1029 private boolean isEmpty() {
1030 if (result < 0)
1031 return (names.length == arity);
1032 else if (result == arity && names.length == arity + 1)
1033 return names[arity].isConstantZero();
1034 else
1035 return false;
1036 }
1037
1038 public String toString() {
1039 return debugString(-1);
1040 }
1041
1042 String debugString(int indentLevel) {
1043 String prefix = MethodHandle.debugPrefix(indentLevel);
1044 String lambdaName = lambdaName();
1045 StringBuilder buf = new StringBuilder(lambdaName);
1046 buf.append("=Lambda(");
1047 for (int i = 0; i < names.length; i++) {
1048 if (i == arity) buf.append(")=>{");
1049 Name n = names[i];
1050 if (i >= arity) buf.append("\n ").append(prefix);
1051 buf.append(n.paramString());
1052 if (i < arity) {
1053 if (i+1 < arity) buf.append(",");
1054 continue;
1055 }
1056 buf.append("=").append(n.exprString());
1057 buf.append(";");
1058 }
1059 if (arity == names.length) buf.append(")=>{");
1060 buf.append(result < 0 ? "void" : names[result]).append("}");
1061 if (TRACE_INTERPRETER) {
1062 // Extra verbosity:
1063 buf.append(":").append(basicTypeSignature());
1064 buf.append("/").append(vmentry);
1065 }
1066 return buf.toString();
1067 }
1068
1069 @Override
1070 public boolean equals(Object obj) {
1071 return obj instanceof LambdaForm lf && equals(lf);
1072 }
1073 public boolean equals(LambdaForm that) {
1074 if (this.result != that.result) return false;
1075 return Arrays.equals(this.names, that.names);
1076 }
1077 public int hashCode() {
1078 return result + 31 * Arrays.hashCode(names);
1079 }
1080 LambdaFormEditor editor() {
1081 return LambdaFormEditor.lambdaFormEditor(this);
1082 }
1083
1084 boolean contains(Name name) {
1085 int pos = name.index();
1086 if (pos >= 0) {
1087 return pos < names.length && name.equals(names[pos]);
1088 }
1089 for (int i = arity; i < names.length; i++) {
1090 if (name.equals(names[i]))
1091 return true;
1092 }
1093 return false;
1094 }
1095
1096 static class NamedFunction {
1097 final MemberName member;
1098 private @Stable MethodHandle resolvedHandle;
1099 private @Stable MethodType type;
1100
1101 NamedFunction(MethodHandle resolvedHandle) {
1102 this(resolvedHandle.internalMemberName(), resolvedHandle);
1103 }
1104 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1105 this.member = member;
1106 this.resolvedHandle = resolvedHandle;
1107 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1108 //assert(!isInvokeBasic(member));
1109 }
1110 NamedFunction(MethodType basicInvokerType) {
1111 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1112 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1113 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1114 this.member = resolvedHandle.internalMemberName();
1115 } else {
1116 // necessary to pass BigArityTest
1117 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1118 }
1119 assert(isInvokeBasic(member));
1120 }
1121
1122 private static boolean isInvokeBasic(MemberName member) {
1123 return member != null &&
1124 member.getDeclaringClass() == MethodHandle.class &&
1125 "invokeBasic".equals(member.getName());
1126 }
1127
1128 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1129 // Any LambdaForm containing such a member is not interpretable.
1130 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1131 // And even without the resolvedHandle, the name can still be compiled and optimized.
1132 NamedFunction(Method method) {
1133 this(new MemberName(method));
1134 }
1135 NamedFunction(MemberName member) {
1136 this(member, null);
1137 }
1138
1139 MethodHandle resolvedHandle() {
1140 if (resolvedHandle == null) resolve();
1141 return resolvedHandle;
1142 }
1143
1144 synchronized void resolve() {
1145 if (resolvedHandle == null) {
1146 resolvedHandle = DirectMethodHandle.make(member);
1147 }
1148 }
1149
1150 @Override
1151 public boolean equals(Object other) {
1152 if (this == other) return true;
1153 if (other == null) return false;
1154 return (other instanceof NamedFunction that)
1155 && this.member != null
1156 && this.member.equals(that.member);
1157 }
1158
1159 @Override
1160 public int hashCode() {
1161 if (member != null)
1162 return member.hashCode();
1163 return super.hashCode();
1164 }
1165
1166 static final MethodType INVOKER_METHOD_TYPE;
1167 private static @Stable MethodType[] archivedObjects;
1168
1169 static {
1170 CDS.initializeFromArchive(NamedFunction.class);
1171 if (archivedObjects != null) {
1172 INVOKER_METHOD_TYPE = archivedObjects[0];
1173 } else {
1174 INVOKER_METHOD_TYPE =
1175 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1176 }
1177 }
1178
1179 static void dumpSharedArchive() {
1180 archivedObjects = new MethodType[1];
1181 archivedObjects[0] = INVOKER_METHOD_TYPE;
1182 }
1183
1184 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1185 typeForm = typeForm.basicType().form(); // normalize to basic type
1186 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1187 if (mh != null) return mh;
1188 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1189 mh = DirectMethodHandle.make(invoker);
1190 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1191 if (mh2 != null) return mh2; // benign race
1192 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1193 throw newInternalError(mh.debugString());
1194 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1195 }
1196
1197 @Hidden
1198 Object invokeWithArguments(Object... arguments) throws Throwable {
1199 // If we have a cached invoker, call it right away.
1200 // NOTE: The invoker always returns a reference value.
1201 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1202 return invoker().invokeBasic(resolvedHandle(), arguments);
1203 }
1204
1205 @Hidden
1206 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1207 Object rval;
1208 try {
1209 traceInterpreter("[ call", this, arguments);
1210 // resolvedHandle might be uninitialized, ok for tracing
1211 if (resolvedHandle == null) {
1212 traceInterpreter("| resolve", this);
1213 resolvedHandle();
1214 }
1215 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1216 } catch (Throwable ex) {
1217 traceInterpreter("] throw =>", ex);
1218 throw ex;
1219 }
1220 traceInterpreter("] return =>", rval);
1221 return rval;
1222 }
1223
1224 private MethodHandle invoker() {
1225 return computeInvoker(methodType().form());
1226 }
1227
1228 MethodType methodType() {
1229 MethodType type = this.type;
1230 if (type == null) {
1231 this.type = type = calculateMethodType(member, resolvedHandle);
1232 }
1233 return type;
1234 }
1235
1236 private static MethodType calculateMethodType(MemberName member, MethodHandle resolvedHandle) {
1237 if (resolvedHandle != null) {
1238 return resolvedHandle.type();
1239 } else {
1240 // only for certain internal LFs during bootstrapping
1241 return member.getInvocationType();
1242 }
1243 }
1244
1245 MemberName member() {
1246 assert(assertMemberIsConsistent());
1247 return member;
1248 }
1249
1250 // Called only from assert.
1251 private boolean assertMemberIsConsistent() {
1252 if (resolvedHandle instanceof DirectMethodHandle) {
1253 MemberName m = resolvedHandle.internalMemberName();
1254 assert(m.equals(member));
1255 }
1256 return true;
1257 }
1258
1259 Class<?> memberDeclaringClassOrNull() {
1260 return (member == null) ? null : member.getDeclaringClass();
1261 }
1262
1263 BasicType returnType() {
1264 return basicType(methodType().returnType());
1265 }
1266
1267 BasicType parameterType(int n) {
1268 return basicType(methodType().parameterType(n));
1269 }
1270
1271 int arity() {
1272 return methodType().parameterCount();
1273 }
1274
1275 public String toString() {
1276 if (member == null) return String.valueOf(resolvedHandle);
1277 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1278 }
1279
1280 public boolean isIdentity() {
1281 return this.equals(identity(returnType()));
1282 }
1283
1284 public boolean isConstantZero() {
1285 return this.equals(constantZero(returnType()));
1286 }
1287
1288 public MethodHandleImpl.Intrinsic intrinsicName() {
1289 return resolvedHandle != null
1290 ? resolvedHandle.intrinsicName()
1291 : MethodHandleImpl.Intrinsic.NONE;
1292 }
1293
1294 public Object intrinsicData() {
1295 return resolvedHandle != null
1296 ? resolvedHandle.intrinsicData()
1297 : null;
1298 }
1299 }
1300
1301 public static String basicTypeSignature(MethodType type) {
1302 int params = type.parameterCount();
1303 char[] sig = new char[params + 2];
1304 int sigp = 0;
1305 while (sigp < params) {
1306 sig[sigp] = basicTypeChar(type.parameterType(sigp++));
1307 }
1308 sig[sigp++] = '_';
1309 sig[sigp++] = basicTypeChar(type.returnType());
1310 assert(sigp == sig.length);
1311 return String.valueOf(sig);
1312 }
1313
1314 /** Hack to make signatures more readable when they show up in method names.
1315 * Signature should start with a sequence of uppercase ASCII letters.
1316 * Runs of three or more are replaced by a single letter plus a decimal repeat count.
1317 * A tail of anything other than uppercase ASCII is passed through unchanged.
1318 * @param signature sequence of uppercase ASCII letters with possible repetitions
1319 * @return same sequence, with repetitions counted by decimal numerals
1320 */
1321 public static String shortenSignature(String signature) {
1322 final int NO_CHAR = -1, MIN_RUN = 3;
1323 int c0, c1 = NO_CHAR, c1reps = 0;
1324 StringBuilder buf = null;
1325 int len = signature.length();
1326 if (len < MIN_RUN) return signature;
1327 for (int i = 0; i <= len; i++) {
1328 if (c1 != NO_CHAR && !('A' <= c1 && c1 <= 'Z')) {
1329 // wrong kind of char; bail out here
1330 if (buf != null) {
1331 buf.append(signature, i - c1reps, len);
1332 }
1333 break;
1334 }
1335 // shift in the next char:
1336 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1337 if (c1 == c0) { ++c1reps; continue; }
1338 // shift in the next count:
1339 int c0reps = c1reps; c1reps = 1;
1340 // end of a character run
1341 if (c0reps < MIN_RUN) {
1342 if (buf != null) {
1343 while (--c0reps >= 0)
1344 buf.append((char)c0);
1345 }
1346 continue;
1347 }
1348 // found three or more in a row
1349 if (buf == null)
1350 buf = new StringBuilder().append(signature, 0, i - c0reps);
1351 buf.append((char)c0).append(c0reps);
1352 }
1353 return (buf == null) ? signature : buf.toString();
1354 }
1355
1356 static final class Name {
1357 final BasicType type;
1358 @Stable short index;
1359 final NamedFunction function;
1360 final Object constraint; // additional type information, if not null
1361 @Stable final Object[] arguments;
1362
1363 private static final Object[] EMPTY_ARGS = new Object[0];
1364
1365 private Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1366 this.index = (short)index;
1367 this.type = type;
1368 this.function = function;
1369 this.arguments = arguments;
1370 this.constraint = null;
1371 assert(this.index == index && typesMatch(function, this.arguments));
1372 }
1373 private Name(Name that, Object constraint) {
1374 this.index = that.index;
1375 this.type = that.type;
1376 this.function = that.function;
1377 this.arguments = that.arguments;
1378 this.constraint = constraint;
1379 assert(constraint == null || isParam()); // only params have constraints
1380 assert(constraint == null || constraint instanceof ClassSpecializer.SpeciesData || constraint instanceof Class);
1381 }
1382 Name(MethodHandle function, Object... arguments) {
1383 this(new NamedFunction(function), arguments);
1384 }
1385 Name(MethodType functionType, Object... arguments) {
1386 this(new NamedFunction(functionType), arguments);
1387 assert(arguments[0] instanceof Name name && name.type == L_TYPE);
1388 }
1389 Name(MemberName function, Object... arguments) {
1390 this(new NamedFunction(function), arguments);
1391 }
1392 Name(NamedFunction function) {
1393 this(-1, function.returnType(), function, EMPTY_ARGS);
1394 }
1395 Name(NamedFunction function, Object arg) {
1396 this(-1, function.returnType(), function, new Object[] { arg });
1397 }
1398 Name(NamedFunction function, Object arg0, Object arg1) {
1399 this(-1, function.returnType(), function, new Object[] { arg0, arg1 });
1400 }
1401 Name(NamedFunction function, Object... arguments) {
1402 this(-1, function.returnType(), function, Arrays.copyOf(arguments, arguments.length, Object[].class));
1403 }
1404 /** Create a raw parameter of the given type, with an expected index. */
1405 Name(int index, BasicType type) {
1406 this(index, type, null, null);
1407 }
1408 /** Create a raw parameter of the given type. */
1409 Name(BasicType type) { this(-1, type); }
1410
1411 BasicType type() { return type; }
1412 int index() { return index; }
1413 boolean initIndex(int i) {
1414 if (index != i) {
1415 if (index != -1) return false;
1416 index = (short)i;
1417 }
1418 return true;
1419 }
1420 char typeChar() {
1421 return type.btChar;
1422 }
1423
1424 Name newIndex(int i) {
1425 if (initIndex(i)) return this;
1426 return cloneWithIndex(i);
1427 }
1428 Name cloneWithIndex(int i) {
1429 Object[] newArguments = (arguments == null) ? null : arguments.clone();
1430 return new Name(i, type, function, newArguments).withConstraint(constraint);
1431 }
1432 Name withConstraint(Object constraint) {
1433 if (constraint == this.constraint) return this;
1434 return new Name(this, constraint);
1435 }
1436 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1437 if (oldName == newName) return this;
1438 @SuppressWarnings("LocalVariableHidesMemberVariable")
1439 Object[] arguments = this.arguments;
1440 if (arguments == null) return this;
1441 boolean replaced = false;
1442 for (int j = 0; j < arguments.length; j++) {
1443 if (arguments[j] == oldName) {
1444 if (!replaced) {
1445 replaced = true;
1446 arguments = arguments.clone();
1447 }
1448 arguments[j] = newName;
1449 }
1450 }
1451 if (!replaced) return this;
1452 return new Name(function, arguments);
1453 }
1454 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1455 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1456 */
1457 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1458 if (start >= end) return this;
1459 @SuppressWarnings("LocalVariableHidesMemberVariable")
1460 Object[] arguments = this.arguments;
1461 boolean replaced = false;
1462 eachArg:
1463 for (int j = 0; j < arguments.length; j++) {
1464 if (arguments[j] instanceof Name n) {
1465 int check = n.index;
1466 // harmless check to see if the thing is already in newNames:
1467 if (check >= 0 && check < newNames.length && n == newNames[check])
1468 continue eachArg;
1469 // n might not have the correct index: n != oldNames[n.index].
1470 for (int i = start; i < end; i++) {
1471 if (n == oldNames[i]) {
1472 if (n == newNames[i])
1473 continue eachArg;
1474 if (!replaced) {
1475 replaced = true;
1476 arguments = arguments.clone();
1477 }
1478 arguments[j] = newNames[i];
1479 continue eachArg;
1480 }
1481 }
1482 }
1483 }
1484 if (!replaced) return this;
1485 return new Name(function, arguments);
1486 }
1487 void internArguments() {
1488 @SuppressWarnings("LocalVariableHidesMemberVariable")
1489 Object[] arguments = this.arguments;
1490 for (int j = 0; j < arguments.length; j++) {
1491 if (arguments[j] instanceof Name n) {
1492 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1493 arguments[j] = internArgument(n);
1494 }
1495 }
1496 }
1497 boolean isParam() {
1498 return function == null;
1499 }
1500 boolean isConstantZero() {
1501 return !isParam() && arguments.length == 0 && function.isConstantZero();
1502 }
1503
1504 boolean refersTo(Class<?> declaringClass, String methodName) {
1505 return function != null &&
1506 function.member() != null && function.member().refersTo(declaringClass, methodName);
1507 }
1508
1509 /**
1510 * Check if MemberName is a call to MethodHandle.invokeBasic.
1511 */
1512 boolean isInvokeBasic() {
1513 if (function == null)
1514 return false;
1515 if (arguments.length < 1)
1516 return false; // must have MH argument
1517 MemberName member = function.member();
1518 return member != null && member.refersTo(MethodHandle.class, "invokeBasic") &&
1519 !member.isPublic() && !member.isStatic();
1520 }
1521
1522 /**
1523 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1524 */
1525 boolean isLinkerMethodInvoke() {
1526 if (function == null)
1527 return false;
1528 if (arguments.length < 1)
1529 return false; // must have MH argument
1530 MemberName member = function.member();
1531 return member != null &&
1532 member.getDeclaringClass() == MethodHandle.class &&
1533 !member.isPublic() && member.isStatic() &&
1534 member.getName().startsWith("linkTo");
1535 }
1536
1537 public String toString() {
1538 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1539 }
1540 public String debugString() {
1541 String s = paramString();
1542 return (function == null) ? s : s + "=" + exprString();
1543 }
1544 public String paramString() {
1545 String s = toString();
1546 Object c = constraint;
1547 if (c == null)
1548 return s;
1549 if (c instanceof Class<?> cl) c = cl.getSimpleName();
1550 return s + "/" + c;
1551 }
1552 public String exprString() {
1553 if (function == null) return toString();
1554 StringBuilder buf = new StringBuilder(function.toString());
1555 buf.append("(");
1556 String cma = "";
1557 for (Object a : arguments) {
1558 buf.append(cma); cma = ",";
1559 if (a instanceof Name || a instanceof Integer)
1560 buf.append(a);
1561 else
1562 buf.append("(").append(a).append(")");
1563 }
1564 buf.append(")");
1565 return buf.toString();
1566 }
1567
1568 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1569 if (arguments == null) {
1570 assert(function == null);
1571 return true;
1572 }
1573 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1574 for (int i = 0; i < arguments.length; i++) {
1575 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1576 }
1577 return true;
1578 }
1579
1580 private static boolean typesMatch(BasicType parameterType, Object object) {
1581 if (object instanceof Name name) {
1582 return name.type == parameterType;
1583 }
1584 switch (parameterType) {
1585 case I_TYPE: return object instanceof Integer;
1586 case J_TYPE: return object instanceof Long;
1587 case F_TYPE: return object instanceof Float;
1588 case D_TYPE: return object instanceof Double;
1589 }
1590 assert(parameterType == L_TYPE);
1591 return true;
1592 }
1593
1594 /** Return the index of the last occurrence of n in the argument array.
1595 * Return -1 if the name is not used.
1596 */
1597 int lastUseIndex(Name n) {
1598 if (arguments == null) return -1;
1599 for (int i = arguments.length; --i >= 0; ) {
1600 if (arguments[i] == n) return i;
1601 }
1602 return -1;
1603 }
1604
1605 /** Return the number of occurrences of n in the argument array.
1606 * Return 0 if the name is not used.
1607 */
1608 int useCount(Name n) {
1609 int count = 0;
1610 if (arguments != null) {
1611 for (Object argument : arguments) {
1612 if (argument == n) {
1613 count++;
1614 }
1615 }
1616 }
1617 return count;
1618 }
1619
1620 public boolean equals(Name that) {
1621 if (this == that) return true;
1622 if (isParam())
1623 // each parameter is a unique atom
1624 return false; // this != that
1625 return
1626 //this.index == that.index &&
1627 this.type == that.type &&
1628 this.function.equals(that.function) &&
1629 Arrays.equals(this.arguments, that.arguments);
1630 }
1631 @Override
1632 public boolean equals(Object x) {
1633 return x instanceof Name n && equals(n);
1634 }
1635 @Override
1636 public int hashCode() {
1637 if (isParam())
1638 return index | (type.ordinal() << 8);
1639 return function.hashCode() ^ Arrays.hashCode(arguments);
1640 }
1641 }
1642
1643 /** Return the index of the last name which contains n as an argument.
1644 * Return -1 if the name is not used. Return names.length if it is the return value.
1645 */
1646 int lastUseIndex(Name n) {
1647 int ni = n.index, nmax = names.length;
1648 assert(names[ni] == n);
1649 if (result == ni) return nmax; // live all the way beyond the end
1650 for (int i = nmax; --i > ni; ) {
1651 if (names[i].lastUseIndex(n) >= 0)
1652 return i;
1653 }
1654 return -1;
1655 }
1656
1657 /** Return the number of times n is used as an argument or return value. */
1658 int useCount(Name n) {
1659 int count = (result == n.index) ? 1 : 0;
1660 int i = Math.max(n.index + 1, arity);
1661 while (i < names.length) {
1662 count += names[i++].useCount(n);
1663 }
1664 return count;
1665 }
1666
1667 static Name argument(int which, BasicType type) {
1668 if (which >= INTERNED_ARGUMENT_LIMIT)
1669 return new Name(which, type);
1670 return INTERNED_ARGUMENTS[type.ordinal()][which];
1671 }
1672 static Name internArgument(Name n) {
1673 assert(n.isParam()) : "not param: " + n;
1674 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1675 if (n.constraint != null) return n;
1676 return argument(n.index, n.type);
1677 }
1678 static Name[] arguments(int extra, MethodType types) {
1679 int length = types.parameterCount();
1680 Name[] names = new Name[length + extra];
1681 for (int i = 0; i < length; i++)
1682 names[i] = argument(i, basicType(types.parameterType(i)));
1683 return names;
1684 }
1685 static final int INTERNED_ARGUMENT_LIMIT = 10;
1686 private static final Name[][] INTERNED_ARGUMENTS
1687 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1688 static {
1689 for (BasicType type : BasicType.ARG_TYPES) {
1690 int ord = type.ordinal();
1691 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1692 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1693 }
1694 }
1695 }
1696
1697 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1698
1699 static LambdaForm identityForm(BasicType type) {
1700 int ord = type.ordinal();
1701 LambdaForm form = LF_identity[ord];
1702 if (form != null) {
1703 return form;
1704 }
1705 createFormsFor(type);
1706 return LF_identity[ord];
1707 }
1708
1709 static LambdaForm zeroForm(BasicType type) {
1710 int ord = type.ordinal();
1711 LambdaForm form = LF_zero[ord];
1712 if (form != null) {
1713 return form;
1714 }
1715 createFormsFor(type);
1716 return LF_zero[ord];
1717 }
1718
1719 static NamedFunction identity(BasicType type) {
1720 int ord = type.ordinal();
1721 NamedFunction function = NF_identity[ord];
1722 if (function != null) {
1723 return function;
1724 }
1725 createFormsFor(type);
1726 return NF_identity[ord];
1727 }
1728
1729 static NamedFunction constantZero(BasicType type) {
1730 int ord = type.ordinal();
1731 NamedFunction function = NF_zero[ord];
1732 if (function != null) {
1733 return function;
1734 }
1735 createFormsFor(type);
1736 return NF_zero[ord];
1737 }
1738
1739 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1740 private static final @Stable LambdaForm[] LF_zero = new LambdaForm[TYPE_LIMIT];
1741 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1742 private static final @Stable NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1743
1744 private static final Object createFormsLock = new Object();
1745 private static void createFormsFor(BasicType type) {
1746 // Avoid racy initialization during bootstrap
1747 UNSAFE.ensureClassInitialized(BoundMethodHandle.class);
1748 synchronized (createFormsLock) {
1749 final int ord = type.ordinal();
1750 LambdaForm idForm = LF_identity[ord];
1751 if (idForm != null) {
1752 return;
1753 }
1754 char btChar = type.basicTypeChar();
1755 boolean isVoid = (type == V_TYPE);
1756 Class<?> btClass = type.btClass;
1757 MethodType zeType = MethodType.methodType(btClass);
1758 MethodType idType = (isVoid) ? zeType : MethodType.methodType(btClass, btClass);
1759
1760 // Look up symbolic names. It might not be necessary to have these,
1761 // but if we need to emit direct references to bytecodes, it helps.
1762 // Zero is built from a call to an identity function with a constant zero input.
1763 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1764 MemberName zeMem = null;
1765 try {
1766 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, LM_TRUSTED, NoSuchMethodException.class);
1767 if (!isVoid) {
1768 zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1769 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, LM_TRUSTED, NoSuchMethodException.class);
1770 }
1771 } catch (IllegalAccessException|NoSuchMethodException ex) {
1772 throw newInternalError(ex);
1773 }
1774
1775 NamedFunction idFun;
1776 LambdaForm zeForm;
1777 NamedFunction zeFun;
1778
1779 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1780 // bootstrap dependency on this method in case we're interpreting LFs
1781 if (isVoid) {
1782 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1783 idForm = LambdaForm.create(1, idNames, VOID_RESULT, Kind.IDENTITY);
1784 idForm.compileToBytecode();
1785 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1786
1787 zeForm = idForm;
1788 zeFun = idFun;
1789 } else {
1790 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1791 idForm = LambdaForm.create(2, idNames, 1, Kind.IDENTITY);
1792 idForm.compileToBytecode();
1793 idFun = new NamedFunction(idMem, MethodHandleImpl.makeIntrinsic(SimpleMethodHandle.make(idMem.getInvocationType(), idForm),
1794 MethodHandleImpl.Intrinsic.IDENTITY));
1795
1796 Object zeValue = Wrapper.forBasicType(btChar).zero();
1797 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1798 zeForm = LambdaForm.create(1, zeNames, 1, Kind.ZERO);
1799 zeForm.compileToBytecode();
1800 zeFun = new NamedFunction(zeMem, MethodHandleImpl.makeIntrinsic(SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm),
1801 MethodHandleImpl.Intrinsic.ZERO));
1802 }
1803
1804 LF_zero[ord] = zeForm;
1805 NF_zero[ord] = zeFun;
1806 LF_identity[ord] = idForm;
1807 NF_identity[ord] = idFun;
1808
1809 assert(idFun.isIdentity());
1810 assert(zeFun.isConstantZero());
1811 assert(new Name(zeFun).isConstantZero());
1812 }
1813 }
1814
1815 // Avoid appealing to ValueConversions at bootstrap time:
1816 private static int identity_I(int x) { return x; }
1817 private static long identity_J(long x) { return x; }
1818 private static float identity_F(float x) { return x; }
1819 private static double identity_D(double x) { return x; }
1820 private static Object identity_L(Object x) { return x; }
1821 private static void identity_V() { return; }
1822 private static int zero_I() { return 0; }
1823 private static long zero_J() { return 0; }
1824 private static float zero_F() { return 0; }
1825 private static double zero_D() { return 0; }
1826 private static Object zero_L() { return null; }
1827
1828 /**
1829 * Internal marker for byte-compiled LambdaForms.
1830 */
1831 /*non-public*/
1832 @Target(ElementType.METHOD)
1833 @Retention(RetentionPolicy.RUNTIME)
1834 @interface Compiled {
1835 }
1836
1837 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1838 private static final HashMap<LambdaForm,String> DEBUG_NAMES;
1839 static {
1840 if (debugEnabled()) {
1841 DEBUG_NAME_COUNTERS = new HashMap<>();
1842 DEBUG_NAMES = new HashMap<>();
1843 } else {
1844 DEBUG_NAME_COUNTERS = null;
1845 DEBUG_NAMES = null;
1846 }
1847 }
1848
1849 static {
1850 // The Holder class will contain pre-generated forms resolved
1851 // using MemberName.getFactory(). However, that doesn't initialize the
1852 // class, which subtly breaks inlining etc. By forcing
1853 // initialization of the Holder class we avoid these issues.
1854 UNSAFE.ensureClassInitialized(Holder.class);
1855 }
1856
1857 /* Placeholder class for zero and identity forms generated ahead of time */
1858 final class Holder {}
1859
1860 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1861 // during execution of the static initializes of this class.
1862 // Turning on TRACE_INTERPRETER too early will cause
1863 // stack overflows and other misbehavior during attempts to trace events
1864 // that occur during LambdaForm.<clinit>.
1865 // Therefore, do not move this line higher in this file, and do not remove.
1866 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1867 }