1 /*
2 * Copyright (c) 2011, 2018, 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.perf.PerfCounter;
29 import jdk.internal.vm.annotation.DontInline;
30 import jdk.internal.vm.annotation.Hidden;
31 import jdk.internal.vm.annotation.Stable;
32 import sun.invoke.util.Wrapper;
33
34 import java.lang.annotation.ElementType;
35 import java.lang.annotation.Retention;
36 import java.lang.annotation.RetentionPolicy;
37 import java.lang.annotation.Target;
38 import java.lang.reflect.Method;
39 import java.util.Arrays;
40 import java.util.HashMap;
41
42 import static java.lang.invoke.LambdaForm.BasicType.*;
43 import static java.lang.invoke.MethodHandleNatives.Constants.REF_invokeStatic;
44 import static java.lang.invoke.MethodHandleStatics.*;
45
46 /**
47 * The symbolic, non-executable form of a method handle's invocation semantics.
48 * It consists of a series of names.
49 * The first N (N=arity) names are parameters,
50 * while any remaining names are temporary values.
51 * Each temporary specifies the application of a function to some arguments.
52 * The functions are method handles, while the arguments are mixes of
53 * constant values and local names.
54 * The result of the lambda is defined as one of the names, often the last one.
55 * <p>
56 * Here is an approximate grammar:
57 * <blockquote><pre>{@code
58 * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
59 * ArgName = "a" N ":" T
60 * TempName = "t" N ":" T "=" Function "(" Argument* ");"
61 * Function = ConstantValue
62 * Argument = NameRef | ConstantValue
63 * Result = NameRef | "void"
64 * NameRef = "a" N | "t" N
65 * N = (any whole number)
66 * T = "L" | "I" | "J" | "F" | "D" | "V"
67 * }</pre></blockquote>
68 * Names are numbered consecutively from left to right starting at zero.
69 * (The letters are merely a taste of syntax sugar.)
70 * Thus, the first temporary (if any) is always numbered N (where N=arity).
71 * Every occurrence of a name reference in an argument list must refer to
72 * a name previously defined within the same lambda.
73 * A lambda has a void result if and only if its result index is -1.
74 * If a temporary has the type "V", it cannot be the subject of a NameRef,
75 * even though possesses a number.
76 * Note that all reference types are erased to "L", which stands for {@code Object}.
77 * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
78 * The other types stand for the usual primitive types.
79 * <p>
80 * Function invocation closely follows the static rules of the Java verifier.
81 * Arguments and return values must exactly match when their "Name" types are
82 * considered.
83 * Conversions are allowed only if they do not change the erased type.
84 * <ul>
85 * <li>L = Object: casts are used freely to convert into and out of reference types
86 * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
87 * <li>J = long: no implicit conversions
88 * <li>F = float: no implicit conversions
89 * <li>D = double: no implicit conversions
90 * <li>V = void: a function result may be void if and only if its Name is of type "V"
91 * </ul>
92 * Although implicit conversions are not allowed, explicit ones can easily be
93 * encoded by using temporary expressions which call type-transformed identity functions.
94 * <p>
95 * Examples:
96 * <blockquote><pre>{@code
97 * (a0:J)=>{ a0 }
98 * == identity(long)
99 * (a0:I)=>{ t1:V = System.out#println(a0); void }
100 * == System.out#println(int)
101 * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
102 * == identity, with printing side-effect
103 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
104 * t3:L = BoundMethodHandle#target(a0);
105 * t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
106 * == general invoker for unary insertArgument combination
107 * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
108 * t3:L = MethodHandle#invoke(t2, a1);
109 * t4:L = FilterMethodHandle#target(a0);
110 * t5:L = MethodHandle#invoke(t4, t3); t5 }
111 * == general invoker for unary filterArgument combination
112 * (a0:L, a1:L)=>{ ...(same as previous example)...
113 * t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
114 * == general invoker for unary/unary foldArgument combination
115 * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
116 * == invoker for identity method handle which performs i2l
117 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
118 * t3:L = Class#cast(t2,a1); t3 }
119 * == invoker for identity method handle which performs cast
120 * }</pre></blockquote>
121 * <p>
122 * @author John Rose, JSR 292 EG
123 */
124 class LambdaForm {
125 final int arity;
126 final int result;
127 final boolean forceInline;
128 final MethodHandle customized;
129 @Stable final Name[] names;
130 final Kind kind;
131 MemberName vmentry; // low-level behavior, or null if not yet prepared
132 private boolean isCompiled;
133
134 // Either a LambdaForm cache (managed by LambdaFormEditor) or a link to uncustomized version (for customized LF)
135 volatile Object transformCache;
136
137 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
138
139 enum BasicType {
140 L_TYPE('L', Object.class, Wrapper.OBJECT), // all reference types
141 I_TYPE('I', int.class, Wrapper.INT),
142 J_TYPE('J', long.class, Wrapper.LONG),
143 F_TYPE('F', float.class, Wrapper.FLOAT),
144 D_TYPE('D', double.class, Wrapper.DOUBLE), // all primitive types
145 V_TYPE('V', void.class, Wrapper.VOID); // not valid in all contexts
146
147 static final @Stable BasicType[] ALL_TYPES = BasicType.values();
148 static final @Stable BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
149
150 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
151 static final int TYPE_LIMIT = ALL_TYPES.length;
152
153 // Derived int constants, which (unlike the enums) can be constant folded.
154 // We can remove them when JDK-8161245 is fixed.
155 static final byte
156 L_TYPE_NUM = (byte) L_TYPE.ordinal(),
157 I_TYPE_NUM = (byte) I_TYPE.ordinal(),
158 J_TYPE_NUM = (byte) J_TYPE.ordinal(),
159 F_TYPE_NUM = (byte) F_TYPE.ordinal(),
160 D_TYPE_NUM = (byte) D_TYPE.ordinal(),
161 V_TYPE_NUM = (byte) V_TYPE.ordinal();
162
163 final char btChar;
164 final Class<?> btClass;
165 final Wrapper btWrapper;
166
167 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper) {
168 this.btChar = btChar;
169 this.btClass = btClass;
170 this.btWrapper = wrapper;
171 }
172
173 char basicTypeChar() {
174 return btChar;
175 }
176 Class<?> basicTypeClass() {
177 return btClass;
178 }
179 Wrapper basicTypeWrapper() {
180 return btWrapper;
181 }
182 int basicTypeSlots() {
183 return btWrapper.stackSlots();
184 }
185
186 static BasicType basicType(byte type) {
187 return ALL_TYPES[type];
188 }
189 static BasicType basicType(char type) {
190 switch (type) {
191 case 'L': return L_TYPE;
192 case 'I': return I_TYPE;
193 case 'J': return J_TYPE;
194 case 'F': return F_TYPE;
195 case 'D': return D_TYPE;
196 case 'V': return V_TYPE;
197 // all subword types are represented as ints
198 case 'Z':
199 case 'B':
200 case 'S':
201 case 'C':
202 return I_TYPE;
203 default:
204 throw newInternalError("Unknown type char: '"+type+"'");
205 }
206 }
207 static BasicType basicType(Wrapper type) {
208 char c = type.basicTypeChar();
209 return basicType(c);
210 }
211 static BasicType basicType(Class<?> type) {
212 if (!type.isPrimitive()) return L_TYPE;
213 return basicType(Wrapper.forPrimitiveType(type));
214 }
215 static BasicType[] basicTypes(String types) {
216 BasicType[] btypes = new BasicType[types.length()];
217 for (int i = 0; i < btypes.length; i++) {
218 btypes[i] = basicType(types.charAt(i));
219 }
220 return btypes;
221 }
222 static String basicTypeDesc(BasicType[] types) {
223 if (types == null) {
224 return null;
225 }
226 if (types.length == 0) {
227 return "";
228 }
229 StringBuilder sb = new StringBuilder();
230 for (BasicType bt : types) {
231 sb.append(bt.basicTypeChar());
232 }
233 return sb.toString();
234 }
235 static int[] basicTypeOrds(BasicType[] types) {
236 if (types == null) {
237 return null;
238 }
239 int[] a = new int[types.length];
240 for(int i = 0; i < types.length; ++i) {
241 a[i] = types[i].ordinal();
242 }
243 return a;
244 }
245
246 static char basicTypeChar(Class<?> type) {
247 return basicType(type).btChar;
248 }
249
250 static byte[] basicTypesOrd(Class<?>[] types) {
251 byte[] ords = new byte[types.length];
252 for (int i = 0; i < ords.length; i++) {
253 ords[i] = (byte)basicType(types[i]).ordinal();
254 }
255 return ords;
256 }
257
258 static boolean isBasicTypeChar(char c) {
259 return "LIJFDV".indexOf(c) >= 0;
260 }
261 static boolean isArgBasicTypeChar(char c) {
262 return "LIJFD".indexOf(c) >= 0;
263 }
264
265 static { assert(checkBasicType()); }
266 private static boolean checkBasicType() {
267 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
268 assert ARG_TYPES[i].ordinal() == i;
269 assert ARG_TYPES[i] == ALL_TYPES[i];
270 }
271 for (int i = 0; i < TYPE_LIMIT; i++) {
272 assert ALL_TYPES[i].ordinal() == i;
273 }
274 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
275 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
276 return true;
277 }
278 }
279
280 enum Kind {
281 GENERIC("invoke"),
282 ZERO("zero"),
283 IDENTITY("identity"),
284 BOUND_REINVOKER("BMH.reinvoke", "reinvoke"),
285 REINVOKER("MH.reinvoke", "reinvoke"),
286 DELEGATE("MH.delegate", "delegate"),
287 EXACT_LINKER("MH.invokeExact_MT", "invokeExact_MT"),
288 EXACT_INVOKER("MH.exactInvoker", "exactInvoker"),
289 GENERIC_LINKER("MH.invoke_MT", "invoke_MT"),
290 GENERIC_INVOKER("MH.invoker", "invoker"),
291 LINK_TO_TARGET_METHOD("linkToTargetMethod"),
292 LINK_TO_CALL_SITE("linkToCallSite"),
293 DIRECT_INVOKE_VIRTUAL("DMH.invokeVirtual", "invokeVirtual"),
294 DIRECT_INVOKE_SPECIAL("DMH.invokeSpecial", "invokeSpecial"),
295 DIRECT_INVOKE_SPECIAL_IFC("DMH.invokeSpecialIFC", "invokeSpecialIFC"),
296 DIRECT_INVOKE_STATIC("DMH.invokeStatic", "invokeStatic"),
297 DIRECT_NEW_INVOKE_SPECIAL("DMH.newInvokeSpecial", "newInvokeSpecial"),
298 DIRECT_INVOKE_INTERFACE("DMH.invokeInterface", "invokeInterface"),
299 DIRECT_INVOKE_STATIC_INIT("DMH.invokeStaticInit", "invokeStaticInit"),
300 GET_REFERENCE("getReference"),
301 PUT_REFERENCE("putReference"),
302 GET_REFERENCE_VOLATILE("getReferenceVolatile"),
303 PUT_REFERENCE_VOLATILE("putReferenceVolatile"),
304 GET_VALUE("getValue"),
305 PUT_VALUE("putValue"),
306 GET_VALUE_VOLATILE("getValueVolatile"),
307 PUT_VALUE_VOLATILE("putValueVolatile"),
308 GET_INT("getInt"),
309 PUT_INT("putInt"),
310 GET_INT_VOLATILE("getIntVolatile"),
311 PUT_INT_VOLATILE("putIntVolatile"),
312 GET_BOOLEAN("getBoolean"),
313 PUT_BOOLEAN("putBoolean"),
314 GET_BOOLEAN_VOLATILE("getBooleanVolatile"),
315 PUT_BOOLEAN_VOLATILE("putBooleanVolatile"),
316 GET_BYTE("getByte"),
317 PUT_BYTE("putByte"),
318 GET_BYTE_VOLATILE("getByteVolatile"),
319 PUT_BYTE_VOLATILE("putByteVolatile"),
320 GET_CHAR("getChar"),
321 PUT_CHAR("putChar"),
322 GET_CHAR_VOLATILE("getCharVolatile"),
323 PUT_CHAR_VOLATILE("putCharVolatile"),
324 GET_SHORT("getShort"),
325 PUT_SHORT("putShort"),
326 GET_SHORT_VOLATILE("getShortVolatile"),
327 PUT_SHORT_VOLATILE("putShortVolatile"),
328 GET_LONG("getLong"),
329 PUT_LONG("putLong"),
330 GET_LONG_VOLATILE("getLongVolatile"),
331 PUT_LONG_VOLATILE("putLongVolatile"),
332 GET_FLOAT("getFloat"),
333 PUT_FLOAT("putFloat"),
334 GET_FLOAT_VOLATILE("getFloatVolatile"),
335 PUT_FLOAT_VOLATILE("putFloatVolatile"),
336 GET_DOUBLE("getDouble"),
337 PUT_DOUBLE("putDouble"),
338 GET_DOUBLE_VOLATILE("getDoubleVolatile"),
339 PUT_DOUBLE_VOLATILE("putDoubleVolatile"),
340 TRY_FINALLY("tryFinally"),
341 COLLECT("collect"),
342 CONVERT("convert"),
343 SPREAD("spread"),
344 LOOP("loop"),
345 FIELD("field"),
346 GUARD("guard"),
347 GUARD_WITH_CATCH("guardWithCatch"),
348 VARHANDLE_EXACT_INVOKER("VH.exactInvoker"),
349 VARHANDLE_INVOKER("VH.invoker", "invoker"),
350 VARHANDLE_LINKER("VH.invoke_MT", "invoke_MT");
351
352 final String defaultLambdaName;
353 final String methodName;
354
355 private Kind(String defaultLambdaName) {
356 this(defaultLambdaName, defaultLambdaName);
357 }
358
359 private Kind(String defaultLambdaName, String methodName) {
360 this.defaultLambdaName = defaultLambdaName;
361 this.methodName = methodName;
362 }
363 }
364
365 LambdaForm(int arity, Name[] names, int result) {
366 this(arity, names, result, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
367 }
368 LambdaForm(int arity, Name[] names, int result, Kind kind) {
369 this(arity, names, result, /*forceInline=*/true, /*customized=*/null, kind);
370 }
371 LambdaForm(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized) {
372 this(arity, names, result, forceInline, customized, Kind.GENERIC);
373 }
374 LambdaForm(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
375 assert(namesOK(arity, names));
376 this.arity = arity;
377 this.result = fixResult(result, names);
378 this.names = names.clone();
379 this.forceInline = forceInline;
380 this.customized = customized;
381 this.kind = kind;
382 int maxOutArity = normalize();
383 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
384 // Cannot use LF interpreter on very high arity expressions.
385 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
386 compileToBytecode();
387 }
388 }
389 LambdaForm(int arity, Name[] names) {
390 this(arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
391 }
392 LambdaForm(int arity, Name[] names, Kind kind) {
393 this(arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null, kind);
394 }
395 LambdaForm(int arity, Name[] names, boolean forceInline) {
396 this(arity, names, LAST_RESULT, forceInline, /*customized=*/null, Kind.GENERIC);
397 }
398 LambdaForm(int arity, Name[] names, boolean forceInline, Kind kind) {
399 this(arity, names, LAST_RESULT, forceInline, /*customized=*/null, kind);
400 }
401 LambdaForm(Name[] formals, Name[] temps, Name result) {
402 this(formals.length, buildNames(formals, temps, result), LAST_RESULT, /*forceInline=*/true, /*customized=*/null);
403 }
404 LambdaForm(Name[] formals, Name[] temps, Name result, boolean forceInline) {
405 this(formals.length, buildNames(formals, temps, result), LAST_RESULT, forceInline, /*customized=*/null);
406 }
407
408 private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
409 int arity = formals.length;
410 int length = arity + temps.length + (result == null ? 0 : 1);
411 Name[] names = Arrays.copyOf(formals, length);
412 System.arraycopy(temps, 0, names, arity, temps.length);
413 if (result != null)
414 names[length - 1] = result;
415 return names;
416 }
417
418 private LambdaForm(MethodType mt) {
419 // Make a blank lambda form, which returns a constant zero or null.
420 // It is used as a template for managing the invocation of similar forms that are non-empty.
421 // Called only from getPreparedForm.
422 this.arity = mt.parameterCount();
423 this.result = (mt.returnType() == void.class || mt.returnType() == Void.class) ? -1 : arity;
424 this.names = buildEmptyNames(arity, mt, result == -1);
425 this.forceInline = true;
426 this.customized = null;
427 this.kind = Kind.ZERO;
428 assert(nameRefsAreLegal());
429 assert(isEmpty());
430 String sig = null;
431 assert(isValidSignature(sig = basicTypeSignature()));
432 assert(sig.equals(basicTypeSignature())) : sig + " != " + basicTypeSignature();
433 }
434
435 private static Name[] buildEmptyNames(int arity, MethodType mt, boolean isVoid) {
436 Name[] names = arguments(isVoid ? 0 : 1, mt);
437 if (!isVoid) {
438 Name zero = new Name(constantZero(basicType(mt.returnType())));
439 names[arity] = zero.newIndex(arity);
440 }
441 return names;
442 }
443
444 private static int fixResult(int result, Name[] names) {
445 if (result == LAST_RESULT)
446 result = names.length - 1; // might still be void
447 if (result >= 0 && names[result].type == V_TYPE)
448 result = VOID_RESULT;
449 return result;
450 }
451
452 static boolean debugNames() {
453 return DEBUG_NAME_COUNTERS != null;
454 }
455
456 static void associateWithDebugName(LambdaForm form, String name) {
457 assert (debugNames());
458 synchronized (DEBUG_NAMES) {
459 DEBUG_NAMES.put(form, name);
460 }
461 }
462
463 String lambdaName() {
464 if (DEBUG_NAMES != null) {
465 synchronized (DEBUG_NAMES) {
466 String name = DEBUG_NAMES.get(this);
467 if (name == null) {
468 name = generateDebugName();
469 }
470 return name;
471 }
472 }
473 return kind.defaultLambdaName;
474 }
475
476 private String generateDebugName() {
477 assert (debugNames());
478 String debugNameStem = kind.defaultLambdaName;
479 Integer ctr = DEBUG_NAME_COUNTERS.getOrDefault(debugNameStem, 0);
480 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr + 1);
481 StringBuilder buf = new StringBuilder(debugNameStem);
482 int leadingZero = buf.length();
483 buf.append((int) ctr);
484 for (int i = buf.length() - leadingZero; i < 3; i++) {
485 buf.insert(leadingZero, '0');
486 }
487 buf.append('_');
488 buf.append(basicTypeSignature());
489 String name = buf.toString();
490 associateWithDebugName(this, name);
491 return name;
492 }
493
494 private static boolean namesOK(int arity, Name[] names) {
495 for (int i = 0; i < names.length; i++) {
496 Name n = names[i];
497 assert(n != null) : "n is null";
498 if (i < arity)
499 assert( n.isParam()) : n + " is not param at " + i;
500 else
501 assert(!n.isParam()) : n + " is param at " + i;
502 }
503 return true;
504 }
505
506 /** Customize LambdaForm for a particular MethodHandle */
507 LambdaForm customize(MethodHandle mh) {
508 LambdaForm customForm = new LambdaForm(arity, names, result, forceInline, mh, kind);
509 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
510 // If shared LambdaForm has been compiled, compile customized version as well.
511 customForm.compileToBytecode();
512 }
513 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
514 return customForm;
515 }
516
517 /** Get uncustomized flavor of the LambdaForm */
518 LambdaForm uncustomize() {
519 if (customized == null) {
520 return this;
521 }
522 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
523 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
524 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
525 // If customized LambdaForm has been compiled, compile uncustomized version as well.
526 uncustomizedForm.compileToBytecode();
527 }
528 return uncustomizedForm;
529 }
530
531 /** Renumber and/or replace params so that they are interned and canonically numbered.
532 * @return maximum argument list length among the names (since we have to pass over them anyway)
533 */
534 private int normalize() {
535 Name[] oldNames = null;
536 int maxOutArity = 0;
537 int changesStart = 0;
538 for (int i = 0; i < names.length; i++) {
539 Name n = names[i];
540 if (!n.initIndex(i)) {
541 if (oldNames == null) {
542 oldNames = names.clone();
543 changesStart = i;
544 }
545 names[i] = n.cloneWithIndex(i);
546 }
547 if (n.arguments != null && maxOutArity < n.arguments.length)
548 maxOutArity = n.arguments.length;
549 }
550 if (oldNames != null) {
551 int startFixing = arity;
552 if (startFixing <= changesStart)
553 startFixing = changesStart+1;
554 for (int i = startFixing; i < names.length; i++) {
555 Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
556 names[i] = fixed.newIndex(i);
557 }
558 }
559 assert(nameRefsAreLegal());
560 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
561 boolean needIntern = false;
562 for (int i = 0; i < maxInterned; i++) {
563 Name n = names[i], n2 = internArgument(n);
564 if (n != n2) {
565 names[i] = n2;
566 needIntern = true;
567 }
568 }
569 if (needIntern) {
570 for (int i = arity; i < names.length; i++) {
571 names[i].internArguments();
572 }
573 }
574 assert(nameRefsAreLegal());
575 return maxOutArity;
576 }
577
578 /**
579 * Check that all embedded Name references are localizable to this lambda,
580 * and are properly ordered after their corresponding definitions.
581 * <p>
582 * Note that a Name can be local to multiple lambdas, as long as
583 * it possesses the same index in each use site.
584 * This allows Name references to be freely reused to construct
585 * fresh lambdas, without confusion.
586 */
587 boolean nameRefsAreLegal() {
588 assert(arity >= 0 && arity <= names.length);
589 assert(result >= -1 && result < names.length);
590 // Do all names possess an index consistent with their local definition order?
591 for (int i = 0; i < arity; i++) {
592 Name n = names[i];
593 assert(n.index() == i) : Arrays.asList(n.index(), i);
594 assert(n.isParam());
595 }
596 // Also, do all local name references
597 for (int i = arity; i < names.length; i++) {
598 Name n = names[i];
599 assert(n.index() == i);
600 for (Object arg : n.arguments) {
601 if (arg instanceof Name) {
602 Name n2 = (Name) arg;
603 int i2 = n2.index;
604 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
605 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
606 assert(i2 < i); // ref must come after def!
607 }
608 }
609 }
610 return true;
611 }
612
613 /** Invoke this form on the given arguments. */
614 // final Object invoke(Object... args) throws Throwable {
615 // // NYI: fit this into the fast path?
616 // return interpretWithArguments(args);
617 // }
618
619 /** Report the return type. */
620 BasicType returnType() {
621 if (result < 0) return V_TYPE;
622 Name n = names[result];
623 return n.type;
624 }
625
626 /** Report the N-th argument type. */
627 BasicType parameterType(int n) {
628 return parameter(n).type;
629 }
630
631 /** Report the N-th argument name. */
632 Name parameter(int n) {
633 assert(n < arity);
634 Name param = names[n];
635 assert(param.isParam());
636 return param;
637 }
638
639 /** Report the N-th argument type constraint. */
640 Object parameterConstraint(int n) {
641 return parameter(n).constraint;
642 }
643
644 /** Report the arity. */
645 int arity() {
646 return arity;
647 }
648
649 /** Report the number of expressions (non-parameter names). */
650 int expressionCount() {
651 return names.length - arity;
652 }
653
654 /** Return the method type corresponding to my basic type signature. */
655 MethodType methodType() {
656 Class<?>[] ptypes = new Class<?>[arity];
657 for (int i = 0; i < arity; ++i) {
658 ptypes[i] = parameterType(i).btClass;
659 }
660 return MethodType.makeImpl(returnType().btClass, ptypes, true);
661 }
662
663 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
664 final String basicTypeSignature() {
665 StringBuilder buf = new StringBuilder(arity() + 3);
666 for (int i = 0, a = arity(); i < a; i++)
667 buf.append(parameterType(i).basicTypeChar());
668 return buf.append('_').append(returnType().basicTypeChar()).toString();
669 }
670 static int signatureArity(String sig) {
671 assert(isValidSignature(sig));
672 return sig.indexOf('_');
673 }
674 static BasicType signatureReturn(String sig) {
675 return basicType(sig.charAt(signatureArity(sig) + 1));
676 }
677 static boolean isValidSignature(String sig) {
678 int arity = sig.indexOf('_');
679 if (arity < 0) return false; // must be of the form *_*
680 int siglen = sig.length();
681 if (siglen != arity + 2) return false; // *_X
682 for (int i = 0; i < siglen; i++) {
683 if (i == arity) continue; // skip '_'
684 char c = sig.charAt(i);
685 if (c == 'V')
686 return (i == siglen - 1 && arity == siglen - 2);
687 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
688 }
689 return true; // [LIJFD]*_[LIJFDV]
690 }
691 static MethodType signatureType(String sig) {
692 Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
693 for (int i = 0; i < ptypes.length; i++)
694 ptypes[i] = basicType(sig.charAt(i)).btClass;
695 Class<?> rtype = signatureReturn(sig).btClass;
696 return MethodType.makeImpl(rtype, ptypes, true);
697 }
698 static MethodType basicMethodType(MethodType mt) {
699 return signatureType(basicTypeSignature(mt));
700 }
701
702 /**
703 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
704 */
705 boolean isSelectAlternative(int pos) {
706 // selectAlternative idiom:
707 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
708 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
709 if (pos+1 >= names.length) return false;
710 Name name0 = names[pos];
711 Name name1 = names[pos+1];
712 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
713 name1.isInvokeBasic() &&
714 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
715 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
716 }
717
718 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
719 if (pos+2 >= names.length) return false;
720 Name name0 = names[pos];
721 Name name1 = names[pos+1];
722 Name name2 = names[pos+2];
723 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
724 name0.isInvokeBasic() &&
725 name2.isInvokeBasic() &&
726 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
727 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
728 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
729 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
730 }
731
732 /**
733 * Check if i-th name is a start of GuardWithCatch idiom.
734 */
735 boolean isGuardWithCatch(int pos) {
736 // GuardWithCatch idiom:
737 // t_{n}:L=MethodHandle.invokeBasic(...)
738 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
739 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
740 return isMatchingIdiom(pos, "guardWithCatch", 3);
741 }
742
743 /**
744 * Check if i-th name is a start of the tryFinally idiom.
745 */
746 boolean isTryFinally(int pos) {
747 // tryFinally idiom:
748 // t_{n}:L=MethodHandle.invokeBasic(...)
749 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
750 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
751 return isMatchingIdiom(pos, "tryFinally", 2);
752 }
753
754 /**
755 * Check if i-th name is a start of the loop idiom.
756 */
757 boolean isLoop(int pos) {
758 // loop idiom:
759 // t_{n}:L=MethodHandle.invokeBasic(...)
760 // t_{n+1}:L=MethodHandleImpl.loop(types, *, t_{n})
761 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
762 return isMatchingIdiom(pos, "loop", 2);
763 }
764
765 /*
766 * Code generation issues:
767 *
768 * Compiled LFs should be reusable in general.
769 * The biggest issue is how to decide when to pull a name into
770 * the bytecode, versus loading a reified form from the MH data.
771 *
772 * For example, an asType wrapper may require execution of a cast
773 * after a call to a MH. The target type of the cast can be placed
774 * as a constant in the LF itself. This will force the cast type
775 * to be compiled into the bytecodes and native code for the MH.
776 * Or, the target type of the cast can be erased in the LF, and
777 * loaded from the MH data. (Later on, if the MH as a whole is
778 * inlined, the data will flow into the inlined instance of the LF,
779 * as a constant, and the end result will be an optimal cast.)
780 *
781 * This erasure of cast types can be done with any use of
782 * reference types. It can also be done with whole method
783 * handles. Erasing a method handle might leave behind
784 * LF code that executes correctly for any MH of a given
785 * type, and load the required MH from the enclosing MH's data.
786 * Or, the erasure might even erase the expected MT.
787 *
788 * Also, for direct MHs, the MemberName of the target
789 * could be erased, and loaded from the containing direct MH.
790 * As a simple case, a LF for all int-valued non-static
791 * field getters would perform a cast on its input argument
792 * (to non-constant base type derived from the MemberName)
793 * and load an integer value from the input object
794 * (at a non-constant offset also derived from the MemberName).
795 * Such MN-erased LFs would be inlinable back to optimized
796 * code, whenever a constant enclosing DMH is available
797 * to supply a constant MN from its data.
798 *
799 * The main problem here is to keep LFs reasonably generic,
800 * while ensuring that hot spots will inline good instances.
801 * "Reasonably generic" means that we don't end up with
802 * repeated versions of bytecode or machine code that do
803 * not differ in their optimized form. Repeated versions
804 * of machine would have the undesirable overheads of
805 * (a) redundant compilation work and (b) extra I$ pressure.
806 * To control repeated versions, we need to be ready to
807 * erase details from LFs and move them into MH data,
808 * whevener those details are not relevant to significant
809 * optimization. "Significant" means optimization of
810 * code that is actually hot.
811 *
812 * Achieving this may require dynamic splitting of MHs, by replacing
813 * a generic LF with a more specialized one, on the same MH,
814 * if (a) the MH is frequently executed and (b) the MH cannot
815 * be inlined into a containing caller, such as an invokedynamic.
816 *
817 * Compiled LFs that are no longer used should be GC-able.
818 * If they contain non-BCP references, they should be properly
819 * interlinked with the class loader(s) that their embedded types
820 * depend on. This probably means that reusable compiled LFs
821 * will be tabulated (indexed) on relevant class loaders,
822 * or else that the tables that cache them will have weak links.
823 */
824
825 /**
826 * Make this LF directly executable, as part of a MethodHandle.
827 * Invariant: Every MH which is invoked must prepare its LF
828 * before invocation.
829 * (In principle, the JVM could do this very lazily,
830 * as a sort of pre-invocation linkage step.)
831 */
832 public void prepare() {
833 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
834 compileToBytecode();
835 }
836 if (this.vmentry != null) {
837 // already prepared (e.g., a primitive DMH invoker form)
838 return;
839 }
840 MethodType mtype = methodType();
841 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
842 if (prep == null) {
843 assert (isValidSignature(basicTypeSignature()));
844 prep = new LambdaForm(mtype);
845 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
846 prep = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
847 }
848 this.vmentry = prep.vmentry;
849 // TO DO: Maybe add invokeGeneric, invokeWithArguments
850 }
851
852 private static @Stable PerfCounter LF_FAILED;
853
854 private static PerfCounter failedCompilationCounter() {
855 if (LF_FAILED == null) {
856 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
857 }
858 return LF_FAILED;
859 }
860
861 /** Generate optimizable bytecode for this form. */
862 void compileToBytecode() {
863 if (forceInterpretation()) {
864 return; // this should not be compiled
865 }
866 if (vmentry != null && isCompiled) {
867 return; // already compiled somehow
868 }
869
870 // Obtain the invoker MethodType outside of the following try block.
871 // This ensures that an IllegalArgumentException is directly thrown if the
872 // type would have 256 or more parameters
873 MethodType invokerType = methodType();
874 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
875 try {
876 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
877 if (TRACE_INTERPRETER)
878 traceInterpreter("compileToBytecode", this);
879 isCompiled = true;
880 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
881 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
882 invocationCounter = -1;
883 failedCompilationCounter().increment();
884 if (LOG_LF_COMPILATION_FAILURE) {
885 System.out.println("LambdaForm compilation failed: " + this);
886 bge.printStackTrace(System.out);
887 }
888 } catch (Error e) {
889 // Pass through any error
890 throw e;
891 } catch (Exception e) {
892 // Wrap any exception
893 throw newInternalError(this.toString(), e);
894 }
895 }
896
897 // The next few routines are called only from assert expressions
898 // They verify that the built-in invokers process the correct raw data types.
899 private static boolean argumentTypesMatch(String sig, Object[] av) {
900 int arity = signatureArity(sig);
901 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
902 assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
903 MethodHandle mh = (MethodHandle) av[0];
904 MethodType mt = mh.type();
905 assert(mt.parameterCount() == arity-1);
906 for (int i = 0; i < av.length; i++) {
907 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
908 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
909 }
910 return true;
911 }
912 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
913 // The following line is needed because (...)void method handles can use non-void invokers
914 if (type == void.class) tc = V_TYPE; // can drop any kind of value
915 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
916 switch (tc) {
917 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
918 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
919 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
920 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
921 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
922 case V_TYPE: break; // allow anything here; will be dropped
923 default: assert(false);
924 }
925 return true;
926 }
927 private static boolean checkInt(Class<?> type, Object x) {
928 assert(x instanceof Integer);
929 if (type == int.class) return true;
930 Wrapper w = Wrapper.forBasicType(type);
931 assert(w.isSubwordOrInt());
932 Object x1 = Wrapper.INT.wrap(w.wrap(x));
933 return x.equals(x1);
934 }
935 private static boolean checkRef(Class<?> type, Object x) {
936 assert(!type.isPrimitive());
937 if (x == null) return true;
938 if (type.isInterface()) return true;
939 return type.isInstance(x);
940 }
941
942 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
943 private static final int COMPILE_THRESHOLD;
944 static {
945 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
946 }
947 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
948
949 private boolean forceInterpretation() {
950 return invocationCounter == -1;
951 }
952
953 @Hidden
954 @DontInline
955 /** Interpretively invoke this form on the given arguments. */
956 Object interpretWithArguments(Object... argumentValues) throws Throwable {
957 if (TRACE_INTERPRETER)
958 return interpretWithArgumentsTracing(argumentValues);
959 checkInvocationCounter();
960 assert(arityCheck(argumentValues));
961 Object[] values = Arrays.copyOf(argumentValues, names.length);
962 for (int i = argumentValues.length; i < values.length; i++) {
963 values[i] = interpretName(names[i], values);
964 }
965 Object rv = (result < 0) ? null : values[result];
966 assert(resultCheck(argumentValues, rv));
967 return rv;
968 }
969
970 @Hidden
971 @DontInline
972 /** Evaluate a single Name within this form, applying its function to its arguments. */
973 Object interpretName(Name name, Object[] values) throws Throwable {
974 if (TRACE_INTERPRETER)
975 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
976 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
977 for (int i = 0; i < arguments.length; i++) {
978 Object a = arguments[i];
979 if (a instanceof Name) {
980 int i2 = ((Name)a).index();
981 assert(names[i2] == a);
982 a = values[i2];
983 arguments[i] = a;
984 }
985 }
986 return name.function.invokeWithArguments(arguments);
987 }
988
989 private void checkInvocationCounter() {
990 if (COMPILE_THRESHOLD != 0 &&
991 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
992 invocationCounter++; // benign race
993 if (invocationCounter >= COMPILE_THRESHOLD) {
994 // Replace vmentry with a bytecode version of this LF.
995 compileToBytecode();
996 }
997 }
998 }
999 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
1000 traceInterpreter("[ interpretWithArguments", this, argumentValues);
1001 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
1002 int ctr = invocationCounter++; // benign race
1003 traceInterpreter("| invocationCounter", ctr);
1004 if (invocationCounter >= COMPILE_THRESHOLD) {
1005 compileToBytecode();
1006 }
1007 }
1008 Object rval;
1009 try {
1010 assert(arityCheck(argumentValues));
1011 Object[] values = Arrays.copyOf(argumentValues, names.length);
1012 for (int i = argumentValues.length; i < values.length; i++) {
1013 values[i] = interpretName(names[i], values);
1014 }
1015 rval = (result < 0) ? null : values[result];
1016 } catch (Throwable ex) {
1017 traceInterpreter("] throw =>", ex);
1018 throw ex;
1019 }
1020 traceInterpreter("] return =>", rval);
1021 return rval;
1022 }
1023
1024 static void traceInterpreter(String event, Object obj, Object... args) {
1025 if (TRACE_INTERPRETER) {
1026 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
1027 }
1028 }
1029 static void traceInterpreter(String event, Object obj) {
1030 traceInterpreter(event, obj, (Object[])null);
1031 }
1032 private boolean arityCheck(Object[] argumentValues) {
1033 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
1034 // also check that the leading (receiver) argument is somehow bound to this LF:
1035 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
1036 MethodHandle mh = (MethodHandle) argumentValues[0];
1037 assert(mh.internalForm() == this);
1038 // note: argument #0 could also be an interface wrapper, in the future
1039 argumentTypesMatch(basicTypeSignature(), argumentValues);
1040 return true;
1041 }
1042 private boolean resultCheck(Object[] argumentValues, Object result) {
1043 MethodHandle mh = (MethodHandle) argumentValues[0];
1044 MethodType mt = mh.type();
1045 assert(valueMatches(returnType(), mt.returnType(), result));
1046 return true;
1047 }
1048
1049 private boolean isEmpty() {
1050 if (result < 0)
1051 return (names.length == arity);
1052 else if (result == arity && names.length == arity + 1)
1053 return names[arity].isConstantZero();
1054 else
1055 return false;
1056 }
1057
1058 public String toString() {
1059 String lambdaName = lambdaName();
1060 StringBuilder buf = new StringBuilder(lambdaName + "=Lambda(");
1061 for (int i = 0; i < names.length; i++) {
1062 if (i == arity) buf.append(")=>{");
1063 Name n = names[i];
1064 if (i >= arity) buf.append("\n ");
1065 buf.append(n.paramString());
1066 if (i < arity) {
1067 if (i+1 < arity) buf.append(",");
1068 continue;
1069 }
1070 buf.append("=").append(n.exprString());
1071 buf.append(";");
1072 }
1073 if (arity == names.length) buf.append(")=>{");
1074 buf.append(result < 0 ? "void" : names[result]).append("}");
1075 if (TRACE_INTERPRETER) {
1076 // Extra verbosity:
1077 buf.append(":").append(basicTypeSignature());
1078 buf.append("/").append(vmentry);
1079 }
1080 return buf.toString();
1081 }
1082
1083 @Override
1084 public boolean equals(Object obj) {
1085 return obj instanceof LambdaForm && equals((LambdaForm)obj);
1086 }
1087 public boolean equals(LambdaForm that) {
1088 if (this.result != that.result) return false;
1089 return Arrays.equals(this.names, that.names);
1090 }
1091 public int hashCode() {
1092 return result + 31 * Arrays.hashCode(names);
1093 }
1094 LambdaFormEditor editor() {
1095 return LambdaFormEditor.lambdaFormEditor(this);
1096 }
1097
1098 boolean contains(Name name) {
1099 int pos = name.index();
1100 if (pos >= 0) {
1101 return pos < names.length && name.equals(names[pos]);
1102 }
1103 for (int i = arity; i < names.length; i++) {
1104 if (name.equals(names[i]))
1105 return true;
1106 }
1107 return false;
1108 }
1109
1110 static class NamedFunction {
1111 final MemberName member;
1112 private @Stable MethodHandle resolvedHandle;
1113 @Stable MethodHandle invoker;
1114 private final MethodHandleImpl.Intrinsic intrinsicName;
1115
1116 NamedFunction(MethodHandle resolvedHandle) {
1117 this(resolvedHandle.internalMemberName(), resolvedHandle, MethodHandleImpl.Intrinsic.NONE);
1118 }
1119 NamedFunction(MethodHandle resolvedHandle, MethodHandleImpl.Intrinsic intrinsic) {
1120 this(resolvedHandle.internalMemberName(), resolvedHandle, intrinsic);
1121 }
1122 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1123 this(member, resolvedHandle, MethodHandleImpl.Intrinsic.NONE);
1124 }
1125 NamedFunction(MemberName member, MethodHandle resolvedHandle, MethodHandleImpl.Intrinsic intrinsic) {
1126 this.member = member;
1127 this.resolvedHandle = resolvedHandle;
1128 this.intrinsicName = intrinsic;
1129 assert(resolvedHandle == null ||
1130 resolvedHandle.intrinsicName() == MethodHandleImpl.Intrinsic.NONE ||
1131 resolvedHandle.intrinsicName() == intrinsic) : resolvedHandle.intrinsicName() + " != " + intrinsic;
1132 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1133 //assert(!isInvokeBasic(member));
1134 }
1135 NamedFunction(MethodType basicInvokerType) {
1136 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1137 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1138 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1139 this.member = resolvedHandle.internalMemberName();
1140 } else {
1141 // necessary to pass BigArityTest
1142 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1143 }
1144 this.intrinsicName = MethodHandleImpl.Intrinsic.NONE;
1145 assert(isInvokeBasic(member));
1146 }
1147
1148 private static boolean isInvokeBasic(MemberName member) {
1149 return member != null &&
1150 member.getDeclaringClass() == MethodHandle.class &&
1151 "invokeBasic".equals(member.getName());
1152 }
1153
1154 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1155 // Any LambdaForm containing such a member is not interpretable.
1156 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1157 // And even without the resolvedHandle, the name can still be compiled and optimized.
1158 NamedFunction(Method method) {
1159 this(new MemberName(method));
1160 }
1161 NamedFunction(MemberName member) {
1162 this(member, null);
1163 }
1164
1165 MethodHandle resolvedHandle() {
1166 if (resolvedHandle == null) resolve();
1167 return resolvedHandle;
1168 }
1169
1170 synchronized void resolve() {
1171 if (resolvedHandle == null) {
1172 resolvedHandle = DirectMethodHandle.make(member);
1173 }
1174 }
1175
1176 @Override
1177 public boolean equals(Object other) {
1178 if (this == other) return true;
1179 if (other == null) return false;
1180 if (!(other instanceof NamedFunction)) return false;
1181 NamedFunction that = (NamedFunction) other;
1182 return this.member != null && this.member.equals(that.member);
1183 }
1184
1185 @Override
1186 public int hashCode() {
1187 if (member != null)
1188 return member.hashCode();
1189 return super.hashCode();
1190 }
1191
1192 static final MethodType INVOKER_METHOD_TYPE =
1193 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1194
1195 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1196 typeForm = typeForm.basicType().form(); // normalize to basic type
1197 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1198 if (mh != null) return mh;
1199 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1200 mh = DirectMethodHandle.make(invoker);
1201 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1202 if (mh2 != null) return mh2; // benign race
1203 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1204 throw newInternalError(mh.debugString());
1205 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1206 }
1207
1208 @Hidden
1209 Object invokeWithArguments(Object... arguments) throws Throwable {
1210 // If we have a cached invoker, call it right away.
1211 // NOTE: The invoker always returns a reference value.
1212 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1213 return invoker().invokeBasic(resolvedHandle(), arguments);
1214 }
1215
1216 @Hidden
1217 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1218 Object rval;
1219 try {
1220 traceInterpreter("[ call", this, arguments);
1221 if (invoker == null) {
1222 traceInterpreter("| getInvoker", this);
1223 invoker();
1224 }
1225 // resolvedHandle might be uninitialized, ok for tracing
1226 if (resolvedHandle == null) {
1227 traceInterpreter("| resolve", this);
1228 resolvedHandle();
1229 }
1230 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1231 } catch (Throwable ex) {
1232 traceInterpreter("] throw =>", ex);
1233 throw ex;
1234 }
1235 traceInterpreter("] return =>", rval);
1236 return rval;
1237 }
1238
1239 private MethodHandle invoker() {
1240 if (invoker != null) return invoker;
1241 // Get an invoker and cache it.
1242 return invoker = computeInvoker(methodType().form());
1243 }
1244
1245 MethodType methodType() {
1246 if (resolvedHandle != null)
1247 return resolvedHandle.type();
1248 else
1249 // only for certain internal LFs during bootstrapping
1250 return member.getInvocationType();
1251 }
1252
1253 MemberName member() {
1254 assert(assertMemberIsConsistent());
1255 return member;
1256 }
1257
1258 // Called only from assert.
1259 private boolean assertMemberIsConsistent() {
1260 if (resolvedHandle instanceof DirectMethodHandle) {
1261 MemberName m = resolvedHandle.internalMemberName();
1262 assert(m.equals(member));
1263 }
1264 return true;
1265 }
1266
1267 Class<?> memberDeclaringClassOrNull() {
1268 return (member == null) ? null : member.getDeclaringClass();
1269 }
1270
1271 BasicType returnType() {
1272 return basicType(methodType().returnType());
1273 }
1274
1275 BasicType parameterType(int n) {
1276 return basicType(methodType().parameterType(n));
1277 }
1278
1279 int arity() {
1280 return methodType().parameterCount();
1281 }
1282
1283 public String toString() {
1284 if (member == null) return String.valueOf(resolvedHandle);
1285 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1286 }
1287
1288 public boolean isIdentity() {
1289 return this.equals(identity(returnType()));
1290 }
1291
1292 public boolean isConstantZero() {
1293 return this.equals(constantZero(returnType()));
1294 }
1295
1296 public MethodHandleImpl.Intrinsic intrinsicName() {
1297 return intrinsicName;
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.substring(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 Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1364 this.index = (short)index;
1365 this.type = type;
1366 this.function = function;
1367 this.arguments = arguments;
1368 this.constraint = null;
1369 assert(this.index == index);
1370 }
1371 private Name(Name that, Object constraint) {
1372 this.index = that.index;
1373 this.type = that.type;
1374 this.function = that.function;
1375 this.arguments = that.arguments;
1376 this.constraint = constraint;
1377 assert(constraint == null || isParam()); // only params have constraints
1378 assert(constraint == null || constraint instanceof ClassSpecializer.SpeciesData || constraint instanceof Class);
1379 }
1380 Name(MethodHandle function, Object... arguments) {
1381 this(new NamedFunction(function), arguments);
1382 }
1383 Name(MethodType functionType, Object... arguments) {
1384 this(new NamedFunction(functionType), arguments);
1385 assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == L_TYPE);
1386 }
1387 Name(MemberName function, Object... arguments) {
1388 this(new NamedFunction(function), arguments);
1389 }
1390 Name(NamedFunction function, Object... arguments) {
1391 this(-1, function.returnType(), function, arguments = Arrays.copyOf(arguments, arguments.length, Object[].class));
1392 assert(typesMatch(function, arguments));
1393 }
1394 /** Create a raw parameter of the given type, with an expected index. */
1395 Name(int index, BasicType type) {
1396 this(index, type, null, null);
1397 }
1398 /** Create a raw parameter of the given type. */
1399 Name(BasicType type) { this(-1, type); }
1400
1401 BasicType type() { return type; }
1402 int index() { return index; }
1403 boolean initIndex(int i) {
1404 if (index != i) {
1405 if (index != -1) return false;
1406 index = (short)i;
1407 }
1408 return true;
1409 }
1410 char typeChar() {
1411 return type.btChar;
1412 }
1413
1414 void resolve() {
1415 if (function != null)
1416 function.resolve();
1417 }
1418
1419 Name newIndex(int i) {
1420 if (initIndex(i)) return this;
1421 return cloneWithIndex(i);
1422 }
1423 Name cloneWithIndex(int i) {
1424 Object[] newArguments = (arguments == null) ? null : arguments.clone();
1425 return new Name(i, type, function, newArguments).withConstraint(constraint);
1426 }
1427 Name withConstraint(Object constraint) {
1428 if (constraint == this.constraint) return this;
1429 return new Name(this, constraint);
1430 }
1431 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1432 if (oldName == newName) return this;
1433 @SuppressWarnings("LocalVariableHidesMemberVariable")
1434 Object[] arguments = this.arguments;
1435 if (arguments == null) return this;
1436 boolean replaced = false;
1437 for (int j = 0; j < arguments.length; j++) {
1438 if (arguments[j] == oldName) {
1439 if (!replaced) {
1440 replaced = true;
1441 arguments = arguments.clone();
1442 }
1443 arguments[j] = newName;
1444 }
1445 }
1446 if (!replaced) return this;
1447 return new Name(function, arguments);
1448 }
1449 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1450 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1451 */
1452 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1453 if (start >= end) return this;
1454 @SuppressWarnings("LocalVariableHidesMemberVariable")
1455 Object[] arguments = this.arguments;
1456 boolean replaced = false;
1457 eachArg:
1458 for (int j = 0; j < arguments.length; j++) {
1459 if (arguments[j] instanceof Name) {
1460 Name n = (Name) arguments[j];
1461 int check = n.index;
1462 // harmless check to see if the thing is already in newNames:
1463 if (check >= 0 && check < newNames.length && n == newNames[check])
1464 continue eachArg;
1465 // n might not have the correct index: n != oldNames[n.index].
1466 for (int i = start; i < end; i++) {
1467 if (n == oldNames[i]) {
1468 if (n == newNames[i])
1469 continue eachArg;
1470 if (!replaced) {
1471 replaced = true;
1472 arguments = arguments.clone();
1473 }
1474 arguments[j] = newNames[i];
1475 continue eachArg;
1476 }
1477 }
1478 }
1479 }
1480 if (!replaced) return this;
1481 return new Name(function, arguments);
1482 }
1483 void internArguments() {
1484 @SuppressWarnings("LocalVariableHidesMemberVariable")
1485 Object[] arguments = this.arguments;
1486 for (int j = 0; j < arguments.length; j++) {
1487 if (arguments[j] instanceof Name) {
1488 Name n = (Name) arguments[j];
1489 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1490 arguments[j] = internArgument(n);
1491 }
1492 }
1493 }
1494 boolean isParam() {
1495 return function == null;
1496 }
1497 boolean isConstantZero() {
1498 return !isParam() && arguments.length == 0 && function.isConstantZero();
1499 }
1500
1501 boolean refersTo(Class<?> declaringClass, String methodName) {
1502 return function != null &&
1503 function.member() != null && function.member().refersTo(declaringClass, methodName);
1504 }
1505
1506 /**
1507 * Check if MemberName is a call to MethodHandle.invokeBasic.
1508 */
1509 boolean isInvokeBasic() {
1510 if (function == null)
1511 return false;
1512 if (arguments.length < 1)
1513 return false; // must have MH argument
1514 MemberName member = function.member();
1515 return member != null && member.refersTo(MethodHandle.class, "invokeBasic") &&
1516 !member.isPublic() && !member.isStatic();
1517 }
1518
1519 /**
1520 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1521 */
1522 boolean isLinkerMethodInvoke() {
1523 if (function == null)
1524 return false;
1525 if (arguments.length < 1)
1526 return false; // must have MH argument
1527 MemberName member = function.member();
1528 return member != null &&
1529 member.getDeclaringClass() == MethodHandle.class &&
1530 !member.isPublic() && member.isStatic() &&
1531 member.getName().startsWith("linkTo");
1532 }
1533
1534 public String toString() {
1535 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1536 }
1537 public String debugString() {
1538 String s = paramString();
1539 return (function == null) ? s : s + "=" + exprString();
1540 }
1541 public String paramString() {
1542 String s = toString();
1543 Object c = constraint;
1544 if (c == null)
1545 return s;
1546 if (c instanceof Class) c = ((Class<?>)c).getSimpleName();
1547 return s + "/" + c;
1548 }
1549 public String exprString() {
1550 if (function == null) return toString();
1551 StringBuilder buf = new StringBuilder(function.toString());
1552 buf.append("(");
1553 String cma = "";
1554 for (Object a : arguments) {
1555 buf.append(cma); cma = ",";
1556 if (a instanceof Name || a instanceof Integer)
1557 buf.append(a);
1558 else
1559 buf.append("(").append(a).append(")");
1560 }
1561 buf.append(")");
1562 return buf.toString();
1563 }
1564
1565 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1566 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1567 for (int i = 0; i < arguments.length; i++) {
1568 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1569 }
1570 return true;
1571 }
1572
1573 private static boolean typesMatch(BasicType parameterType, Object object) {
1574 if (object instanceof Name) {
1575 return ((Name)object).type == parameterType;
1576 }
1577 switch (parameterType) {
1578 case I_TYPE: return object instanceof Integer;
1579 case J_TYPE: return object instanceof Long;
1580 case F_TYPE: return object instanceof Float;
1581 case D_TYPE: return object instanceof Double;
1582 }
1583 assert(parameterType == L_TYPE);
1584 return true;
1585 }
1586
1587 /** Return the index of the last occurrence of n in the argument array.
1588 * Return -1 if the name is not used.
1589 */
1590 int lastUseIndex(Name n) {
1591 if (arguments == null) return -1;
1592 for (int i = arguments.length; --i >= 0; ) {
1593 if (arguments[i] == n) return i;
1594 }
1595 return -1;
1596 }
1597
1598 /** Return the number of occurrences of n in the argument array.
1599 * Return 0 if the name is not used.
1600 */
1601 int useCount(Name n) {
1602 if (arguments == null) return 0;
1603 int count = 0;
1604 for (int i = arguments.length; --i >= 0; ) {
1605 if (arguments[i] == n) ++count;
1606 }
1607 return count;
1608 }
1609
1610 boolean contains(Name n) {
1611 return this == n || lastUseIndex(n) >= 0;
1612 }
1613
1614 public boolean equals(Name that) {
1615 if (this == that) return true;
1616 if (isParam())
1617 // each parameter is a unique atom
1618 return false; // this != that
1619 return
1620 //this.index == that.index &&
1621 this.type == that.type &&
1622 this.function.equals(that.function) &&
1623 Arrays.equals(this.arguments, that.arguments);
1624 }
1625 @Override
1626 public boolean equals(Object x) {
1627 return x instanceof Name && equals((Name)x);
1628 }
1629 @Override
1630 public int hashCode() {
1631 if (isParam())
1632 return index | (type.ordinal() << 8);
1633 return function.hashCode() ^ Arrays.hashCode(arguments);
1634 }
1635 }
1636
1637 /** Return the index of the last name which contains n as an argument.
1638 * Return -1 if the name is not used. Return names.length if it is the return value.
1639 */
1640 int lastUseIndex(Name n) {
1641 int ni = n.index, nmax = names.length;
1642 assert(names[ni] == n);
1643 if (result == ni) return nmax; // live all the way beyond the end
1644 for (int i = nmax; --i > ni; ) {
1645 if (names[i].lastUseIndex(n) >= 0)
1646 return i;
1647 }
1648 return -1;
1649 }
1650
1651 /** Return the number of times n is used as an argument or return value. */
1652 int useCount(Name n) {
1653 int nmax = names.length;
1654 int end = lastUseIndex(n);
1655 if (end < 0) return 0;
1656 int count = 0;
1657 if (end == nmax) { count++; end--; }
1658 int beg = n.index() + 1;
1659 if (beg < arity) beg = arity;
1660 for (int i = beg; i <= end; i++) {
1661 count += names[i].useCount(n);
1662 }
1663 return count;
1664 }
1665
1666 static Name argument(int which, BasicType type) {
1667 if (which >= INTERNED_ARGUMENT_LIMIT)
1668 return new Name(which, type);
1669 return INTERNED_ARGUMENTS[type.ordinal()][which];
1670 }
1671 static Name internArgument(Name n) {
1672 assert(n.isParam()) : "not param: " + n;
1673 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1674 if (n.constraint != null) return n;
1675 return argument(n.index, n.type);
1676 }
1677 static Name[] arguments(int extra, MethodType types) {
1678 int length = types.parameterCount();
1679 Name[] names = new Name[length + extra];
1680 for (int i = 0; i < length; i++)
1681 names[i] = argument(i, basicType(types.parameterType(i)));
1682 return names;
1683 }
1684 static final int INTERNED_ARGUMENT_LIMIT = 10;
1685 private static final Name[][] INTERNED_ARGUMENTS
1686 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1687 static {
1688 for (BasicType type : BasicType.ARG_TYPES) {
1689 int ord = type.ordinal();
1690 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1691 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1692 }
1693 }
1694 }
1695
1696 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1697
1698 static LambdaForm identityForm(BasicType type) {
1699 int ord = type.ordinal();
1700 LambdaForm form = LF_identity[ord];
1701 if (form != null) {
1702 return form;
1703 }
1704 createFormsFor(type);
1705 return LF_identity[ord];
1706 }
1707
1708 static LambdaForm zeroForm(BasicType type) {
1709 int ord = type.ordinal();
1710 LambdaForm form = LF_zero[ord];
1711 if (form != null) {
1712 return form;
1713 }
1714 createFormsFor(type);
1715 return LF_zero[ord];
1716 }
1717
1718 static NamedFunction identity(BasicType type) {
1719 int ord = type.ordinal();
1720 NamedFunction function = NF_identity[ord];
1721 if (function != null) {
1722 return function;
1723 }
1724 createFormsFor(type);
1725 return NF_identity[ord];
1726 }
1727
1728 static NamedFunction constantZero(BasicType type) {
1729 int ord = type.ordinal();
1730 NamedFunction function = NF_zero[ord];
1731 if (function != null) {
1732 return function;
1733 }
1734 createFormsFor(type);
1735 return NF_zero[ord];
1736 }
1737
1738 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1739 private static final @Stable LambdaForm[] LF_zero = new LambdaForm[TYPE_LIMIT];
1740 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1741 private static final @Stable NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1742
1743 private static final Object createFormsLock = new Object();
1744 private static void createFormsFor(BasicType type) {
1745 // Avoid racy initialization during bootstrap
1746 UNSAFE.ensureClassInitialized(BoundMethodHandle.class);
1747 synchronized (createFormsLock) {
1748 final int ord = type.ordinal();
1749 LambdaForm idForm = LF_identity[ord];
1750 if (idForm != null) {
1751 return;
1752 }
1753 char btChar = type.basicTypeChar();
1754 boolean isVoid = (type == V_TYPE);
1755 Class<?> btClass = type.btClass;
1756 MethodType zeType = MethodType.methodType(btClass);
1757 MethodType idType = (isVoid) ? zeType : MethodType.methodType(btClass, btClass);
1758
1759 // Look up symbolic names. It might not be necessary to have these,
1760 // but if we need to emit direct references to bytecodes, it helps.
1761 // Zero is built from a call to an identity function with a constant zero input.
1762 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1763 MemberName zeMem = null;
1764 try {
1765 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, NoSuchMethodException.class);
1766 if (!isVoid) {
1767 zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1768 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, NoSuchMethodException.class);
1769 }
1770 } catch (IllegalAccessException|NoSuchMethodException ex) {
1771 throw newInternalError(ex);
1772 }
1773
1774 NamedFunction idFun;
1775 LambdaForm zeForm;
1776 NamedFunction zeFun;
1777
1778 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1779 // bootstrap dependency on this method in case we're interpreting LFs
1780 if (isVoid) {
1781 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1782 idForm = new LambdaForm(1, idNames, VOID_RESULT, Kind.IDENTITY);
1783 idForm.compileToBytecode();
1784 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1785
1786 zeForm = idForm;
1787 zeFun = idFun;
1788 } else {
1789 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1790 idForm = new LambdaForm(2, idNames, 1, Kind.IDENTITY);
1791 idForm.compileToBytecode();
1792 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm),
1793 MethodHandleImpl.Intrinsic.IDENTITY);
1794
1795 Object zeValue = Wrapper.forBasicType(btChar).zero();
1796 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1797 zeForm = new LambdaForm(1, zeNames, 1, Kind.ZERO);
1798 zeForm.compileToBytecode();
1799 zeFun = new NamedFunction(zeMem, SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm),
1800 MethodHandleImpl.Intrinsic.ZERO);
1801 }
1802
1803 LF_zero[ord] = zeForm;
1804 NF_zero[ord] = zeFun;
1805 LF_identity[ord] = idForm;
1806 NF_identity[ord] = idFun;
1807
1808 assert(idFun.isIdentity());
1809 assert(zeFun.isConstantZero());
1810 assert(new Name(zeFun).isConstantZero());
1811 }
1812 }
1813
1814 // Avoid appealing to ValueConversions at bootstrap time:
1815 private static int identity_I(int x) { return x; }
1816 private static long identity_J(long x) { return x; }
1817 private static float identity_F(float x) { return x; }
1818 private static double identity_D(double x) { return x; }
1819 private static Object identity_L(Object x) { return x; }
1820 private static void identity_V() { return; }
1821 private static int zero_I() { return 0; }
1822 private static long zero_J() { return 0; }
1823 private static float zero_F() { return 0; }
1824 private static double zero_D() { return 0; }
1825 private static Object zero_L() { return null; }
1826
1827 /**
1828 * Internal marker for byte-compiled LambdaForms.
1829 */
1830 /*non-public*/
1831 @Target(ElementType.METHOD)
1832 @Retention(RetentionPolicy.RUNTIME)
1833 @interface Compiled {
1834 }
1835
1836 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1837 private static final HashMap<LambdaForm,String> DEBUG_NAMES;
1838 static {
1839 if (debugEnabled()) {
1840 DEBUG_NAME_COUNTERS = new HashMap<>();
1841 DEBUG_NAMES = new HashMap<>();
1842 } else {
1843 DEBUG_NAME_COUNTERS = null;
1844 DEBUG_NAMES = null;
1845 }
1846 }
1847
1848 static {
1849 // The Holder class will contain pre-generated forms resolved
1850 // using MemberName.getFactory(). However, that doesn't initialize the
1851 // class, which subtly breaks inlining etc. By forcing
1852 // initialization of the Holder class we avoid these issues.
1853 UNSAFE.ensureClassInitialized(Holder.class);
1854 }
1855
1856 /* Placeholder class for zero and identity forms generated ahead of time */
1857 final class Holder {}
1858
1859 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1860 // during execution of the static initializes of this class.
1861 // Turning on TRACE_INTERPRETER too early will cause
1862 // stack overflows and other misbehavior during attempts to trace events
1863 // that occur during LambdaForm.<clinit>.
1864 // Therefore, do not move this line higher in this file, and do not remove.
1865 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1866 }