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.Stable;
31 import sun.invoke.util.Wrapper;
32
33 import java.lang.annotation.ElementType;
34 import java.lang.annotation.Retention;
35 import java.lang.annotation.RetentionPolicy;
36 import java.lang.annotation.Target;
37 import java.lang.reflect.Method;
38 import java.util.Arrays;
39 import java.util.HashMap;
40
41 import static java.lang.invoke.LambdaForm.BasicType.*;
42 import static java.lang.invoke.MethodHandleNatives.Constants.REF_invokeStatic;
43 import static java.lang.invoke.MethodHandleStatics.*;
44
45 /**
46 * The symbolic, non-executable form of a method handle's invocation semantics.
47 * It consists of a series of names.
48 * The first N (N=arity) names are parameters,
49 * while any remaining names are temporary values.
50 * Each temporary specifies the application of a function to some arguments.
51 * The functions are method handles, while the arguments are mixes of
52 * constant values and local names.
53 * The result of the lambda is defined as one of the names, often the last one.
54 * <p>
55 * Here is an approximate grammar:
56 * <blockquote><pre>{@code
57 * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
58 * ArgName = "a" N ":" T
59 * TempName = "t" N ":" T "=" Function "(" Argument* ");"
60 * Function = ConstantValue
61 * Argument = NameRef | ConstantValue
62 * Result = NameRef | "void"
63 * NameRef = "a" N | "t" N
64 * N = (any whole number)
65 * T = "L" | "I" | "J" | "F" | "D" | "V"
66 * }</pre></blockquote>
67 * Names are numbered consecutively from left to right starting at zero.
68 * (The letters are merely a taste of syntax sugar.)
69 * Thus, the first temporary (if any) is always numbered N (where N=arity).
70 * Every occurrence of a name reference in an argument list must refer to
71 * a name previously defined within the same lambda.
72 * A lambda has a void result if and only if its result index is -1.
73 * If a temporary has the type "V", it cannot be the subject of a NameRef,
74 * even though possesses a number.
75 * Note that all reference types are erased to "L", which stands for {@code Object}.
76 * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
77 * The other types stand for the usual primitive types.
78 * <p>
79 * Function invocation closely follows the static rules of the Java verifier.
80 * Arguments and return values must exactly match when their "Name" types are
81 * considered.
82 * Conversions are allowed only if they do not change the erased type.
83 * <ul>
84 * <li>L = Object: casts are used freely to convert into and out of reference types
85 * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
86 * <li>J = long: no implicit conversions
87 * <li>F = float: no implicit conversions
88 * <li>D = double: no implicit conversions
89 * <li>V = void: a function result may be void if and only if its Name is of type "V"
90 * </ul>
91 * Although implicit conversions are not allowed, explicit ones can easily be
92 * encoded by using temporary expressions which call type-transformed identity functions.
93 * <p>
94 * Examples:
95 * <blockquote><pre>{@code
96 * (a0:J)=>{ a0 }
97 * == identity(long)
98 * (a0:I)=>{ t1:V = System.out#println(a0); void }
99 * == System.out#println(int)
100 * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
101 * == identity, with printing side-effect
102 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
103 * t3:L = BoundMethodHandle#target(a0);
104 * t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
105 * == general invoker for unary insertArgument combination
106 * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
107 * t3:L = MethodHandle#invoke(t2, a1);
108 * t4:L = FilterMethodHandle#target(a0);
109 * t5:L = MethodHandle#invoke(t4, t3); t5 }
110 * == general invoker for unary filterArgument combination
111 * (a0:L, a1:L)=>{ ...(same as previous example)...
112 * t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
113 * == general invoker for unary/unary foldArgument combination
114 * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
115 * == invoker for identity method handle which performs i2l
116 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
117 * t3:L = Class#cast(t2,a1); t3 }
118 * == invoker for identity method handle which performs cast
119 * }</pre></blockquote>
120 * <p>
121 * @author John Rose, JSR 292 EG
122 */
123 class LambdaForm {
124 final int arity;
125 final int result;
126 final boolean forceInline;
127 final MethodHandle customized;
128 @Stable final Name[] names;
129 final Kind kind;
130 MemberName vmentry; // low-level behavior, or null if not yet prepared
131 private boolean isCompiled;
132
133 // Either a LambdaForm cache (managed by LambdaFormEditor) or a link to uncustomized version (for customized LF)
134 volatile Object transformCache;
135
136 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
137
138 enum BasicType {
139 L_TYPE('L', Object.class, Wrapper.OBJECT), // all reference types
140 I_TYPE('I', int.class, Wrapper.INT),
141 J_TYPE('J', long.class, Wrapper.LONG),
142 F_TYPE('F', float.class, Wrapper.FLOAT),
143 D_TYPE('D', double.class, Wrapper.DOUBLE), // all primitive types
144 V_TYPE('V', void.class, Wrapper.VOID); // not valid in all contexts
145
146 static final @Stable BasicType[] ALL_TYPES = BasicType.values();
147 static final @Stable BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
148
149 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
150 static final int TYPE_LIMIT = ALL_TYPES.length;
151
152 // Derived int constants, which (unlike the enums) can be constant folded.
153 // We can remove them when JDK-8161245 is fixed.
154 static final byte
155 L_TYPE_NUM = (byte) L_TYPE.ordinal(),
156 I_TYPE_NUM = (byte) I_TYPE.ordinal(),
157 J_TYPE_NUM = (byte) J_TYPE.ordinal(),
158 F_TYPE_NUM = (byte) F_TYPE.ordinal(),
159 D_TYPE_NUM = (byte) D_TYPE.ordinal(),
160 V_TYPE_NUM = (byte) V_TYPE.ordinal();
161
162 final char btChar;
163 final Class<?> btClass;
164 final Wrapper btWrapper;
165
166 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper) {
167 this.btChar = btChar;
168 this.btClass = btClass;
169 this.btWrapper = wrapper;
170 }
171
172 char basicTypeChar() {
173 return btChar;
174 }
175 Class<?> basicTypeClass() {
176 return btClass;
177 }
178 Wrapper basicTypeWrapper() {
179 return btWrapper;
180 }
181 int basicTypeSlots() {
182 return btWrapper.stackSlots();
183 }
184
185 static BasicType basicType(byte type) {
186 return ALL_TYPES[type];
187 }
188 static BasicType basicType(char type) {
189 switch (type) {
190 case 'L': return L_TYPE;
191 case 'I': return I_TYPE;
192 case 'J': return J_TYPE;
193 case 'F': return F_TYPE;
194 case 'D': return D_TYPE;
195 case 'V': return V_TYPE;
196 // all subword types are represented as ints
197 case 'Z':
198 case 'B':
199 case 'S':
200 case 'C':
201 return I_TYPE;
202 default:
203 throw newInternalError("Unknown type char: '"+type+"'");
204 }
205 }
206 static BasicType basicType(Wrapper type) {
207 char c = type.basicTypeChar();
208 return basicType(c);
209 }
210 static BasicType basicType(Class<?> type) {
211 if (!type.isPrimitive()) return L_TYPE;
212 return basicType(Wrapper.forPrimitiveType(type));
213 }
214 static BasicType[] basicTypes(String types) {
215 BasicType[] btypes = new BasicType[types.length()];
216 for (int i = 0; i < btypes.length; i++) {
217 btypes[i] = basicType(types.charAt(i));
218 }
219 return btypes;
220 }
221 static String basicTypeDesc(BasicType[] types) {
222 if (types == null) {
223 return null;
224 }
225 if (types.length == 0) {
226 return "";
227 }
228 StringBuilder sb = new StringBuilder();
229 for (BasicType bt : types) {
230 sb.append(bt.basicTypeChar());
231 }
232 return sb.toString();
233 }
234 static int[] basicTypeOrds(BasicType[] types) {
235 if (types == null) {
236 return null;
237 }
238 int[] a = new int[types.length];
239 for(int i = 0; i < types.length; ++i) {
240 a[i] = types[i].ordinal();
241 }
242 return a;
243 }
244
245 static char basicTypeChar(Class<?> type) {
246 return basicType(type).btChar;
247 }
248
249 static byte[] basicTypesOrd(Class<?>[] types) {
250 byte[] ords = new byte[types.length];
251 for (int i = 0; i < ords.length; i++) {
252 ords[i] = (byte)basicType(types[i]).ordinal();
253 }
254 return ords;
255 }
256
257 static boolean isBasicTypeChar(char c) {
258 return "LIJFDV".indexOf(c) >= 0;
259 }
260 static boolean isArgBasicTypeChar(char c) {
261 return "LIJFD".indexOf(c) >= 0;
262 }
263
264 static { assert(checkBasicType()); }
265 private static boolean checkBasicType() {
266 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
267 assert ARG_TYPES[i].ordinal() == i;
268 assert ARG_TYPES[i] == ALL_TYPES[i];
269 }
270 for (int i = 0; i < TYPE_LIMIT; i++) {
271 assert ALL_TYPES[i].ordinal() == i;
272 }
273 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
274 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
275 return true;
276 }
277 }
278
279 enum Kind {
280 GENERIC("invoke"),
281 ZERO("zero"),
282 IDENTITY("identity"),
283 BOUND_REINVOKER("BMH.reinvoke", "reinvoke"),
284 REINVOKER("MH.reinvoke", "reinvoke"),
285 DELEGATE("MH.delegate", "delegate"),
286 EXACT_LINKER("MH.invokeExact_MT", "invokeExact_MT"),
287 EXACT_INVOKER("MH.exactInvoker", "exactInvoker"),
288 GENERIC_LINKER("MH.invoke_MT", "invoke_MT"),
289 GENERIC_INVOKER("MH.invoker", "invoker"),
290 LINK_TO_TARGET_METHOD("linkToTargetMethod"),
291 LINK_TO_CALL_SITE("linkToCallSite"),
292 DIRECT_INVOKE_VIRTUAL("DMH.invokeVirtual", "invokeVirtual"),
293 DIRECT_INVOKE_SPECIAL("DMH.invokeSpecial", "invokeSpecial"),
294 DIRECT_INVOKE_SPECIAL_IFC("DMH.invokeSpecialIFC", "invokeSpecialIFC"),
295 DIRECT_INVOKE_STATIC("DMH.invokeStatic", "invokeStatic"),
296 DIRECT_NEW_INVOKE_SPECIAL("DMH.newInvokeSpecial", "newInvokeSpecial"),
297 DIRECT_INVOKE_INTERFACE("DMH.invokeInterface", "invokeInterface"),
298 DIRECT_INVOKE_STATIC_INIT("DMH.invokeStaticInit", "invokeStaticInit"),
299 GET_REFERENCE("getObject"),
300 PUT_REFERENCE("putObject"),
301 GET_REFERENCE_VOLATILE("getObjectVolatile"),
302 PUT_REFERENCE_VOLATILE("putObjectVolatile"),
303 GET_VALUE("getValue"),
304 PUT_VALUE("putValue"),
305 GET_VALUE_VOLATILE("getValueVolatile"),
306 PUT_VALUE_VOLATILE("putValueVolatile"),
307 GET_INT("getInt"),
308 PUT_INT("putInt"),
309 GET_INT_VOLATILE("getIntVolatile"),
310 PUT_INT_VOLATILE("putIntVolatile"),
311 GET_BOOLEAN("getBoolean"),
312 PUT_BOOLEAN("putBoolean"),
313 GET_BOOLEAN_VOLATILE("getBooleanVolatile"),
314 PUT_BOOLEAN_VOLATILE("putBooleanVolatile"),
315 GET_BYTE("getByte"),
316 PUT_BYTE("putByte"),
317 GET_BYTE_VOLATILE("getByteVolatile"),
318 PUT_BYTE_VOLATILE("putByteVolatile"),
319 GET_CHAR("getChar"),
320 PUT_CHAR("putChar"),
321 GET_CHAR_VOLATILE("getCharVolatile"),
322 PUT_CHAR_VOLATILE("putCharVolatile"),
323 GET_SHORT("getShort"),
324 PUT_SHORT("putShort"),
325 GET_SHORT_VOLATILE("getShortVolatile"),
326 PUT_SHORT_VOLATILE("putShortVolatile"),
327 GET_LONG("getLong"),
328 PUT_LONG("putLong"),
329 GET_LONG_VOLATILE("getLongVolatile"),
330 PUT_LONG_VOLATILE("putLongVolatile"),
331 GET_FLOAT("getFloat"),
332 PUT_FLOAT("putFloat"),
333 GET_FLOAT_VOLATILE("getFloatVolatile"),
334 PUT_FLOAT_VOLATILE("putFloatVolatile"),
335 GET_DOUBLE("getDouble"),
336 PUT_DOUBLE("putDouble"),
337 GET_DOUBLE_VOLATILE("getDoubleVolatile"),
338 PUT_DOUBLE_VOLATILE("putDoubleVolatile"),
339 TRY_FINALLY("tryFinally"),
340 COLLECT("collect"),
341 CONVERT("convert"),
342 SPREAD("spread"),
343 LOOP("loop"),
344 FIELD("field"),
345 GUARD("guard"),
346 GUARD_WITH_CATCH("guardWithCatch"),
347 VARHANDLE_EXACT_INVOKER("VH.exactInvoker"),
348 VARHANDLE_INVOKER("VH.invoker", "invoker"),
349 VARHANDLE_LINKER("VH.invoke_MT", "invoke_MT");
350
351 final String defaultLambdaName;
352 final String methodName;
353
354 private Kind(String defaultLambdaName) {
355 this(defaultLambdaName, defaultLambdaName);
356 }
357
358 private Kind(String defaultLambdaName, String methodName) {
359 this.defaultLambdaName = defaultLambdaName;
360 this.methodName = methodName;
361 }
362 }
363
364 LambdaForm(int arity, Name[] names, int result) {
365 this(arity, names, result, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
366 }
367 LambdaForm(int arity, Name[] names, int result, Kind kind) {
368 this(arity, names, result, /*forceInline=*/true, /*customized=*/null, kind);
369 }
370 LambdaForm(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized) {
371 this(arity, names, result, forceInline, customized, Kind.GENERIC);
372 }
373 LambdaForm(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
374 assert(namesOK(arity, names));
375 this.arity = arity;
376 this.result = fixResult(result, names);
377 this.names = names.clone();
378 this.forceInline = forceInline;
379 this.customized = customized;
380 this.kind = kind;
381 int maxOutArity = normalize();
382 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
383 // Cannot use LF interpreter on very high arity expressions.
384 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
385 compileToBytecode();
386 }
387 }
388 LambdaForm(int arity, Name[] names) {
389 this(arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
390 }
391 LambdaForm(int arity, Name[] names, Kind kind) {
392 this(arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null, kind);
393 }
394 LambdaForm(int arity, Name[] names, boolean forceInline) {
395 this(arity, names, LAST_RESULT, forceInline, /*customized=*/null, Kind.GENERIC);
396 }
397 LambdaForm(int arity, Name[] names, boolean forceInline, Kind kind) {
398 this(arity, names, LAST_RESULT, forceInline, /*customized=*/null, kind);
399 }
400 LambdaForm(Name[] formals, Name[] temps, Name result) {
401 this(formals.length, buildNames(formals, temps, result), LAST_RESULT, /*forceInline=*/true, /*customized=*/null);
402 }
403 LambdaForm(Name[] formals, Name[] temps, Name result, boolean forceInline) {
404 this(formals.length, buildNames(formals, temps, result), LAST_RESULT, forceInline, /*customized=*/null);
405 }
406
407 private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
408 int arity = formals.length;
409 int length = arity + temps.length + (result == null ? 0 : 1);
410 Name[] names = Arrays.copyOf(formals, length);
411 System.arraycopy(temps, 0, names, arity, temps.length);
412 if (result != null)
413 names[length - 1] = result;
414 return names;
415 }
416
417 private LambdaForm(MethodType mt) {
418 // Make a blank lambda form, which returns a constant zero or null.
419 // It is used as a template for managing the invocation of similar forms that are non-empty.
420 // Called only from getPreparedForm.
421 this.arity = mt.parameterCount();
422 this.result = (mt.returnType() == void.class || mt.returnType() == Void.class) ? -1 : arity;
423 this.names = buildEmptyNames(arity, mt, result == -1);
424 this.forceInline = true;
425 this.customized = null;
426 this.kind = Kind.ZERO;
427 assert(nameRefsAreLegal());
428 assert(isEmpty());
429 String sig = null;
430 assert(isValidSignature(sig = basicTypeSignature()));
431 assert(sig.equals(basicTypeSignature())) : sig + " != " + basicTypeSignature();
432 }
433
434 private static Name[] buildEmptyNames(int arity, MethodType mt, boolean isVoid) {
435 Name[] names = arguments(isVoid ? 0 : 1, mt);
436 if (!isVoid) {
437 Name zero = new Name(constantZero(basicType(mt.returnType())));
438 names[arity] = zero.newIndex(arity);
439 }
440 return names;
441 }
442
443 private static int fixResult(int result, Name[] names) {
444 if (result == LAST_RESULT)
445 result = names.length - 1; // might still be void
446 if (result >= 0 && names[result].type == V_TYPE)
447 result = VOID_RESULT;
448 return result;
449 }
450
451 static boolean debugNames() {
452 return DEBUG_NAME_COUNTERS != null;
453 }
454
455 static void associateWithDebugName(LambdaForm form, String name) {
456 assert (debugNames());
457 synchronized (DEBUG_NAMES) {
458 DEBUG_NAMES.put(form, name);
459 }
460 }
461
462 String lambdaName() {
463 if (DEBUG_NAMES != null) {
464 synchronized (DEBUG_NAMES) {
465 String name = DEBUG_NAMES.get(this);
466 if (name == null) {
467 name = generateDebugName();
468 }
469 return name;
470 }
471 }
472 return kind.defaultLambdaName;
473 }
474
475 private String generateDebugName() {
476 assert (debugNames());
477 String debugNameStem = kind.defaultLambdaName;
478 Integer ctr = DEBUG_NAME_COUNTERS.getOrDefault(debugNameStem, 0);
479 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr + 1);
480 StringBuilder buf = new StringBuilder(debugNameStem);
481 int leadingZero = buf.length();
482 buf.append((int) ctr);
483 for (int i = buf.length() - leadingZero; i < 3; i++) {
484 buf.insert(leadingZero, '0');
485 }
486 buf.append('_');
487 buf.append(basicTypeSignature());
488 String name = buf.toString();
489 associateWithDebugName(this, name);
490 return name;
491 }
492
493 private static boolean namesOK(int arity, Name[] names) {
494 for (int i = 0; i < names.length; i++) {
495 Name n = names[i];
496 assert(n != null) : "n is null";
497 if (i < arity)
498 assert( n.isParam()) : n + " is not param at " + i;
499 else
500 assert(!n.isParam()) : n + " is param at " + i;
501 }
502 return true;
503 }
504
505 /** Customize LambdaForm for a particular MethodHandle */
506 LambdaForm customize(MethodHandle mh) {
507 LambdaForm customForm = new LambdaForm(arity, names, result, forceInline, mh, kind);
508 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
509 // If shared LambdaForm has been compiled, compile customized version as well.
510 customForm.compileToBytecode();
511 }
512 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
513 return customForm;
514 }
515
516 /** Get uncustomized flavor of the LambdaForm */
517 LambdaForm uncustomize() {
518 if (customized == null) {
519 return this;
520 }
521 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
522 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
523 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
524 // If customized LambdaForm has been compiled, compile uncustomized version as well.
525 uncustomizedForm.compileToBytecode();
526 }
527 return uncustomizedForm;
528 }
529
530 /** Renumber and/or replace params so that they are interned and canonically numbered.
531 * @return maximum argument list length among the names (since we have to pass over them anyway)
532 */
533 private int normalize() {
534 Name[] oldNames = null;
535 int maxOutArity = 0;
536 int changesStart = 0;
537 for (int i = 0; i < names.length; i++) {
538 Name n = names[i];
539 if (!n.initIndex(i)) {
540 if (oldNames == null) {
541 oldNames = names.clone();
542 changesStart = i;
543 }
544 names[i] = n.cloneWithIndex(i);
545 }
546 if (n.arguments != null && maxOutArity < n.arguments.length)
547 maxOutArity = n.arguments.length;
548 }
549 if (oldNames != null) {
550 int startFixing = arity;
551 if (startFixing <= changesStart)
552 startFixing = changesStart+1;
553 for (int i = startFixing; i < names.length; i++) {
554 Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
555 names[i] = fixed.newIndex(i);
556 }
557 }
558 assert(nameRefsAreLegal());
559 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
560 boolean needIntern = false;
561 for (int i = 0; i < maxInterned; i++) {
562 Name n = names[i], n2 = internArgument(n);
563 if (n != n2) {
564 names[i] = n2;
565 needIntern = true;
566 }
567 }
568 if (needIntern) {
569 for (int i = arity; i < names.length; i++) {
570 names[i].internArguments();
571 }
572 }
573 assert(nameRefsAreLegal());
574 return maxOutArity;
575 }
576
577 /**
578 * Check that all embedded Name references are localizable to this lambda,
579 * and are properly ordered after their corresponding definitions.
580 * <p>
581 * Note that a Name can be local to multiple lambdas, as long as
582 * it possesses the same index in each use site.
583 * This allows Name references to be freely reused to construct
584 * fresh lambdas, without confusion.
585 */
586 boolean nameRefsAreLegal() {
587 assert(arity >= 0 && arity <= names.length);
588 assert(result >= -1 && result < names.length);
589 // Do all names possess an index consistent with their local definition order?
590 for (int i = 0; i < arity; i++) {
591 Name n = names[i];
592 assert(n.index() == i) : Arrays.asList(n.index(), i);
593 assert(n.isParam());
594 }
595 // Also, do all local name references
596 for (int i = arity; i < names.length; i++) {
597 Name n = names[i];
598 assert(n.index() == i);
599 for (Object arg : n.arguments) {
600 if (arg instanceof Name) {
601 Name n2 = (Name) arg;
602 int i2 = n2.index;
603 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
604 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
605 assert(i2 < i); // ref must come after def!
606 }
607 }
608 }
609 return true;
610 }
611
612 /** Invoke this form on the given arguments. */
613 // final Object invoke(Object... args) throws Throwable {
614 // // NYI: fit this into the fast path?
615 // return interpretWithArguments(args);
616 // }
617
618 /** Report the return type. */
619 BasicType returnType() {
620 if (result < 0) return V_TYPE;
621 Name n = names[result];
622 return n.type;
623 }
624
625 /** Report the N-th argument type. */
626 BasicType parameterType(int n) {
627 return parameter(n).type;
628 }
629
630 /** Report the N-th argument name. */
631 Name parameter(int n) {
632 assert(n < arity);
633 Name param = names[n];
634 assert(param.isParam());
635 return param;
636 }
637
638 /** Report the N-th argument type constraint. */
639 Object parameterConstraint(int n) {
640 return parameter(n).constraint;
641 }
642
643 /** Report the arity. */
644 int arity() {
645 return arity;
646 }
647
648 /** Report the number of expressions (non-parameter names). */
649 int expressionCount() {
650 return names.length - arity;
651 }
652
653 /** Return the method type corresponding to my basic type signature. */
654 MethodType methodType() {
655 Class<?>[] ptypes = new Class<?>[arity];
656 for (int i = 0; i < arity; ++i) {
657 ptypes[i] = parameterType(i).btClass;
658 }
659 return MethodType.makeImpl(returnType().btClass, ptypes, true);
660 }
661
662 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
663 final String basicTypeSignature() {
664 StringBuilder buf = new StringBuilder(arity() + 3);
665 for (int i = 0, a = arity(); i < a; i++)
666 buf.append(parameterType(i).basicTypeChar());
667 return buf.append('_').append(returnType().basicTypeChar()).toString();
668 }
669 static int signatureArity(String sig) {
670 assert(isValidSignature(sig));
671 return sig.indexOf('_');
672 }
673 static BasicType signatureReturn(String sig) {
674 return basicType(sig.charAt(signatureArity(sig) + 1));
675 }
676 static boolean isValidSignature(String sig) {
677 int arity = sig.indexOf('_');
678 if (arity < 0) return false; // must be of the form *_*
679 int siglen = sig.length();
680 if (siglen != arity + 2) return false; // *_X
681 for (int i = 0; i < siglen; i++) {
682 if (i == arity) continue; // skip '_'
683 char c = sig.charAt(i);
684 if (c == 'V')
685 return (i == siglen - 1 && arity == siglen - 2);
686 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
687 }
688 return true; // [LIJFD]*_[LIJFDV]
689 }
690 static MethodType signatureType(String sig) {
691 Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
692 for (int i = 0; i < ptypes.length; i++)
693 ptypes[i] = basicType(sig.charAt(i)).btClass;
694 Class<?> rtype = signatureReturn(sig).btClass;
695 return MethodType.makeImpl(rtype, ptypes, true);
696 }
697 static MethodType basicMethodType(MethodType mt) {
698 return signatureType(basicTypeSignature(mt));
699 }
700
701 /**
702 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
703 */
704 boolean isSelectAlternative(int pos) {
705 // selectAlternative idiom:
706 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
707 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
708 if (pos+1 >= names.length) return false;
709 Name name0 = names[pos];
710 Name name1 = names[pos+1];
711 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
712 name1.isInvokeBasic() &&
713 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
714 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
715 }
716
717 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
718 if (pos+2 >= names.length) return false;
719 Name name0 = names[pos];
720 Name name1 = names[pos+1];
721 Name name2 = names[pos+2];
722 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
723 name0.isInvokeBasic() &&
724 name2.isInvokeBasic() &&
725 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
726 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
727 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
728 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
729 }
730
731 /**
732 * Check if i-th name is a start of GuardWithCatch idiom.
733 */
734 boolean isGuardWithCatch(int pos) {
735 // GuardWithCatch idiom:
736 // t_{n}:L=MethodHandle.invokeBasic(...)
737 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
738 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
739 return isMatchingIdiom(pos, "guardWithCatch", 3);
740 }
741
742 /**
743 * Check if i-th name is a start of the tryFinally idiom.
744 */
745 boolean isTryFinally(int pos) {
746 // tryFinally idiom:
747 // t_{n}:L=MethodHandle.invokeBasic(...)
748 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
749 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
750 return isMatchingIdiom(pos, "tryFinally", 2);
751 }
752
753 /**
754 * Check if i-th name is a start of the loop idiom.
755 */
756 boolean isLoop(int pos) {
757 // loop idiom:
758 // t_{n}:L=MethodHandle.invokeBasic(...)
759 // t_{n+1}:L=MethodHandleImpl.loop(types, *, t_{n})
760 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
761 return isMatchingIdiom(pos, "loop", 2);
762 }
763
764 /*
765 * Code generation issues:
766 *
767 * Compiled LFs should be reusable in general.
768 * The biggest issue is how to decide when to pull a name into
769 * the bytecode, versus loading a reified form from the MH data.
770 *
771 * For example, an asType wrapper may require execution of a cast
772 * after a call to a MH. The target type of the cast can be placed
773 * as a constant in the LF itself. This will force the cast type
774 * to be compiled into the bytecodes and native code for the MH.
775 * Or, the target type of the cast can be erased in the LF, and
776 * loaded from the MH data. (Later on, if the MH as a whole is
777 * inlined, the data will flow into the inlined instance of the LF,
778 * as a constant, and the end result will be an optimal cast.)
779 *
780 * This erasure of cast types can be done with any use of
781 * reference types. It can also be done with whole method
782 * handles. Erasing a method handle might leave behind
783 * LF code that executes correctly for any MH of a given
784 * type, and load the required MH from the enclosing MH's data.
785 * Or, the erasure might even erase the expected MT.
786 *
787 * Also, for direct MHs, the MemberName of the target
788 * could be erased, and loaded from the containing direct MH.
789 * As a simple case, a LF for all int-valued non-static
790 * field getters would perform a cast on its input argument
791 * (to non-constant base type derived from the MemberName)
792 * and load an integer value from the input object
793 * (at a non-constant offset also derived from the MemberName).
794 * Such MN-erased LFs would be inlinable back to optimized
795 * code, whenever a constant enclosing DMH is available
796 * to supply a constant MN from its data.
797 *
798 * The main problem here is to keep LFs reasonably generic,
799 * while ensuring that hot spots will inline good instances.
800 * "Reasonably generic" means that we don't end up with
801 * repeated versions of bytecode or machine code that do
802 * not differ in their optimized form. Repeated versions
803 * of machine would have the undesirable overheads of
804 * (a) redundant compilation work and (b) extra I$ pressure.
805 * To control repeated versions, we need to be ready to
806 * erase details from LFs and move them into MH data,
807 * whevener those details are not relevant to significant
808 * optimization. "Significant" means optimization of
809 * code that is actually hot.
810 *
811 * Achieving this may require dynamic splitting of MHs, by replacing
812 * a generic LF with a more specialized one, on the same MH,
813 * if (a) the MH is frequently executed and (b) the MH cannot
814 * be inlined into a containing caller, such as an invokedynamic.
815 *
816 * Compiled LFs that are no longer used should be GC-able.
817 * If they contain non-BCP references, they should be properly
818 * interlinked with the class loader(s) that their embedded types
819 * depend on. This probably means that reusable compiled LFs
820 * will be tabulated (indexed) on relevant class loaders,
821 * or else that the tables that cache them will have weak links.
822 */
823
824 /**
825 * Make this LF directly executable, as part of a MethodHandle.
826 * Invariant: Every MH which is invoked must prepare its LF
827 * before invocation.
828 * (In principle, the JVM could do this very lazily,
829 * as a sort of pre-invocation linkage step.)
830 */
831 public void prepare() {
832 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
833 compileToBytecode();
834 }
835 if (this.vmentry != null) {
836 // already prepared (e.g., a primitive DMH invoker form)
837 return;
838 }
839 MethodType mtype = methodType();
840 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
841 if (prep == null) {
842 assert (isValidSignature(basicTypeSignature()));
843 prep = new LambdaForm(mtype);
844 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
845 prep = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
846 }
847 this.vmentry = prep.vmentry;
848 // TO DO: Maybe add invokeGeneric, invokeWithArguments
849 }
850
851 private static @Stable PerfCounter LF_FAILED;
852
853 private static PerfCounter failedCompilationCounter() {
854 if (LF_FAILED == null) {
855 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
856 }
857 return LF_FAILED;
858 }
859
860 /** Generate optimizable bytecode for this form. */
861 void compileToBytecode() {
862 if (forceInterpretation()) {
863 return; // this should not be compiled
864 }
865 if (vmentry != null && isCompiled) {
866 return; // already compiled somehow
867 }
868
869 // Obtain the invoker MethodType outside of the following try block.
870 // This ensures that an IllegalArgumentException is directly thrown if the
871 // type would have 256 or more parameters
872 MethodType invokerType = methodType();
873 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
874 try {
875 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
876 if (TRACE_INTERPRETER)
877 traceInterpreter("compileToBytecode", this);
878 isCompiled = true;
879 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
880 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
881 invocationCounter = -1;
882 failedCompilationCounter().increment();
883 if (LOG_LF_COMPILATION_FAILURE) {
884 System.out.println("LambdaForm compilation failed: " + this);
885 bge.printStackTrace(System.out);
886 }
887 } catch (Error e) {
888 // Pass through any error
889 throw e;
890 } catch (Exception e) {
891 // Wrap any exception
892 throw newInternalError(this.toString(), e);
893 }
894 }
895
896 // The next few routines are called only from assert expressions
897 // They verify that the built-in invokers process the correct raw data types.
898 private static boolean argumentTypesMatch(String sig, Object[] av) {
899 int arity = signatureArity(sig);
900 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
901 assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
902 MethodHandle mh = (MethodHandle) av[0];
903 MethodType mt = mh.type();
904 assert(mt.parameterCount() == arity-1);
905 for (int i = 0; i < av.length; i++) {
906 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
907 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
908 }
909 return true;
910 }
911 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
912 // The following line is needed because (...)void method handles can use non-void invokers
913 if (type == void.class) tc = V_TYPE; // can drop any kind of value
914 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
915 switch (tc) {
916 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
917 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
918 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
919 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
920 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
921 case V_TYPE: break; // allow anything here; will be dropped
922 default: assert(false);
923 }
924 return true;
925 }
926 private static boolean checkInt(Class<?> type, Object x) {
927 assert(x instanceof Integer);
928 if (type == int.class) return true;
929 Wrapper w = Wrapper.forBasicType(type);
930 assert(w.isSubwordOrInt());
931 Object x1 = Wrapper.INT.wrap(w.wrap(x));
932 return x.equals(x1);
933 }
934 private static boolean checkRef(Class<?> type, Object x) {
935 assert(!type.isPrimitive());
936 if (x == null) return true;
937 if (type.isInterface()) return true;
938 return type.isInstance(x);
939 }
940
941 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
942 private static final int COMPILE_THRESHOLD;
943 static {
944 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
945 }
946 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
947
948 private boolean forceInterpretation() {
949 return invocationCounter == -1;
950 }
951
952 @Hidden
953 @DontInline
954 /** Interpretively invoke this form on the given arguments. */
955 Object interpretWithArguments(Object... argumentValues) throws Throwable {
956 if (TRACE_INTERPRETER)
957 return interpretWithArgumentsTracing(argumentValues);
958 checkInvocationCounter();
959 assert(arityCheck(argumentValues));
960 Object[] values = Arrays.copyOf(argumentValues, names.length);
961 for (int i = argumentValues.length; i < values.length; i++) {
962 values[i] = interpretName(names[i], values);
963 }
964 Object rv = (result < 0) ? null : values[result];
965 assert(resultCheck(argumentValues, rv));
966 return rv;
967 }
968
969 @Hidden
970 @DontInline
971 /** Evaluate a single Name within this form, applying its function to its arguments. */
972 Object interpretName(Name name, Object[] values) throws Throwable {
973 if (TRACE_INTERPRETER)
974 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
975 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
976 for (int i = 0; i < arguments.length; i++) {
977 Object a = arguments[i];
978 if (a instanceof Name) {
979 int i2 = ((Name)a).index();
980 assert(names[i2] == a);
981 a = values[i2];
982 arguments[i] = a;
983 }
984 }
985 return name.function.invokeWithArguments(arguments);
986 }
987
988 private void checkInvocationCounter() {
989 if (COMPILE_THRESHOLD != 0 &&
990 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
991 invocationCounter++; // benign race
992 if (invocationCounter >= COMPILE_THRESHOLD) {
993 // Replace vmentry with a bytecode version of this LF.
994 compileToBytecode();
995 }
996 }
997 }
998 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
999 traceInterpreter("[ interpretWithArguments", this, argumentValues);
1000 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
1001 int ctr = invocationCounter++; // benign race
1002 traceInterpreter("| invocationCounter", ctr);
1003 if (invocationCounter >= COMPILE_THRESHOLD) {
1004 compileToBytecode();
1005 }
1006 }
1007 Object rval;
1008 try {
1009 assert(arityCheck(argumentValues));
1010 Object[] values = Arrays.copyOf(argumentValues, names.length);
1011 for (int i = argumentValues.length; i < values.length; i++) {
1012 values[i] = interpretName(names[i], values);
1013 }
1014 rval = (result < 0) ? null : values[result];
1015 } catch (Throwable ex) {
1016 traceInterpreter("] throw =>", ex);
1017 throw ex;
1018 }
1019 traceInterpreter("] return =>", rval);
1020 return rval;
1021 }
1022
1023 static void traceInterpreter(String event, Object obj, Object... args) {
1024 if (TRACE_INTERPRETER) {
1025 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
1026 }
1027 }
1028 static void traceInterpreter(String event, Object obj) {
1029 traceInterpreter(event, obj, (Object[])null);
1030 }
1031 private boolean arityCheck(Object[] argumentValues) {
1032 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
1033 // also check that the leading (receiver) argument is somehow bound to this LF:
1034 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
1035 MethodHandle mh = (MethodHandle) argumentValues[0];
1036 assert(mh.internalForm() == this);
1037 // note: argument #0 could also be an interface wrapper, in the future
1038 argumentTypesMatch(basicTypeSignature(), argumentValues);
1039 return true;
1040 }
1041 private boolean resultCheck(Object[] argumentValues, Object result) {
1042 MethodHandle mh = (MethodHandle) argumentValues[0];
1043 MethodType mt = mh.type();
1044 assert(valueMatches(returnType(), mt.returnType(), result));
1045 return true;
1046 }
1047
1048 private boolean isEmpty() {
1049 if (result < 0)
1050 return (names.length == arity);
1051 else if (result == arity && names.length == arity + 1)
1052 return names[arity].isConstantZero();
1053 else
1054 return false;
1055 }
1056
1057 public String toString() {
1058 String lambdaName = lambdaName();
1059 StringBuilder buf = new StringBuilder(lambdaName + "=Lambda(");
1060 for (int i = 0; i < names.length; i++) {
1061 if (i == arity) buf.append(")=>{");
1062 Name n = names[i];
1063 if (i >= arity) buf.append("\n ");
1064 buf.append(n.paramString());
1065 if (i < arity) {
1066 if (i+1 < arity) buf.append(",");
1067 continue;
1068 }
1069 buf.append("=").append(n.exprString());
1070 buf.append(";");
1071 }
1072 if (arity == names.length) buf.append(")=>{");
1073 buf.append(result < 0 ? "void" : names[result]).append("}");
1074 if (TRACE_INTERPRETER) {
1075 // Extra verbosity:
1076 buf.append(":").append(basicTypeSignature());
1077 buf.append("/").append(vmentry);
1078 }
1079 return buf.toString();
1080 }
1081
1082 @Override
1083 public boolean equals(Object obj) {
1084 return obj instanceof LambdaForm && equals((LambdaForm)obj);
1085 }
1086 public boolean equals(LambdaForm that) {
1087 if (this.result != that.result) return false;
1088 return Arrays.equals(this.names, that.names);
1089 }
1090 public int hashCode() {
1091 return result + 31 * Arrays.hashCode(names);
1092 }
1093 LambdaFormEditor editor() {
1094 return LambdaFormEditor.lambdaFormEditor(this);
1095 }
1096
1097 boolean contains(Name name) {
1098 int pos = name.index();
1099 if (pos >= 0) {
1100 return pos < names.length && name.equals(names[pos]);
1101 }
1102 for (int i = arity; i < names.length; i++) {
1103 if (name.equals(names[i]))
1104 return true;
1105 }
1106 return false;
1107 }
1108
1109 static class NamedFunction {
1110 final MemberName member;
1111 private @Stable MethodHandle resolvedHandle;
1112 @Stable MethodHandle invoker;
1113 private final MethodHandleImpl.Intrinsic intrinsicName;
1114
1115 NamedFunction(MethodHandle resolvedHandle) {
1116 this(resolvedHandle.internalMemberName(), resolvedHandle, MethodHandleImpl.Intrinsic.NONE);
1117 }
1118 NamedFunction(MethodHandle resolvedHandle, MethodHandleImpl.Intrinsic intrinsic) {
1119 this(resolvedHandle.internalMemberName(), resolvedHandle, intrinsic);
1120 }
1121 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1122 this(member, resolvedHandle, MethodHandleImpl.Intrinsic.NONE);
1123 }
1124 NamedFunction(MemberName member, MethodHandle resolvedHandle, MethodHandleImpl.Intrinsic intrinsic) {
1125 this.member = member;
1126 this.resolvedHandle = resolvedHandle;
1127 this.intrinsicName = intrinsic;
1128 assert(resolvedHandle == null ||
1129 resolvedHandle.intrinsicName() == MethodHandleImpl.Intrinsic.NONE ||
1130 resolvedHandle.intrinsicName() == intrinsic) : resolvedHandle.intrinsicName() + " != " + intrinsic;
1131 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1132 //assert(!isInvokeBasic(member));
1133 }
1134 NamedFunction(MethodType basicInvokerType) {
1135 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1136 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1137 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1138 this.member = resolvedHandle.internalMemberName();
1139 } else {
1140 // necessary to pass BigArityTest
1141 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1142 }
1143 this.intrinsicName = MethodHandleImpl.Intrinsic.NONE;
1144 assert(isInvokeBasic(member));
1145 }
1146
1147 private static boolean isInvokeBasic(MemberName member) {
1148 return member != null &&
1149 member.getDeclaringClass() == MethodHandle.class &&
1150 "invokeBasic".equals(member.getName());
1151 }
1152
1153 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1154 // Any LambdaForm containing such a member is not interpretable.
1155 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1156 // And even without the resolvedHandle, the name can still be compiled and optimized.
1157 NamedFunction(Method method) {
1158 this(new MemberName(method));
1159 }
1160 NamedFunction(MemberName member) {
1161 this(member, null);
1162 }
1163
1164 MethodHandle resolvedHandle() {
1165 if (resolvedHandle == null) resolve();
1166 return resolvedHandle;
1167 }
1168
1169 synchronized void resolve() {
1170 if (resolvedHandle == null) {
1171 resolvedHandle = DirectMethodHandle.make(member);
1172 }
1173 }
1174
1175 @Override
1176 public boolean equals(Object other) {
1177 if (this == other) return true;
1178 if (other == null) return false;
1179 if (!(other instanceof NamedFunction)) return false;
1180 NamedFunction that = (NamedFunction) other;
1181 return this.member != null && this.member.equals(that.member);
1182 }
1183
1184 @Override
1185 public int hashCode() {
1186 if (member != null)
1187 return member.hashCode();
1188 return super.hashCode();
1189 }
1190
1191 static final MethodType INVOKER_METHOD_TYPE =
1192 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1193
1194 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1195 typeForm = typeForm.basicType().form(); // normalize to basic type
1196 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1197 if (mh != null) return mh;
1198 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1199 mh = DirectMethodHandle.make(invoker);
1200 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1201 if (mh2 != null) return mh2; // benign race
1202 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1203 throw newInternalError(mh.debugString());
1204 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1205 }
1206
1207 @Hidden
1208 Object invokeWithArguments(Object... arguments) throws Throwable {
1209 // If we have a cached invoker, call it right away.
1210 // NOTE: The invoker always returns a reference value.
1211 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1212 return invoker().invokeBasic(resolvedHandle(), arguments);
1213 }
1214
1215 @Hidden
1216 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1217 Object rval;
1218 try {
1219 traceInterpreter("[ call", this, arguments);
1220 if (invoker == null) {
1221 traceInterpreter("| getInvoker", this);
1222 invoker();
1223 }
1224 // resolvedHandle might be uninitialized, ok for tracing
1225 if (resolvedHandle == null) {
1226 traceInterpreter("| resolve", this);
1227 resolvedHandle();
1228 }
1229 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1230 } catch (Throwable ex) {
1231 traceInterpreter("] throw =>", ex);
1232 throw ex;
1233 }
1234 traceInterpreter("] return =>", rval);
1235 return rval;
1236 }
1237
1238 private MethodHandle invoker() {
1239 if (invoker != null) return invoker;
1240 // Get an invoker and cache it.
1241 return invoker = computeInvoker(methodType().form());
1242 }
1243
1244 MethodType methodType() {
1245 if (resolvedHandle != null)
1246 return resolvedHandle.type();
1247 else
1248 // only for certain internal LFs during bootstrapping
1249 return member.getInvocationType();
1250 }
1251
1252 MemberName member() {
1253 assert(assertMemberIsConsistent());
1254 return member;
1255 }
1256
1257 // Called only from assert.
1258 private boolean assertMemberIsConsistent() {
1259 if (resolvedHandle instanceof DirectMethodHandle) {
1260 MemberName m = resolvedHandle.internalMemberName();
1261 assert(m.equals(member));
1262 }
1263 return true;
1264 }
1265
1266 Class<?> memberDeclaringClassOrNull() {
1267 return (member == null) ? null : member.getDeclaringClass();
1268 }
1269
1270 BasicType returnType() {
1271 return basicType(methodType().returnType());
1272 }
1273
1274 BasicType parameterType(int n) {
1275 return basicType(methodType().parameterType(n));
1276 }
1277
1278 int arity() {
1279 return methodType().parameterCount();
1280 }
1281
1282 public String toString() {
1283 if (member == null) return String.valueOf(resolvedHandle);
1284 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1285 }
1286
1287 public boolean isIdentity() {
1288 return this.equals(identity(returnType()));
1289 }
1290
1291 public boolean isConstantZero() {
1292 return this.equals(constantZero(returnType()));
1293 }
1294
1295 public MethodHandleImpl.Intrinsic intrinsicName() {
1296 return intrinsicName;
1297 }
1298 }
1299
1300 public static String basicTypeSignature(MethodType type) {
1301 int params = type.parameterCount();
1302 char[] sig = new char[params + 2];
1303 int sigp = 0;
1304 while (sigp < params) {
1305 sig[sigp] = basicTypeChar(type.parameterType(sigp++));
1306 }
1307 sig[sigp++] = '_';
1308 sig[sigp++] = basicTypeChar(type.returnType());
1309 assert(sigp == sig.length);
1310 return String.valueOf(sig);
1311 }
1312
1313 /** Hack to make signatures more readable when they show up in method names.
1314 * Signature should start with a sequence of uppercase ASCII letters.
1315 * Runs of three or more are replaced by a single letter plus a decimal repeat count.
1316 * A tail of anything other than uppercase ASCII is passed through unchanged.
1317 * @param signature sequence of uppercase ASCII letters with possible repetitions
1318 * @return same sequence, with repetitions counted by decimal numerals
1319 */
1320 public static String shortenSignature(String signature) {
1321 final int NO_CHAR = -1, MIN_RUN = 3;
1322 int c0, c1 = NO_CHAR, c1reps = 0;
1323 StringBuilder buf = null;
1324 int len = signature.length();
1325 if (len < MIN_RUN) return signature;
1326 for (int i = 0; i <= len; i++) {
1327 if (c1 != NO_CHAR && !('A' <= c1 && c1 <= 'Z')) {
1328 // wrong kind of char; bail out here
1329 if (buf != null) {
1330 buf.append(signature.substring(i - c1reps, len));
1331 }
1332 break;
1333 }
1334 // shift in the next char:
1335 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1336 if (c1 == c0) { ++c1reps; continue; }
1337 // shift in the next count:
1338 int c0reps = c1reps; c1reps = 1;
1339 // end of a character run
1340 if (c0reps < MIN_RUN) {
1341 if (buf != null) {
1342 while (--c0reps >= 0)
1343 buf.append((char)c0);
1344 }
1345 continue;
1346 }
1347 // found three or more in a row
1348 if (buf == null)
1349 buf = new StringBuilder().append(signature, 0, i - c0reps);
1350 buf.append((char)c0).append(c0reps);
1351 }
1352 return (buf == null) ? signature : buf.toString();
1353 }
1354
1355 static final class Name {
1356 final BasicType type;
1357 @Stable short index;
1358 final NamedFunction function;
1359 final Object constraint; // additional type information, if not null
1360 @Stable final Object[] arguments;
1361
1362 private Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1363 this.index = (short)index;
1364 this.type = type;
1365 this.function = function;
1366 this.arguments = arguments;
1367 this.constraint = null;
1368 assert(this.index == index);
1369 }
1370 private Name(Name that, Object constraint) {
1371 this.index = that.index;
1372 this.type = that.type;
1373 this.function = that.function;
1374 this.arguments = that.arguments;
1375 this.constraint = constraint;
1376 assert(constraint == null || isParam()); // only params have constraints
1377 assert(constraint == null || constraint instanceof ClassSpecializer.SpeciesData || constraint instanceof Class);
1378 }
1379 Name(MethodHandle function, Object... arguments) {
1380 this(new NamedFunction(function), arguments);
1381 }
1382 Name(MethodType functionType, Object... arguments) {
1383 this(new NamedFunction(functionType), arguments);
1384 assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == L_TYPE);
1385 }
1386 Name(MemberName function, Object... arguments) {
1387 this(new NamedFunction(function), arguments);
1388 }
1389 Name(NamedFunction function, Object... arguments) {
1390 this(-1, function.returnType(), function, arguments = Arrays.copyOf(arguments, arguments.length, Object[].class));
1391 assert(typesMatch(function, arguments));
1392 }
1393 /** Create a raw parameter of the given type, with an expected index. */
1394 Name(int index, BasicType type) {
1395 this(index, type, null, null);
1396 }
1397 /** Create a raw parameter of the given type. */
1398 Name(BasicType type) { this(-1, type); }
1399
1400 BasicType type() { return type; }
1401 int index() { return index; }
1402 boolean initIndex(int i) {
1403 if (index != i) {
1404 if (index != -1) return false;
1405 index = (short)i;
1406 }
1407 return true;
1408 }
1409 char typeChar() {
1410 return type.btChar;
1411 }
1412
1413 void resolve() {
1414 if (function != null)
1415 function.resolve();
1416 }
1417
1418 Name newIndex(int i) {
1419 if (initIndex(i)) return this;
1420 return cloneWithIndex(i);
1421 }
1422 Name cloneWithIndex(int i) {
1423 Object[] newArguments = (arguments == null) ? null : arguments.clone();
1424 return new Name(i, type, function, newArguments).withConstraint(constraint);
1425 }
1426 Name withConstraint(Object constraint) {
1427 if (constraint == this.constraint) return this;
1428 return new Name(this, constraint);
1429 }
1430 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1431 if (oldName == newName) return this;
1432 @SuppressWarnings("LocalVariableHidesMemberVariable")
1433 Object[] arguments = this.arguments;
1434 if (arguments == null) return this;
1435 boolean replaced = false;
1436 for (int j = 0; j < arguments.length; j++) {
1437 if (arguments[j] == oldName) {
1438 if (!replaced) {
1439 replaced = true;
1440 arguments = arguments.clone();
1441 }
1442 arguments[j] = newName;
1443 }
1444 }
1445 if (!replaced) return this;
1446 return new Name(function, arguments);
1447 }
1448 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1449 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1450 */
1451 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1452 if (start >= end) return this;
1453 @SuppressWarnings("LocalVariableHidesMemberVariable")
1454 Object[] arguments = this.arguments;
1455 boolean replaced = false;
1456 eachArg:
1457 for (int j = 0; j < arguments.length; j++) {
1458 if (arguments[j] instanceof Name) {
1459 Name n = (Name) arguments[j];
1460 int check = n.index;
1461 // harmless check to see if the thing is already in newNames:
1462 if (check >= 0 && check < newNames.length && n == newNames[check])
1463 continue eachArg;
1464 // n might not have the correct index: n != oldNames[n.index].
1465 for (int i = start; i < end; i++) {
1466 if (n == oldNames[i]) {
1467 if (n == newNames[i])
1468 continue eachArg;
1469 if (!replaced) {
1470 replaced = true;
1471 arguments = arguments.clone();
1472 }
1473 arguments[j] = newNames[i];
1474 continue eachArg;
1475 }
1476 }
1477 }
1478 }
1479 if (!replaced) return this;
1480 return new Name(function, arguments);
1481 }
1482 void internArguments() {
1483 @SuppressWarnings("LocalVariableHidesMemberVariable")
1484 Object[] arguments = this.arguments;
1485 for (int j = 0; j < arguments.length; j++) {
1486 if (arguments[j] instanceof Name) {
1487 Name n = (Name) arguments[j];
1488 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1489 arguments[j] = internArgument(n);
1490 }
1491 }
1492 }
1493 boolean isParam() {
1494 return function == null;
1495 }
1496 boolean isConstantZero() {
1497 return !isParam() && arguments.length == 0 && function.isConstantZero();
1498 }
1499
1500 boolean refersTo(Class<?> declaringClass, String methodName) {
1501 return function != null &&
1502 function.member() != null && function.member().refersTo(declaringClass, methodName);
1503 }
1504
1505 /**
1506 * Check if MemberName is a call to MethodHandle.invokeBasic.
1507 */
1508 boolean isInvokeBasic() {
1509 if (function == null)
1510 return false;
1511 if (arguments.length < 1)
1512 return false; // must have MH argument
1513 MemberName member = function.member();
1514 return member != null && member.refersTo(MethodHandle.class, "invokeBasic") &&
1515 !member.isPublic() && !member.isStatic();
1516 }
1517
1518 /**
1519 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1520 */
1521 boolean isLinkerMethodInvoke() {
1522 if (function == null)
1523 return false;
1524 if (arguments.length < 1)
1525 return false; // must have MH argument
1526 MemberName member = function.member();
1527 return member != null &&
1528 member.getDeclaringClass() == MethodHandle.class &&
1529 !member.isPublic() && member.isStatic() &&
1530 member.getName().startsWith("linkTo");
1531 }
1532
1533 public String toString() {
1534 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1535 }
1536 public String debugString() {
1537 String s = paramString();
1538 return (function == null) ? s : s + "=" + exprString();
1539 }
1540 public String paramString() {
1541 String s = toString();
1542 Object c = constraint;
1543 if (c == null)
1544 return s;
1545 if (c instanceof Class) c = ((Class<?>)c).getSimpleName();
1546 return s + "/" + c;
1547 }
1548 public String exprString() {
1549 if (function == null) return toString();
1550 StringBuilder buf = new StringBuilder(function.toString());
1551 buf.append("(");
1552 String cma = "";
1553 for (Object a : arguments) {
1554 buf.append(cma); cma = ",";
1555 if (a instanceof Name || a instanceof Integer)
1556 buf.append(a);
1557 else
1558 buf.append("(").append(a).append(")");
1559 }
1560 buf.append(")");
1561 return buf.toString();
1562 }
1563
1564 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1565 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1566 for (int i = 0; i < arguments.length; i++) {
1567 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1568 }
1569 return true;
1570 }
1571
1572 private static boolean typesMatch(BasicType parameterType, Object object) {
1573 if (object instanceof Name) {
1574 return ((Name)object).type == parameterType;
1575 }
1576 switch (parameterType) {
1577 case I_TYPE: return object instanceof Integer;
1578 case J_TYPE: return object instanceof Long;
1579 case F_TYPE: return object instanceof Float;
1580 case D_TYPE: return object instanceof Double;
1581 }
1582 assert(parameterType == L_TYPE);
1583 return true;
1584 }
1585
1586 /** Return the index of the last occurrence of n in the argument array.
1587 * Return -1 if the name is not used.
1588 */
1589 int lastUseIndex(Name n) {
1590 if (arguments == null) return -1;
1591 for (int i = arguments.length; --i >= 0; ) {
1592 if (arguments[i] == n) return i;
1593 }
1594 return -1;
1595 }
1596
1597 /** Return the number of occurrences of n in the argument array.
1598 * Return 0 if the name is not used.
1599 */
1600 int useCount(Name n) {
1601 if (arguments == null) return 0;
1602 int count = 0;
1603 for (int i = arguments.length; --i >= 0; ) {
1604 if (arguments[i] == n) ++count;
1605 }
1606 return count;
1607 }
1608
1609 boolean contains(Name n) {
1610 return this == n || lastUseIndex(n) >= 0;
1611 }
1612
1613 public boolean equals(Name that) {
1614 if (this == that) return true;
1615 if (isParam())
1616 // each parameter is a unique atom
1617 return false; // this != that
1618 return
1619 //this.index == that.index &&
1620 this.type == that.type &&
1621 this.function.equals(that.function) &&
1622 Arrays.equals(this.arguments, that.arguments);
1623 }
1624 @Override
1625 public boolean equals(Object x) {
1626 return x instanceof Name && equals((Name)x);
1627 }
1628 @Override
1629 public int hashCode() {
1630 if (isParam())
1631 return index | (type.ordinal() << 8);
1632 return function.hashCode() ^ Arrays.hashCode(arguments);
1633 }
1634 }
1635
1636 /** Return the index of the last name which contains n as an argument.
1637 * Return -1 if the name is not used. Return names.length if it is the return value.
1638 */
1639 int lastUseIndex(Name n) {
1640 int ni = n.index, nmax = names.length;
1641 assert(names[ni] == n);
1642 if (result == ni) return nmax; // live all the way beyond the end
1643 for (int i = nmax; --i > ni; ) {
1644 if (names[i].lastUseIndex(n) >= 0)
1645 return i;
1646 }
1647 return -1;
1648 }
1649
1650 /** Return the number of times n is used as an argument or return value. */
1651 int useCount(Name n) {
1652 int nmax = names.length;
1653 int end = lastUseIndex(n);
1654 if (end < 0) return 0;
1655 int count = 0;
1656 if (end == nmax) { count++; end--; }
1657 int beg = n.index() + 1;
1658 if (beg < arity) beg = arity;
1659 for (int i = beg; i <= end; i++) {
1660 count += names[i].useCount(n);
1661 }
1662 return count;
1663 }
1664
1665 static Name argument(int which, BasicType type) {
1666 if (which >= INTERNED_ARGUMENT_LIMIT)
1667 return new Name(which, type);
1668 return INTERNED_ARGUMENTS[type.ordinal()][which];
1669 }
1670 static Name internArgument(Name n) {
1671 assert(n.isParam()) : "not param: " + n;
1672 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1673 if (n.constraint != null) return n;
1674 return argument(n.index, n.type);
1675 }
1676 static Name[] arguments(int extra, MethodType types) {
1677 int length = types.parameterCount();
1678 Name[] names = new Name[length + extra];
1679 for (int i = 0; i < length; i++)
1680 names[i] = argument(i, basicType(types.parameterType(i)));
1681 return names;
1682 }
1683 static final int INTERNED_ARGUMENT_LIMIT = 10;
1684 private static final Name[][] INTERNED_ARGUMENTS
1685 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1686 static {
1687 for (BasicType type : BasicType.ARG_TYPES) {
1688 int ord = type.ordinal();
1689 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1690 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1691 }
1692 }
1693 }
1694
1695 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1696
1697 static LambdaForm identityForm(BasicType type) {
1698 int ord = type.ordinal();
1699 LambdaForm form = LF_identity[ord];
1700 if (form != null) {
1701 return form;
1702 }
1703 createFormsFor(type);
1704 return LF_identity[ord];
1705 }
1706
1707 static LambdaForm zeroForm(BasicType type) {
1708 int ord = type.ordinal();
1709 LambdaForm form = LF_zero[ord];
1710 if (form != null) {
1711 return form;
1712 }
1713 createFormsFor(type);
1714 return LF_zero[ord];
1715 }
1716
1717 static NamedFunction identity(BasicType type) {
1718 int ord = type.ordinal();
1719 NamedFunction function = NF_identity[ord];
1720 if (function != null) {
1721 return function;
1722 }
1723 createFormsFor(type);
1724 return NF_identity[ord];
1725 }
1726
1727 static NamedFunction constantZero(BasicType type) {
1728 int ord = type.ordinal();
1729 NamedFunction function = NF_zero[ord];
1730 if (function != null) {
1731 return function;
1732 }
1733 createFormsFor(type);
1734 return NF_zero[ord];
1735 }
1736
1737 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1738 private static final @Stable LambdaForm[] LF_zero = new LambdaForm[TYPE_LIMIT];
1739 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1740 private static final @Stable NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1741
1742 private static final Object createFormsLock = new Object();
1743 private static void createFormsFor(BasicType type) {
1744 // Avoid racy initialization during bootstrap
1745 UNSAFE.ensureClassInitialized(BoundMethodHandle.class);
1746 synchronized (createFormsLock) {
1747 final int ord = type.ordinal();
1748 LambdaForm idForm = LF_identity[ord];
1749 if (idForm != null) {
1750 return;
1751 }
1752 char btChar = type.basicTypeChar();
1753 boolean isVoid = (type == V_TYPE);
1754 Class<?> btClass = type.btClass;
1755 MethodType zeType = MethodType.methodType(btClass);
1756 MethodType idType = (isVoid) ? zeType : MethodType.methodType(btClass, btClass);
1757
1758 // Look up symbolic names. It might not be necessary to have these,
1759 // but if we need to emit direct references to bytecodes, it helps.
1760 // Zero is built from a call to an identity function with a constant zero input.
1761 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1762 MemberName zeMem = null;
1763 try {
1764 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, NoSuchMethodException.class);
1765 if (!isVoid) {
1766 zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1767 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, NoSuchMethodException.class);
1768 }
1769 } catch (IllegalAccessException|NoSuchMethodException ex) {
1770 throw newInternalError(ex);
1771 }
1772
1773 NamedFunction idFun;
1774 LambdaForm zeForm;
1775 NamedFunction zeFun;
1776
1777 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1778 // bootstrap dependency on this method in case we're interpreting LFs
1779 if (isVoid) {
1780 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1781 idForm = new LambdaForm(1, idNames, VOID_RESULT, Kind.IDENTITY);
1782 idForm.compileToBytecode();
1783 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1784
1785 zeForm = idForm;
1786 zeFun = idFun;
1787 } else {
1788 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1789 idForm = new LambdaForm(2, idNames, 1, Kind.IDENTITY);
1790 idForm.compileToBytecode();
1791 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm),
1792 MethodHandleImpl.Intrinsic.IDENTITY);
1793
1794 Object zeValue = Wrapper.forBasicType(btChar).zero();
1795 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1796 zeForm = new LambdaForm(1, zeNames, 1, Kind.ZERO);
1797 zeForm.compileToBytecode();
1798 zeFun = new NamedFunction(zeMem, SimpleMethodHandle.make(zeMem.getInvocationType(), zeForm),
1799 MethodHandleImpl.Intrinsic.ZERO);
1800 }
1801
1802 LF_zero[ord] = zeForm;
1803 NF_zero[ord] = zeFun;
1804 LF_identity[ord] = idForm;
1805 NF_identity[ord] = idFun;
1806
1807 assert(idFun.isIdentity());
1808 assert(zeFun.isConstantZero());
1809 assert(new Name(zeFun).isConstantZero());
1810 }
1811 }
1812
1813 // Avoid appealing to ValueConversions at bootstrap time:
1814 private static int identity_I(int x) { return x; }
1815 private static long identity_J(long x) { return x; }
1816 private static float identity_F(float x) { return x; }
1817 private static double identity_D(double x) { return x; }
1818 private static Object identity_L(Object x) { return x; }
1819 private static void identity_V() { return; }
1820 private static int zero_I() { return 0; }
1821 private static long zero_J() { return 0; }
1822 private static float zero_F() { return 0; }
1823 private static double zero_D() { return 0; }
1824 private static Object zero_L() { return null; }
1825
1826 /**
1827 * Internal marker for byte-compiled LambdaForms.
1828 */
1829 /*non-public*/
1830 @Target(ElementType.METHOD)
1831 @Retention(RetentionPolicy.RUNTIME)
1832 @interface Compiled {
1833 }
1834
1835 /**
1836 * Internal marker for LambdaForm interpreter frames.
1837 */
1838 /*non-public*/
1839 @Target(ElementType.METHOD)
1840 @Retention(RetentionPolicy.RUNTIME)
1841 @interface Hidden {
1842 }
1843
1844 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1845 private static final HashMap<LambdaForm,String> DEBUG_NAMES;
1846 static {
1847 if (debugEnabled()) {
1848 DEBUG_NAME_COUNTERS = new HashMap<>();
1849 DEBUG_NAMES = new HashMap<>();
1850 } else {
1851 DEBUG_NAME_COUNTERS = null;
1852 DEBUG_NAMES = null;
1853 }
1854 }
1855
1856 static {
1857 // The Holder class will contain pre-generated forms resolved
1858 // using MemberName.getFactory(). However, that doesn't initialize the
1859 // class, which subtly breaks inlining etc. By forcing
1860 // initialization of the Holder class we avoid these issues.
1861 UNSAFE.ensureClassInitialized(Holder.class);
1862 }
1863
1864 /* Placeholder class for zero and identity forms generated ahead of time */
1865 final class Holder {}
1866
1867 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1868 // during execution of the static initializes of this class.
1869 // Turning on TRACE_INTERPRETER too early will cause
1870 // stack overflows and other misbehavior during attempts to trace events
1871 // that occur during LambdaForm.<clinit>.
1872 // Therefore, do not move this line higher in this file, and do not remove.
1873 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1874 }