1 /*
2 * Copyright (c) 2011, 2016, 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 import java.util.Objects;
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 String debugName;
131 final Kind kind;
132 MemberName vmentry; // low-level behavior, or null if not yet prepared
133 private boolean isCompiled;
134
135 // Either a LambdaForm cache (managed by LambdaFormEditor) or a link to uncustomized version (for customized LF)
136 volatile Object transformCache;
137
138 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
139
140 enum BasicType {
141 L_TYPE('L', Object.class, Wrapper.OBJECT), // all reference types
142 I_TYPE('I', int.class, Wrapper.INT),
143 J_TYPE('J', long.class, Wrapper.LONG),
144 F_TYPE('F', float.class, Wrapper.FLOAT),
145 D_TYPE('D', double.class, Wrapper.DOUBLE), // all primitive types
146 V_TYPE('V', void.class, Wrapper.VOID); // not valid in all contexts
147
148 static final BasicType[] ALL_TYPES = BasicType.values();
149 static final BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
150
151 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
152 static final int TYPE_LIMIT = ALL_TYPES.length;
153
154 final char btChar;
155 final Class<?> btClass;
156 final Wrapper btWrapper;
157
158 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper) {
159 this.btChar = btChar;
160 this.btClass = btClass;
161 this.btWrapper = wrapper;
162 }
163
164 char basicTypeChar() {
165 return btChar;
166 }
167 Class<?> basicTypeClass() {
168 return btClass;
169 }
170 Wrapper basicTypeWrapper() {
171 return btWrapper;
172 }
173 int basicTypeSlots() {
174 return btWrapper.stackSlots();
175 }
176
177 static BasicType basicType(byte type) {
178 return ALL_TYPES[type];
179 }
180 static BasicType basicType(char type) {
181 switch (type) {
182 case 'L': return L_TYPE;
183 case 'I': return I_TYPE;
184 case 'J': return J_TYPE;
185 case 'F': return F_TYPE;
186 case 'D': return D_TYPE;
187 case 'V': return V_TYPE;
188 // all subword types are represented as ints
189 case 'Z':
190 case 'B':
191 case 'S':
192 case 'C':
193 return I_TYPE;
194 default:
195 throw newInternalError("Unknown type char: '"+type+"'");
196 }
197 }
198 static BasicType basicType(Wrapper type) {
199 char c = type.basicTypeChar();
200 return basicType(c);
201 }
202 static BasicType basicType(Class<?> type) {
203 if (!type.isPrimitive()) return L_TYPE;
204 return basicType(Wrapper.forPrimitiveType(type));
205 }
206 static BasicType[] basicTypes(String types) {
207 BasicType[] btypes = new BasicType[types.length()];
208 for (int i = 0; i < btypes.length; i++) {
209 btypes[i] = basicType(types.charAt(i));
210 }
211 return btypes;
212 }
213 static String basicTypeDesc(BasicType[] types) {
214 if (types == null) {
215 return null;
216 }
217 if (types.length == 0) {
218 return "";
219 }
220 StringBuilder sb = new StringBuilder();
221 for (BasicType bt : types) {
222 sb.append(bt.basicTypeChar());
223 }
224 return sb.toString();
225 }
226 static int[] basicTypeOrds(BasicType[] types) {
227 if (types == null) {
228 return null;
229 }
230 int[] a = new int[types.length];
231 for(int i = 0; i < types.length; ++i) {
232 a[i] = types[i].ordinal();
233 }
234 return a;
235 }
236
237 static char basicTypeChar(Class<?> type) {
238 return basicType(type).btChar;
239 }
240
241 static byte[] basicTypesOrd(Class<?>[] types) {
242 byte[] ords = new byte[types.length];
243 for (int i = 0; i < ords.length; i++) {
244 ords[i] = (byte)basicType(types[i]).ordinal();
245 }
246 return ords;
247 }
248
249 static boolean isBasicTypeChar(char c) {
250 return "LIJFDV".indexOf(c) >= 0;
251 }
252 static boolean isArgBasicTypeChar(char c) {
253 return "LIJFD".indexOf(c) >= 0;
254 }
255
256 static { assert(checkBasicType()); }
257 private static boolean checkBasicType() {
258 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
259 assert ARG_TYPES[i].ordinal() == i;
260 assert ARG_TYPES[i] == ALL_TYPES[i];
261 }
262 for (int i = 0; i < TYPE_LIMIT; i++) {
263 assert ALL_TYPES[i].ordinal() == i;
264 }
265 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
266 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
267 return true;
268 }
269 }
270
271 enum Kind {
272 GENERIC(""),
273 ZERO("zero"),
274 IDENTITY("identity"),
275 BOUND_REINVOKER("BMH.reinvoke"),
276 REINVOKER("MH.reinvoke"),
277 DELEGATE("MH.delegate"),
278 DIRECT_INVOKE_VIRTUAL("DMH.invokeVirtual"),
279 DIRECT_INVOKE_SPECIAL("DMH.invokeSpecial"),
280 DIRECT_INVOKE_STATIC("DMH.invokeStatic"),
281 DIRECT_NEW_INVOKE_SPECIAL("DMH.newInvokeSpecial"),
282 DIRECT_INVOKE_INTERFACE("DMH.invokeInterface"),
283 DIRECT_INVOKE_STATIC_INIT("DMH.invokeStaticInit"),
284 GET_OBJECT("getObject"),
285 PUT_OBJECT("putObject"),
286 GET_OBJECT_VOLATILE("getObjectVolatile"),
287 PUT_OBJECT_VOLATILE("putObjectVolatile"),
288 GET_INT("getInt"),
289 PUT_INT("putInt"),
290 GET_INT_VOLATILE("getIntVolatile"),
291 PUT_INT_VOLATILE("putIntVolatile"),
292 GET_BOOLEAN("getBoolean"),
293 PUT_BOOLEAN("putBoolean"),
294 GET_BOOLEAN_VOLATILE("getBooleanVolatile"),
295 PUT_BOOLEAN_VOLATILE("putBooleanVolatile"),
296 GET_BYTE("getByte"),
297 PUT_BYTE("putByte"),
298 GET_BYTE_VOLATILE("getByteVolatile"),
299 PUT_BYTE_VOLATILE("putByteVolatile"),
300 GET_CHAR("getChar"),
301 PUT_CHAR("putChar"),
302 GET_CHAR_VOLATILE("getCharVolatile"),
303 PUT_CHAR_VOLATILE("putCharVolatile"),
304 GET_SHORT("getShort"),
305 PUT_SHORT("putShort"),
306 GET_SHORT_VOLATILE("getShortVolatile"),
307 PUT_SHORT_VOLATILE("putShortVolatile"),
308 GET_LONG("getLong"),
309 PUT_LONG("putLong"),
310 GET_LONG_VOLATILE("getLongVolatile"),
311 PUT_LONG_VOLATILE("putLongVolatile"),
312 GET_FLOAT("getFloat"),
313 PUT_FLOAT("putFloat"),
314 GET_FLOAT_VOLATILE("getFloatVolatile"),
315 PUT_FLOAT_VOLATILE("putFloatVolatile"),
316 GET_DOUBLE("getDouble"),
317 PUT_DOUBLE("putDouble"),
318 GET_DOUBLE_VOLATILE("getDoubleVolatile"),
319 PUT_DOUBLE_VOLATILE("putDoubleVolatile");
320
321 final String defaultLambdaName;
322 final String methodName;
323
324 private Kind(String defaultLambdaName) {
325 this.defaultLambdaName = defaultLambdaName;
326 int p = defaultLambdaName.indexOf('.');
327 if (p > -1) {
328 this.methodName = defaultLambdaName.substring(p + 1);
329 } else {
330 this.methodName = defaultLambdaName;
331 }
332 }
333 }
334
335 LambdaForm(String debugName,
336 int arity, Name[] names, int result) {
337 this(debugName, arity, names, result, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
338 }
339 LambdaForm(String debugName,
340 int arity, Name[] names, int result, Kind kind) {
341 this(debugName, arity, names, result, /*forceInline=*/true, /*customized=*/null, kind);
342 }
343 LambdaForm(String debugName,
344 int arity, Name[] names, int result, boolean forceInline, MethodHandle customized) {
345 this(debugName, arity, names, result, forceInline, customized, Kind.GENERIC);
346 }
347 LambdaForm(String debugName,
348 int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
349 assert(namesOK(arity, names));
350 this.arity = arity;
351 this.result = fixResult(result, names);
352 this.names = names.clone();
353 this.debugName = fixDebugName(debugName);
354 this.forceInline = forceInline;
355 this.customized = customized;
356 this.kind = kind;
357 int maxOutArity = normalize();
358 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
359 // Cannot use LF interpreter on very high arity expressions.
360 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
361 compileToBytecode();
362 }
363 }
364 LambdaForm(String debugName,
365 int arity, Name[] names) {
366 this(debugName, arity, names, LAST_RESULT, /*forceInline=*/true, /*customized=*/null, Kind.GENERIC);
367 }
368 LambdaForm(String debugName,
369 int arity, Name[] names, boolean forceInline) {
370 this(debugName, arity, names, LAST_RESULT, forceInline, /*customized=*/null, Kind.GENERIC);
371 }
372 LambdaForm(String debugName,
373 int arity, Name[] names, boolean forceInline, Kind kind) {
374 this(debugName, arity, names, LAST_RESULT, forceInline, /*customized=*/null, kind);
375 }
376 LambdaForm(String debugName,
377 Name[] formals, Name[] temps, Name result) {
378 this(debugName,
379 formals.length, buildNames(formals, temps, result), LAST_RESULT, /*forceInline=*/true, /*customized=*/null);
380 }
381 LambdaForm(String debugName,
382 Name[] formals, Name[] temps, Name result, boolean forceInline) {
383 this(debugName,
384 formals.length, buildNames(formals, temps, result), LAST_RESULT, forceInline, /*customized=*/null);
385 }
386
387 private static Name[] buildNames(Name[] formals, Name[] temps, Name result) {
388 int arity = formals.length;
389 int length = arity + temps.length + (result == null ? 0 : 1);
390 Name[] names = Arrays.copyOf(formals, length);
391 System.arraycopy(temps, 0, names, arity, temps.length);
392 if (result != null)
393 names[length - 1] = result;
394 return names;
395 }
396
397 private LambdaForm(MethodType mt) {
398 // Make a blank lambda form, which returns a constant zero or null.
399 // It is used as a template for managing the invocation of similar forms that are non-empty.
400 // Called only from getPreparedForm.
401 this.arity = mt.parameterCount();
402 this.result = (mt.returnType() == void.class || mt.returnType() == Void.class) ? -1 : arity;
403 this.names = buildEmptyNames(arity, mt, result == -1);
404 this.debugName = "LF.zero";
405 this.forceInline = true;
406 this.customized = null;
407 this.kind = Kind.GENERIC;
408 assert(nameRefsAreLegal());
409 assert(isEmpty());
410 String sig = null;
411 assert(isValidSignature(sig = basicTypeSignature()));
412 assert(sig.equals(basicTypeSignature())) : sig + " != " + basicTypeSignature();
413 }
414
415 private static Name[] buildEmptyNames(int arity, MethodType mt, boolean isVoid) {
416 Name[] names = arguments(isVoid ? 0 : 1, mt);
417 if (!isVoid) {
418 Name zero = new Name(constantZero(basicType(mt.returnType())));
419 names[arity] = zero.newIndex(arity);
420 }
421 return names;
422 }
423
424 private static int fixResult(int result, Name[] names) {
425 if (result == LAST_RESULT)
426 result = names.length - 1; // might still be void
427 if (result >= 0 && names[result].type == V_TYPE)
428 result = VOID_RESULT;
429 return result;
430 }
431
432 private static String fixDebugName(String debugName) {
433 if (DEBUG_NAME_COUNTERS != null) {
434 int under = debugName.indexOf('_');
435 int length = debugName.length();
436 if (under < 0) under = length;
437 String debugNameStem = debugName.substring(0, under);
438 Integer ctr;
439 synchronized (DEBUG_NAME_COUNTERS) {
440 ctr = DEBUG_NAME_COUNTERS.get(debugNameStem);
441 if (ctr == null) ctr = 0;
442 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr+1);
443 }
444 StringBuilder buf = new StringBuilder(debugNameStem);
445 buf.append('_');
446 int leadingZero = buf.length();
447 buf.append((int) ctr);
448 for (int i = buf.length() - leadingZero; i < 3; i++)
449 buf.insert(leadingZero, '0');
450 if (under < length) {
451 ++under; // skip "_"
452 while (under < length && Character.isDigit(debugName.charAt(under))) {
453 ++under;
454 }
455 if (under < length && debugName.charAt(under) == '_') ++under;
456 if (under < length)
457 buf.append('_').append(debugName, under, length);
458 }
459 return buf.toString();
460 }
461 return debugName;
462 }
463
464 private static boolean namesOK(int arity, Name[] names) {
465 for (int i = 0; i < names.length; i++) {
466 Name n = names[i];
467 assert(n != null) : "n is null";
468 if (i < arity)
469 assert( n.isParam()) : n + " is not param at " + i;
470 else
471 assert(!n.isParam()) : n + " is param at " + i;
472 }
473 return true;
474 }
475
476 /** Customize LambdaForm for a particular MethodHandle */
477 LambdaForm customize(MethodHandle mh) {
478 LambdaForm customForm = new LambdaForm(debugName, arity, names, result, forceInline, mh, kind);
479 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
480 // If shared LambdaForm has been compiled, compile customized version as well.
481 customForm.compileToBytecode();
482 }
483 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
484 return customForm;
485 }
486
487 /** Get uncustomized flavor of the LambdaForm */
488 LambdaForm uncustomize() {
489 if (customized == null) {
490 return this;
491 }
492 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
493 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
494 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
495 // If customized LambdaForm has been compiled, compile uncustomized version as well.
496 uncustomizedForm.compileToBytecode();
497 }
498 return uncustomizedForm;
499 }
500
501 /** Renumber and/or replace params so that they are interned and canonically numbered.
502 * @return maximum argument list length among the names (since we have to pass over them anyway)
503 */
504 private int normalize() {
505 Name[] oldNames = null;
506 int maxOutArity = 0;
507 int changesStart = 0;
508 for (int i = 0; i < names.length; i++) {
509 Name n = names[i];
510 if (!n.initIndex(i)) {
511 if (oldNames == null) {
512 oldNames = names.clone();
513 changesStart = i;
514 }
515 names[i] = n.cloneWithIndex(i);
516 }
517 if (n.arguments != null && maxOutArity < n.arguments.length)
518 maxOutArity = n.arguments.length;
519 }
520 if (oldNames != null) {
521 int startFixing = arity;
522 if (startFixing <= changesStart)
523 startFixing = changesStart+1;
524 for (int i = startFixing; i < names.length; i++) {
525 Name fixed = names[i].replaceNames(oldNames, names, changesStart, i);
526 names[i] = fixed.newIndex(i);
527 }
528 }
529 assert(nameRefsAreLegal());
530 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
531 boolean needIntern = false;
532 for (int i = 0; i < maxInterned; i++) {
533 Name n = names[i], n2 = internArgument(n);
534 if (n != n2) {
535 names[i] = n2;
536 needIntern = true;
537 }
538 }
539 if (needIntern) {
540 for (int i = arity; i < names.length; i++) {
541 names[i].internArguments();
542 }
543 }
544 assert(nameRefsAreLegal());
545 return maxOutArity;
546 }
547
548 /**
549 * Check that all embedded Name references are localizable to this lambda,
550 * and are properly ordered after their corresponding definitions.
551 * <p>
552 * Note that a Name can be local to multiple lambdas, as long as
553 * it possesses the same index in each use site.
554 * This allows Name references to be freely reused to construct
555 * fresh lambdas, without confusion.
556 */
557 boolean nameRefsAreLegal() {
558 assert(arity >= 0 && arity <= names.length);
559 assert(result >= -1 && result < names.length);
560 // Do all names possess an index consistent with their local definition order?
561 for (int i = 0; i < arity; i++) {
562 Name n = names[i];
563 assert(n.index() == i) : Arrays.asList(n.index(), i);
564 assert(n.isParam());
565 }
566 // Also, do all local name references
567 for (int i = arity; i < names.length; i++) {
568 Name n = names[i];
569 assert(n.index() == i);
570 for (Object arg : n.arguments) {
571 if (arg instanceof Name) {
572 Name n2 = (Name) arg;
573 int i2 = n2.index;
574 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
575 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
576 assert(i2 < i); // ref must come after def!
577 }
578 }
579 }
580 return true;
581 }
582
583 /** Invoke this form on the given arguments. */
584 // final Object invoke(Object... args) throws Throwable {
585 // // NYI: fit this into the fast path?
586 // return interpretWithArguments(args);
587 // }
588
589 /** Report the return type. */
590 BasicType returnType() {
591 if (result < 0) return V_TYPE;
592 Name n = names[result];
593 return n.type;
594 }
595
596 /** Report the N-th argument type. */
597 BasicType parameterType(int n) {
598 return parameter(n).type;
599 }
600
601 /** Report the N-th argument name. */
602 Name parameter(int n) {
603 assert(n < arity);
604 Name param = names[n];
605 assert(param.isParam());
606 return param;
607 }
608
609 /** Report the N-th argument type constraint. */
610 Object parameterConstraint(int n) {
611 return parameter(n).constraint;
612 }
613
614 /** Report the arity. */
615 int arity() {
616 return arity;
617 }
618
619 /** Report the number of expressions (non-parameter names). */
620 int expressionCount() {
621 return names.length - arity;
622 }
623
624 /** Return the method type corresponding to my basic type signature. */
625 MethodType methodType() {
626 Class<?>[] ptypes = new Class<?>[arity];
627 for (int i = 0; i < arity; ++i) {
628 ptypes[i] = parameterType(i).btClass;
629 }
630 return MethodType.methodType(returnType().btClass, ptypes);
631 }
632
633 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
634 final String basicTypeSignature() {
635 StringBuilder buf = new StringBuilder(arity() + 3);
636 for (int i = 0, a = arity(); i < a; i++)
637 buf.append(parameterType(i).basicTypeChar());
638 return buf.append('_').append(returnType().basicTypeChar()).toString();
639 }
640 static int signatureArity(String sig) {
641 assert(isValidSignature(sig));
642 return sig.indexOf('_');
643 }
644 static BasicType signatureReturn(String sig) {
645 return basicType(sig.charAt(signatureArity(sig) + 1));
646 }
647 static boolean isValidSignature(String sig) {
648 int arity = sig.indexOf('_');
649 if (arity < 0) return false; // must be of the form *_*
650 int siglen = sig.length();
651 if (siglen != arity + 2) return false; // *_X
652 for (int i = 0; i < siglen; i++) {
653 if (i == arity) continue; // skip '_'
654 char c = sig.charAt(i);
655 if (c == 'V')
656 return (i == siglen - 1 && arity == siglen - 2);
657 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
658 }
659 return true; // [LIJFD]*_[LIJFDV]
660 }
661 static MethodType signatureType(String sig) {
662 Class<?>[] ptypes = new Class<?>[signatureArity(sig)];
663 for (int i = 0; i < ptypes.length; i++)
664 ptypes[i] = basicType(sig.charAt(i)).btClass;
665 Class<?> rtype = signatureReturn(sig).btClass;
666 return MethodType.methodType(rtype, ptypes);
667 }
668
669 /**
670 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
671 */
672 boolean isSelectAlternative(int pos) {
673 // selectAlternative idiom:
674 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
675 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
676 if (pos+1 >= names.length) return false;
677 Name name0 = names[pos];
678 Name name1 = names[pos+1];
679 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
680 name1.isInvokeBasic() &&
681 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
682 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
683 }
684
685 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
686 if (pos+2 >= names.length) return false;
687 Name name0 = names[pos];
688 Name name1 = names[pos+1];
689 Name name2 = names[pos+2];
690 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
691 name0.isInvokeBasic() &&
692 name2.isInvokeBasic() &&
693 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
694 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
695 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
696 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
697 }
698
699 /**
700 * Check if i-th name is a start of GuardWithCatch idiom.
701 */
702 boolean isGuardWithCatch(int pos) {
703 // GuardWithCatch idiom:
704 // t_{n}:L=MethodHandle.invokeBasic(...)
705 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
706 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
707 return isMatchingIdiom(pos, "guardWithCatch", 3);
708 }
709
710 /**
711 * Check if i-th name is a start of the tryFinally idiom.
712 */
713 boolean isTryFinally(int pos) {
714 // tryFinally idiom:
715 // t_{n}:L=MethodHandle.invokeBasic(...)
716 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
717 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
718 return isMatchingIdiom(pos, "tryFinally", 2);
719 }
720
721 /**
722 * Check if i-th name is a start of the loop idiom.
723 */
724 boolean isLoop(int pos) {
725 // loop idiom:
726 // t_{n}:L=MethodHandle.invokeBasic(...)
727 // t_{n+1}:L=MethodHandleImpl.loop(types, *, *, *, *, t_{n})
728 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
729 return isMatchingIdiom(pos, "loop", 5);
730 }
731
732 /*
733 * Code generation issues:
734 *
735 * Compiled LFs should be reusable in general.
736 * The biggest issue is how to decide when to pull a name into
737 * the bytecode, versus loading a reified form from the MH data.
738 *
739 * For example, an asType wrapper may require execution of a cast
740 * after a call to a MH. The target type of the cast can be placed
741 * as a constant in the LF itself. This will force the cast type
742 * to be compiled into the bytecodes and native code for the MH.
743 * Or, the target type of the cast can be erased in the LF, and
744 * loaded from the MH data. (Later on, if the MH as a whole is
745 * inlined, the data will flow into the inlined instance of the LF,
746 * as a constant, and the end result will be an optimal cast.)
747 *
748 * This erasure of cast types can be done with any use of
749 * reference types. It can also be done with whole method
750 * handles. Erasing a method handle might leave behind
751 * LF code that executes correctly for any MH of a given
752 * type, and load the required MH from the enclosing MH's data.
753 * Or, the erasure might even erase the expected MT.
754 *
755 * Also, for direct MHs, the MemberName of the target
756 * could be erased, and loaded from the containing direct MH.
757 * As a simple case, a LF for all int-valued non-static
758 * field getters would perform a cast on its input argument
759 * (to non-constant base type derived from the MemberName)
760 * and load an integer value from the input object
761 * (at a non-constant offset also derived from the MemberName).
762 * Such MN-erased LFs would be inlinable back to optimized
763 * code, whenever a constant enclosing DMH is available
764 * to supply a constant MN from its data.
765 *
766 * The main problem here is to keep LFs reasonably generic,
767 * while ensuring that hot spots will inline good instances.
768 * "Reasonably generic" means that we don't end up with
769 * repeated versions of bytecode or machine code that do
770 * not differ in their optimized form. Repeated versions
771 * of machine would have the undesirable overheads of
772 * (a) redundant compilation work and (b) extra I$ pressure.
773 * To control repeated versions, we need to be ready to
774 * erase details from LFs and move them into MH data,
775 * whevener those details are not relevant to significant
776 * optimization. "Significant" means optimization of
777 * code that is actually hot.
778 *
779 * Achieving this may require dynamic splitting of MHs, by replacing
780 * a generic LF with a more specialized one, on the same MH,
781 * if (a) the MH is frequently executed and (b) the MH cannot
782 * be inlined into a containing caller, such as an invokedynamic.
783 *
784 * Compiled LFs that are no longer used should be GC-able.
785 * If they contain non-BCP references, they should be properly
786 * interlinked with the class loader(s) that their embedded types
787 * depend on. This probably means that reusable compiled LFs
788 * will be tabulated (indexed) on relevant class loaders,
789 * or else that the tables that cache them will have weak links.
790 */
791
792 /**
793 * Make this LF directly executable, as part of a MethodHandle.
794 * Invariant: Every MH which is invoked must prepare its LF
795 * before invocation.
796 * (In principle, the JVM could do this very lazily,
797 * as a sort of pre-invocation linkage step.)
798 */
799 public void prepare() {
800 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
801 compileToBytecode();
802 }
803 if (this.vmentry != null) {
804 // already prepared (e.g., a primitive DMH invoker form)
805 return;
806 }
807 MethodType mtype = methodType();
808 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
809 if (prep == null) {
810 assert (isValidSignature(basicTypeSignature()));
811 prep = new LambdaForm(mtype);
812 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
813 prep = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
814 }
815 this.vmentry = prep.vmentry;
816 // TO DO: Maybe add invokeGeneric, invokeWithArguments
817 }
818
819 private static @Stable PerfCounter LF_FAILED;
820
821 private static PerfCounter failedCompilationCounter() {
822 if (LF_FAILED == null) {
823 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
824 }
825 return LF_FAILED;
826 }
827
828 /** Generate optimizable bytecode for this form. */
829 void compileToBytecode() {
830 if (forceInterpretation()) {
831 return; // this should not be compiled
832 }
833 if (vmentry != null && isCompiled) {
834 return; // already compiled somehow
835 }
836 MethodType invokerType = methodType();
837 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
838 try {
839 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
840 if (TRACE_INTERPRETER)
841 traceInterpreter("compileToBytecode", this);
842 isCompiled = true;
843 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
844 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
845 invocationCounter = -1;
846 failedCompilationCounter().increment();
847 if (LOG_LF_COMPILATION_FAILURE) {
848 System.out.println("LambdaForm compilation failed: " + this);
849 bge.printStackTrace(System.out);
850 }
851 } catch (Error | Exception e) {
852 throw newInternalError(this.toString(), e);
853 }
854 }
855
856 private static void computeInitialPreparedForms() {
857 // Find all predefined invokers and associate them with canonical empty lambda forms.
858 for (MemberName m : MemberName.getFactory().getMethods(LambdaForm.class, false, null, null, null)) {
859 if (!m.isStatic() || !m.isPackage()) continue;
860 MethodType mt = m.getMethodType();
861 if (mt.parameterCount() > 0 &&
862 mt.parameterType(0) == MethodHandle.class &&
863 m.getName().startsWith("interpret_")) {
864 String sig = null;
865 assert((sig = basicTypeSignature(mt)) != null &&
866 m.getName().equals("interpret" + sig.substring(sig.indexOf('_'))));
867 LambdaForm form = new LambdaForm(mt);
868 form.vmentry = m;
869 form = mt.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, form);
870 }
871 }
872 }
873
874 // Set this false to disable use of the interpret_L methods defined in this file.
875 private static final boolean USE_PREDEFINED_INTERPRET_METHODS = true;
876
877 // The following are predefined exact invokers. The system must build
878 // a separate invoker for each distinct signature.
879 static Object interpret_L(MethodHandle mh) throws Throwable {
880 Object[] av = {mh};
881 String sig = null;
882 assert(argumentTypesMatch(sig = "L_L", av));
883 Object res = mh.form.interpretWithArguments(av);
884 assert(returnTypesMatch(sig, av, res));
885 return res;
886 }
887 static Object interpret_L(MethodHandle mh, Object x1) throws Throwable {
888 Object[] av = {mh, x1};
889 String sig = null;
890 assert(argumentTypesMatch(sig = "LL_L", av));
891 Object res = mh.form.interpretWithArguments(av);
892 assert(returnTypesMatch(sig, av, res));
893 return res;
894 }
895 static Object interpret_L(MethodHandle mh, Object x1, Object x2) throws Throwable {
896 Object[] av = {mh, x1, x2};
897 String sig = null;
898 assert(argumentTypesMatch(sig = "LLL_L", av));
899 Object res = mh.form.interpretWithArguments(av);
900 assert(returnTypesMatch(sig, av, res));
901 return res;
902 }
903
904 // The next few routines are called only from assert expressions
905 // They verify that the built-in invokers process the correct raw data types.
906 private static boolean argumentTypesMatch(String sig, Object[] av) {
907 int arity = signatureArity(sig);
908 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
909 assert(av[0] instanceof MethodHandle) : "av[0] not instace of MethodHandle: " + av[0];
910 MethodHandle mh = (MethodHandle) av[0];
911 MethodType mt = mh.type();
912 assert(mt.parameterCount() == arity-1);
913 for (int i = 0; i < av.length; i++) {
914 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
915 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
916 }
917 return true;
918 }
919 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
920 // The following line is needed because (...)void method handles can use non-void invokers
921 if (type == void.class) tc = V_TYPE; // can drop any kind of value
922 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
923 switch (tc) {
924 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
925 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
926 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
927 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
928 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
929 case V_TYPE: break; // allow anything here; will be dropped
930 default: assert(false);
931 }
932 return true;
933 }
934 private static boolean returnTypesMatch(String sig, Object[] av, Object res) {
935 MethodHandle mh = (MethodHandle) av[0];
936 return valueMatches(signatureReturn(sig), mh.type().returnType(), res);
937 }
938 private static boolean checkInt(Class<?> type, Object x) {
939 assert(x instanceof Integer);
940 if (type == int.class) return true;
941 Wrapper w = Wrapper.forBasicType(type);
942 assert(w.isSubwordOrInt());
943 Object x1 = Wrapper.INT.wrap(w.wrap(x));
944 return x.equals(x1);
945 }
946 private static boolean checkRef(Class<?> type, Object x) {
947 assert(!type.isPrimitive());
948 if (x == null) return true;
949 if (type.isInterface()) return true;
950 return type.isInstance(x);
951 }
952
953 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
954 private static final int COMPILE_THRESHOLD;
955 static {
956 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
957 }
958 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
959
960 private boolean forceInterpretation() {
961 return invocationCounter == -1;
962 }
963
964 @Hidden
965 @DontInline
966 /** Interpretively invoke this form on the given arguments. */
967 Object interpretWithArguments(Object... argumentValues) throws Throwable {
968 if (TRACE_INTERPRETER)
969 return interpretWithArgumentsTracing(argumentValues);
970 checkInvocationCounter();
971 assert(arityCheck(argumentValues));
972 Object[] values = Arrays.copyOf(argumentValues, names.length);
973 for (int i = argumentValues.length; i < values.length; i++) {
974 values[i] = interpretName(names[i], values);
975 }
976 Object rv = (result < 0) ? null : values[result];
977 assert(resultCheck(argumentValues, rv));
978 return rv;
979 }
980
981 @Hidden
982 @DontInline
983 /** Evaluate a single Name within this form, applying its function to its arguments. */
984 Object interpretName(Name name, Object[] values) throws Throwable {
985 if (TRACE_INTERPRETER)
986 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
987 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
988 for (int i = 0; i < arguments.length; i++) {
989 Object a = arguments[i];
990 if (a instanceof Name) {
991 int i2 = ((Name)a).index();
992 assert(names[i2] == a);
993 a = values[i2];
994 arguments[i] = a;
995 }
996 }
997 return name.function.invokeWithArguments(arguments);
998 }
999
1000 private void checkInvocationCounter() {
1001 if (COMPILE_THRESHOLD != 0 &&
1002 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
1003 invocationCounter++; // benign race
1004 if (invocationCounter >= COMPILE_THRESHOLD) {
1005 // Replace vmentry with a bytecode version of this LF.
1006 compileToBytecode();
1007 }
1008 }
1009 }
1010 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
1011 traceInterpreter("[ interpretWithArguments", this, argumentValues);
1012 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
1013 int ctr = invocationCounter++; // benign race
1014 traceInterpreter("| invocationCounter", ctr);
1015 if (invocationCounter >= COMPILE_THRESHOLD) {
1016 compileToBytecode();
1017 }
1018 }
1019 Object rval;
1020 try {
1021 assert(arityCheck(argumentValues));
1022 Object[] values = Arrays.copyOf(argumentValues, names.length);
1023 for (int i = argumentValues.length; i < values.length; i++) {
1024 values[i] = interpretName(names[i], values);
1025 }
1026 rval = (result < 0) ? null : values[result];
1027 } catch (Throwable ex) {
1028 traceInterpreter("] throw =>", ex);
1029 throw ex;
1030 }
1031 traceInterpreter("] return =>", rval);
1032 return rval;
1033 }
1034
1035 static void traceInterpreter(String event, Object obj, Object... args) {
1036 if (TRACE_INTERPRETER) {
1037 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
1038 }
1039 }
1040 static void traceInterpreter(String event, Object obj) {
1041 traceInterpreter(event, obj, (Object[])null);
1042 }
1043 private boolean arityCheck(Object[] argumentValues) {
1044 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
1045 // also check that the leading (receiver) argument is somehow bound to this LF:
1046 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
1047 MethodHandle mh = (MethodHandle) argumentValues[0];
1048 assert(mh.internalForm() == this);
1049 // note: argument #0 could also be an interface wrapper, in the future
1050 argumentTypesMatch(basicTypeSignature(), argumentValues);
1051 return true;
1052 }
1053 private boolean resultCheck(Object[] argumentValues, Object result) {
1054 MethodHandle mh = (MethodHandle) argumentValues[0];
1055 MethodType mt = mh.type();
1056 assert(valueMatches(returnType(), mt.returnType(), result));
1057 return true;
1058 }
1059
1060 private boolean isEmpty() {
1061 if (result < 0)
1062 return (names.length == arity);
1063 else if (result == arity && names.length == arity + 1)
1064 return names[arity].isConstantZero();
1065 else
1066 return false;
1067 }
1068
1069 public String toString() {
1070 StringBuilder buf = new StringBuilder(debugName+"=Lambda(");
1071 for (int i = 0; i < names.length; i++) {
1072 if (i == arity) buf.append(")=>{");
1073 Name n = names[i];
1074 if (i >= arity) buf.append("\n ");
1075 buf.append(n.paramString());
1076 if (i < arity) {
1077 if (i+1 < arity) buf.append(",");
1078 continue;
1079 }
1080 buf.append("=").append(n.exprString());
1081 buf.append(";");
1082 }
1083 if (arity == names.length) buf.append(")=>{");
1084 buf.append(result < 0 ? "void" : names[result]).append("}");
1085 if (TRACE_INTERPRETER) {
1086 // Extra verbosity:
1087 buf.append(":").append(basicTypeSignature());
1088 buf.append("/").append(vmentry);
1089 }
1090 return buf.toString();
1091 }
1092
1093 @Override
1094 public boolean equals(Object obj) {
1095 return obj instanceof LambdaForm && equals((LambdaForm)obj);
1096 }
1097 public boolean equals(LambdaForm that) {
1098 if (this.result != that.result) return false;
1099 return Arrays.equals(this.names, that.names);
1100 }
1101 public int hashCode() {
1102 return result + 31 * Arrays.hashCode(names);
1103 }
1104 LambdaFormEditor editor() {
1105 return LambdaFormEditor.lambdaFormEditor(this);
1106 }
1107
1108 boolean contains(Name name) {
1109 int pos = name.index();
1110 if (pos >= 0) {
1111 return pos < names.length && name.equals(names[pos]);
1112 }
1113 for (int i = arity; i < names.length; i++) {
1114 if (name.equals(names[i]))
1115 return true;
1116 }
1117 return false;
1118 }
1119
1120 static class NamedFunction {
1121 final MemberName member;
1122 private @Stable MethodHandle resolvedHandle;
1123 @Stable MethodHandle invoker;
1124
1125 NamedFunction(MethodHandle resolvedHandle) {
1126 this(resolvedHandle.internalMemberName(), resolvedHandle);
1127 }
1128 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1129 this.member = member;
1130 this.resolvedHandle = resolvedHandle;
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 assert(isInvokeBasic(member));
1144 }
1145
1146 private static boolean isInvokeBasic(MemberName member) {
1147 return member != null &&
1148 member.getDeclaringClass() == MethodHandle.class &&
1149 "invokeBasic".equals(member.getName());
1150 }
1151
1152 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1153 // Any LambdaForm containing such a member is not interpretable.
1154 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1155 // And even without the resolvedHandle, the name can still be compiled and optimized.
1156 NamedFunction(Method method) {
1157 this(new MemberName(method));
1158 }
1159 NamedFunction(MemberName member) {
1160 this(member, null);
1161 }
1162
1163 MethodHandle resolvedHandle() {
1164 if (resolvedHandle == null) resolve();
1165 return resolvedHandle;
1166 }
1167
1168 synchronized void resolve() {
1169 if (resolvedHandle == null) {
1170 resolvedHandle = DirectMethodHandle.make(member);
1171 }
1172 }
1173
1174 @Override
1175 public boolean equals(Object other) {
1176 if (this == other) return true;
1177 if (other == null) return false;
1178 if (!(other instanceof NamedFunction)) return false;
1179 NamedFunction that = (NamedFunction) other;
1180 return this.member != null && this.member.equals(that.member);
1181 }
1182
1183 @Override
1184 public int hashCode() {
1185 if (member != null)
1186 return member.hashCode();
1187 return super.hashCode();
1188 }
1189
1190 // Put the predefined NamedFunction invokers into the table.
1191 static void initializeInvokers() {
1192 for (MemberName m : MemberName.getFactory().getMethods(NamedFunction.class, false, null, null, null)) {
1193 if (!m.isStatic() || !m.isPackage()) continue;
1194 MethodType type = m.getMethodType();
1195 if (type.equals(INVOKER_METHOD_TYPE) &&
1196 m.getName().startsWith("invoke_")) {
1197 String sig = m.getName().substring("invoke_".length());
1198 int arity = LambdaForm.signatureArity(sig);
1199 MethodType srcType = MethodType.genericMethodType(arity);
1200 if (LambdaForm.signatureReturn(sig) == V_TYPE)
1201 srcType = srcType.changeReturnType(void.class);
1202 MethodTypeForm typeForm = srcType.form();
1203 typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, DirectMethodHandle.make(m));
1204 }
1205 }
1206 }
1207
1208 // The following are predefined NamedFunction invokers. The system must build
1209 // a separate invoker for each distinct signature.
1210 /** void return type invokers. */
1211 @Hidden
1212 static Object invoke__V(MethodHandle mh, Object[] a) throws Throwable {
1213 assert(arityCheck(0, void.class, mh, a));
1214 mh.invokeBasic();
1215 return null;
1216 }
1217 @Hidden
1218 static Object invoke_L_V(MethodHandle mh, Object[] a) throws Throwable {
1219 assert(arityCheck(1, void.class, mh, a));
1220 mh.invokeBasic(a[0]);
1221 return null;
1222 }
1223 @Hidden
1224 static Object invoke_LL_V(MethodHandle mh, Object[] a) throws Throwable {
1225 assert(arityCheck(2, void.class, mh, a));
1226 mh.invokeBasic(a[0], a[1]);
1227 return null;
1228 }
1229 @Hidden
1230 static Object invoke_LLL_V(MethodHandle mh, Object[] a) throws Throwable {
1231 assert(arityCheck(3, void.class, mh, a));
1232 mh.invokeBasic(a[0], a[1], a[2]);
1233 return null;
1234 }
1235 @Hidden
1236 static Object invoke_LLLL_V(MethodHandle mh, Object[] a) throws Throwable {
1237 assert(arityCheck(4, void.class, mh, a));
1238 mh.invokeBasic(a[0], a[1], a[2], a[3]);
1239 return null;
1240 }
1241 @Hidden
1242 static Object invoke_LLLLL_V(MethodHandle mh, Object[] a) throws Throwable {
1243 assert(arityCheck(5, void.class, mh, a));
1244 mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1245 return null;
1246 }
1247 /** Object return type invokers. */
1248 @Hidden
1249 static Object invoke__L(MethodHandle mh, Object[] a) throws Throwable {
1250 assert(arityCheck(0, mh, a));
1251 return mh.invokeBasic();
1252 }
1253 @Hidden
1254 static Object invoke_L_L(MethodHandle mh, Object[] a) throws Throwable {
1255 assert(arityCheck(1, mh, a));
1256 return mh.invokeBasic(a[0]);
1257 }
1258 @Hidden
1259 static Object invoke_LL_L(MethodHandle mh, Object[] a) throws Throwable {
1260 assert(arityCheck(2, mh, a));
1261 return mh.invokeBasic(a[0], a[1]);
1262 }
1263 @Hidden
1264 static Object invoke_LLL_L(MethodHandle mh, Object[] a) throws Throwable {
1265 assert(arityCheck(3, mh, a));
1266 return mh.invokeBasic(a[0], a[1], a[2]);
1267 }
1268 @Hidden
1269 static Object invoke_LLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1270 assert(arityCheck(4, mh, a));
1271 return mh.invokeBasic(a[0], a[1], a[2], a[3]);
1272 }
1273 @Hidden
1274 static Object invoke_LLLLL_L(MethodHandle mh, Object[] a) throws Throwable {
1275 assert(arityCheck(5, mh, a));
1276 return mh.invokeBasic(a[0], a[1], a[2], a[3], a[4]);
1277 }
1278 private static boolean arityCheck(int arity, MethodHandle mh, Object[] a) {
1279 return arityCheck(arity, Object.class, mh, a);
1280 }
1281 private static boolean arityCheck(int arity, Class<?> rtype, MethodHandle mh, Object[] a) {
1282 assert(a.length == arity)
1283 : Arrays.asList(a.length, arity);
1284 assert(mh.type().basicType() == MethodType.genericMethodType(arity).changeReturnType(rtype))
1285 : Arrays.asList(mh, rtype, arity);
1286 MemberName member = mh.internalMemberName();
1287 if (isInvokeBasic(member)) {
1288 assert(arity > 0);
1289 assert(a[0] instanceof MethodHandle);
1290 MethodHandle mh2 = (MethodHandle) a[0];
1291 assert(mh2.type().basicType() == MethodType.genericMethodType(arity-1).changeReturnType(rtype))
1292 : Arrays.asList(member, mh2, rtype, arity);
1293 }
1294 return true;
1295 }
1296
1297 static final MethodType INVOKER_METHOD_TYPE =
1298 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1299
1300 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1301 typeForm = typeForm.basicType().form(); // normalize to basic type
1302 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1303 if (mh != null) return mh;
1304 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1305 mh = DirectMethodHandle.make(invoker);
1306 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1307 if (mh2 != null) return mh2; // benign race
1308 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1309 throw newInternalError(mh.debugString());
1310 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1311 }
1312
1313 @Hidden
1314 Object invokeWithArguments(Object... arguments) throws Throwable {
1315 // If we have a cached invoker, call it right away.
1316 // NOTE: The invoker always returns a reference value.
1317 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1318 assert(checkArgumentTypes(arguments, methodType()));
1319 return invoker().invokeBasic(resolvedHandle(), arguments);
1320 }
1321
1322 @Hidden
1323 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1324 Object rval;
1325 try {
1326 traceInterpreter("[ call", this, arguments);
1327 if (invoker == null) {
1328 traceInterpreter("| getInvoker", this);
1329 invoker();
1330 }
1331 // resolvedHandle might be uninitialized, ok for tracing
1332 if (resolvedHandle == null) {
1333 traceInterpreter("| resolve", this);
1334 resolvedHandle();
1335 }
1336 assert(checkArgumentTypes(arguments, methodType()));
1337 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1338 } catch (Throwable ex) {
1339 traceInterpreter("] throw =>", ex);
1340 throw ex;
1341 }
1342 traceInterpreter("] return =>", rval);
1343 return rval;
1344 }
1345
1346 private MethodHandle invoker() {
1347 if (invoker != null) return invoker;
1348 // Get an invoker and cache it.
1349 return invoker = computeInvoker(methodType().form());
1350 }
1351
1352 private static boolean checkArgumentTypes(Object[] arguments, MethodType methodType) {
1353 if (true) return true; // FIXME
1354 MethodType dstType = methodType.form().erasedType();
1355 MethodType srcType = dstType.basicType().wrap();
1356 Class<?>[] ptypes = new Class<?>[arguments.length];
1357 for (int i = 0; i < arguments.length; i++) {
1358 Object arg = arguments[i];
1359 Class<?> ptype = arg == null ? Object.class : arg.getClass();
1360 // If the dest. type is a primitive we keep the
1361 // argument type.
1362 ptypes[i] = dstType.parameterType(i).isPrimitive() ? ptype : Object.class;
1363 }
1364 MethodType argType = MethodType.methodType(srcType.returnType(), ptypes).wrap();
1365 assert(argType.isConvertibleTo(srcType)) : "wrong argument types: cannot convert " + argType + " to " + srcType;
1366 return true;
1367 }
1368
1369 MethodType methodType() {
1370 if (resolvedHandle != null)
1371 return resolvedHandle.type();
1372 else
1373 // only for certain internal LFs during bootstrapping
1374 return member.getInvocationType();
1375 }
1376
1377 MemberName member() {
1378 assert(assertMemberIsConsistent());
1379 return member;
1380 }
1381
1382 // Called only from assert.
1383 private boolean assertMemberIsConsistent() {
1384 if (resolvedHandle instanceof DirectMethodHandle) {
1385 MemberName m = resolvedHandle.internalMemberName();
1386 assert(m.equals(member));
1387 }
1388 return true;
1389 }
1390
1391 Class<?> memberDeclaringClassOrNull() {
1392 return (member == null) ? null : member.getDeclaringClass();
1393 }
1394
1395 BasicType returnType() {
1396 return basicType(methodType().returnType());
1397 }
1398
1399 BasicType parameterType(int n) {
1400 return basicType(methodType().parameterType(n));
1401 }
1402
1403 int arity() {
1404 return methodType().parameterCount();
1405 }
1406
1407 public String toString() {
1408 if (member == null) return String.valueOf(resolvedHandle);
1409 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1410 }
1411
1412 public boolean isIdentity() {
1413 return this.equals(identity(returnType()));
1414 }
1415
1416 public boolean isConstantZero() {
1417 return this.equals(constantZero(returnType()));
1418 }
1419
1420 public MethodHandleImpl.Intrinsic intrinsicName() {
1421 return resolvedHandle == null ? MethodHandleImpl.Intrinsic.NONE
1422 : resolvedHandle.intrinsicName();
1423 }
1424 }
1425
1426 public static String basicTypeSignature(MethodType type) {
1427 int params = type.parameterCount();
1428 char[] sig = new char[params + 2];
1429 int sigp = 0;
1430 while (sigp < params) {
1431 sig[sigp] = basicTypeChar(type.parameterType(sigp++));
1432 }
1433 sig[sigp++] = '_';
1434 sig[sigp++] = basicTypeChar(type.returnType());
1435 assert(sigp == sig.length);
1436 return String.valueOf(sig);
1437 }
1438 public static String shortenSignature(String signature) {
1439 // Hack to make signatures more readable when they show up in method names.
1440 final int NO_CHAR = -1, MIN_RUN = 3;
1441 int c0, c1 = NO_CHAR, c1reps = 0;
1442 StringBuilder buf = null;
1443 int len = signature.length();
1444 if (len < MIN_RUN) return signature;
1445 for (int i = 0; i <= len; i++) {
1446 // shift in the next char:
1447 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1448 if (c1 == c0) { ++c1reps; continue; }
1449 // shift in the next count:
1450 int c0reps = c1reps; c1reps = 1;
1451 // end of a character run
1452 if (c0reps < MIN_RUN) {
1453 if (buf != null) {
1454 while (--c0reps >= 0)
1455 buf.append((char)c0);
1456 }
1457 continue;
1458 }
1459 // found three or more in a row
1460 if (buf == null)
1461 buf = new StringBuilder().append(signature, 0, i - c0reps);
1462 buf.append((char)c0).append(c0reps);
1463 }
1464 return (buf == null) ? signature : buf.toString();
1465 }
1466
1467 static final class Name {
1468 final BasicType type;
1469 @Stable short index;
1470 final NamedFunction function;
1471 final Object constraint; // additional type information, if not null
1472 @Stable final Object[] arguments;
1473
1474 private Name(int index, BasicType type, NamedFunction function, Object[] arguments) {
1475 this.index = (short)index;
1476 this.type = type;
1477 this.function = function;
1478 this.arguments = arguments;
1479 this.constraint = null;
1480 assert(this.index == index);
1481 }
1482 private Name(Name that, Object constraint) {
1483 this.index = that.index;
1484 this.type = that.type;
1485 this.function = that.function;
1486 this.arguments = that.arguments;
1487 this.constraint = constraint;
1488 assert(constraint == null || isParam()); // only params have constraints
1489 assert(constraint == null || constraint instanceof BoundMethodHandle.SpeciesData || constraint instanceof Class);
1490 }
1491 Name(MethodHandle function, Object... arguments) {
1492 this(new NamedFunction(function), arguments);
1493 }
1494 Name(MethodType functionType, Object... arguments) {
1495 this(new NamedFunction(functionType), arguments);
1496 assert(arguments[0] instanceof Name && ((Name)arguments[0]).type == L_TYPE);
1497 }
1498 Name(MemberName function, Object... arguments) {
1499 this(new NamedFunction(function), arguments);
1500 }
1501 Name(NamedFunction function, Object... arguments) {
1502 this(-1, function.returnType(), function, arguments = Arrays.copyOf(arguments, arguments.length, Object[].class));
1503 assert(typesMatch(function, arguments));
1504 }
1505 /** Create a raw parameter of the given type, with an expected index. */
1506 Name(int index, BasicType type) {
1507 this(index, type, null, null);
1508 }
1509 /** Create a raw parameter of the given type. */
1510 Name(BasicType type) { this(-1, type); }
1511
1512 BasicType type() { return type; }
1513 int index() { return index; }
1514 boolean initIndex(int i) {
1515 if (index != i) {
1516 if (index != -1) return false;
1517 index = (short)i;
1518 }
1519 return true;
1520 }
1521 char typeChar() {
1522 return type.btChar;
1523 }
1524
1525 void resolve() {
1526 if (function != null)
1527 function.resolve();
1528 }
1529
1530 Name newIndex(int i) {
1531 if (initIndex(i)) return this;
1532 return cloneWithIndex(i);
1533 }
1534 Name cloneWithIndex(int i) {
1535 Object[] newArguments = (arguments == null) ? null : arguments.clone();
1536 return new Name(i, type, function, newArguments).withConstraint(constraint);
1537 }
1538 Name withConstraint(Object constraint) {
1539 if (constraint == this.constraint) return this;
1540 return new Name(this, constraint);
1541 }
1542 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1543 if (oldName == newName) return this;
1544 @SuppressWarnings("LocalVariableHidesMemberVariable")
1545 Object[] arguments = this.arguments;
1546 if (arguments == null) return this;
1547 boolean replaced = false;
1548 for (int j = 0; j < arguments.length; j++) {
1549 if (arguments[j] == oldName) {
1550 if (!replaced) {
1551 replaced = true;
1552 arguments = arguments.clone();
1553 }
1554 arguments[j] = newName;
1555 }
1556 }
1557 if (!replaced) return this;
1558 return new Name(function, arguments);
1559 }
1560 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1561 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1562 */
1563 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1564 if (start >= end) return this;
1565 @SuppressWarnings("LocalVariableHidesMemberVariable")
1566 Object[] arguments = this.arguments;
1567 boolean replaced = false;
1568 eachArg:
1569 for (int j = 0; j < arguments.length; j++) {
1570 if (arguments[j] instanceof Name) {
1571 Name n = (Name) arguments[j];
1572 int check = n.index;
1573 // harmless check to see if the thing is already in newNames:
1574 if (check >= 0 && check < newNames.length && n == newNames[check])
1575 continue eachArg;
1576 // n might not have the correct index: n != oldNames[n.index].
1577 for (int i = start; i < end; i++) {
1578 if (n == oldNames[i]) {
1579 if (n == newNames[i])
1580 continue eachArg;
1581 if (!replaced) {
1582 replaced = true;
1583 arguments = arguments.clone();
1584 }
1585 arguments[j] = newNames[i];
1586 continue eachArg;
1587 }
1588 }
1589 }
1590 }
1591 if (!replaced) return this;
1592 return new Name(function, arguments);
1593 }
1594 void internArguments() {
1595 @SuppressWarnings("LocalVariableHidesMemberVariable")
1596 Object[] arguments = this.arguments;
1597 for (int j = 0; j < arguments.length; j++) {
1598 if (arguments[j] instanceof Name) {
1599 Name n = (Name) arguments[j];
1600 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1601 arguments[j] = internArgument(n);
1602 }
1603 }
1604 }
1605 boolean isParam() {
1606 return function == null;
1607 }
1608 boolean isConstantZero() {
1609 return !isParam() && arguments.length == 0 && function.isConstantZero();
1610 }
1611
1612 boolean refersTo(Class<?> declaringClass, String methodName) {
1613 return function != null &&
1614 function.member() != null && function.member().refersTo(declaringClass, methodName);
1615 }
1616
1617 /**
1618 * Check if MemberName is a call to MethodHandle.invokeBasic.
1619 */
1620 boolean isInvokeBasic() {
1621 if (function == null)
1622 return false;
1623 if (arguments.length < 1)
1624 return false; // must have MH argument
1625 MemberName member = function.member();
1626 return member != null && member.refersTo(MethodHandle.class, "invokeBasic") &&
1627 !member.isPublic() && !member.isStatic();
1628 }
1629
1630 /**
1631 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1632 */
1633 boolean isLinkerMethodInvoke() {
1634 if (function == null)
1635 return false;
1636 if (arguments.length < 1)
1637 return false; // must have MH argument
1638 MemberName member = function.member();
1639 return member != null &&
1640 member.getDeclaringClass() == MethodHandle.class &&
1641 !member.isPublic() && member.isStatic() &&
1642 member.getName().startsWith("linkTo");
1643 }
1644
1645 public String toString() {
1646 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1647 }
1648 public String debugString() {
1649 String s = paramString();
1650 return (function == null) ? s : s + "=" + exprString();
1651 }
1652 public String paramString() {
1653 String s = toString();
1654 Object c = constraint;
1655 if (c == null)
1656 return s;
1657 if (c instanceof Class) c = ((Class<?>)c).getSimpleName();
1658 return s + "/" + c;
1659 }
1660 public String exprString() {
1661 if (function == null) return toString();
1662 StringBuilder buf = new StringBuilder(function.toString());
1663 buf.append("(");
1664 String cma = "";
1665 for (Object a : arguments) {
1666 buf.append(cma); cma = ",";
1667 if (a instanceof Name || a instanceof Integer)
1668 buf.append(a);
1669 else
1670 buf.append("(").append(a).append(")");
1671 }
1672 buf.append(")");
1673 return buf.toString();
1674 }
1675
1676 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1677 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1678 for (int i = 0; i < arguments.length; i++) {
1679 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1680 }
1681 return true;
1682 }
1683
1684 private static boolean typesMatch(BasicType parameterType, Object object) {
1685 if (object instanceof Name) {
1686 return ((Name)object).type == parameterType;
1687 }
1688 switch (parameterType) {
1689 case I_TYPE: return object instanceof Integer;
1690 case J_TYPE: return object instanceof Long;
1691 case F_TYPE: return object instanceof Float;
1692 case D_TYPE: return object instanceof Double;
1693 }
1694 assert(parameterType == L_TYPE);
1695 return true;
1696 }
1697
1698 /** Return the index of the last occurrence of n in the argument array.
1699 * Return -1 if the name is not used.
1700 */
1701 int lastUseIndex(Name n) {
1702 if (arguments == null) return -1;
1703 for (int i = arguments.length; --i >= 0; ) {
1704 if (arguments[i] == n) return i;
1705 }
1706 return -1;
1707 }
1708
1709 /** Return the number of occurrences of n in the argument array.
1710 * Return 0 if the name is not used.
1711 */
1712 int useCount(Name n) {
1713 if (arguments == null) return 0;
1714 int count = 0;
1715 for (int i = arguments.length; --i >= 0; ) {
1716 if (arguments[i] == n) ++count;
1717 }
1718 return count;
1719 }
1720
1721 boolean contains(Name n) {
1722 return this == n || lastUseIndex(n) >= 0;
1723 }
1724
1725 public boolean equals(Name that) {
1726 if (this == that) return true;
1727 if (isParam())
1728 // each parameter is a unique atom
1729 return false; // this != that
1730 return
1731 //this.index == that.index &&
1732 this.type == that.type &&
1733 this.function.equals(that.function) &&
1734 Arrays.equals(this.arguments, that.arguments);
1735 }
1736 @Override
1737 public boolean equals(Object x) {
1738 return x instanceof Name && equals((Name)x);
1739 }
1740 @Override
1741 public int hashCode() {
1742 if (isParam())
1743 return index | (type.ordinal() << 8);
1744 return function.hashCode() ^ Arrays.hashCode(arguments);
1745 }
1746 }
1747
1748 /** Return the index of the last name which contains n as an argument.
1749 * Return -1 if the name is not used. Return names.length if it is the return value.
1750 */
1751 int lastUseIndex(Name n) {
1752 int ni = n.index, nmax = names.length;
1753 assert(names[ni] == n);
1754 if (result == ni) return nmax; // live all the way beyond the end
1755 for (int i = nmax; --i > ni; ) {
1756 if (names[i].lastUseIndex(n) >= 0)
1757 return i;
1758 }
1759 return -1;
1760 }
1761
1762 /** Return the number of times n is used as an argument or return value. */
1763 int useCount(Name n) {
1764 int nmax = names.length;
1765 int end = lastUseIndex(n);
1766 if (end < 0) return 0;
1767 int count = 0;
1768 if (end == nmax) { count++; end--; }
1769 int beg = n.index() + 1;
1770 if (beg < arity) beg = arity;
1771 for (int i = beg; i <= end; i++) {
1772 count += names[i].useCount(n);
1773 }
1774 return count;
1775 }
1776
1777 static Name argument(int which, BasicType type) {
1778 if (which >= INTERNED_ARGUMENT_LIMIT)
1779 return new Name(which, type);
1780 return INTERNED_ARGUMENTS[type.ordinal()][which];
1781 }
1782 static Name internArgument(Name n) {
1783 assert(n.isParam()) : "not param: " + n;
1784 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1785 if (n.constraint != null) return n;
1786 return argument(n.index, n.type);
1787 }
1788 static Name[] arguments(int extra, MethodType types) {
1789 int length = types.parameterCount();
1790 Name[] names = new Name[length + extra];
1791 for (int i = 0; i < length; i++)
1792 names[i] = argument(i, basicType(types.parameterType(i)));
1793 return names;
1794 }
1795 static final int INTERNED_ARGUMENT_LIMIT = 10;
1796 private static final Name[][] INTERNED_ARGUMENTS
1797 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1798 static {
1799 for (BasicType type : BasicType.ARG_TYPES) {
1800 int ord = type.ordinal();
1801 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1802 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1803 }
1804 }
1805 }
1806
1807 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1808
1809 static LambdaForm identityForm(BasicType type) {
1810 int ord = type.ordinal();
1811 LambdaForm form = LF_identity[ord];
1812 if (form != null) {
1813 return form;
1814 }
1815 createFormsFor(type);
1816 return LF_identity[ord];
1817 }
1818
1819 static LambdaForm zeroForm(BasicType type) {
1820 int ord = type.ordinal();
1821 LambdaForm form = LF_zero[ord];
1822 if (form != null) {
1823 return form;
1824 }
1825 createFormsFor(type);
1826 return LF_zero[ord];
1827 }
1828
1829 static NamedFunction identity(BasicType type) {
1830 int ord = type.ordinal();
1831 NamedFunction function = NF_identity[ord];
1832 if (function != null) {
1833 return function;
1834 }
1835 createFormsFor(type);
1836 return NF_identity[ord];
1837 }
1838
1839 static NamedFunction constantZero(BasicType type) {
1840 int ord = type.ordinal();
1841 NamedFunction function = NF_zero[ord];
1842 if (function != null) {
1843 return function;
1844 }
1845 createFormsFor(type);
1846 return NF_zero[ord];
1847 }
1848
1849 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1850 private static final @Stable LambdaForm[] LF_zero = new LambdaForm[TYPE_LIMIT];
1851 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1852 private static final @Stable NamedFunction[] NF_zero = new NamedFunction[TYPE_LIMIT];
1853
1854 private static synchronized void createFormsFor(BasicType type) {
1855 final int ord = type.ordinal();
1856 LambdaForm idForm = LF_identity[ord];
1857 if (idForm != null) {
1858 return;
1859 }
1860 char btChar = type.basicTypeChar();
1861 boolean isVoid = (type == V_TYPE);
1862 Class<?> btClass = type.btClass;
1863 MethodType zeType = MethodType.methodType(btClass);
1864 MethodType idType = (isVoid) ? zeType : zeType.appendParameterTypes(btClass);
1865
1866 // Look up symbolic names. It might not be necessary to have these,
1867 // but if we need to emit direct references to bytecodes, it helps.
1868 // Zero is built from a call to an identity function with a constant zero input.
1869 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1870 MemberName zeMem = null;
1871 try {
1872 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, NoSuchMethodException.class);
1873 if (!isVoid) {
1874 zeMem = new MemberName(LambdaForm.class, "zero_"+btChar, zeType, REF_invokeStatic);
1875 zeMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, zeMem, null, NoSuchMethodException.class);
1876 }
1877 } catch (IllegalAccessException|NoSuchMethodException ex) {
1878 throw newInternalError(ex);
1879 }
1880
1881 NamedFunction idFun;
1882 LambdaForm zeForm;
1883 NamedFunction zeFun;
1884
1885 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1886 // bootstrap dependency on this method in case we're interpreting LFs
1887 if (isVoid) {
1888 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1889 idForm = new LambdaForm(idMem.getName(), 1, idNames, VOID_RESULT, Kind.IDENTITY);
1890 idForm.compileToBytecode();
1891 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1892
1893 zeForm = idForm;
1894 zeFun = idFun;
1895 } else {
1896 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1897 idForm = new LambdaForm(idMem.getName(), 2, idNames, 1, Kind.IDENTITY);
1898 idForm.compileToBytecode();
1899 idFun = new NamedFunction(idMem, MethodHandleImpl.makeIntrinsic(
1900 idMem.getInvocationType(), idForm, MethodHandleImpl.Intrinsic.IDENTITY));
1901
1902 Object zeValue = Wrapper.forBasicType(btChar).zero();
1903 Name[] zeNames = new Name[] { argument(0, L_TYPE), new Name(idFun, zeValue) };
1904 zeForm = new LambdaForm(zeMem.getName(), 1, zeNames, 1, Kind.ZERO);
1905 zeForm.compileToBytecode();
1906 zeFun = new NamedFunction(zeMem, MethodHandleImpl.makeIntrinsic(
1907 zeMem.getInvocationType(), zeForm, MethodHandleImpl.Intrinsic.ZERO));
1908 }
1909
1910 LF_zero[ord] = zeForm;
1911 NF_zero[ord] = zeFun;
1912 LF_identity[ord] = idForm;
1913 NF_identity[ord] = idFun;
1914
1915 assert(idFun.isIdentity());
1916 assert(zeFun.isConstantZero());
1917 assert(new Name(zeFun).isConstantZero());
1918 }
1919
1920 // Avoid appealing to ValueConversions at bootstrap time:
1921 private static int identity_I(int x) { return x; }
1922 private static long identity_J(long x) { return x; }
1923 private static float identity_F(float x) { return x; }
1924 private static double identity_D(double x) { return x; }
1925 private static Object identity_L(Object x) { return x; }
1926 private static void identity_V() { return; }
1927 private static int zero_I() { return 0; }
1928 private static long zero_J() { return 0; }
1929 private static float zero_F() { return 0; }
1930 private static double zero_D() { return 0; }
1931 private static Object zero_L() { return null; }
1932
1933 /**
1934 * Internal marker for byte-compiled LambdaForms.
1935 */
1936 /*non-public*/
1937 @Target(ElementType.METHOD)
1938 @Retention(RetentionPolicy.RUNTIME)
1939 @interface Compiled {
1940 }
1941
1942 /**
1943 * Internal marker for LambdaForm interpreter frames.
1944 */
1945 /*non-public*/
1946 @Target(ElementType.METHOD)
1947 @Retention(RetentionPolicy.RUNTIME)
1948 @interface Hidden {
1949 }
1950
1951 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1952 static {
1953 if (debugEnabled())
1954 DEBUG_NAME_COUNTERS = new HashMap<>();
1955 else
1956 DEBUG_NAME_COUNTERS = null;
1957 }
1958
1959 // Put this last, so that previous static inits can run before.
1960 static {
1961 if (USE_PREDEFINED_INTERPRET_METHODS)
1962 computeInitialPreparedForms();
1963 NamedFunction.initializeInvokers();
1964
1965 // The Holder class will contain pre-generated forms resolved
1966 // using MemberName.getFactory(). However, that doesn't initialize the
1967 // class, which subtly breaks inlining etc. By forcing
1968 // initialization of the Holder class we avoid these issues.
1969 UNSAFE.ensureClassInitialized(Holder.class);
1970 }
1971
1972 /* Placeholder class for zero and identity forms generated ahead of time */
1973 final class Holder {}
1974
1975 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1976 // during execution of the static initializes of this class.
1977 // Turning on TRACE_INTERPRETER too early will cause
1978 // stack overflows and other misbehavior during attempts to trace events
1979 // that occur during LambdaForm.<clinit>.
1980 // Therefore, do not move this line higher in this file, and do not remove.
1981 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1982 }