1 /*
2 * Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import java.lang.classfile.TypeKind;
29 import jdk.internal.perf.PerfCounter;
30 import jdk.internal.vm.annotation.AOTSafeClassInitializer;
31 import jdk.internal.vm.annotation.DontInline;
32 import jdk.internal.vm.annotation.Hidden;
33 import jdk.internal.vm.annotation.Stable;
34 import sun.invoke.util.Wrapper;
35
36 import java.lang.annotation.ElementType;
37 import java.lang.annotation.Retention;
38 import java.lang.annotation.RetentionPolicy;
39 import java.lang.annotation.Target;
40 import java.lang.reflect.Method;
41 import java.util.Arrays;
42 import java.util.HashMap;
43
44 import static java.lang.invoke.LambdaForm.BasicType.*;
45 import static java.lang.invoke.MethodHandleNatives.Constants.*;
46 import static java.lang.invoke.MethodHandleStatics.*;
47
48 /**
49 * The symbolic, non-executable form of a method handle's invocation semantics.
50 * It consists of a series of names.
51 * The first N (N=arity) names are parameters,
52 * while any remaining names are temporary values.
53 * Each temporary specifies the application of a function to some arguments.
54 * The functions are method handles, while the arguments are mixes of
55 * constant values and local names.
56 * The result of the lambda is defined as one of the names, often the last one.
57 * <p>
58 * Here is an approximate grammar:
59 * <blockquote><pre>{@code
60 * LambdaForm = "(" ArgName* ")=>{" TempName* Result "}"
61 * ArgName = "a" N ":" T
62 * TempName = "t" N ":" T "=" Function "(" Argument* ");"
63 * Function = ConstantValue
64 * Argument = NameRef | ConstantValue
65 * Result = NameRef | "void"
66 * NameRef = "a" N | "t" N
67 * N = (any whole number)
68 * T = "L" | "I" | "J" | "F" | "D" | "V"
69 * }</pre></blockquote>
70 * Names are numbered consecutively from left to right starting at zero.
71 * (The letters are merely a taste of syntax sugar.)
72 * Thus, the first temporary (if any) is always numbered N (where N=arity).
73 * Every occurrence of a name reference in an argument list must refer to
74 * a name previously defined within the same lambda.
75 * A lambda has a void result if and only if its result index is -1.
76 * If a temporary has the type "V", it cannot be the subject of a NameRef,
77 * even though possesses a number.
78 * Note that all reference types are erased to "L", which stands for {@code Object}.
79 * All subword types (boolean, byte, short, char) are erased to "I" which is {@code int}.
80 * The other types stand for the usual primitive types.
81 * <p>
82 * Function invocation closely follows the static rules of the Java verifier.
83 * Arguments and return values must exactly match when their "Name" types are
84 * considered.
85 * Conversions are allowed only if they do not change the erased type.
86 * <ul>
87 * <li>L = Object: casts are used freely to convert into and out of reference types
88 * <li>I = int: subword types are forcibly narrowed when passed as arguments (see {@code explicitCastArguments})
89 * <li>J = long: no implicit conversions
90 * <li>F = float: no implicit conversions
91 * <li>D = double: no implicit conversions
92 * <li>V = void: a function result may be void if and only if its Name is of type "V"
93 * </ul>
94 * Although implicit conversions are not allowed, explicit ones can easily be
95 * encoded by using temporary expressions which call type-transformed identity functions.
96 * <p>
97 * Examples:
98 * <blockquote><pre>{@code
99 * (a0:J)=>{ a0 }
100 * == identity(long)
101 * (a0:I)=>{ t1:V = System.out#println(a0); void }
102 * == System.out#println(int)
103 * (a0:L)=>{ t1:V = System.out#println(a0); a0 }
104 * == identity, with printing side-effect
105 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
106 * t3:L = BoundMethodHandle#target(a0);
107 * t4:L = MethodHandle#invoke(t3, t2, a1); t4 }
108 * == general invoker for unary insertArgument combination
109 * (a0:L, a1:L)=>{ t2:L = FilterMethodHandle#filter(a0);
110 * t3:L = MethodHandle#invoke(t2, a1);
111 * t4:L = FilterMethodHandle#target(a0);
112 * t5:L = MethodHandle#invoke(t4, t3); t5 }
113 * == general invoker for unary filterArgument combination
114 * (a0:L, a1:L)=>{ ...(same as previous example)...
115 * t5:L = MethodHandle#invoke(t4, t3, a1); t5 }
116 * == general invoker for unary/unary foldArgument combination
117 * (a0:L, a1:I)=>{ t2:I = identity(long).asType((int)->long)(a1); t2 }
118 * == invoker for identity method handle which performs i2l
119 * (a0:L, a1:L)=>{ t2:L = BoundMethodHandle#argument(a0);
120 * t3:L = Class#cast(t2,a1); t3 }
121 * == invoker for identity method handle which performs cast
122 * }</pre></blockquote>
123 * <p>
124 * @author John Rose, JSR 292 EG
125 */
126 @AOTSafeClassInitializer
127 class LambdaForm {
128 final int arity;
129 final int result;
130 final boolean forceInline;
131 final MethodHandle customized;
132 @Stable final Name[] names;
133 final Kind kind;
134 MemberName vmentry; // low-level behavior, or null if not yet prepared
135 private boolean isCompiled;
136
137 // Either a LambdaForm cache (managed by LambdaFormEditor) or a link to uncustomized version (for customized LF)
138 volatile Object transformCache;
139
140 public static final int VOID_RESULT = -1, LAST_RESULT = -2;
141
142 enum BasicType {
143 L_TYPE('L', Object.class, Wrapper.OBJECT, TypeKind.REFERENCE), // all reference types
144 I_TYPE('I', int.class, Wrapper.INT, TypeKind.INT),
145 J_TYPE('J', long.class, Wrapper.LONG, TypeKind.LONG),
146 F_TYPE('F', float.class, Wrapper.FLOAT, TypeKind.FLOAT),
147 D_TYPE('D', double.class, Wrapper.DOUBLE, TypeKind.DOUBLE), // all primitive types
148 V_TYPE('V', void.class, Wrapper.VOID, TypeKind.VOID); // not valid in all contexts
149
150 static final @Stable BasicType[] ALL_TYPES = BasicType.values();
151 static final @Stable BasicType[] ARG_TYPES = Arrays.copyOf(ALL_TYPES, ALL_TYPES.length-1);
152
153 static final int ARG_TYPE_LIMIT = ARG_TYPES.length;
154 static final int TYPE_LIMIT = ALL_TYPES.length;
155
156 final char btChar;
157 final Class<?> btClass;
158 final Wrapper btWrapper;
159 final TypeKind btKind;
160
161 private BasicType(char btChar, Class<?> btClass, Wrapper wrapper, TypeKind typeKind) {
162 this.btChar = btChar;
163 this.btClass = btClass;
164 this.btWrapper = wrapper;
165 this.btKind = typeKind;
166 }
167
168 char basicTypeChar() {
169 return btChar;
170 }
171 Class<?> basicTypeClass() {
172 return btClass;
173 }
174 Wrapper basicTypeWrapper() {
175 return btWrapper;
176 }
177 TypeKind basicTypeKind() {
178 return btKind;
179 }
180 int basicTypeSlots() {
181 return btWrapper.stackSlots();
182 }
183
184 static BasicType basicType(byte type) {
185 return ALL_TYPES[type];
186 }
187 static BasicType basicType(char type) {
188 return switch (type) {
189 case 'L' -> L_TYPE;
190 case 'I' -> I_TYPE;
191 case 'J' -> J_TYPE;
192 case 'F' -> F_TYPE;
193 case 'D' -> D_TYPE;
194 case 'V' -> V_TYPE;
195 // all subword types are represented as ints
196 case 'Z', 'B', 'S', 'C' -> I_TYPE;
197 default -> throw newInternalError("Unknown type char: '" + type + "'");
198 };
199 }
200 static BasicType basicType(Class<?> type) {
201 return basicType(Wrapper.basicTypeChar(type));
202 }
203 static int[] basicTypeOrds(BasicType[] types) {
204 if (types == null) {
205 return null;
206 }
207 int[] a = new int[types.length];
208 for(int i = 0; i < types.length; ++i) {
209 a[i] = types[i].ordinal();
210 }
211 return a;
212 }
213
214 static char basicTypeChar(Class<?> type) {
215 return basicType(type).btChar;
216 }
217
218 static int[] basicTypesOrd(Class<?>[] types) {
219 int[] ords = new int[types.length];
220 for (int i = 0; i < ords.length; i++) {
221 ords[i] = basicType(types[i]).ordinal();
222 }
223 return ords;
224 }
225
226 static boolean isBasicTypeChar(char c) {
227 return "LIJFDV".indexOf(c) >= 0;
228 }
229 static boolean isArgBasicTypeChar(char c) {
230 return "LIJFD".indexOf(c) >= 0;
231 }
232
233 static { assert(checkBasicType()); }
234 private static boolean checkBasicType() {
235 for (int i = 0; i < ARG_TYPE_LIMIT; i++) {
236 assert ARG_TYPES[i].ordinal() == i;
237 assert ARG_TYPES[i] == ALL_TYPES[i];
238 }
239 for (int i = 0; i < TYPE_LIMIT; i++) {
240 assert ALL_TYPES[i].ordinal() == i;
241 }
242 assert ALL_TYPES[TYPE_LIMIT - 1] == V_TYPE;
243 assert !Arrays.asList(ARG_TYPES).contains(V_TYPE);
244 return true;
245 }
246 }
247
248 enum Kind {
249 GENERIC("invoke"),
250 IDENTITY("identity"),
251 CONSTANT("constant"),
252 BOUND_REINVOKER("BMH.reinvoke", "reinvoke"),
253 REINVOKER("MH.reinvoke", "reinvoke"),
254 DELEGATE("MH.delegate", "delegate"),
255 EXACT_LINKER("MH.invokeExact_MT", "invokeExact_MT"),
256 EXACT_INVOKER("MH.exactInvoker", "exactInvoker"),
257 GENERIC_LINKER("MH.invoke_MT", "invoke_MT"),
258 GENERIC_INVOKER("MH.invoker", "invoker"),
259 LINK_TO_TARGET_METHOD("linkToTargetMethod"),
260 LINK_TO_CALL_SITE("linkToCallSite"),
261 DIRECT_INVOKE_VIRTUAL("DMH.invokeVirtual", "invokeVirtual"),
262 DIRECT_INVOKE_SPECIAL("DMH.invokeSpecial", "invokeSpecial"),
263 DIRECT_INVOKE_SPECIAL_IFC("DMH.invokeSpecialIFC", "invokeSpecialIFC"),
264 DIRECT_INVOKE_STATIC("DMH.invokeStatic", "invokeStatic"),
265 DIRECT_NEW_INVOKE_SPECIAL("DMH.newInvokeSpecial", "newInvokeSpecial"),
266 DIRECT_INVOKE_INTERFACE("DMH.invokeInterface", "invokeInterface"),
267 DIRECT_INVOKE_STATIC_INIT("DMH.invokeStaticInit", "invokeStaticInit"),
268 FIELD_ACCESS("fieldAccess"),
269 FIELD_ACCESS_INIT("fieldAccessInit"),
270 VOLATILE_FIELD_ACCESS("volatileFieldAccess"),
271 VOLATILE_FIELD_ACCESS_INIT("volatileFieldAccessInit"),
272 FIELD_ACCESS_B("fieldAccessB"),
273 FIELD_ACCESS_INIT_B("fieldAccessInitB"),
274 VOLATILE_FIELD_ACCESS_B("volatileFieldAccessB"),
275 VOLATILE_FIELD_ACCESS_INIT_B("volatileFieldAccessInitB"),
276 FIELD_ACCESS_C("fieldAccessC"),
277 FIELD_ACCESS_INIT_C("fieldAccessInitC"),
278 VOLATILE_FIELD_ACCESS_C("volatileFieldAccessC"),
279 VOLATILE_FIELD_ACCESS_INIT_C("volatileFieldAccessInitC"),
280 FIELD_ACCESS_S("fieldAccessS"),
281 FIELD_ACCESS_INIT_S("fieldAccessInitS"),
282 VOLATILE_FIELD_ACCESS_S("volatileFieldAccessS"),
283 VOLATILE_FIELD_ACCESS_INIT_S("volatileFieldAccessInitS"),
284 FIELD_ACCESS_Z("fieldAccessZ"),
285 FIELD_ACCESS_INIT_Z("fieldAccessInitZ"),
286 VOLATILE_FIELD_ACCESS_Z("volatileFieldAccessZ"),
287 VOLATILE_FIELD_ACCESS_INIT_Z("volatileFieldAccessInitZ"),
288 FIELD_ACCESS_CAST("fieldAccessCast"),
289 FIELD_ACCESS_INIT_CAST("fieldAccessInitCast"),
290 VOLATILE_FIELD_ACCESS_CAST("volatileFieldAccessCast"),
291 VOLATILE_FIELD_ACCESS_INIT_CAST("volatileFieldAccessInitCast"),
292 TRY_FINALLY("tryFinally"),
293 TABLE_SWITCH("tableSwitch"),
294 COLLECTOR("collector"),
295 LOOP("loop"),
296 GUARD("guard"),
297 GUARD_WITH_CATCH("guardWithCatch"),
298 VARHANDLE_EXACT_INVOKER("VH.exactInvoker"),
299 VARHANDLE_INVOKER("VH.invoker", "invoker"),
300 VARHANDLE_LINKER("VH.invoke_MT", "invoke_MT");
301
302 final String defaultLambdaName;
303 final String methodName;
304
305 private Kind(String defaultLambdaName) {
306 this(defaultLambdaName, defaultLambdaName);
307 }
308
309 private Kind(String defaultLambdaName, String methodName) {
310 this.defaultLambdaName = defaultLambdaName;
311 this.methodName = methodName;
312 }
313 }
314
315 // private version that doesn't do checks or defensive copies
316 private LambdaForm(int arity, int result, boolean forceInline, MethodHandle customized, Name[] names, Kind kind) {
317 this.arity = arity;
318 this.result = result;
319 this.forceInline = forceInline;
320 this.customized = customized;
321 this.names = names;
322 this.kind = kind;
323 this.vmentry = null;
324 this.isCompiled = false;
325 }
326
327 // root factory pre/post processing and calls simple constructor
328 private static LambdaForm create(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
329 names = names.clone();
330 assert(namesOK(arity, names));
331 result = fixResult(result, names);
332
333 boolean canInterpret = normalizeNames(arity, names);
334 LambdaForm form = new LambdaForm(arity, result, forceInline, customized, names, kind);
335 assert(form.nameRefsAreLegal());
336 if (!canInterpret) {
337 form.compileToBytecode();
338 }
339 return form;
340 }
341
342 // derived factories with defaults
343 private static final int DEFAULT_RESULT = LAST_RESULT;
344 private static final boolean DEFAULT_FORCE_INLINE = true;
345 private static final MethodHandle DEFAULT_CUSTOMIZED = null;
346 private static final Kind DEFAULT_KIND = Kind.GENERIC;
347
348 static LambdaForm create(int arity, Name[] names, int result) {
349 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
350 }
351 static LambdaForm create(int arity, Name[] names, int result, Kind kind) {
352 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
353 }
354 static LambdaForm create(int arity, Name[] names) {
355 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
356 }
357 static LambdaForm create(int arity, Name[] names, Kind kind) {
358 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
359 }
360 static LambdaForm create(int arity, Name[] names, boolean forceInline, Kind kind) {
361 return create(arity, names, DEFAULT_RESULT, forceInline, DEFAULT_CUSTOMIZED, kind);
362 }
363
364 private static int fixResult(int result, Name[] names) {
365 if (result == LAST_RESULT)
366 result = names.length - 1; // might still be void
367 if (result >= 0 && names[result].type == V_TYPE)
368 result = VOID_RESULT;
369 return result;
370 }
371
372 static boolean debugNames() {
373 return DEBUG_NAME_COUNTERS != null;
374 }
375
376 static void associateWithDebugName(LambdaForm form, String name) {
377 assert (debugNames());
378 synchronized (DEBUG_NAMES) {
379 DEBUG_NAMES.put(form, name);
380 }
381 }
382
383 String lambdaName() {
384 if (DEBUG_NAMES != null) {
385 synchronized (DEBUG_NAMES) {
386 String name = DEBUG_NAMES.get(this);
387 if (name == null) {
388 name = generateDebugName();
389 }
390 return name;
391 }
392 }
393 return kind.defaultLambdaName;
394 }
395
396 private String generateDebugName() {
397 assert (debugNames());
398 String debugNameStem = kind.defaultLambdaName;
399 Integer ctr = DEBUG_NAME_COUNTERS.getOrDefault(debugNameStem, 0);
400 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr + 1);
401 StringBuilder buf = new StringBuilder(debugNameStem);
402 int leadingZero = buf.length();
403 buf.append((int) ctr);
404 for (int i = buf.length() - leadingZero; i < 3; i++) {
405 buf.insert(leadingZero, '0');
406 }
407 buf.append('_');
408 buf.append(basicTypeSignature());
409 String name = buf.toString();
410 associateWithDebugName(this, name);
411 return name;
412 }
413
414 private static boolean namesOK(int arity, Name[] names) {
415 for (int i = 0; i < names.length; i++) {
416 Name n = names[i];
417 assert(n != null) : "n is null";
418 if (i < arity)
419 assert( n.isParam()) : n + " is not param at " + i;
420 else
421 assert(!n.isParam()) : n + " is param at " + i;
422 }
423 return true;
424 }
425
426 /** Customize LambdaForm for a particular MethodHandle */
427 LambdaForm customize(MethodHandle mh) {
428 if (customized == mh) {
429 return this;
430 }
431 LambdaForm customForm = LambdaForm.create(arity, names, result, forceInline, mh, kind);
432 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
433 // If shared LambdaForm has been compiled, compile customized version as well.
434 customForm.compileToBytecode();
435 }
436 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
437 return customForm;
438 }
439
440 /** Get uncustomized flavor of the LambdaForm */
441 LambdaForm uncustomize() {
442 if (customized == null) {
443 return this;
444 }
445 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
446 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
447 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
448 // If customized LambdaForm has been compiled, compile uncustomized version as well.
449 uncustomizedForm.compileToBytecode();
450 }
451 return uncustomizedForm;
452 }
453
454 /** Renumber and/or replace params so that they are interned and canonically numbered.
455 * @return true if we can interpret
456 */
457 private static boolean normalizeNames(int arity, Name[] names) {
458 Name[] oldNames = names.clone();
459 int maxOutArity = 0;
460 for (int i = 0; i < names.length; i++) {
461 Name n = names[i];
462 names[i] = n.withIndex(i);
463 if (n.arguments != null && maxOutArity < n.arguments.length)
464 maxOutArity = n.arguments.length;
465 }
466 if (oldNames != null) {
467 for (int i = Math.max(1, arity); i < names.length; i++) {
468 Name fixed = names[i].replaceNames(oldNames, names, 0, i);
469 names[i] = fixed.withIndex(i);
470 }
471 }
472 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
473 boolean needIntern = false;
474 for (int i = 0; i < maxInterned; i++) {
475 Name n = names[i], n2 = internArgument(n);
476 if (n != n2) {
477 names[i] = n2;
478 needIntern = true;
479 }
480 }
481 if (needIntern) {
482 for (int i = arity; i < names.length; i++) {
483 names[i].internArguments();
484 }
485 }
486
487 // return true if we can interpret
488 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
489 // Cannot use LF interpreter on very high arity expressions.
490 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
491 return false;
492 }
493 return true;
494 }
495
496 /**
497 * Check that all embedded Name references are localizable to this lambda,
498 * and are properly ordered after their corresponding definitions.
499 * <p>
500 * Note that a Name can be local to multiple lambdas, as long as
501 * it possesses the same index in each use site.
502 * This allows Name references to be freely reused to construct
503 * fresh lambdas, without confusion.
504 */
505 boolean nameRefsAreLegal() {
506 assert(arity >= 0 && arity <= names.length);
507 assert(result >= -1 && result < names.length);
508 // Do all names possess an index consistent with their local definition order?
509 for (int i = 0; i < arity; i++) {
510 Name n = names[i];
511 assert(n.index() == i) : Arrays.asList(n.index(), i);
512 assert(n.isParam());
513 }
514 // Also, do all local name references
515 for (int i = arity; i < names.length; i++) {
516 Name n = names[i];
517 assert(n.index() == i);
518 for (Object arg : n.arguments) {
519 if (arg instanceof Name n2) {
520 int i2 = n2.index;
521 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
522 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
523 assert(i2 < i); // ref must come after def!
524 }
525 }
526 }
527 return true;
528 }
529
530 // /** Invoke this form on the given arguments. */
531 // final Object invoke(Object... args) throws Throwable {
532 // // NYI: fit this into the fast path?
533 // return interpretWithArguments(args);
534 // }
535
536 /** Report the return type. */
537 BasicType returnType() {
538 if (result < 0) return V_TYPE;
539 Name n = names[result];
540 return n.type;
541 }
542
543 /** Report the N-th argument type. */
544 BasicType parameterType(int n) {
545 return parameter(n).type;
546 }
547
548 /** Report the N-th argument name. */
549 Name parameter(int n) {
550 Name param = names[n];
551 assert(n < arity && param.isParam());
552 return param;
553 }
554
555 /** Report the N-th argument type constraint. */
556 Object parameterConstraint(int n) {
557 return parameter(n).constraint;
558 }
559
560 /** Report the arity. */
561 int arity() {
562 return arity;
563 }
564
565 /** Report the number of expressions (non-parameter names). */
566 int expressionCount() {
567 return names.length - arity;
568 }
569
570 /** Return the method type corresponding to my basic type signature. */
571 MethodType methodType() {
572 Class<?>[] ptypes = new Class<?>[arity];
573 for (int i = 0; i < arity; ++i) {
574 ptypes[i] = parameterType(i).btClass;
575 }
576 return MethodType.methodType(returnType().btClass, ptypes, true);
577 }
578
579 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
580 final String basicTypeSignature() {
581 StringBuilder buf = new StringBuilder(arity() + 3);
582 for (int i = 0, a = arity(); i < a; i++)
583 buf.append(parameterType(i).basicTypeChar());
584 return buf.append('_').append(returnType().basicTypeChar()).toString();
585 }
586 static int signatureArity(String sig) {
587 assert(isValidSignature(sig));
588 return sig.indexOf('_');
589 }
590 static boolean isValidSignature(String sig) {
591 int arity = sig.indexOf('_');
592 if (arity < 0) return false; // must be of the form *_*
593 int siglen = sig.length();
594 if (siglen != arity + 2) return false; // *_X
595 for (int i = 0; i < siglen; i++) {
596 if (i == arity) continue; // skip '_'
597 char c = sig.charAt(i);
598 if (c == 'V')
599 return (i == siglen - 1 && arity == siglen - 2);
600 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
601 }
602 return true; // [LIJFD]*_[LIJFDV]
603 }
604
605 /**
606 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
607 */
608 boolean isSelectAlternative(int pos) {
609 // selectAlternative idiom:
610 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
611 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
612 if (pos+1 >= names.length) return false;
613 Name name0 = names[pos];
614 Name name1 = names[pos+1];
615 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
616 name1.isInvokeBasic() &&
617 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
618 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
619 }
620
621 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
622 if (pos+2 >= names.length) return false;
623 Name name0 = names[pos];
624 Name name1 = names[pos+1];
625 Name name2 = names[pos+2];
626 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
627 name0.isInvokeBasic() &&
628 name2.isInvokeBasic() &&
629 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
630 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
631 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
632 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
633 }
634
635 /**
636 * Check if i-th name is a start of GuardWithCatch idiom.
637 */
638 boolean isGuardWithCatch(int pos) {
639 // GuardWithCatch idiom:
640 // t_{n}:L=MethodHandle.invokeBasic(...)
641 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
642 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
643 return isMatchingIdiom(pos, "guardWithCatch", 3);
644 }
645
646 /**
647 * Check if i-th name is a start of the tryFinally idiom.
648 */
649 boolean isTryFinally(int pos) {
650 // tryFinally idiom:
651 // t_{n}:L=MethodHandle.invokeBasic(...)
652 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
653 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
654 return isMatchingIdiom(pos, "tryFinally", 2);
655 }
656
657 /**
658 * Check if i-th name is a start of the tableSwitch idiom.
659 */
660 boolean isTableSwitch(int pos) {
661 // tableSwitch idiom:
662 // t_{n}:L=MethodHandle.invokeBasic(...) // args
663 // t_{n+1}:L=MethodHandleImpl.tableSwitch(*, *, *, t_{n})
664 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
665 if (pos + 2 >= names.length) return false;
666
667 final int POS_COLLECT_ARGS = pos;
668 final int POS_TABLE_SWITCH = pos + 1;
669 final int POS_UNBOX_RESULT = pos + 2;
670
671 Name collectArgs = names[POS_COLLECT_ARGS];
672 Name tableSwitch = names[POS_TABLE_SWITCH];
673 Name unboxResult = names[POS_UNBOX_RESULT];
674 return tableSwitch.refersTo(MethodHandleImpl.class, "tableSwitch") &&
675 collectArgs.isInvokeBasic() &&
676 unboxResult.isInvokeBasic() &&
677 tableSwitch.lastUseIndex(collectArgs) == 3 && // t_{n+1}:L=MethodHandleImpl.<invoker>(*, *, *, t_{n});
678 lastUseIndex(collectArgs) == POS_TABLE_SWITCH && // t_{n} is local: used only in t_{n+1}
679 unboxResult.lastUseIndex(tableSwitch) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
680 lastUseIndex(tableSwitch) == POS_UNBOX_RESULT; // t_{n+1} is local: used only in t_{n+2}
681 }
682
683 /**
684 * Check if i-th name is a start of the loop idiom.
685 */
686 boolean isLoop(int pos) {
687 // loop idiom:
688 // t_{n}:L=MethodHandle.invokeBasic(...)
689 // t_{n+1}:L=MethodHandleImpl.loop(types, *, t_{n})
690 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
691 return isMatchingIdiom(pos, "loop", 2);
692 }
693
694 /*
695 * Code generation issues:
696 *
697 * Compiled LFs should be reusable in general.
698 * The biggest issue is how to decide when to pull a name into
699 * the bytecode, versus loading a reified form from the MH data.
700 *
701 * For example, an asType wrapper may require execution of a cast
702 * after a call to a MH. The target type of the cast can be placed
703 * as a constant in the LF itself. This will force the cast type
704 * to be compiled into the bytecodes and native code for the MH.
705 * Or, the target type of the cast can be erased in the LF, and
706 * loaded from the MH data. (Later on, if the MH as a whole is
707 * inlined, the data will flow into the inlined instance of the LF,
708 * as a constant, and the end result will be an optimal cast.)
709 *
710 * This erasure of cast types can be done with any use of
711 * reference types. It can also be done with whole method
712 * handles. Erasing a method handle might leave behind
713 * LF code that executes correctly for any MH of a given
714 * type, and load the required MH from the enclosing MH's data.
715 * Or, the erasure might even erase the expected MT.
716 *
717 * Also, for direct MHs, the MemberName of the target
718 * could be erased, and loaded from the containing direct MH.
719 * As a simple case, a LF for all int-valued non-static
720 * field getters would perform a cast on its input argument
721 * (to non-constant base type derived from the MemberName)
722 * and load an integer value from the input object
723 * (at a non-constant offset also derived from the MemberName).
724 * Such MN-erased LFs would be inlinable back to optimized
725 * code, whenever a constant enclosing DMH is available
726 * to supply a constant MN from its data.
727 *
728 * The main problem here is to keep LFs reasonably generic,
729 * while ensuring that hot spots will inline good instances.
730 * "Reasonably generic" means that we don't end up with
731 * repeated versions of bytecode or machine code that do
732 * not differ in their optimized form. Repeated versions
733 * of machine would have the undesirable overheads of
734 * (a) redundant compilation work and (b) extra I$ pressure.
735 * To control repeated versions, we need to be ready to
736 * erase details from LFs and move them into MH data,
737 * whenever those details are not relevant to significant
738 * optimization. "Significant" means optimization of
739 * code that is actually hot.
740 *
741 * Achieving this may require dynamic splitting of MHs, by replacing
742 * a generic LF with a more specialized one, on the same MH,
743 * if (a) the MH is frequently executed and (b) the MH cannot
744 * be inlined into a containing caller, such as an invokedynamic.
745 *
746 * Compiled LFs that are no longer used should be GC-able.
747 * If they contain non-BCP references, they should be properly
748 * interlinked with the class loader(s) that their embedded types
749 * depend on. This probably means that reusable compiled LFs
750 * will be tabulated (indexed) on relevant class loaders,
751 * or else that the tables that cache them will have weak links.
752 */
753
754 /**
755 * Make this LF directly executable, as part of a MethodHandle.
756 * Invariant: Every MH which is invoked must prepare its LF
757 * before invocation.
758 * (In principle, the JVM could do this very lazily,
759 * as a sort of pre-invocation linkage step.)
760 */
761 public void prepare() {
762 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
763 compileToBytecode();
764 }
765 if (this.vmentry != null) {
766 // already prepared (e.g., a primitive DMH invoker form)
767 return;
768 }
769 MethodType mtype = methodType();
770 MethodTypeForm form = mtype.form();
771
772 MemberName entry = form.cachedInterpretEntry();
773 if (entry == null) {
774 assert (isValidSignature(basicTypeSignature()));
775 entry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
776 entry = form.setCachedInterpretEntry(entry);
777 }
778 this.vmentry = entry;
779 // TO DO: Maybe add invokeGeneric, invokeWithArguments
780 }
781
782 private static @Stable PerfCounter LF_FAILED;
783
784 private static PerfCounter failedCompilationCounter() {
785 if (LF_FAILED == null) {
786 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
787 }
788 return LF_FAILED;
789 }
790
791 /** Generate optimizable bytecode for this form. */
792 void compileToBytecode() {
793 if (forceInterpretation()) {
794 return; // this should not be compiled
795 }
796 if (vmentry != null && isCompiled) {
797 return; // already compiled somehow
798 }
799
800 // Obtain the invoker MethodType outside of the following try block.
801 // This ensures that an IllegalArgumentException is directly thrown if the
802 // type would have 256 or more parameters
803 MethodType invokerType = methodType();
804 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
805 try {
806 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
807 if (TRACE_INTERPRETER)
808 traceInterpreter("compileToBytecode", this);
809 isCompiled = true;
810 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
811 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
812 invocationCounter = -1;
813 failedCompilationCounter().increment();
814 if (LOG_LF_COMPILATION_FAILURE) {
815 System.out.println("LambdaForm compilation failed: " + this);
816 bge.printStackTrace(System.out);
817 }
818 } catch (Error e) {
819 // Pass through any error
820 throw e;
821 } catch (Exception e) {
822 // Wrap any exception
823 throw newInternalError(this.toString(), e);
824 }
825 }
826
827 // The next few routines are called only from assert expressions
828 // They verify that the built-in invokers process the correct raw data types.
829 private static boolean argumentTypesMatch(String sig, Object[] av) {
830 int arity = signatureArity(sig);
831 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
832 assert(av[0] instanceof MethodHandle) : "av[0] not instance of MethodHandle: " + av[0];
833 MethodHandle mh = (MethodHandle) av[0];
834 MethodType mt = mh.type();
835 assert(mt.parameterCount() == arity-1);
836 for (int i = 0; i < av.length; i++) {
837 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
838 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
839 }
840 return true;
841 }
842 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
843 // The following line is needed because (...)void method handles can use non-void invokers
844 if (type == void.class) tc = V_TYPE; // can drop any kind of value
845 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
846 switch (tc) {
847 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
848 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
849 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
850 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
851 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
852 case V_TYPE: break; // allow anything here; will be dropped
853 default: assert(false);
854 }
855 return true;
856 }
857 private static boolean checkInt(Class<?> type, Object x) {
858 assert(x instanceof Integer);
859 if (type == int.class) return true;
860 Wrapper w = Wrapper.forBasicType(type);
861 assert(w.isSubwordOrInt());
862 Object x1 = Wrapper.INT.wrap(w.wrap(x));
863 return x.equals(x1);
864 }
865 private static boolean checkRef(Class<?> type, Object x) {
866 assert(!type.isPrimitive());
867 if (x == null) return true;
868 if (type.isInterface()) return true;
869 return type.isInstance(x);
870 }
871
872 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
873 private static final int COMPILE_THRESHOLD;
874 static {
875 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
876 }
877 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
878
879 private boolean forceInterpretation() {
880 return invocationCounter == -1;
881 }
882
883 /** Interpretively invoke this form on the given arguments. */
884 @Hidden
885 @DontInline
886 Object interpretWithArguments(Object... argumentValues) throws Throwable {
887 if (TRACE_INTERPRETER)
888 return interpretWithArgumentsTracing(argumentValues);
889 checkInvocationCounter();
890 assert(arityCheck(argumentValues));
891 Object[] values = Arrays.copyOf(argumentValues, names.length);
892 for (int i = argumentValues.length; i < values.length; i++) {
893 values[i] = interpretName(names[i], values);
894 }
895 Object rv = (result < 0) ? null : values[result];
896 assert(resultCheck(argumentValues, rv));
897 return rv;
898 }
899
900 /** Evaluate a single Name within this form, applying its function to its arguments. */
901 @Hidden
902 @DontInline
903 Object interpretName(Name name, Object[] values) throws Throwable {
904 if (TRACE_INTERPRETER)
905 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
906 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
907 for (int i = 0; i < arguments.length; i++) {
908 Object a = arguments[i];
909 if (a instanceof Name n) {
910 int i2 = n.index();
911 assert(names[i2] == a);
912 a = values[i2];
913 arguments[i] = a;
914 }
915 }
916 return name.function.invokeWithArguments(arguments);
917 }
918
919 private void checkInvocationCounter() {
920 if (COMPILE_THRESHOLD != 0 &&
921 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
922 invocationCounter++; // benign race
923 if (invocationCounter >= COMPILE_THRESHOLD) {
924 // Replace vmentry with a bytecode version of this LF.
925 compileToBytecode();
926 }
927 }
928 }
929 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
930 traceInterpreter("[ interpretWithArguments", this, argumentValues);
931 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
932 int ctr = invocationCounter++; // benign race
933 traceInterpreter("| invocationCounter", ctr);
934 if (invocationCounter >= COMPILE_THRESHOLD) {
935 compileToBytecode();
936 }
937 }
938 Object rval;
939 try {
940 assert(arityCheck(argumentValues));
941 Object[] values = Arrays.copyOf(argumentValues, names.length);
942 for (int i = argumentValues.length; i < values.length; i++) {
943 values[i] = interpretName(names[i], values);
944 }
945 rval = (result < 0) ? null : values[result];
946 } catch (Throwable ex) {
947 traceInterpreter("] throw =>", ex);
948 throw ex;
949 }
950 traceInterpreter("] return =>", rval);
951 return rval;
952 }
953
954 static void traceInterpreter(String event, Object obj, Object... args) {
955 if (TRACE_INTERPRETER) {
956 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
957 }
958 }
959 static void traceInterpreter(String event, Object obj) {
960 traceInterpreter(event, obj, (Object[])null);
961 }
962 private boolean arityCheck(Object[] argumentValues) {
963 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
964 // also check that the leading (receiver) argument is somehow bound to this LF:
965 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
966 MethodHandle mh = (MethodHandle) argumentValues[0];
967 assert(mh.internalForm() == this);
968 // note: argument #0 could also be an interface wrapper, in the future
969 argumentTypesMatch(basicTypeSignature(), argumentValues);
970 return true;
971 }
972 private boolean resultCheck(Object[] argumentValues, Object result) {
973 MethodHandle mh = (MethodHandle) argumentValues[0];
974 MethodType mt = mh.type();
975 assert(valueMatches(returnType(), mt.returnType(), result));
976 return true;
977 }
978
979 public String toString() {
980 return debugString(-1);
981 }
982
983 String debugString(int indentLevel) {
984 String prefix = MethodHandle.debugPrefix(indentLevel);
985 String lambdaName = lambdaName();
986 StringBuilder buf = new StringBuilder(lambdaName);
987 buf.append("=Lambda(");
988 for (int i = 0; i < names.length; i++) {
989 if (i == arity) buf.append(")=>{");
990 Name n = names[i];
991 if (i >= arity) buf.append("\n ").append(prefix);
992 buf.append(n.paramString());
993 if (i < arity) {
994 if (i+1 < arity) buf.append(",");
995 continue;
996 }
997 buf.append("=").append(n.exprString());
998 buf.append(";");
999 }
1000 if (arity == names.length) buf.append(")=>{");
1001 buf.append(result < 0 ? "void" : names[result]).append("}");
1002 if (TRACE_INTERPRETER) {
1003 // Extra verbosity:
1004 buf.append(":").append(basicTypeSignature());
1005 buf.append("/").append(vmentry);
1006 }
1007 return buf.toString();
1008 }
1009
1010 @Override
1011 public boolean equals(Object obj) {
1012 return obj instanceof LambdaForm lf && equals(lf);
1013 }
1014 public boolean equals(LambdaForm that) {
1015 if (this.result != that.result) return false;
1016 return Arrays.equals(this.names, that.names);
1017 }
1018 public int hashCode() {
1019 return result + 31 * Arrays.hashCode(names);
1020 }
1021 LambdaFormEditor editor() {
1022 return LambdaFormEditor.lambdaFormEditor(this);
1023 }
1024
1025 boolean contains(Name name) {
1026 int pos = name.index();
1027 if (pos >= 0) {
1028 return pos < names.length && name.equals(names[pos]);
1029 }
1030 for (int i = arity; i < names.length; i++) {
1031 if (name.equals(names[i]))
1032 return true;
1033 }
1034 return false;
1035 }
1036
1037 @AOTSafeClassInitializer
1038 static class NamedFunction {
1039 final MemberName member;
1040 private @Stable MethodHandle resolvedHandle;
1041 private @Stable MethodType type;
1042
1043 NamedFunction(MethodHandle resolvedHandle) {
1044 this(resolvedHandle.internalMemberName(), resolvedHandle);
1045 }
1046 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1047 this.member = member;
1048 this.resolvedHandle = resolvedHandle;
1049 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1050 //assert(!isInvokeBasic(member));
1051 }
1052 NamedFunction(MethodType basicInvokerType) {
1053 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1054 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1055 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1056 this.member = resolvedHandle.internalMemberName();
1057 } else {
1058 // necessary to pass BigArityTest
1059 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1060 }
1061 assert(isInvokeBasic(member));
1062 }
1063
1064 private static boolean isInvokeBasic(MemberName member) {
1065 return member != null &&
1066 member.getDeclaringClass() == MethodHandle.class &&
1067 "invokeBasic".equals(member.getName());
1068 }
1069
1070 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1071 // Any LambdaForm containing such a member is not interpretable.
1072 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1073 // And even without the resolvedHandle, the name can still be compiled and optimized.
1074 NamedFunction(Method method) {
1075 this(new MemberName(method));
1076 }
1077 NamedFunction(MemberName member) {
1078 this(member, null);
1079 }
1080
1081 MethodHandle resolvedHandle() {
1082 if (resolvedHandle == null) resolve();
1083 return resolvedHandle;
1084 }
1085
1086 synchronized void resolve() {
1087 if (resolvedHandle == null) {
1088 resolvedHandle = DirectMethodHandle.make(member);
1089 }
1090 }
1091
1092 @Override
1093 public boolean equals(Object other) {
1094 if (this == other) return true;
1095 if (other == null) return false;
1096 return (other instanceof NamedFunction that)
1097 && this.member != null
1098 && this.member.equals(that.member);
1099 }
1100
1101 @Override
1102 public int hashCode() {
1103 if (member != null)
1104 return member.hashCode();
1105 return super.hashCode();
1106 }
1107
1108 static final MethodType INVOKER_METHOD_TYPE =
1109 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1110
1111 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1112 typeForm = typeForm.basicType().form(); // normalize to basic type
1113 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1114 if (mh != null) return mh;
1115 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1116 mh = DirectMethodHandle.make(invoker);
1117 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1118 if (mh2 != null) return mh2; // benign race
1119 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1120 throw newInternalError(mh.debugString());
1121 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1122 }
1123
1124 @Hidden
1125 Object invokeWithArguments(Object... arguments) throws Throwable {
1126 // If we have a cached invoker, call it right away.
1127 // NOTE: The invoker always returns a reference value.
1128 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1129 return invoker().invokeBasic(resolvedHandle(), arguments);
1130 }
1131
1132 @Hidden
1133 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1134 Object rval;
1135 try {
1136 traceInterpreter("[ call", this, arguments);
1137 // resolvedHandle might be uninitialized, ok for tracing
1138 if (resolvedHandle == null) {
1139 traceInterpreter("| resolve", this);
1140 resolvedHandle();
1141 }
1142 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1143 } catch (Throwable ex) {
1144 traceInterpreter("] throw =>", ex);
1145 throw ex;
1146 }
1147 traceInterpreter("] return =>", rval);
1148 return rval;
1149 }
1150
1151 private MethodHandle invoker() {
1152 return computeInvoker(methodType().form());
1153 }
1154
1155 MethodType methodType() {
1156 MethodType type = this.type;
1157 if (type == null) {
1158 this.type = type = calculateMethodType(member, resolvedHandle);
1159 }
1160 return type;
1161 }
1162
1163 private static MethodType calculateMethodType(MemberName member, MethodHandle resolvedHandle) {
1164 if (resolvedHandle != null) {
1165 return resolvedHandle.type();
1166 } else {
1167 // only for certain internal LFs during bootstrapping
1168 return member.getInvocationType();
1169 }
1170 }
1171
1172 MemberName member() {
1173 assert(assertMemberIsConsistent());
1174 return member;
1175 }
1176
1177 // Called only from assert.
1178 private boolean assertMemberIsConsistent() {
1179 if (resolvedHandle instanceof DirectMethodHandle) {
1180 MemberName m = resolvedHandle.internalMemberName();
1181 assert(m.equals(member));
1182 }
1183 return true;
1184 }
1185
1186 Class<?> memberDeclaringClassOrNull() {
1187 return (member == null) ? null : member.getDeclaringClass();
1188 }
1189
1190 BasicType returnType() {
1191 return basicType(methodType().returnType());
1192 }
1193
1194 BasicType parameterType(int n) {
1195 return basicType(methodType().parameterType(n));
1196 }
1197
1198 int arity() {
1199 return methodType().parameterCount();
1200 }
1201
1202 public String toString() {
1203 if (member == null) return String.valueOf(resolvedHandle);
1204 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1205 }
1206
1207 public boolean isIdentity() {
1208 return this.equals(identity(returnType()));
1209 }
1210
1211 public MethodHandleImpl.Intrinsic intrinsicName() {
1212 return resolvedHandle != null
1213 ? resolvedHandle.intrinsicName()
1214 : MethodHandleImpl.Intrinsic.NONE;
1215 }
1216
1217 public Object intrinsicData() {
1218 return resolvedHandle != null
1219 ? resolvedHandle.intrinsicData()
1220 : null;
1221 }
1222 }
1223
1224 public static String basicTypeSignature(MethodType type) {
1225 int params = type.parameterCount();
1226 char[] sig = new char[params + 2];
1227 int sigp = 0;
1228 while (sigp < params) {
1229 sig[sigp] = basicTypeChar(type.parameterType(sigp++));
1230 }
1231 sig[sigp++] = '_';
1232 sig[sigp++] = basicTypeChar(type.returnType());
1233 assert(sigp == sig.length);
1234 return String.valueOf(sig);
1235 }
1236
1237 /** Hack to make signatures more readable when they show up in method names.
1238 * Signature should start with a sequence of uppercase ASCII letters.
1239 * Runs of three or more are replaced by a single letter plus a decimal repeat count.
1240 * A tail of anything other than uppercase ASCII is passed through unchanged.
1241 * @param signature sequence of uppercase ASCII letters with possible repetitions
1242 * @return same sequence, with repetitions counted by decimal numerals
1243 */
1244 public static String shortenSignature(String signature) {
1245 final int NO_CHAR = -1, MIN_RUN = 3;
1246 int c0, c1 = NO_CHAR, c1reps = 0;
1247 StringBuilder buf = null;
1248 int len = signature.length();
1249 if (len < MIN_RUN) return signature;
1250 for (int i = 0; i <= len; i++) {
1251 if (c1 != NO_CHAR && !('A' <= c1 && c1 <= 'Z')) {
1252 // wrong kind of char; bail out here
1253 if (buf != null) {
1254 buf.append(signature, i - c1reps, len);
1255 }
1256 break;
1257 }
1258 // shift in the next char:
1259 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1260 if (c1 == c0) { ++c1reps; continue; }
1261 // shift in the next count:
1262 int c0reps = c1reps; c1reps = 1;
1263 // end of a character run
1264 if (c0reps < MIN_RUN) {
1265 if (buf != null) {
1266 while (--c0reps >= 0)
1267 buf.append((char)c0);
1268 }
1269 continue;
1270 }
1271 // found three or more in a row
1272 if (buf == null)
1273 buf = new StringBuilder().append(signature, 0, i - c0reps);
1274 buf.append((char)c0).append(c0reps);
1275 }
1276 return (buf == null) ? signature : buf.toString();
1277 }
1278
1279 static final class Name {
1280 final BasicType type;
1281 final short index;
1282 final NamedFunction function;
1283 final Object constraint; // additional type information, if not null
1284 @Stable final Object[] arguments;
1285
1286 private static final Object[] EMPTY_ARGS = new Object[0];
1287
1288 private Name(int index, BasicType type, NamedFunction function, Object[] arguments, Object constraint) {
1289 this.index = (short)index;
1290 this.type = type;
1291 this.function = function;
1292 this.arguments = arguments;
1293 this.constraint = constraint;
1294 assert(this.index == index && typesMatch(function, arguments));
1295 assert(constraint == null || isParam()); // only params have constraints
1296 assert(constraint == null || constraint instanceof ClassSpecializer.SpeciesData || constraint instanceof Class);
1297 }
1298
1299 Name(MethodHandle function, Object... arguments) {
1300 this(new NamedFunction(function), arguments);
1301 }
1302 Name(MethodType functionType, Object... arguments) {
1303 this(new NamedFunction(functionType), arguments);
1304 assert(arguments[0] instanceof Name name && name.type == L_TYPE);
1305 }
1306 Name(MemberName function, Object... arguments) {
1307 this(new NamedFunction(function), arguments);
1308 }
1309 Name(NamedFunction function) {
1310 this(-1, function.returnType(), function, EMPTY_ARGS, null);
1311 }
1312 Name(NamedFunction function, Object arg) {
1313 this(-1, function.returnType(), function, new Object[] { arg }, null);
1314 }
1315 Name(NamedFunction function, Object arg0, Object arg1) {
1316 this(-1, function.returnType(), function, new Object[] { arg0, arg1 }, null);
1317 }
1318 Name(NamedFunction function, Object... arguments) {
1319 this(-1, function.returnType(), function, Arrays.copyOf(arguments, arguments.length, Object[].class), null);
1320 }
1321 /** Create a raw parameter of the given type, with an expected index. */
1322 Name(int index, BasicType type) {
1323 this(index, type, null, null, null);
1324 }
1325 /** Create a raw parameter of the given type. */
1326 Name(BasicType type) { this(-1, type); }
1327
1328 BasicType type() { return type; }
1329 int index() { return index; }
1330
1331 char typeChar() {
1332 return type.btChar;
1333 }
1334
1335 Name withIndex(int i) {
1336 if (i == this.index) return this;
1337 return new Name(i, type, function, arguments, constraint);
1338 }
1339
1340 Name withConstraint(Object constraint) {
1341 if (constraint == this.constraint) return this;
1342 return new Name(index, type, function, arguments, constraint);
1343 }
1344
1345 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1346 if (oldName == newName) return this;
1347 @SuppressWarnings("LocalVariableHidesMemberVariable")
1348 Object[] arguments = this.arguments;
1349 if (arguments == null) return this;
1350 boolean replaced = false;
1351 for (int j = 0; j < arguments.length; j++) {
1352 if (arguments[j] == oldName) {
1353 if (!replaced) {
1354 replaced = true;
1355 arguments = arguments.clone();
1356 }
1357 arguments[j] = newName;
1358 }
1359 }
1360 if (!replaced) return this;
1361 return new Name(function, arguments);
1362 }
1363 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1364 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1365 */
1366 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1367 if (start >= end) return this;
1368 @SuppressWarnings("LocalVariableHidesMemberVariable")
1369 Object[] arguments = this.arguments;
1370 boolean replaced = false;
1371 eachArg:
1372 for (int j = 0; j < arguments.length; j++) {
1373 if (arguments[j] instanceof Name n) {
1374 int check = n.index;
1375 // harmless check to see if the thing is already in newNames:
1376 if (check >= 0 && check < newNames.length && n == newNames[check])
1377 continue eachArg;
1378 // n might not have the correct index: n != oldNames[n.index].
1379 for (int i = start; i < end; i++) {
1380 if (n == oldNames[i]) {
1381 if (n == newNames[i])
1382 continue eachArg;
1383 if (!replaced) {
1384 replaced = true;
1385 arguments = arguments.clone();
1386 }
1387 arguments[j] = newNames[i];
1388 continue eachArg;
1389 }
1390 }
1391 }
1392 }
1393 if (!replaced) return this;
1394 return new Name(function, arguments);
1395 }
1396 void internArguments() {
1397 @SuppressWarnings("LocalVariableHidesMemberVariable")
1398 Object[] arguments = this.arguments;
1399 for (int j = 0; j < arguments.length; j++) {
1400 if (arguments[j] instanceof Name n) {
1401 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1402 arguments[j] = internArgument(n);
1403 }
1404 }
1405 }
1406 boolean isParam() {
1407 return function == null;
1408 }
1409
1410 boolean refersTo(Class<?> declaringClass, String methodName) {
1411 return function != null &&
1412 function.member() != null && function.member().refersTo(declaringClass, methodName);
1413 }
1414
1415 /**
1416 * Check if MemberName is a call to MethodHandle.invokeBasic.
1417 */
1418 boolean isInvokeBasic() {
1419 if (function == null)
1420 return false;
1421 if (arguments.length < 1)
1422 return false; // must have MH argument
1423 MemberName member = function.member();
1424 return member != null && member.refersTo(MethodHandle.class, "invokeBasic") &&
1425 !member.isPublic() && !member.isStatic();
1426 }
1427
1428 /**
1429 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1430 */
1431 boolean isLinkerMethodInvoke() {
1432 if (function == null)
1433 return false;
1434 if (arguments.length < 1)
1435 return false; // must have MH argument
1436 MemberName member = function.member();
1437 return member != null &&
1438 member.getDeclaringClass() == MethodHandle.class &&
1439 !member.isPublic() && member.isStatic() &&
1440 member.getName().startsWith("linkTo");
1441 }
1442
1443 public String toString() {
1444 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1445 }
1446 public String debugString() {
1447 String s = paramString();
1448 return (function == null) ? s : s + "=" + exprString();
1449 }
1450 public String paramString() {
1451 String s = toString();
1452 Object c = constraint;
1453 if (c == null)
1454 return s;
1455 if (c instanceof Class<?> cl) c = cl.getSimpleName();
1456 return s + "/" + c;
1457 }
1458 public String exprString() {
1459 if (function == null) return toString();
1460 StringBuilder buf = new StringBuilder(function.toString());
1461 buf.append("(");
1462 String cma = "";
1463 for (Object a : arguments) {
1464 buf.append(cma); cma = ",";
1465 if (a instanceof Name || a instanceof Integer)
1466 buf.append(a);
1467 else
1468 buf.append("(").append(a).append(")");
1469 }
1470 buf.append(")");
1471 return buf.toString();
1472 }
1473
1474 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1475 if (arguments == null) {
1476 assert(function == null);
1477 return true;
1478 }
1479 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1480 for (int i = 0; i < arguments.length; i++) {
1481 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1482 }
1483 return true;
1484 }
1485
1486 private static boolean typesMatch(BasicType parameterType, Object object) {
1487 if (object instanceof Name name) {
1488 return name.type == parameterType;
1489 }
1490 switch (parameterType) {
1491 case I_TYPE: return object instanceof Integer;
1492 case J_TYPE: return object instanceof Long;
1493 case F_TYPE: return object instanceof Float;
1494 case D_TYPE: return object instanceof Double;
1495 }
1496 assert(parameterType == L_TYPE);
1497 return true;
1498 }
1499
1500 /** Return the index of the last occurrence of n in the argument array.
1501 * Return -1 if the name is not used.
1502 */
1503 int lastUseIndex(Name n) {
1504 Object[] arguments = this.arguments;
1505 if (arguments == null) return -1;
1506 for (int i = arguments.length; --i >= 0; ) {
1507 if (arguments[i] == n) return i;
1508 }
1509 return -1;
1510 }
1511
1512 public boolean equals(Name that) {
1513 if (this == that) return true;
1514 if (isParam())
1515 // each parameter is a unique atom
1516 return false; // this != that
1517 return
1518 //this.index == that.index &&
1519 this.type == that.type &&
1520 this.function.equals(that.function) &&
1521 Arrays.equals(this.arguments, that.arguments);
1522 }
1523 @Override
1524 public boolean equals(Object x) {
1525 return x instanceof Name n && equals(n);
1526 }
1527 @Override
1528 public int hashCode() {
1529 if (isParam())
1530 return index | (type.ordinal() << 8);
1531 return function.hashCode() ^ Arrays.hashCode(arguments);
1532 }
1533 }
1534
1535 /** Return the index of the last name which contains n as an argument.
1536 * Return -1 if the name is not used. Return names.length if it is the return value.
1537 */
1538 int lastUseIndex(Name n) {
1539 int ni = n.index, nmax = names.length;
1540 assert(names[ni] == n);
1541 if (result == ni) return nmax; // live all the way beyond the end
1542 for (int i = nmax; --i > ni; ) {
1543 if (names[i].lastUseIndex(n) >= 0)
1544 return i;
1545 }
1546 return -1;
1547 }
1548
1549 /** Return the number of times n is used as an argument or return value. */
1550 int useCount(Name n) {
1551 int count = (result == n.index) ? 1 : 0;
1552 int i = Math.max(n.index + 1, arity);
1553 Name[] names = this.names;
1554 while (i < names.length) {
1555 Object[] arguments = names[i++].arguments;
1556 if (arguments != null) {
1557 for (Object argument : arguments) {
1558 if (argument == n) {
1559 count++;
1560 }
1561 }
1562 }
1563 }
1564 return count;
1565 }
1566
1567 static Name argument(int which, BasicType type) {
1568 if (which >= INTERNED_ARGUMENT_LIMIT)
1569 return new Name(which, type);
1570 return INTERNED_ARGUMENTS[type.ordinal()][which];
1571 }
1572 static Name internArgument(Name n) {
1573 assert(n.isParam()) : "not param: " + n;
1574 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1575 if (n.constraint != null) return n;
1576 return argument(n.index, n.type);
1577 }
1578 static Name[] arguments(int extra, MethodType types) {
1579 int length = types.parameterCount();
1580 Name[] names = new Name[length + extra];
1581 for (int i = 0; i < length; i++)
1582 names[i] = argument(i, basicType(types.parameterType(i)));
1583 return names;
1584 }
1585
1586 static Name[] invokeArguments(int extra, MethodType types) {
1587 int length = types.parameterCount();
1588 Name[] names = new Name[length + extra + 1];
1589 names[0] = argument(0, L_TYPE);
1590 for (int i = 0; i < length; i++)
1591 names[i + 1] = argument(i + 1, basicType(types.parameterType(i)));
1592 return names;
1593 }
1594
1595 static final int INTERNED_ARGUMENT_LIMIT = 10;
1596 private static final Name[][] INTERNED_ARGUMENTS
1597 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1598 static {
1599 for (BasicType type : BasicType.ARG_TYPES) {
1600 int ord = type.ordinal();
1601 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1602 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1603 }
1604 }
1605 }
1606
1607 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1608
1609 static LambdaForm identityForm(BasicType type) {
1610 int ord = type.ordinal();
1611 LambdaForm form = LF_identity[ord];
1612 if (form != null) {
1613 return form;
1614 }
1615 createIdentityForm(type);
1616 return LF_identity[ord];
1617 }
1618
1619 static NamedFunction identity(BasicType type) {
1620 int ord = type.ordinal();
1621 NamedFunction function = NF_identity[ord];
1622 if (function != null) {
1623 return function;
1624 }
1625 createIdentityForm(type);
1626 return NF_identity[ord];
1627 }
1628
1629 static LambdaForm constantForm(BasicType type) {
1630 assert type != null && type != V_TYPE : type;
1631 var cached = LF_constant[type.ordinal()];
1632 if (cached != null)
1633 return cached;
1634 return createConstantForm(type);
1635 }
1636
1637 private static LambdaForm createConstantForm(BasicType type) {
1638 UNSAFE.ensureClassInitialized(BoundMethodHandle.class); // defend access to SimpleMethodHandle
1639 var species = SimpleMethodHandle.BMH_SPECIES.extendWith(type);
1640 var carrier = argument(0, L_TYPE).withConstraint(species); // BMH bound with data
1641 Name[] constNames = new Name[] { carrier, new Name(species.getterFunction(0), carrier) };
1642 return LF_constant[type.ordinal()] = create(1, constNames, Kind.CONSTANT);
1643 }
1644
1645 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1646 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1647 private static final @Stable LambdaForm[] LF_constant = new LambdaForm[ARG_TYPE_LIMIT]; // no void
1648
1649 private static final Object createIdentityFormLock = new Object();
1650 private static void createIdentityForm(BasicType type) {
1651 // Avoid racy initialization during bootstrap
1652 UNSAFE.ensureClassInitialized(BoundMethodHandle.class);
1653 synchronized (createIdentityFormLock) {
1654 final int ord = type.ordinal();
1655 LambdaForm idForm = LF_identity[ord];
1656 if (idForm != null) {
1657 return;
1658 }
1659 char btChar = type.basicTypeChar();
1660 boolean isVoid = (type == V_TYPE);
1661 Class<?> btClass = type.btClass;
1662 MethodType idType = (isVoid) ? MethodType.methodType(btClass) : MethodType.methodType(btClass, btClass);
1663
1664 // Look up symbolic names. It might not be necessary to have these,
1665 // but if we need to emit direct references to bytecodes, it helps.
1666 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1667 try {
1668 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, LM_TRUSTED, NoSuchMethodException.class);
1669 } catch (IllegalAccessException|NoSuchMethodException ex) {
1670 throw newInternalError(ex);
1671 }
1672
1673 NamedFunction idFun;
1674
1675 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1676 // bootstrap dependency on this method in case we're interpreting LFs
1677 if (isVoid) {
1678 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1679 idForm = LambdaForm.create(1, idNames, VOID_RESULT, Kind.IDENTITY);
1680 idForm.compileToBytecode();
1681 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1682 } else {
1683 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1684 idForm = LambdaForm.create(2, idNames, 1, Kind.IDENTITY);
1685 idForm.compileToBytecode();
1686 idFun = new NamedFunction(idMem, MethodHandleImpl.makeIntrinsic(idMem.getInvocationType(), idForm,
1687 MethodHandleImpl.Intrinsic.IDENTITY));
1688 }
1689
1690 LF_identity[ord] = idForm;
1691 NF_identity[ord] = idFun;
1692
1693 assert(idFun.isIdentity());
1694 }
1695 }
1696
1697 // Avoid appealing to ValueConversions at bootstrap time:
1698 private static int identity_I(int x) { return x; }
1699 private static long identity_J(long x) { return x; }
1700 private static float identity_F(float x) { return x; }
1701 private static double identity_D(double x) { return x; }
1702 private static Object identity_L(Object x) { return x; }
1703 private static void identity_V() { return; }
1704 /**
1705 * Internal marker for byte-compiled LambdaForms.
1706 */
1707 /*non-public*/
1708 @Target(ElementType.METHOD)
1709 @Retention(RetentionPolicy.RUNTIME)
1710 @interface Compiled {
1711 }
1712
1713 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1714 private static final HashMap<LambdaForm,String> DEBUG_NAMES;
1715 static {
1716 if (debugEnabled()) {
1717 DEBUG_NAME_COUNTERS = new HashMap<>();
1718 DEBUG_NAMES = new HashMap<>();
1719 } else {
1720 DEBUG_NAME_COUNTERS = null;
1721 DEBUG_NAMES = null;
1722 }
1723 }
1724
1725 static {
1726 // The Holder class will contain pre-generated forms resolved
1727 // using MemberName.getFactory(). However, that doesn't initialize the
1728 // class, which subtly breaks inlining etc. By forcing
1729 // initialization of the Holder class we avoid these issues.
1730 UNSAFE.ensureClassInitialized(Holder.class);
1731 }
1732
1733 /* Placeholder class for identity and constant forms generated ahead of time */
1734 @AOTSafeClassInitializer
1735 final class Holder {}
1736
1737 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1738 // during execution of the static initializes of this class.
1739 // Turning on TRACE_INTERPRETER too early will cause
1740 // stack overflows and other misbehavior during attempts to trace events
1741 // that occur during LambdaForm.<clinit>.
1742 // Therefore, do not move this line higher in this file, and do not remove.
1743 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1744 }