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