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 GET_REFERENCE("getReference"),
267 PUT_REFERENCE("putReference"),
268 GET_REFERENCE_VOLATILE("getReferenceVolatile"),
269 PUT_REFERENCE_VOLATILE("putReferenceVolatile"),
270 GET_FLAT_VALUE("getFlatValue"),
271 PUT_FLAT_VALUE("putFlatValue"),
272 GET_FLAT_VALUE_VOLATILE("getFlatValueVolatile"),
273 PUT_FLAT_VALUE_VOLATILE("putFlatValueVolatile"),
274 GET_INT("getInt"),
275 PUT_INT("putInt"),
276 GET_INT_VOLATILE("getIntVolatile"),
277 PUT_INT_VOLATILE("putIntVolatile"),
278 GET_BOOLEAN("getBoolean"),
279 PUT_BOOLEAN("putBoolean"),
280 GET_BOOLEAN_VOLATILE("getBooleanVolatile"),
281 PUT_BOOLEAN_VOLATILE("putBooleanVolatile"),
282 GET_BYTE("getByte"),
283 PUT_BYTE("putByte"),
284 GET_BYTE_VOLATILE("getByteVolatile"),
285 PUT_BYTE_VOLATILE("putByteVolatile"),
286 GET_CHAR("getChar"),
287 PUT_CHAR("putChar"),
288 GET_CHAR_VOLATILE("getCharVolatile"),
289 PUT_CHAR_VOLATILE("putCharVolatile"),
290 GET_SHORT("getShort"),
291 PUT_SHORT("putShort"),
292 GET_SHORT_VOLATILE("getShortVolatile"),
293 PUT_SHORT_VOLATILE("putShortVolatile"),
294 GET_LONG("getLong"),
295 PUT_LONG("putLong"),
296 GET_LONG_VOLATILE("getLongVolatile"),
297 PUT_LONG_VOLATILE("putLongVolatile"),
298 GET_FLOAT("getFloat"),
299 PUT_FLOAT("putFloat"),
300 GET_FLOAT_VOLATILE("getFloatVolatile"),
301 PUT_FLOAT_VOLATILE("putFloatVolatile"),
302 GET_DOUBLE("getDouble"),
303 PUT_DOUBLE("putDouble"),
304 GET_DOUBLE_VOLATILE("getDoubleVolatile"),
305 PUT_DOUBLE_VOLATILE("putDoubleVolatile"),
306 TRY_FINALLY("tryFinally"),
307 TABLE_SWITCH("tableSwitch"),
308 COLLECTOR("collector"),
309 LOOP("loop"),
310 GUARD("guard"),
311 GUARD_WITH_CATCH("guardWithCatch"),
312 VARHANDLE_EXACT_INVOKER("VH.exactInvoker"),
313 VARHANDLE_INVOKER("VH.invoker", "invoker"),
314 VARHANDLE_LINKER("VH.invoke_MT", "invoke_MT");
315
316 final String defaultLambdaName;
317 final String methodName;
318
319 private Kind(String defaultLambdaName) {
320 this(defaultLambdaName, defaultLambdaName);
321 }
322
323 private Kind(String defaultLambdaName, String methodName) {
324 this.defaultLambdaName = defaultLambdaName;
325 this.methodName = methodName;
326 }
327 }
328
329 // private version that doesn't do checks or defensive copies
330 private LambdaForm(int arity, int result, boolean forceInline, MethodHandle customized, Name[] names, Kind kind) {
331 this.arity = arity;
332 this.result = result;
333 this.forceInline = forceInline;
334 this.customized = customized;
335 this.names = names;
336 this.kind = kind;
337 this.vmentry = null;
338 this.isCompiled = false;
339 }
340
341 // root factory pre/post processing and calls simple constructor
342 private static LambdaForm create(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
343 names = names.clone();
344 assert(namesOK(arity, names));
345 result = fixResult(result, names);
346
347 boolean canInterpret = normalizeNames(arity, names);
348 LambdaForm form = new LambdaForm(arity, result, forceInline, customized, names, kind);
349 assert(form.nameRefsAreLegal());
350 if (!canInterpret) {
351 form.compileToBytecode();
352 }
353 return form;
354 }
355
356 // derived factories with defaults
357 private static final int DEFAULT_RESULT = LAST_RESULT;
358 private static final boolean DEFAULT_FORCE_INLINE = true;
359 private static final MethodHandle DEFAULT_CUSTOMIZED = null;
360 private static final Kind DEFAULT_KIND = Kind.GENERIC;
361
362 static LambdaForm create(int arity, Name[] names, int result) {
363 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
364 }
365 static LambdaForm create(int arity, Name[] names, int result, Kind kind) {
366 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
367 }
368 static LambdaForm create(int arity, Name[] names) {
369 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
370 }
371 static LambdaForm create(int arity, Name[] names, Kind kind) {
372 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
373 }
374 static LambdaForm create(int arity, Name[] names, boolean forceInline, Kind kind) {
375 return create(arity, names, DEFAULT_RESULT, forceInline, DEFAULT_CUSTOMIZED, kind);
376 }
377
378 private static int fixResult(int result, Name[] names) {
379 if (result == LAST_RESULT)
380 result = names.length - 1; // might still be void
381 if (result >= 0 && names[result].type == V_TYPE)
382 result = VOID_RESULT;
383 return result;
384 }
385
386 static boolean debugNames() {
387 return DEBUG_NAME_COUNTERS != null;
388 }
389
390 static void associateWithDebugName(LambdaForm form, String name) {
391 assert (debugNames());
392 synchronized (DEBUG_NAMES) {
393 DEBUG_NAMES.put(form, name);
394 }
395 }
396
397 String lambdaName() {
398 if (DEBUG_NAMES != null) {
399 synchronized (DEBUG_NAMES) {
400 String name = DEBUG_NAMES.get(this);
401 if (name == null) {
402 name = generateDebugName();
403 }
404 return name;
405 }
406 }
407 return kind.defaultLambdaName;
408 }
409
410 private String generateDebugName() {
411 assert (debugNames());
412 String debugNameStem = kind.defaultLambdaName;
413 Integer ctr = DEBUG_NAME_COUNTERS.getOrDefault(debugNameStem, 0);
414 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr + 1);
415 StringBuilder buf = new StringBuilder(debugNameStem);
416 int leadingZero = buf.length();
417 buf.append((int) ctr);
418 for (int i = buf.length() - leadingZero; i < 3; i++) {
419 buf.insert(leadingZero, '0');
420 }
421 buf.append('_');
422 buf.append(basicTypeSignature());
423 String name = buf.toString();
424 associateWithDebugName(this, name);
425 return name;
426 }
427
428 private static boolean namesOK(int arity, Name[] names) {
429 for (int i = 0; i < names.length; i++) {
430 Name n = names[i];
431 assert(n != null) : "n is null";
432 if (i < arity)
433 assert( n.isParam()) : n + " is not param at " + i;
434 else
435 assert(!n.isParam()) : n + " is param at " + i;
436 }
437 return true;
438 }
439
440 /** Customize LambdaForm for a particular MethodHandle */
441 LambdaForm customize(MethodHandle mh) {
442 if (customized == mh) {
443 return this;
444 }
445 LambdaForm customForm = LambdaForm.create(arity, names, result, forceInline, mh, kind);
446 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
447 // If shared LambdaForm has been compiled, compile customized version as well.
448 customForm.compileToBytecode();
449 }
450 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
451 return customForm;
452 }
453
454 /** Get uncustomized flavor of the LambdaForm */
455 LambdaForm uncustomize() {
456 if (customized == null) {
457 return this;
458 }
459 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
460 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
461 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
462 // If customized LambdaForm has been compiled, compile uncustomized version as well.
463 uncustomizedForm.compileToBytecode();
464 }
465 return uncustomizedForm;
466 }
467
468 /** Renumber and/or replace params so that they are interned and canonically numbered.
469 * @return true if we can interpret
470 */
471 private static boolean normalizeNames(int arity, Name[] names) {
472 Name[] oldNames = names.clone();
473 int maxOutArity = 0;
474 for (int i = 0; i < names.length; i++) {
475 Name n = names[i];
476 names[i] = n.withIndex(i);
477 if (n.arguments != null && maxOutArity < n.arguments.length)
478 maxOutArity = n.arguments.length;
479 }
480 if (oldNames != null) {
481 for (int i = Math.max(1, arity); i < names.length; i++) {
482 Name fixed = names[i].replaceNames(oldNames, names, 0, i);
483 names[i] = fixed.withIndex(i);
484 }
485 }
486 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
487 boolean needIntern = false;
488 for (int i = 0; i < maxInterned; i++) {
489 Name n = names[i], n2 = internArgument(n);
490 if (n != n2) {
491 names[i] = n2;
492 needIntern = true;
493 }
494 }
495 if (needIntern) {
496 for (int i = arity; i < names.length; i++) {
497 names[i].internArguments();
498 }
499 }
500
501 // return true if we can interpret
502 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
503 // Cannot use LF interpreter on very high arity expressions.
504 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
505 return false;
506 }
507 return true;
508 }
509
510 /**
511 * Check that all embedded Name references are localizable to this lambda,
512 * and are properly ordered after their corresponding definitions.
513 * <p>
514 * Note that a Name can be local to multiple lambdas, as long as
515 * it possesses the same index in each use site.
516 * This allows Name references to be freely reused to construct
517 * fresh lambdas, without confusion.
518 */
519 boolean nameRefsAreLegal() {
520 assert(arity >= 0 && arity <= names.length);
521 assert(result >= -1 && result < names.length);
522 // Do all names possess an index consistent with their local definition order?
523 for (int i = 0; i < arity; i++) {
524 Name n = names[i];
525 assert(n.index() == i) : Arrays.asList(n.index(), i);
526 assert(n.isParam());
527 }
528 // Also, do all local name references
529 for (int i = arity; i < names.length; i++) {
530 Name n = names[i];
531 assert(n.index() == i);
532 for (Object arg : n.arguments) {
533 if (arg instanceof Name n2) {
534 int i2 = n2.index;
535 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
536 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
537 assert(i2 < i); // ref must come after def!
538 }
539 }
540 }
541 return true;
542 }
543
544 // /** Invoke this form on the given arguments. */
545 // final Object invoke(Object... args) throws Throwable {
546 // // NYI: fit this into the fast path?
547 // return interpretWithArguments(args);
548 // }
549
550 /** Report the return type. */
551 BasicType returnType() {
552 if (result < 0) return V_TYPE;
553 Name n = names[result];
554 return n.type;
555 }
556
557 /** Report the N-th argument type. */
558 BasicType parameterType(int n) {
559 return parameter(n).type;
560 }
561
562 /** Report the N-th argument name. */
563 Name parameter(int n) {
564 Name param = names[n];
565 assert(n < arity && param.isParam());
566 return param;
567 }
568
569 /** Report the N-th argument type constraint. */
570 Object parameterConstraint(int n) {
571 return parameter(n).constraint;
572 }
573
574 /** Report the arity. */
575 int arity() {
576 return arity;
577 }
578
579 /** Report the number of expressions (non-parameter names). */
580 int expressionCount() {
581 return names.length - arity;
582 }
583
584 /** Return the method type corresponding to my basic type signature. */
585 MethodType methodType() {
586 Class<?>[] ptypes = new Class<?>[arity];
587 for (int i = 0; i < arity; ++i) {
588 ptypes[i] = parameterType(i).btClass;
589 }
590 return MethodType.methodType(returnType().btClass, ptypes, true);
591 }
592
593 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
594 final String basicTypeSignature() {
595 StringBuilder buf = new StringBuilder(arity() + 3);
596 for (int i = 0, a = arity(); i < a; i++)
597 buf.append(parameterType(i).basicTypeChar());
598 return buf.append('_').append(returnType().basicTypeChar()).toString();
599 }
600 static int signatureArity(String sig) {
601 assert(isValidSignature(sig));
602 return sig.indexOf('_');
603 }
604 static boolean isValidSignature(String sig) {
605 int arity = sig.indexOf('_');
606 if (arity < 0) return false; // must be of the form *_*
607 int siglen = sig.length();
608 if (siglen != arity + 2) return false; // *_X
609 for (int i = 0; i < siglen; i++) {
610 if (i == arity) continue; // skip '_'
611 char c = sig.charAt(i);
612 if (c == 'V')
613 return (i == siglen - 1 && arity == siglen - 2);
614 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
615 }
616 return true; // [LIJFD]*_[LIJFDV]
617 }
618
619 /**
620 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
621 */
622 boolean isSelectAlternative(int pos) {
623 // selectAlternative idiom:
624 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
625 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
626 if (pos+1 >= names.length) return false;
627 Name name0 = names[pos];
628 Name name1 = names[pos+1];
629 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
630 name1.isInvokeBasic() &&
631 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
632 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
633 }
634
635 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
636 if (pos+2 >= names.length) return false;
637 Name name0 = names[pos];
638 Name name1 = names[pos+1];
639 Name name2 = names[pos+2];
640 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
641 name0.isInvokeBasic() &&
642 name2.isInvokeBasic() &&
643 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
644 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
645 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
646 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
647 }
648
649 /**
650 * Check if i-th name is a start of GuardWithCatch idiom.
651 */
652 boolean isGuardWithCatch(int pos) {
653 // GuardWithCatch idiom:
654 // t_{n}:L=MethodHandle.invokeBasic(...)
655 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
656 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
657 return isMatchingIdiom(pos, "guardWithCatch", 3);
658 }
659
660 /**
661 * Check if i-th name is a start of the tryFinally idiom.
662 */
663 boolean isTryFinally(int pos) {
664 // tryFinally idiom:
665 // t_{n}:L=MethodHandle.invokeBasic(...)
666 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
667 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
668 return isMatchingIdiom(pos, "tryFinally", 2);
669 }
670
671 /**
672 * Check if i-th name is a start of the tableSwitch idiom.
673 */
674 boolean isTableSwitch(int pos) {
675 // tableSwitch idiom:
676 // t_{n}:L=MethodHandle.invokeBasic(...) // args
677 // t_{n+1}:L=MethodHandleImpl.tableSwitch(*, *, *, t_{n})
678 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
679 if (pos + 2 >= names.length) return false;
680
681 final int POS_COLLECT_ARGS = pos;
682 final int POS_TABLE_SWITCH = pos + 1;
683 final int POS_UNBOX_RESULT = pos + 2;
684
685 Name collectArgs = names[POS_COLLECT_ARGS];
686 Name tableSwitch = names[POS_TABLE_SWITCH];
687 Name unboxResult = names[POS_UNBOX_RESULT];
688 return tableSwitch.refersTo(MethodHandleImpl.class, "tableSwitch") &&
689 collectArgs.isInvokeBasic() &&
690 unboxResult.isInvokeBasic() &&
691 tableSwitch.lastUseIndex(collectArgs) == 3 && // t_{n+1}:L=MethodHandleImpl.<invoker>(*, *, *, t_{n});
692 lastUseIndex(collectArgs) == POS_TABLE_SWITCH && // t_{n} is local: used only in t_{n+1}
693 unboxResult.lastUseIndex(tableSwitch) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
694 lastUseIndex(tableSwitch) == POS_UNBOX_RESULT; // t_{n+1} is local: used only in t_{n+2}
695 }
696
697 /**
698 * Check if i-th name is a start of the loop idiom.
699 */
700 boolean isLoop(int pos) {
701 // loop idiom:
702 // t_{n}:L=MethodHandle.invokeBasic(...)
703 // t_{n+1}:L=MethodHandleImpl.loop(types, *, t_{n})
704 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
705 return isMatchingIdiom(pos, "loop", 2);
706 }
707
708 /*
709 * Code generation issues:
710 *
711 * Compiled LFs should be reusable in general.
712 * The biggest issue is how to decide when to pull a name into
713 * the bytecode, versus loading a reified form from the MH data.
714 *
715 * For example, an asType wrapper may require execution of a cast
716 * after a call to a MH. The target type of the cast can be placed
717 * as a constant in the LF itself. This will force the cast type
718 * to be compiled into the bytecodes and native code for the MH.
719 * Or, the target type of the cast can be erased in the LF, and
720 * loaded from the MH data. (Later on, if the MH as a whole is
721 * inlined, the data will flow into the inlined instance of the LF,
722 * as a constant, and the end result will be an optimal cast.)
723 *
724 * This erasure of cast types can be done with any use of
725 * reference types. It can also be done with whole method
726 * handles. Erasing a method handle might leave behind
727 * LF code that executes correctly for any MH of a given
728 * type, and load the required MH from the enclosing MH's data.
729 * Or, the erasure might even erase the expected MT.
730 *
731 * Also, for direct MHs, the MemberName of the target
732 * could be erased, and loaded from the containing direct MH.
733 * As a simple case, a LF for all int-valued non-static
734 * field getters would perform a cast on its input argument
735 * (to non-constant base type derived from the MemberName)
736 * and load an integer value from the input object
737 * (at a non-constant offset also derived from the MemberName).
738 * Such MN-erased LFs would be inlinable back to optimized
739 * code, whenever a constant enclosing DMH is available
740 * to supply a constant MN from its data.
741 *
742 * The main problem here is to keep LFs reasonably generic,
743 * while ensuring that hot spots will inline good instances.
744 * "Reasonably generic" means that we don't end up with
745 * repeated versions of bytecode or machine code that do
746 * not differ in their optimized form. Repeated versions
747 * of machine would have the undesirable overheads of
748 * (a) redundant compilation work and (b) extra I$ pressure.
749 * To control repeated versions, we need to be ready to
750 * erase details from LFs and move them into MH data,
751 * whenever those details are not relevant to significant
752 * optimization. "Significant" means optimization of
753 * code that is actually hot.
754 *
755 * Achieving this may require dynamic splitting of MHs, by replacing
756 * a generic LF with a more specialized one, on the same MH,
757 * if (a) the MH is frequently executed and (b) the MH cannot
758 * be inlined into a containing caller, such as an invokedynamic.
759 *
760 * Compiled LFs that are no longer used should be GC-able.
761 * If they contain non-BCP references, they should be properly
762 * interlinked with the class loader(s) that their embedded types
763 * depend on. This probably means that reusable compiled LFs
764 * will be tabulated (indexed) on relevant class loaders,
765 * or else that the tables that cache them will have weak links.
766 */
767
768 /**
769 * Make this LF directly executable, as part of a MethodHandle.
770 * Invariant: Every MH which is invoked must prepare its LF
771 * before invocation.
772 * (In principle, the JVM could do this very lazily,
773 * as a sort of pre-invocation linkage step.)
774 */
775 public void prepare() {
776 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
777 compileToBytecode();
778 }
779 if (this.vmentry != null) {
780 // already prepared (e.g., a primitive DMH invoker form)
781 return;
782 }
783 MethodType mtype = methodType();
784 MethodTypeForm form = mtype.form();
785
786 MemberName entry = form.cachedInterpretEntry();
787 if (entry == null) {
788 assert (isValidSignature(basicTypeSignature()));
789 entry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
790 entry = form.setCachedInterpretEntry(entry);
791 }
792 this.vmentry = entry;
793 // TO DO: Maybe add invokeGeneric, invokeWithArguments
794 }
795
796 private static @Stable PerfCounter LF_FAILED;
797
798 private static PerfCounter failedCompilationCounter() {
799 if (LF_FAILED == null) {
800 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
801 }
802 return LF_FAILED;
803 }
804
805 /** Generate optimizable bytecode for this form. */
806 void compileToBytecode() {
807 if (forceInterpretation()) {
808 return; // this should not be compiled
809 }
810 if (vmentry != null && isCompiled) {
811 return; // already compiled somehow
812 }
813
814 // Obtain the invoker MethodType outside of the following try block.
815 // This ensures that an IllegalArgumentException is directly thrown if the
816 // type would have 256 or more parameters
817 MethodType invokerType = methodType();
818 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
819 try {
820 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
821 if (TRACE_INTERPRETER)
822 traceInterpreter("compileToBytecode", this);
823 isCompiled = true;
824 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
825 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
826 invocationCounter = -1;
827 failedCompilationCounter().increment();
828 if (LOG_LF_COMPILATION_FAILURE) {
829 System.out.println("LambdaForm compilation failed: " + this);
830 bge.printStackTrace(System.out);
831 }
832 } catch (Error e) {
833 // Pass through any error
834 throw e;
835 } catch (Exception e) {
836 // Wrap any exception
837 throw newInternalError(this.toString(), e);
838 }
839 }
840
841 // The next few routines are called only from assert expressions
842 // They verify that the built-in invokers process the correct raw data types.
843 private static boolean argumentTypesMatch(String sig, Object[] av) {
844 int arity = signatureArity(sig);
845 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
846 assert(av[0] instanceof MethodHandle) : "av[0] not instance of MethodHandle: " + av[0];
847 MethodHandle mh = (MethodHandle) av[0];
848 MethodType mt = mh.type();
849 assert(mt.parameterCount() == arity-1);
850 for (int i = 0; i < av.length; i++) {
851 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
852 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
853 }
854 return true;
855 }
856 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
857 // The following line is needed because (...)void method handles can use non-void invokers
858 if (type == void.class) tc = V_TYPE; // can drop any kind of value
859 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
860 switch (tc) {
861 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
862 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
863 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
864 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
865 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
866 case V_TYPE: break; // allow anything here; will be dropped
867 default: assert(false);
868 }
869 return true;
870 }
871 private static boolean checkInt(Class<?> type, Object x) {
872 assert(x instanceof Integer);
873 if (type == int.class) return true;
874 Wrapper w = Wrapper.forBasicType(type);
875 assert(w.isSubwordOrInt());
876 Object x1 = Wrapper.INT.wrap(w.wrap(x));
877 return x.equals(x1);
878 }
879 private static boolean checkRef(Class<?> type, Object x) {
880 assert(!type.isPrimitive());
881 if (x == null) return true;
882 if (type.isInterface()) return true;
883 return type.isInstance(x);
884 }
885
886 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
887 private static final int COMPILE_THRESHOLD;
888 static {
889 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
890 }
891 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
892
893 private boolean forceInterpretation() {
894 return invocationCounter == -1;
895 }
896
897 /** Interpretively invoke this form on the given arguments. */
898 @Hidden
899 @DontInline
900 Object interpretWithArguments(Object... argumentValues) throws Throwable {
901 if (TRACE_INTERPRETER)
902 return interpretWithArgumentsTracing(argumentValues);
903 checkInvocationCounter();
904 assert(arityCheck(argumentValues));
905 Object[] values = Arrays.copyOf(argumentValues, names.length);
906 for (int i = argumentValues.length; i < values.length; i++) {
907 values[i] = interpretName(names[i], values);
908 }
909 Object rv = (result < 0) ? null : values[result];
910 assert(resultCheck(argumentValues, rv));
911 return rv;
912 }
913
914 /** Evaluate a single Name within this form, applying its function to its arguments. */
915 @Hidden
916 @DontInline
917 Object interpretName(Name name, Object[] values) throws Throwable {
918 if (TRACE_INTERPRETER)
919 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
920 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
921 for (int i = 0; i < arguments.length; i++) {
922 Object a = arguments[i];
923 if (a instanceof Name n) {
924 int i2 = n.index();
925 assert(names[i2] == a);
926 a = values[i2];
927 arguments[i] = a;
928 }
929 }
930 return name.function.invokeWithArguments(arguments);
931 }
932
933 private void checkInvocationCounter() {
934 if (COMPILE_THRESHOLD != 0 &&
935 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
936 invocationCounter++; // benign race
937 if (invocationCounter >= COMPILE_THRESHOLD) {
938 // Replace vmentry with a bytecode version of this LF.
939 compileToBytecode();
940 }
941 }
942 }
943 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
944 traceInterpreter("[ interpretWithArguments", this, argumentValues);
945 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
946 int ctr = invocationCounter++; // benign race
947 traceInterpreter("| invocationCounter", ctr);
948 if (invocationCounter >= COMPILE_THRESHOLD) {
949 compileToBytecode();
950 }
951 }
952 Object rval;
953 try {
954 assert(arityCheck(argumentValues));
955 Object[] values = Arrays.copyOf(argumentValues, names.length);
956 for (int i = argumentValues.length; i < values.length; i++) {
957 values[i] = interpretName(names[i], values);
958 }
959 rval = (result < 0) ? null : values[result];
960 } catch (Throwable ex) {
961 traceInterpreter("] throw =>", ex);
962 throw ex;
963 }
964 traceInterpreter("] return =>", rval);
965 return rval;
966 }
967
968 static void traceInterpreter(String event, Object obj, Object... args) {
969 if (TRACE_INTERPRETER) {
970 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
971 }
972 }
973 static void traceInterpreter(String event, Object obj) {
974 traceInterpreter(event, obj, (Object[])null);
975 }
976 private boolean arityCheck(Object[] argumentValues) {
977 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
978 // also check that the leading (receiver) argument is somehow bound to this LF:
979 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
980 MethodHandle mh = (MethodHandle) argumentValues[0];
981 assert(mh.internalForm() == this);
982 // note: argument #0 could also be an interface wrapper, in the future
983 argumentTypesMatch(basicTypeSignature(), argumentValues);
984 return true;
985 }
986 private boolean resultCheck(Object[] argumentValues, Object result) {
987 MethodHandle mh = (MethodHandle) argumentValues[0];
988 MethodType mt = mh.type();
989 assert(valueMatches(returnType(), mt.returnType(), result));
990 return true;
991 }
992
993 public String toString() {
994 return debugString(-1);
995 }
996
997 String debugString(int indentLevel) {
998 String prefix = MethodHandle.debugPrefix(indentLevel);
999 String lambdaName = lambdaName();
1000 StringBuilder buf = new StringBuilder(lambdaName);
1001 buf.append("=Lambda(");
1002 for (int i = 0; i < names.length; i++) {
1003 if (i == arity) buf.append(")=>{");
1004 Name n = names[i];
1005 if (i >= arity) buf.append("\n ").append(prefix);
1006 buf.append(n.paramString());
1007 if (i < arity) {
1008 if (i+1 < arity) buf.append(",");
1009 continue;
1010 }
1011 buf.append("=").append(n.exprString());
1012 buf.append(";");
1013 }
1014 if (arity == names.length) buf.append(")=>{");
1015 buf.append(result < 0 ? "void" : names[result]).append("}");
1016 if (TRACE_INTERPRETER) {
1017 // Extra verbosity:
1018 buf.append(":").append(basicTypeSignature());
1019 buf.append("/").append(vmentry);
1020 }
1021 return buf.toString();
1022 }
1023
1024 @Override
1025 public boolean equals(Object obj) {
1026 return obj instanceof LambdaForm lf && equals(lf);
1027 }
1028 public boolean equals(LambdaForm that) {
1029 if (this.result != that.result) return false;
1030 return Arrays.equals(this.names, that.names);
1031 }
1032 public int hashCode() {
1033 return result + 31 * Arrays.hashCode(names);
1034 }
1035 LambdaFormEditor editor() {
1036 return LambdaFormEditor.lambdaFormEditor(this);
1037 }
1038
1039 boolean contains(Name name) {
1040 int pos = name.index();
1041 if (pos >= 0) {
1042 return pos < names.length && name.equals(names[pos]);
1043 }
1044 for (int i = arity; i < names.length; i++) {
1045 if (name.equals(names[i]))
1046 return true;
1047 }
1048 return false;
1049 }
1050
1051 static class NamedFunction {
1052 final MemberName member;
1053 private @Stable MethodHandle resolvedHandle;
1054 private @Stable MethodType type;
1055
1056 NamedFunction(MethodHandle resolvedHandle) {
1057 this(resolvedHandle.internalMemberName(), resolvedHandle);
1058 }
1059 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1060 this.member = member;
1061 this.resolvedHandle = resolvedHandle;
1062 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1063 //assert(!isInvokeBasic(member));
1064 }
1065 NamedFunction(MethodType basicInvokerType) {
1066 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1067 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1068 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1069 this.member = resolvedHandle.internalMemberName();
1070 } else {
1071 // necessary to pass BigArityTest
1072 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1073 }
1074 assert(isInvokeBasic(member));
1075 }
1076
1077 private static boolean isInvokeBasic(MemberName member) {
1078 return member != null &&
1079 member.getDeclaringClass() == MethodHandle.class &&
1080 "invokeBasic".equals(member.getName());
1081 }
1082
1083 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1084 // Any LambdaForm containing such a member is not interpretable.
1085 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1086 // And even without the resolvedHandle, the name can still be compiled and optimized.
1087 NamedFunction(Method method) {
1088 this(new MemberName(method));
1089 }
1090 NamedFunction(MemberName member) {
1091 this(member, null);
1092 }
1093
1094 MethodHandle resolvedHandle() {
1095 if (resolvedHandle == null) resolve();
1096 return resolvedHandle;
1097 }
1098
1099 synchronized void resolve() {
1100 if (resolvedHandle == null) {
1101 resolvedHandle = DirectMethodHandle.make(member);
1102 }
1103 }
1104
1105 @Override
1106 public boolean equals(Object other) {
1107 if (this == other) return true;
1108 if (other == null) return false;
1109 return (other instanceof NamedFunction that)
1110 && this.member != null
1111 && this.member.equals(that.member);
1112 }
1113
1114 @Override
1115 public int hashCode() {
1116 if (member != null)
1117 return member.hashCode();
1118 return super.hashCode();
1119 }
1120
1121 static final MethodType INVOKER_METHOD_TYPE =
1122 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1123
1124 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1125 typeForm = typeForm.basicType().form(); // normalize to basic type
1126 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1127 if (mh != null) return mh;
1128 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1129 mh = DirectMethodHandle.make(invoker);
1130 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1131 if (mh2 != null) return mh2; // benign race
1132 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1133 throw newInternalError(mh.debugString());
1134 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1135 }
1136
1137 @Hidden
1138 Object invokeWithArguments(Object... arguments) throws Throwable {
1139 // If we have a cached invoker, call it right away.
1140 // NOTE: The invoker always returns a reference value.
1141 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1142 return invoker().invokeBasic(resolvedHandle(), arguments);
1143 }
1144
1145 @Hidden
1146 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1147 Object rval;
1148 try {
1149 traceInterpreter("[ call", this, arguments);
1150 // resolvedHandle might be uninitialized, ok for tracing
1151 if (resolvedHandle == null) {
1152 traceInterpreter("| resolve", this);
1153 resolvedHandle();
1154 }
1155 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1156 } catch (Throwable ex) {
1157 traceInterpreter("] throw =>", ex);
1158 throw ex;
1159 }
1160 traceInterpreter("] return =>", rval);
1161 return rval;
1162 }
1163
1164 private MethodHandle invoker() {
1165 return computeInvoker(methodType().form());
1166 }
1167
1168 MethodType methodType() {
1169 MethodType type = this.type;
1170 if (type == null) {
1171 this.type = type = calculateMethodType(member, resolvedHandle);
1172 }
1173 return type;
1174 }
1175
1176 private static MethodType calculateMethodType(MemberName member, MethodHandle resolvedHandle) {
1177 if (resolvedHandle != null) {
1178 return resolvedHandle.type();
1179 } else {
1180 // only for certain internal LFs during bootstrapping
1181 return member.getInvocationType();
1182 }
1183 }
1184
1185 MemberName member() {
1186 assert(assertMemberIsConsistent());
1187 return member;
1188 }
1189
1190 // Called only from assert.
1191 private boolean assertMemberIsConsistent() {
1192 if (resolvedHandle instanceof DirectMethodHandle) {
1193 MemberName m = resolvedHandle.internalMemberName();
1194 assert(m.equals(member));
1195 }
1196 return true;
1197 }
1198
1199 Class<?> memberDeclaringClassOrNull() {
1200 return (member == null) ? null : member.getDeclaringClass();
1201 }
1202
1203 BasicType returnType() {
1204 return basicType(methodType().returnType());
1205 }
1206
1207 BasicType parameterType(int n) {
1208 return basicType(methodType().parameterType(n));
1209 }
1210
1211 int arity() {
1212 return methodType().parameterCount();
1213 }
1214
1215 public String toString() {
1216 if (member == null) return String.valueOf(resolvedHandle);
1217 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1218 }
1219
1220 public boolean isIdentity() {
1221 return this.equals(identity(returnType()));
1222 }
1223
1224 public MethodHandleImpl.Intrinsic intrinsicName() {
1225 return resolvedHandle != null
1226 ? resolvedHandle.intrinsicName()
1227 : MethodHandleImpl.Intrinsic.NONE;
1228 }
1229
1230 public Object intrinsicData() {
1231 return resolvedHandle != null
1232 ? resolvedHandle.intrinsicData()
1233 : null;
1234 }
1235 }
1236
1237 public static String basicTypeSignature(MethodType type) {
1238 int params = type.parameterCount();
1239 char[] sig = new char[params + 2];
1240 int sigp = 0;
1241 while (sigp < params) {
1242 sig[sigp] = basicTypeChar(type.parameterType(sigp++));
1243 }
1244 sig[sigp++] = '_';
1245 sig[sigp++] = basicTypeChar(type.returnType());
1246 assert(sigp == sig.length);
1247 return String.valueOf(sig);
1248 }
1249
1250 /** Hack to make signatures more readable when they show up in method names.
1251 * Signature should start with a sequence of uppercase ASCII letters.
1252 * Runs of three or more are replaced by a single letter plus a decimal repeat count.
1253 * A tail of anything other than uppercase ASCII is passed through unchanged.
1254 * @param signature sequence of uppercase ASCII letters with possible repetitions
1255 * @return same sequence, with repetitions counted by decimal numerals
1256 */
1257 public static String shortenSignature(String signature) {
1258 final int NO_CHAR = -1, MIN_RUN = 3;
1259 int c0, c1 = NO_CHAR, c1reps = 0;
1260 StringBuilder buf = null;
1261 int len = signature.length();
1262 if (len < MIN_RUN) return signature;
1263 for (int i = 0; i <= len; i++) {
1264 if (c1 != NO_CHAR && !('A' <= c1 && c1 <= 'Z')) {
1265 // wrong kind of char; bail out here
1266 if (buf != null) {
1267 buf.append(signature, i - c1reps, len);
1268 }
1269 break;
1270 }
1271 // shift in the next char:
1272 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1273 if (c1 == c0) { ++c1reps; continue; }
1274 // shift in the next count:
1275 int c0reps = c1reps; c1reps = 1;
1276 // end of a character run
1277 if (c0reps < MIN_RUN) {
1278 if (buf != null) {
1279 while (--c0reps >= 0)
1280 buf.append((char)c0);
1281 }
1282 continue;
1283 }
1284 // found three or more in a row
1285 if (buf == null)
1286 buf = new StringBuilder().append(signature, 0, i - c0reps);
1287 buf.append((char)c0).append(c0reps);
1288 }
1289 return (buf == null) ? signature : buf.toString();
1290 }
1291
1292 static final class Name {
1293 final BasicType type;
1294 final short index;
1295 final NamedFunction function;
1296 final Object constraint; // additional type information, if not null
1297 @Stable final Object[] arguments;
1298
1299 private static final Object[] EMPTY_ARGS = new Object[0];
1300
1301 private Name(int index, BasicType type, NamedFunction function, Object[] arguments, Object constraint) {
1302 this.index = (short)index;
1303 this.type = type;
1304 this.function = function;
1305 this.arguments = arguments;
1306 this.constraint = constraint;
1307 assert(this.index == index && typesMatch(function, arguments));
1308 assert(constraint == null || isParam()); // only params have constraints
1309 assert(constraint == null || constraint instanceof ClassSpecializer.SpeciesData || constraint instanceof Class);
1310 }
1311
1312 Name(MethodHandle function, Object... arguments) {
1313 this(new NamedFunction(function), arguments);
1314 }
1315 Name(MethodType functionType, Object... arguments) {
1316 this(new NamedFunction(functionType), arguments);
1317 assert(arguments[0] instanceof Name name && name.type == L_TYPE);
1318 }
1319 Name(MemberName function, Object... arguments) {
1320 this(new NamedFunction(function), arguments);
1321 }
1322 Name(NamedFunction function) {
1323 this(-1, function.returnType(), function, EMPTY_ARGS, null);
1324 }
1325 Name(NamedFunction function, Object arg) {
1326 this(-1, function.returnType(), function, new Object[] { arg }, null);
1327 }
1328 Name(NamedFunction function, Object arg0, Object arg1) {
1329 this(-1, function.returnType(), function, new Object[] { arg0, arg1 }, null);
1330 }
1331 Name(NamedFunction function, Object... arguments) {
1332 this(-1, function.returnType(), function, Arrays.copyOf(arguments, arguments.length, Object[].class), null);
1333 }
1334 /** Create a raw parameter of the given type, with an expected index. */
1335 Name(int index, BasicType type) {
1336 this(index, type, null, null, null);
1337 }
1338 /** Create a raw parameter of the given type. */
1339 Name(BasicType type) { this(-1, type); }
1340
1341 BasicType type() { return type; }
1342 int index() { return index; }
1343
1344 char typeChar() {
1345 return type.btChar;
1346 }
1347
1348 Name withIndex(int i) {
1349 if (i == this.index) return this;
1350 return new Name(i, type, function, arguments, constraint);
1351 }
1352
1353 Name withConstraint(Object constraint) {
1354 if (constraint == this.constraint) return this;
1355 return new Name(index, type, function, arguments, constraint);
1356 }
1357
1358 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1359 if (oldName == newName) return this;
1360 @SuppressWarnings("LocalVariableHidesMemberVariable")
1361 Object[] arguments = this.arguments;
1362 if (arguments == null) return this;
1363 boolean replaced = false;
1364 for (int j = 0; j < arguments.length; j++) {
1365 if (arguments[j] == oldName) {
1366 if (!replaced) {
1367 replaced = true;
1368 arguments = arguments.clone();
1369 }
1370 arguments[j] = newName;
1371 }
1372 }
1373 if (!replaced) return this;
1374 return new Name(function, arguments);
1375 }
1376 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1377 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1378 */
1379 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1380 if (start >= end) return this;
1381 @SuppressWarnings("LocalVariableHidesMemberVariable")
1382 Object[] arguments = this.arguments;
1383 boolean replaced = false;
1384 eachArg:
1385 for (int j = 0; j < arguments.length; j++) {
1386 if (arguments[j] instanceof Name n) {
1387 int check = n.index;
1388 // harmless check to see if the thing is already in newNames:
1389 if (check >= 0 && check < newNames.length && n == newNames[check])
1390 continue eachArg;
1391 // n might not have the correct index: n != oldNames[n.index].
1392 for (int i = start; i < end; i++) {
1393 if (n == oldNames[i]) {
1394 if (n == newNames[i])
1395 continue eachArg;
1396 if (!replaced) {
1397 replaced = true;
1398 arguments = arguments.clone();
1399 }
1400 arguments[j] = newNames[i];
1401 continue eachArg;
1402 }
1403 }
1404 }
1405 }
1406 if (!replaced) return this;
1407 return new Name(function, arguments);
1408 }
1409 void internArguments() {
1410 @SuppressWarnings("LocalVariableHidesMemberVariable")
1411 Object[] arguments = this.arguments;
1412 for (int j = 0; j < arguments.length; j++) {
1413 if (arguments[j] instanceof Name n) {
1414 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1415 arguments[j] = internArgument(n);
1416 }
1417 }
1418 }
1419 boolean isParam() {
1420 return function == null;
1421 }
1422
1423 boolean refersTo(Class<?> declaringClass, String methodName) {
1424 return function != null &&
1425 function.member() != null && function.member().refersTo(declaringClass, methodName);
1426 }
1427
1428 /**
1429 * Check if MemberName is a call to MethodHandle.invokeBasic.
1430 */
1431 boolean isInvokeBasic() {
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 && member.refersTo(MethodHandle.class, "invokeBasic") &&
1438 !member.isPublic() && !member.isStatic();
1439 }
1440
1441 /**
1442 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1443 */
1444 boolean isLinkerMethodInvoke() {
1445 if (function == null)
1446 return false;
1447 if (arguments.length < 1)
1448 return false; // must have MH argument
1449 MemberName member = function.member();
1450 return member != null &&
1451 member.getDeclaringClass() == MethodHandle.class &&
1452 !member.isPublic() && member.isStatic() &&
1453 member.getName().startsWith("linkTo");
1454 }
1455
1456 public String toString() {
1457 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1458 }
1459 public String debugString() {
1460 String s = paramString();
1461 return (function == null) ? s : s + "=" + exprString();
1462 }
1463 public String paramString() {
1464 String s = toString();
1465 Object c = constraint;
1466 if (c == null)
1467 return s;
1468 if (c instanceof Class<?> cl) c = cl.getSimpleName();
1469 return s + "/" + c;
1470 }
1471 public String exprString() {
1472 if (function == null) return toString();
1473 StringBuilder buf = new StringBuilder(function.toString());
1474 buf.append("(");
1475 String cma = "";
1476 for (Object a : arguments) {
1477 buf.append(cma); cma = ",";
1478 if (a instanceof Name || a instanceof Integer)
1479 buf.append(a);
1480 else
1481 buf.append("(").append(a).append(")");
1482 }
1483 buf.append(")");
1484 return buf.toString();
1485 }
1486
1487 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1488 if (arguments == null) {
1489 assert(function == null);
1490 return true;
1491 }
1492 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1493 for (int i = 0; i < arguments.length; i++) {
1494 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1495 }
1496 return true;
1497 }
1498
1499 private static boolean typesMatch(BasicType parameterType, Object object) {
1500 if (object instanceof Name name) {
1501 return name.type == parameterType;
1502 }
1503 switch (parameterType) {
1504 case I_TYPE: return object instanceof Integer;
1505 case J_TYPE: return object instanceof Long;
1506 case F_TYPE: return object instanceof Float;
1507 case D_TYPE: return object instanceof Double;
1508 }
1509 assert(parameterType == L_TYPE);
1510 return true;
1511 }
1512
1513 /** Return the index of the last occurrence of n in the argument array.
1514 * Return -1 if the name is not used.
1515 */
1516 int lastUseIndex(Name n) {
1517 Object[] arguments = this.arguments;
1518 if (arguments == null) return -1;
1519 for (int i = arguments.length; --i >= 0; ) {
1520 if (arguments[i] == n) return i;
1521 }
1522 return -1;
1523 }
1524
1525 public boolean equals(Name that) {
1526 if (this == that) return true;
1527 if (isParam())
1528 // each parameter is a unique atom
1529 return false; // this != that
1530 return
1531 //this.index == that.index &&
1532 this.type == that.type &&
1533 this.function.equals(that.function) &&
1534 Arrays.equals(this.arguments, that.arguments);
1535 }
1536 @Override
1537 public boolean equals(Object x) {
1538 return x instanceof Name n && equals(n);
1539 }
1540 @Override
1541 public int hashCode() {
1542 if (isParam())
1543 return index | (type.ordinal() << 8);
1544 return function.hashCode() ^ Arrays.hashCode(arguments);
1545 }
1546 }
1547
1548 /** Return the index of the last name which contains n as an argument.
1549 * Return -1 if the name is not used. Return names.length if it is the return value.
1550 */
1551 int lastUseIndex(Name n) {
1552 int ni = n.index, nmax = names.length;
1553 assert(names[ni] == n);
1554 if (result == ni) return nmax; // live all the way beyond the end
1555 for (int i = nmax; --i > ni; ) {
1556 if (names[i].lastUseIndex(n) >= 0)
1557 return i;
1558 }
1559 return -1;
1560 }
1561
1562 /** Return the number of times n is used as an argument or return value. */
1563 int useCount(Name n) {
1564 int count = (result == n.index) ? 1 : 0;
1565 int i = Math.max(n.index + 1, arity);
1566 Name[] names = this.names;
1567 while (i < names.length) {
1568 Object[] arguments = names[i++].arguments;
1569 if (arguments != null) {
1570 for (Object argument : arguments) {
1571 if (argument == n) {
1572 count++;
1573 }
1574 }
1575 }
1576 }
1577 return count;
1578 }
1579
1580 static Name argument(int which, BasicType type) {
1581 if (which >= INTERNED_ARGUMENT_LIMIT)
1582 return new Name(which, type);
1583 return INTERNED_ARGUMENTS[type.ordinal()][which];
1584 }
1585 static Name internArgument(Name n) {
1586 assert(n.isParam()) : "not param: " + n;
1587 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1588 if (n.constraint != null) return n;
1589 return argument(n.index, n.type);
1590 }
1591 static Name[] arguments(int extra, MethodType types) {
1592 int length = types.parameterCount();
1593 Name[] names = new Name[length + extra];
1594 for (int i = 0; i < length; i++)
1595 names[i] = argument(i, basicType(types.parameterType(i)));
1596 return names;
1597 }
1598
1599 static Name[] invokeArguments(int extra, MethodType types) {
1600 int length = types.parameterCount();
1601 Name[] names = new Name[length + extra + 1];
1602 names[0] = argument(0, L_TYPE);
1603 for (int i = 0; i < length; i++)
1604 names[i + 1] = argument(i + 1, basicType(types.parameterType(i)));
1605 return names;
1606 }
1607
1608 static final int INTERNED_ARGUMENT_LIMIT = 10;
1609 private static final Name[][] INTERNED_ARGUMENTS
1610 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1611 static {
1612 for (BasicType type : BasicType.ARG_TYPES) {
1613 int ord = type.ordinal();
1614 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1615 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1616 }
1617 }
1618 }
1619
1620 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1621
1622 static LambdaForm identityForm(BasicType type) {
1623 int ord = type.ordinal();
1624 LambdaForm form = LF_identity[ord];
1625 if (form != null) {
1626 return form;
1627 }
1628 createIdentityForm(type);
1629 return LF_identity[ord];
1630 }
1631
1632 static NamedFunction identity(BasicType type) {
1633 int ord = type.ordinal();
1634 NamedFunction function = NF_identity[ord];
1635 if (function != null) {
1636 return function;
1637 }
1638 createIdentityForm(type);
1639 return NF_identity[ord];
1640 }
1641
1642 static LambdaForm constantForm(BasicType type) {
1643 assert type != null && type != V_TYPE : type;
1644 var cached = LF_constant[type.ordinal()];
1645 if (cached != null)
1646 return cached;
1647 return createConstantForm(type);
1648 }
1649
1650 private static LambdaForm createConstantForm(BasicType type) {
1651 UNSAFE.ensureClassInitialized(BoundMethodHandle.class); // defend access to SimpleMethodHandle
1652 var species = SimpleMethodHandle.BMH_SPECIES.extendWith(type);
1653 var carrier = argument(0, L_TYPE).withConstraint(species); // BMH bound with data
1654 Name[] constNames = new Name[] { carrier, new Name(species.getterFunction(0), carrier) };
1655 return LF_constant[type.ordinal()] = create(1, constNames, Kind.CONSTANT);
1656 }
1657
1658 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1659 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1660 private static final @Stable LambdaForm[] LF_constant = new LambdaForm[ARG_TYPE_LIMIT]; // no void
1661
1662 private static final Object createIdentityFormLock = new Object();
1663 private static void createIdentityForm(BasicType type) {
1664 // Avoid racy initialization during bootstrap
1665 UNSAFE.ensureClassInitialized(BoundMethodHandle.class);
1666 synchronized (createIdentityFormLock) {
1667 final int ord = type.ordinal();
1668 LambdaForm idForm = LF_identity[ord];
1669 if (idForm != null) {
1670 return;
1671 }
1672 char btChar = type.basicTypeChar();
1673 boolean isVoid = (type == V_TYPE);
1674 Class<?> btClass = type.btClass;
1675 MethodType idType = (isVoid) ? MethodType.methodType(btClass) : MethodType.methodType(btClass, btClass);
1676
1677 // Look up symbolic names. It might not be necessary to have these,
1678 // but if we need to emit direct references to bytecodes, it helps.
1679 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1680 try {
1681 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, LM_TRUSTED, NoSuchMethodException.class);
1682 } catch (IllegalAccessException|NoSuchMethodException ex) {
1683 throw newInternalError(ex);
1684 }
1685
1686 NamedFunction idFun;
1687
1688 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1689 // bootstrap dependency on this method in case we're interpreting LFs
1690 if (isVoid) {
1691 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1692 idForm = LambdaForm.create(1, idNames, VOID_RESULT, Kind.IDENTITY);
1693 idForm.compileToBytecode();
1694 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1695 } else {
1696 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1697 idForm = LambdaForm.create(2, idNames, 1, Kind.IDENTITY);
1698 idForm.compileToBytecode();
1699 idFun = new NamedFunction(idMem, MethodHandleImpl.makeIntrinsic(idMem.getInvocationType(), idForm,
1700 MethodHandleImpl.Intrinsic.IDENTITY));
1701 }
1702
1703 LF_identity[ord] = idForm;
1704 NF_identity[ord] = idFun;
1705
1706 assert(idFun.isIdentity());
1707 }
1708 }
1709
1710 // Avoid appealing to ValueConversions at bootstrap time:
1711 private static int identity_I(int x) { return x; }
1712 private static long identity_J(long x) { return x; }
1713 private static float identity_F(float x) { return x; }
1714 private static double identity_D(double x) { return x; }
1715 private static Object identity_L(Object x) { return x; }
1716 private static void identity_V() { return; }
1717 /**
1718 * Internal marker for byte-compiled LambdaForms.
1719 */
1720 /*non-public*/
1721 @Target(ElementType.METHOD)
1722 @Retention(RetentionPolicy.RUNTIME)
1723 @interface Compiled {
1724 }
1725
1726 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1727 private static final HashMap<LambdaForm,String> DEBUG_NAMES;
1728 static {
1729 if (debugEnabled()) {
1730 DEBUG_NAME_COUNTERS = new HashMap<>();
1731 DEBUG_NAMES = new HashMap<>();
1732 } else {
1733 DEBUG_NAME_COUNTERS = null;
1734 DEBUG_NAMES = null;
1735 }
1736 }
1737
1738 static {
1739 // The Holder class will contain pre-generated forms resolved
1740 // using MemberName.getFactory(). However, that doesn't initialize the
1741 // class, which subtly breaks inlining etc. By forcing
1742 // initialization of the Holder class we avoid these issues.
1743 UNSAFE.ensureClassInitialized(Holder.class);
1744 }
1745
1746 /* Placeholder class for identity and constant forms generated ahead of time */
1747 final class Holder {}
1748
1749 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1750 // during execution of the static initializes of this class.
1751 // Turning on TRACE_INTERPRETER too early will cause
1752 // stack overflows and other misbehavior during attempts to trace events
1753 // that occur during LambdaForm.<clinit>.
1754 // Therefore, do not move this line higher in this file, and do not remove.
1755 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1756 }