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_INT("getInt"),
271 PUT_INT("putInt"),
272 GET_INT_VOLATILE("getIntVolatile"),
273 PUT_INT_VOLATILE("putIntVolatile"),
274 GET_BOOLEAN("getBoolean"),
275 PUT_BOOLEAN("putBoolean"),
276 GET_BOOLEAN_VOLATILE("getBooleanVolatile"),
277 PUT_BOOLEAN_VOLATILE("putBooleanVolatile"),
278 GET_BYTE("getByte"),
279 PUT_BYTE("putByte"),
280 GET_BYTE_VOLATILE("getByteVolatile"),
281 PUT_BYTE_VOLATILE("putByteVolatile"),
282 GET_CHAR("getChar"),
283 PUT_CHAR("putChar"),
284 GET_CHAR_VOLATILE("getCharVolatile"),
285 PUT_CHAR_VOLATILE("putCharVolatile"),
286 GET_SHORT("getShort"),
287 PUT_SHORT("putShort"),
288 GET_SHORT_VOLATILE("getShortVolatile"),
289 PUT_SHORT_VOLATILE("putShortVolatile"),
290 GET_LONG("getLong"),
291 PUT_LONG("putLong"),
292 GET_LONG_VOLATILE("getLongVolatile"),
293 PUT_LONG_VOLATILE("putLongVolatile"),
294 GET_FLOAT("getFloat"),
295 PUT_FLOAT("putFloat"),
296 GET_FLOAT_VOLATILE("getFloatVolatile"),
297 PUT_FLOAT_VOLATILE("putFloatVolatile"),
298 GET_DOUBLE("getDouble"),
299 PUT_DOUBLE("putDouble"),
300 GET_DOUBLE_VOLATILE("getDoubleVolatile"),
301 PUT_DOUBLE_VOLATILE("putDoubleVolatile"),
302 TRY_FINALLY("tryFinally"),
303 TABLE_SWITCH("tableSwitch"),
304 COLLECTOR("collector"),
305 LOOP("loop"),
306 GUARD("guard"),
307 GUARD_WITH_CATCH("guardWithCatch"),
308 VARHANDLE_EXACT_INVOKER("VH.exactInvoker"),
309 VARHANDLE_INVOKER("VH.invoker", "invoker"),
310 VARHANDLE_LINKER("VH.invoke_MT", "invoke_MT");
311
312 final String defaultLambdaName;
313 final String methodName;
314
315 private Kind(String defaultLambdaName) {
316 this(defaultLambdaName, defaultLambdaName);
317 }
318
319 private Kind(String defaultLambdaName, String methodName) {
320 this.defaultLambdaName = defaultLambdaName;
321 this.methodName = methodName;
322 }
323 }
324
325 // private version that doesn't do checks or defensive copies
326 private LambdaForm(int arity, int result, boolean forceInline, MethodHandle customized, Name[] names, Kind kind) {
327 this.arity = arity;
328 this.result = result;
329 this.forceInline = forceInline;
330 this.customized = customized;
331 this.names = names;
332 this.kind = kind;
333 this.vmentry = null;
334 this.isCompiled = false;
335 }
336
337 // root factory pre/post processing and calls simple constructor
338 private static LambdaForm create(int arity, Name[] names, int result, boolean forceInline, MethodHandle customized, Kind kind) {
339 names = names.clone();
340 assert(namesOK(arity, names));
341 result = fixResult(result, names);
342
343 boolean canInterpret = normalizeNames(arity, names);
344 LambdaForm form = new LambdaForm(arity, result, forceInline, customized, names, kind);
345 assert(form.nameRefsAreLegal());
346 if (!canInterpret) {
347 form.compileToBytecode();
348 }
349 return form;
350 }
351
352 // derived factories with defaults
353 private static final int DEFAULT_RESULT = LAST_RESULT;
354 private static final boolean DEFAULT_FORCE_INLINE = true;
355 private static final MethodHandle DEFAULT_CUSTOMIZED = null;
356 private static final Kind DEFAULT_KIND = Kind.GENERIC;
357
358 static LambdaForm create(int arity, Name[] names, int result) {
359 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
360 }
361 static LambdaForm create(int arity, Name[] names, int result, Kind kind) {
362 return create(arity, names, result, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
363 }
364 static LambdaForm create(int arity, Name[] names) {
365 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, DEFAULT_KIND);
366 }
367 static LambdaForm create(int arity, Name[] names, Kind kind) {
368 return create(arity, names, DEFAULT_RESULT, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, kind);
369 }
370 static LambdaForm create(int arity, Name[] names, boolean forceInline, Kind kind) {
371 return create(arity, names, DEFAULT_RESULT, forceInline, DEFAULT_CUSTOMIZED, kind);
372 }
373
374 private static LambdaForm createBlankForType(MethodType mt) {
375 // Make a dummy blank lambda form.
376 // It is used as a template for managing the invocation of similar forms that are non-empty.
377 // Called only from getPreparedForm.
378 LambdaForm form = new LambdaForm(0, 0, DEFAULT_FORCE_INLINE, DEFAULT_CUSTOMIZED, new Name[0], Kind.GENERIC);
379 return form;
380 }
381
382 private static int fixResult(int result, Name[] names) {
383 if (result == LAST_RESULT)
384 result = names.length - 1; // might still be void
385 if (result >= 0 && names[result].type == V_TYPE)
386 result = VOID_RESULT;
387 return result;
388 }
389
390 static boolean debugNames() {
391 return DEBUG_NAME_COUNTERS != null;
392 }
393
394 static void associateWithDebugName(LambdaForm form, String name) {
395 assert (debugNames());
396 synchronized (DEBUG_NAMES) {
397 DEBUG_NAMES.put(form, name);
398 }
399 }
400
401 String lambdaName() {
402 if (DEBUG_NAMES != null) {
403 synchronized (DEBUG_NAMES) {
404 String name = DEBUG_NAMES.get(this);
405 if (name == null) {
406 name = generateDebugName();
407 }
408 return name;
409 }
410 }
411 return kind.defaultLambdaName;
412 }
413
414 private String generateDebugName() {
415 assert (debugNames());
416 String debugNameStem = kind.defaultLambdaName;
417 Integer ctr = DEBUG_NAME_COUNTERS.getOrDefault(debugNameStem, 0);
418 DEBUG_NAME_COUNTERS.put(debugNameStem, ctr + 1);
419 StringBuilder buf = new StringBuilder(debugNameStem);
420 int leadingZero = buf.length();
421 buf.append((int) ctr);
422 for (int i = buf.length() - leadingZero; i < 3; i++) {
423 buf.insert(leadingZero, '0');
424 }
425 buf.append('_');
426 buf.append(basicTypeSignature());
427 String name = buf.toString();
428 associateWithDebugName(this, name);
429 return name;
430 }
431
432 private static boolean namesOK(int arity, Name[] names) {
433 for (int i = 0; i < names.length; i++) {
434 Name n = names[i];
435 assert(n != null) : "n is null";
436 if (i < arity)
437 assert( n.isParam()) : n + " is not param at " + i;
438 else
439 assert(!n.isParam()) : n + " is param at " + i;
440 }
441 return true;
442 }
443
444 /** Customize LambdaForm for a particular MethodHandle */
445 LambdaForm customize(MethodHandle mh) {
446 if (customized == mh) {
447 return this;
448 }
449 LambdaForm customForm = LambdaForm.create(arity, names, result, forceInline, mh, kind);
450 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
451 // If shared LambdaForm has been compiled, compile customized version as well.
452 customForm.compileToBytecode();
453 }
454 customForm.transformCache = this; // LambdaFormEditor should always use uncustomized form.
455 return customForm;
456 }
457
458 /** Get uncustomized flavor of the LambdaForm */
459 LambdaForm uncustomize() {
460 if (customized == null) {
461 return this;
462 }
463 assert(transformCache != null); // Customized LambdaForm should always has a link to uncustomized version.
464 LambdaForm uncustomizedForm = (LambdaForm)transformCache;
465 if (COMPILE_THRESHOLD >= 0 && isCompiled) {
466 // If customized LambdaForm has been compiled, compile uncustomized version as well.
467 uncustomizedForm.compileToBytecode();
468 }
469 return uncustomizedForm;
470 }
471
472 /** Renumber and/or replace params so that they are interned and canonically numbered.
473 * @return true if we can interpret
474 */
475 private static boolean normalizeNames(int arity, Name[] names) {
476 Name[] oldNames = names.clone();
477 int maxOutArity = 0;
478 for (int i = 0; i < names.length; i++) {
479 Name n = names[i];
480 names[i] = n.withIndex(i);
481 if (n.arguments != null && maxOutArity < n.arguments.length)
482 maxOutArity = n.arguments.length;
483 }
484 if (oldNames != null) {
485 for (int i = Math.max(1, arity); i < names.length; i++) {
486 Name fixed = names[i].replaceNames(oldNames, names, 0, i);
487 names[i] = fixed.withIndex(i);
488 }
489 }
490 int maxInterned = Math.min(arity, INTERNED_ARGUMENT_LIMIT);
491 boolean needIntern = false;
492 for (int i = 0; i < maxInterned; i++) {
493 Name n = names[i], n2 = internArgument(n);
494 if (n != n2) {
495 names[i] = n2;
496 needIntern = true;
497 }
498 }
499 if (needIntern) {
500 for (int i = arity; i < names.length; i++) {
501 names[i].internArguments();
502 }
503 }
504
505 // return true if we can interpret
506 if (maxOutArity > MethodType.MAX_MH_INVOKER_ARITY) {
507 // Cannot use LF interpreter on very high arity expressions.
508 assert(maxOutArity <= MethodType.MAX_JVM_ARITY);
509 return false;
510 }
511 return true;
512 }
513
514 /**
515 * Check that all embedded Name references are localizable to this lambda,
516 * and are properly ordered after their corresponding definitions.
517 * <p>
518 * Note that a Name can be local to multiple lambdas, as long as
519 * it possesses the same index in each use site.
520 * This allows Name references to be freely reused to construct
521 * fresh lambdas, without confusion.
522 */
523 boolean nameRefsAreLegal() {
524 assert(arity >= 0 && arity <= names.length);
525 assert(result >= -1 && result < names.length);
526 // Do all names possess an index consistent with their local definition order?
527 for (int i = 0; i < arity; i++) {
528 Name n = names[i];
529 assert(n.index() == i) : Arrays.asList(n.index(), i);
530 assert(n.isParam());
531 }
532 // Also, do all local name references
533 for (int i = arity; i < names.length; i++) {
534 Name n = names[i];
535 assert(n.index() == i);
536 for (Object arg : n.arguments) {
537 if (arg instanceof Name n2) {
538 int i2 = n2.index;
539 assert(0 <= i2 && i2 < names.length) : n.debugString() + ": 0 <= i2 && i2 < names.length: 0 <= " + i2 + " < " + names.length;
540 assert(names[i2] == n2) : Arrays.asList("-1-", i, "-2-", n.debugString(), "-3-", i2, "-4-", n2.debugString(), "-5-", names[i2].debugString(), "-6-", this);
541 assert(i2 < i); // ref must come after def!
542 }
543 }
544 }
545 return true;
546 }
547
548 // /** Invoke this form on the given arguments. */
549 // final Object invoke(Object... args) throws Throwable {
550 // // NYI: fit this into the fast path?
551 // return interpretWithArguments(args);
552 // }
553
554 /** Report the return type. */
555 BasicType returnType() {
556 if (result < 0) return V_TYPE;
557 Name n = names[result];
558 return n.type;
559 }
560
561 /** Report the N-th argument type. */
562 BasicType parameterType(int n) {
563 return parameter(n).type;
564 }
565
566 /** Report the N-th argument name. */
567 Name parameter(int n) {
568 Name param = names[n];
569 assert(n < arity && param.isParam());
570 return param;
571 }
572
573 /** Report the N-th argument type constraint. */
574 Object parameterConstraint(int n) {
575 return parameter(n).constraint;
576 }
577
578 /** Report the arity. */
579 int arity() {
580 return arity;
581 }
582
583 /** Report the number of expressions (non-parameter names). */
584 int expressionCount() {
585 return names.length - arity;
586 }
587
588 /** Return the method type corresponding to my basic type signature. */
589 MethodType methodType() {
590 Class<?>[] ptypes = new Class<?>[arity];
591 for (int i = 0; i < arity; ++i) {
592 ptypes[i] = parameterType(i).btClass;
593 }
594 return MethodType.methodType(returnType().btClass, ptypes, true);
595 }
596
597 /** Return ABC_Z, where the ABC are parameter type characters, and Z is the return type character. */
598 final String basicTypeSignature() {
599 StringBuilder buf = new StringBuilder(arity() + 3);
600 for (int i = 0, a = arity(); i < a; i++)
601 buf.append(parameterType(i).basicTypeChar());
602 return buf.append('_').append(returnType().basicTypeChar()).toString();
603 }
604 static int signatureArity(String sig) {
605 assert(isValidSignature(sig));
606 return sig.indexOf('_');
607 }
608 static boolean isValidSignature(String sig) {
609 int arity = sig.indexOf('_');
610 if (arity < 0) return false; // must be of the form *_*
611 int siglen = sig.length();
612 if (siglen != arity + 2) return false; // *_X
613 for (int i = 0; i < siglen; i++) {
614 if (i == arity) continue; // skip '_'
615 char c = sig.charAt(i);
616 if (c == 'V')
617 return (i == siglen - 1 && arity == siglen - 2);
618 if (!isArgBasicTypeChar(c)) return false; // must be [LIJFD]
619 }
620 return true; // [LIJFD]*_[LIJFDV]
621 }
622
623 /**
624 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
625 */
626 boolean isSelectAlternative(int pos) {
627 // selectAlternative idiom:
628 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
629 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
630 if (pos+1 >= names.length) return false;
631 Name name0 = names[pos];
632 Name name1 = names[pos+1];
633 return name0.refersTo(MethodHandleImpl.class, "selectAlternative") &&
634 name1.isInvokeBasic() &&
635 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
636 lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
637 }
638
639 private boolean isMatchingIdiom(int pos, String idiomName, int nArgs) {
640 if (pos+2 >= names.length) return false;
641 Name name0 = names[pos];
642 Name name1 = names[pos+1];
643 Name name2 = names[pos+2];
644 return name1.refersTo(MethodHandleImpl.class, idiomName) &&
645 name0.isInvokeBasic() &&
646 name2.isInvokeBasic() &&
647 name1.lastUseIndex(name0) == nArgs && // t_{n+1}:L=MethodHandleImpl.<invoker>(<args>, t_{n});
648 lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
649 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
650 lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
651 }
652
653 /**
654 * Check if i-th name is a start of GuardWithCatch idiom.
655 */
656 boolean isGuardWithCatch(int pos) {
657 // GuardWithCatch idiom:
658 // t_{n}:L=MethodHandle.invokeBasic(...)
659 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
660 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
661 return isMatchingIdiom(pos, "guardWithCatch", 3);
662 }
663
664 /**
665 * Check if i-th name is a start of the tryFinally idiom.
666 */
667 boolean isTryFinally(int pos) {
668 // tryFinally idiom:
669 // t_{n}:L=MethodHandle.invokeBasic(...)
670 // t_{n+1}:L=MethodHandleImpl.tryFinally(*, *, t_{n})
671 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
672 return isMatchingIdiom(pos, "tryFinally", 2);
673 }
674
675 /**
676 * Check if i-th name is a start of the tableSwitch idiom.
677 */
678 boolean isTableSwitch(int pos) {
679 // tableSwitch idiom:
680 // t_{n}:L=MethodHandle.invokeBasic(...) // args
681 // t_{n+1}:L=MethodHandleImpl.tableSwitch(*, *, *, t_{n})
682 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
683 if (pos + 2 >= names.length) return false;
684
685 final int POS_COLLECT_ARGS = pos;
686 final int POS_TABLE_SWITCH = pos + 1;
687 final int POS_UNBOX_RESULT = pos + 2;
688
689 Name collectArgs = names[POS_COLLECT_ARGS];
690 Name tableSwitch = names[POS_TABLE_SWITCH];
691 Name unboxResult = names[POS_UNBOX_RESULT];
692 return tableSwitch.refersTo(MethodHandleImpl.class, "tableSwitch") &&
693 collectArgs.isInvokeBasic() &&
694 unboxResult.isInvokeBasic() &&
695 tableSwitch.lastUseIndex(collectArgs) == 3 && // t_{n+1}:L=MethodHandleImpl.<invoker>(*, *, *, t_{n});
696 lastUseIndex(collectArgs) == POS_TABLE_SWITCH && // t_{n} is local: used only in t_{n+1}
697 unboxResult.lastUseIndex(tableSwitch) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
698 lastUseIndex(tableSwitch) == POS_UNBOX_RESULT; // t_{n+1} is local: used only in t_{n+2}
699 }
700
701 /**
702 * Check if i-th name is a start of the loop idiom.
703 */
704 boolean isLoop(int pos) {
705 // loop idiom:
706 // t_{n}:L=MethodHandle.invokeBasic(...)
707 // t_{n+1}:L=MethodHandleImpl.loop(types, *, t_{n})
708 // t_{n+2}:?=MethodHandle.invokeBasic(*, t_{n+1})
709 return isMatchingIdiom(pos, "loop", 2);
710 }
711
712 /*
713 * Code generation issues:
714 *
715 * Compiled LFs should be reusable in general.
716 * The biggest issue is how to decide when to pull a name into
717 * the bytecode, versus loading a reified form from the MH data.
718 *
719 * For example, an asType wrapper may require execution of a cast
720 * after a call to a MH. The target type of the cast can be placed
721 * as a constant in the LF itself. This will force the cast type
722 * to be compiled into the bytecodes and native code for the MH.
723 * Or, the target type of the cast can be erased in the LF, and
724 * loaded from the MH data. (Later on, if the MH as a whole is
725 * inlined, the data will flow into the inlined instance of the LF,
726 * as a constant, and the end result will be an optimal cast.)
727 *
728 * This erasure of cast types can be done with any use of
729 * reference types. It can also be done with whole method
730 * handles. Erasing a method handle might leave behind
731 * LF code that executes correctly for any MH of a given
732 * type, and load the required MH from the enclosing MH's data.
733 * Or, the erasure might even erase the expected MT.
734 *
735 * Also, for direct MHs, the MemberName of the target
736 * could be erased, and loaded from the containing direct MH.
737 * As a simple case, a LF for all int-valued non-static
738 * field getters would perform a cast on its input argument
739 * (to non-constant base type derived from the MemberName)
740 * and load an integer value from the input object
741 * (at a non-constant offset also derived from the MemberName).
742 * Such MN-erased LFs would be inlinable back to optimized
743 * code, whenever a constant enclosing DMH is available
744 * to supply a constant MN from its data.
745 *
746 * The main problem here is to keep LFs reasonably generic,
747 * while ensuring that hot spots will inline good instances.
748 * "Reasonably generic" means that we don't end up with
749 * repeated versions of bytecode or machine code that do
750 * not differ in their optimized form. Repeated versions
751 * of machine would have the undesirable overheads of
752 * (a) redundant compilation work and (b) extra I$ pressure.
753 * To control repeated versions, we need to be ready to
754 * erase details from LFs and move them into MH data,
755 * whenever those details are not relevant to significant
756 * optimization. "Significant" means optimization of
757 * code that is actually hot.
758 *
759 * Achieving this may require dynamic splitting of MHs, by replacing
760 * a generic LF with a more specialized one, on the same MH,
761 * if (a) the MH is frequently executed and (b) the MH cannot
762 * be inlined into a containing caller, such as an invokedynamic.
763 *
764 * Compiled LFs that are no longer used should be GC-able.
765 * If they contain non-BCP references, they should be properly
766 * interlinked with the class loader(s) that their embedded types
767 * depend on. This probably means that reusable compiled LFs
768 * will be tabulated (indexed) on relevant class loaders,
769 * or else that the tables that cache them will have weak links.
770 */
771
772 /**
773 * Make this LF directly executable, as part of a MethodHandle.
774 * Invariant: Every MH which is invoked must prepare its LF
775 * before invocation.
776 * (In principle, the JVM could do this very lazily,
777 * as a sort of pre-invocation linkage step.)
778 */
779 public void prepare() {
780 if (COMPILE_THRESHOLD == 0 && !forceInterpretation() && !isCompiled) {
781 compileToBytecode();
782 }
783 if (this.vmentry != null) {
784 // already prepared (e.g., a primitive DMH invoker form)
785 return;
786 }
787 MethodType mtype = methodType();
788 LambdaForm prep = mtype.form().cachedLambdaForm(MethodTypeForm.LF_INTERPRET);
789 if (prep == null) {
790 assert (isValidSignature(basicTypeSignature()));
791 prep = LambdaForm.createBlankForType(mtype);
792 prep.vmentry = InvokerBytecodeGenerator.generateLambdaFormInterpreterEntryPoint(mtype);
793 prep = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_INTERPRET, prep);
794 }
795 this.vmentry = prep.vmentry;
796 // TO DO: Maybe add invokeGeneric, invokeWithArguments
797 }
798
799 private static @Stable PerfCounter LF_FAILED;
800
801 private static PerfCounter failedCompilationCounter() {
802 if (LF_FAILED == null) {
803 LF_FAILED = PerfCounter.newPerfCounter("java.lang.invoke.failedLambdaFormCompilations");
804 }
805 return LF_FAILED;
806 }
807
808 /** Generate optimizable bytecode for this form. */
809 void compileToBytecode() {
810 if (forceInterpretation()) {
811 return; // this should not be compiled
812 }
813 if (vmentry != null && isCompiled) {
814 return; // already compiled somehow
815 }
816
817 // Obtain the invoker MethodType outside of the following try block.
818 // This ensures that an IllegalArgumentException is directly thrown if the
819 // type would have 256 or more parameters
820 MethodType invokerType = methodType();
821 assert(vmentry == null || vmentry.getMethodType().basicType().equals(invokerType));
822 try {
823 vmentry = InvokerBytecodeGenerator.generateCustomizedCode(this, invokerType);
824 if (TRACE_INTERPRETER)
825 traceInterpreter("compileToBytecode", this);
826 isCompiled = true;
827 } catch (InvokerBytecodeGenerator.BytecodeGenerationException bge) {
828 // bytecode generation failed - mark this LambdaForm as to be run in interpretation mode only
829 invocationCounter = -1;
830 failedCompilationCounter().increment();
831 if (LOG_LF_COMPILATION_FAILURE) {
832 System.out.println("LambdaForm compilation failed: " + this);
833 bge.printStackTrace(System.out);
834 }
835 } catch (Error e) {
836 // Pass through any error
837 throw e;
838 } catch (Exception e) {
839 // Wrap any exception
840 throw newInternalError(this.toString(), e);
841 }
842 }
843
844 // The next few routines are called only from assert expressions
845 // They verify that the built-in invokers process the correct raw data types.
846 private static boolean argumentTypesMatch(String sig, Object[] av) {
847 int arity = signatureArity(sig);
848 assert(av.length == arity) : "av.length == arity: av.length=" + av.length + ", arity=" + arity;
849 assert(av[0] instanceof MethodHandle) : "av[0] not instance of MethodHandle: " + av[0];
850 MethodHandle mh = (MethodHandle) av[0];
851 MethodType mt = mh.type();
852 assert(mt.parameterCount() == arity-1);
853 for (int i = 0; i < av.length; i++) {
854 Class<?> pt = (i == 0 ? MethodHandle.class : mt.parameterType(i-1));
855 assert(valueMatches(basicType(sig.charAt(i)), pt, av[i]));
856 }
857 return true;
858 }
859 private static boolean valueMatches(BasicType tc, Class<?> type, Object x) {
860 // The following line is needed because (...)void method handles can use non-void invokers
861 if (type == void.class) tc = V_TYPE; // can drop any kind of value
862 assert tc == basicType(type) : tc + " == basicType(" + type + ")=" + basicType(type);
863 switch (tc) {
864 case I_TYPE: assert checkInt(type, x) : "checkInt(" + type + "," + x +")"; break;
865 case J_TYPE: assert x instanceof Long : "instanceof Long: " + x; break;
866 case F_TYPE: assert x instanceof Float : "instanceof Float: " + x; break;
867 case D_TYPE: assert x instanceof Double : "instanceof Double: " + x; break;
868 case L_TYPE: assert checkRef(type, x) : "checkRef(" + type + "," + x + ")"; break;
869 case V_TYPE: break; // allow anything here; will be dropped
870 default: assert(false);
871 }
872 return true;
873 }
874 private static boolean checkInt(Class<?> type, Object x) {
875 assert(x instanceof Integer);
876 if (type == int.class) return true;
877 Wrapper w = Wrapper.forBasicType(type);
878 assert(w.isSubwordOrInt());
879 Object x1 = Wrapper.INT.wrap(w.wrap(x));
880 return x.equals(x1);
881 }
882 private static boolean checkRef(Class<?> type, Object x) {
883 assert(!type.isPrimitive());
884 if (x == null) return true;
885 if (type.isInterface()) return true;
886 return type.isInstance(x);
887 }
888
889 /** If the invocation count hits the threshold we spin bytecodes and call that subsequently. */
890 private static final int COMPILE_THRESHOLD;
891 static {
892 COMPILE_THRESHOLD = Math.max(-1, MethodHandleStatics.COMPILE_THRESHOLD);
893 }
894 private int invocationCounter = 0; // a value of -1 indicates LambdaForm interpretation mode forever
895
896 private boolean forceInterpretation() {
897 return invocationCounter == -1;
898 }
899
900 /** Interpretively invoke this form on the given arguments. */
901 @Hidden
902 @DontInline
903 Object interpretWithArguments(Object... argumentValues) throws Throwable {
904 if (TRACE_INTERPRETER)
905 return interpretWithArgumentsTracing(argumentValues);
906 checkInvocationCounter();
907 assert(arityCheck(argumentValues));
908 Object[] values = Arrays.copyOf(argumentValues, names.length);
909 for (int i = argumentValues.length; i < values.length; i++) {
910 values[i] = interpretName(names[i], values);
911 }
912 Object rv = (result < 0) ? null : values[result];
913 assert(resultCheck(argumentValues, rv));
914 return rv;
915 }
916
917 /** Evaluate a single Name within this form, applying its function to its arguments. */
918 @Hidden
919 @DontInline
920 Object interpretName(Name name, Object[] values) throws Throwable {
921 if (TRACE_INTERPRETER)
922 traceInterpreter("| interpretName", name.debugString(), (Object[]) null);
923 Object[] arguments = Arrays.copyOf(name.arguments, name.arguments.length, Object[].class);
924 for (int i = 0; i < arguments.length; i++) {
925 Object a = arguments[i];
926 if (a instanceof Name n) {
927 int i2 = n.index();
928 assert(names[i2] == a);
929 a = values[i2];
930 arguments[i] = a;
931 }
932 }
933 return name.function.invokeWithArguments(arguments);
934 }
935
936 private void checkInvocationCounter() {
937 if (COMPILE_THRESHOLD != 0 &&
938 !forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
939 invocationCounter++; // benign race
940 if (invocationCounter >= COMPILE_THRESHOLD) {
941 // Replace vmentry with a bytecode version of this LF.
942 compileToBytecode();
943 }
944 }
945 }
946 Object interpretWithArgumentsTracing(Object... argumentValues) throws Throwable {
947 traceInterpreter("[ interpretWithArguments", this, argumentValues);
948 if (!forceInterpretation() && invocationCounter < COMPILE_THRESHOLD) {
949 int ctr = invocationCounter++; // benign race
950 traceInterpreter("| invocationCounter", ctr);
951 if (invocationCounter >= COMPILE_THRESHOLD) {
952 compileToBytecode();
953 }
954 }
955 Object rval;
956 try {
957 assert(arityCheck(argumentValues));
958 Object[] values = Arrays.copyOf(argumentValues, names.length);
959 for (int i = argumentValues.length; i < values.length; i++) {
960 values[i] = interpretName(names[i], values);
961 }
962 rval = (result < 0) ? null : values[result];
963 } catch (Throwable ex) {
964 traceInterpreter("] throw =>", ex);
965 throw ex;
966 }
967 traceInterpreter("] return =>", rval);
968 return rval;
969 }
970
971 static void traceInterpreter(String event, Object obj, Object... args) {
972 if (TRACE_INTERPRETER) {
973 System.out.println("LFI: "+event+" "+(obj != null ? obj : "")+(args != null && args.length != 0 ? Arrays.asList(args) : ""));
974 }
975 }
976 static void traceInterpreter(String event, Object obj) {
977 traceInterpreter(event, obj, (Object[])null);
978 }
979 private boolean arityCheck(Object[] argumentValues) {
980 assert(argumentValues.length == arity) : arity+"!="+Arrays.asList(argumentValues)+".length";
981 // also check that the leading (receiver) argument is somehow bound to this LF:
982 assert(argumentValues[0] instanceof MethodHandle) : "not MH: " + argumentValues[0];
983 MethodHandle mh = (MethodHandle) argumentValues[0];
984 assert(mh.internalForm() == this);
985 // note: argument #0 could also be an interface wrapper, in the future
986 argumentTypesMatch(basicTypeSignature(), argumentValues);
987 return true;
988 }
989 private boolean resultCheck(Object[] argumentValues, Object result) {
990 MethodHandle mh = (MethodHandle) argumentValues[0];
991 MethodType mt = mh.type();
992 assert(valueMatches(returnType(), mt.returnType(), result));
993 return true;
994 }
995
996 public String toString() {
997 return debugString(-1);
998 }
999
1000 String debugString(int indentLevel) {
1001 String prefix = MethodHandle.debugPrefix(indentLevel);
1002 String lambdaName = lambdaName();
1003 StringBuilder buf = new StringBuilder(lambdaName);
1004 buf.append("=Lambda(");
1005 for (int i = 0; i < names.length; i++) {
1006 if (i == arity) buf.append(")=>{");
1007 Name n = names[i];
1008 if (i >= arity) buf.append("\n ").append(prefix);
1009 buf.append(n.paramString());
1010 if (i < arity) {
1011 if (i+1 < arity) buf.append(",");
1012 continue;
1013 }
1014 buf.append("=").append(n.exprString());
1015 buf.append(";");
1016 }
1017 if (arity == names.length) buf.append(")=>{");
1018 buf.append(result < 0 ? "void" : names[result]).append("}");
1019 if (TRACE_INTERPRETER) {
1020 // Extra verbosity:
1021 buf.append(":").append(basicTypeSignature());
1022 buf.append("/").append(vmentry);
1023 }
1024 return buf.toString();
1025 }
1026
1027 @Override
1028 public boolean equals(Object obj) {
1029 return obj instanceof LambdaForm lf && equals(lf);
1030 }
1031 public boolean equals(LambdaForm that) {
1032 if (this.result != that.result) return false;
1033 return Arrays.equals(this.names, that.names);
1034 }
1035 public int hashCode() {
1036 return result + 31 * Arrays.hashCode(names);
1037 }
1038 LambdaFormEditor editor() {
1039 return LambdaFormEditor.lambdaFormEditor(this);
1040 }
1041
1042 boolean contains(Name name) {
1043 int pos = name.index();
1044 if (pos >= 0) {
1045 return pos < names.length && name.equals(names[pos]);
1046 }
1047 for (int i = arity; i < names.length; i++) {
1048 if (name.equals(names[i]))
1049 return true;
1050 }
1051 return false;
1052 }
1053
1054 static class NamedFunction {
1055 final MemberName member;
1056 private @Stable MethodHandle resolvedHandle;
1057 private @Stable MethodType type;
1058
1059 NamedFunction(MethodHandle resolvedHandle) {
1060 this(resolvedHandle.internalMemberName(), resolvedHandle);
1061 }
1062 NamedFunction(MemberName member, MethodHandle resolvedHandle) {
1063 this.member = member;
1064 this.resolvedHandle = resolvedHandle;
1065 // The following assert is almost always correct, but will fail for corner cases, such as PrivateInvokeTest.
1066 //assert(!isInvokeBasic(member));
1067 }
1068 NamedFunction(MethodType basicInvokerType) {
1069 assert(basicInvokerType == basicInvokerType.basicType()) : basicInvokerType;
1070 if (basicInvokerType.parameterSlotCount() < MethodType.MAX_MH_INVOKER_ARITY) {
1071 this.resolvedHandle = basicInvokerType.invokers().basicInvoker();
1072 this.member = resolvedHandle.internalMemberName();
1073 } else {
1074 // necessary to pass BigArityTest
1075 this.member = Invokers.invokeBasicMethod(basicInvokerType);
1076 }
1077 assert(isInvokeBasic(member));
1078 }
1079
1080 private static boolean isInvokeBasic(MemberName member) {
1081 return member != null &&
1082 member.getDeclaringClass() == MethodHandle.class &&
1083 "invokeBasic".equals(member.getName());
1084 }
1085
1086 // The next 2 constructors are used to break circular dependencies on MH.invokeStatic, etc.
1087 // Any LambdaForm containing such a member is not interpretable.
1088 // This is OK, since all such LFs are prepared with special primitive vmentry points.
1089 // And even without the resolvedHandle, the name can still be compiled and optimized.
1090 NamedFunction(Method method) {
1091 this(new MemberName(method));
1092 }
1093 NamedFunction(MemberName member) {
1094 this(member, null);
1095 }
1096
1097 MethodHandle resolvedHandle() {
1098 if (resolvedHandle == null) resolve();
1099 return resolvedHandle;
1100 }
1101
1102 synchronized void resolve() {
1103 if (resolvedHandle == null) {
1104 resolvedHandle = DirectMethodHandle.make(member);
1105 }
1106 }
1107
1108 @Override
1109 public boolean equals(Object other) {
1110 if (this == other) return true;
1111 if (other == null) return false;
1112 return (other instanceof NamedFunction that)
1113 && this.member != null
1114 && this.member.equals(that.member);
1115 }
1116
1117 @Override
1118 public int hashCode() {
1119 if (member != null)
1120 return member.hashCode();
1121 return super.hashCode();
1122 }
1123
1124 static final MethodType INVOKER_METHOD_TYPE =
1125 MethodType.methodType(Object.class, MethodHandle.class, Object[].class);
1126
1127 private static MethodHandle computeInvoker(MethodTypeForm typeForm) {
1128 typeForm = typeForm.basicType().form(); // normalize to basic type
1129 MethodHandle mh = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1130 if (mh != null) return mh;
1131 MemberName invoker = InvokerBytecodeGenerator.generateNamedFunctionInvoker(typeForm); // this could take a while
1132 mh = DirectMethodHandle.make(invoker);
1133 MethodHandle mh2 = typeForm.cachedMethodHandle(MethodTypeForm.MH_NF_INV);
1134 if (mh2 != null) return mh2; // benign race
1135 if (!mh.type().equals(INVOKER_METHOD_TYPE))
1136 throw newInternalError(mh.debugString());
1137 return typeForm.setCachedMethodHandle(MethodTypeForm.MH_NF_INV, mh);
1138 }
1139
1140 @Hidden
1141 Object invokeWithArguments(Object... arguments) throws Throwable {
1142 // If we have a cached invoker, call it right away.
1143 // NOTE: The invoker always returns a reference value.
1144 if (TRACE_INTERPRETER) return invokeWithArgumentsTracing(arguments);
1145 return invoker().invokeBasic(resolvedHandle(), arguments);
1146 }
1147
1148 @Hidden
1149 Object invokeWithArgumentsTracing(Object[] arguments) throws Throwable {
1150 Object rval;
1151 try {
1152 traceInterpreter("[ call", this, arguments);
1153 // resolvedHandle might be uninitialized, ok for tracing
1154 if (resolvedHandle == null) {
1155 traceInterpreter("| resolve", this);
1156 resolvedHandle();
1157 }
1158 rval = invoker().invokeBasic(resolvedHandle(), arguments);
1159 } catch (Throwable ex) {
1160 traceInterpreter("] throw =>", ex);
1161 throw ex;
1162 }
1163 traceInterpreter("] return =>", rval);
1164 return rval;
1165 }
1166
1167 private MethodHandle invoker() {
1168 return computeInvoker(methodType().form());
1169 }
1170
1171 MethodType methodType() {
1172 MethodType type = this.type;
1173 if (type == null) {
1174 this.type = type = calculateMethodType(member, resolvedHandle);
1175 }
1176 return type;
1177 }
1178
1179 private static MethodType calculateMethodType(MemberName member, MethodHandle resolvedHandle) {
1180 if (resolvedHandle != null) {
1181 return resolvedHandle.type();
1182 } else {
1183 // only for certain internal LFs during bootstrapping
1184 return member.getInvocationType();
1185 }
1186 }
1187
1188 MemberName member() {
1189 assert(assertMemberIsConsistent());
1190 return member;
1191 }
1192
1193 // Called only from assert.
1194 private boolean assertMemberIsConsistent() {
1195 if (resolvedHandle instanceof DirectMethodHandle) {
1196 MemberName m = resolvedHandle.internalMemberName();
1197 assert(m.equals(member));
1198 }
1199 return true;
1200 }
1201
1202 Class<?> memberDeclaringClassOrNull() {
1203 return (member == null) ? null : member.getDeclaringClass();
1204 }
1205
1206 BasicType returnType() {
1207 return basicType(methodType().returnType());
1208 }
1209
1210 BasicType parameterType(int n) {
1211 return basicType(methodType().parameterType(n));
1212 }
1213
1214 int arity() {
1215 return methodType().parameterCount();
1216 }
1217
1218 public String toString() {
1219 if (member == null) return String.valueOf(resolvedHandle);
1220 return member.getDeclaringClass().getSimpleName()+"."+member.getName();
1221 }
1222
1223 public boolean isIdentity() {
1224 return this.equals(identity(returnType()));
1225 }
1226
1227 public MethodHandleImpl.Intrinsic intrinsicName() {
1228 return resolvedHandle != null
1229 ? resolvedHandle.intrinsicName()
1230 : MethodHandleImpl.Intrinsic.NONE;
1231 }
1232
1233 public Object intrinsicData() {
1234 return resolvedHandle != null
1235 ? resolvedHandle.intrinsicData()
1236 : null;
1237 }
1238 }
1239
1240 public static String basicTypeSignature(MethodType type) {
1241 int params = type.parameterCount();
1242 char[] sig = new char[params + 2];
1243 int sigp = 0;
1244 while (sigp < params) {
1245 sig[sigp] = basicTypeChar(type.parameterType(sigp++));
1246 }
1247 sig[sigp++] = '_';
1248 sig[sigp++] = basicTypeChar(type.returnType());
1249 assert(sigp == sig.length);
1250 return String.valueOf(sig);
1251 }
1252
1253 /** Hack to make signatures more readable when they show up in method names.
1254 * Signature should start with a sequence of uppercase ASCII letters.
1255 * Runs of three or more are replaced by a single letter plus a decimal repeat count.
1256 * A tail of anything other than uppercase ASCII is passed through unchanged.
1257 * @param signature sequence of uppercase ASCII letters with possible repetitions
1258 * @return same sequence, with repetitions counted by decimal numerals
1259 */
1260 public static String shortenSignature(String signature) {
1261 final int NO_CHAR = -1, MIN_RUN = 3;
1262 int c0, c1 = NO_CHAR, c1reps = 0;
1263 StringBuilder buf = null;
1264 int len = signature.length();
1265 if (len < MIN_RUN) return signature;
1266 for (int i = 0; i <= len; i++) {
1267 if (c1 != NO_CHAR && !('A' <= c1 && c1 <= 'Z')) {
1268 // wrong kind of char; bail out here
1269 if (buf != null) {
1270 buf.append(signature, i - c1reps, len);
1271 }
1272 break;
1273 }
1274 // shift in the next char:
1275 c0 = c1; c1 = (i == len ? NO_CHAR : signature.charAt(i));
1276 if (c1 == c0) { ++c1reps; continue; }
1277 // shift in the next count:
1278 int c0reps = c1reps; c1reps = 1;
1279 // end of a character run
1280 if (c0reps < MIN_RUN) {
1281 if (buf != null) {
1282 while (--c0reps >= 0)
1283 buf.append((char)c0);
1284 }
1285 continue;
1286 }
1287 // found three or more in a row
1288 if (buf == null)
1289 buf = new StringBuilder().append(signature, 0, i - c0reps);
1290 buf.append((char)c0).append(c0reps);
1291 }
1292 return (buf == null) ? signature : buf.toString();
1293 }
1294
1295 static final class Name {
1296 final BasicType type;
1297 final short index;
1298 final NamedFunction function;
1299 final Object constraint; // additional type information, if not null
1300 @Stable final Object[] arguments;
1301
1302 private static final Object[] EMPTY_ARGS = new Object[0];
1303
1304 private Name(int index, BasicType type, NamedFunction function, Object[] arguments, Object constraint) {
1305 this.index = (short)index;
1306 this.type = type;
1307 this.function = function;
1308 this.arguments = arguments;
1309 this.constraint = constraint;
1310 assert(this.index == index && typesMatch(function, arguments));
1311 assert(constraint == null || isParam()); // only params have constraints
1312 assert(constraint == null || constraint instanceof ClassSpecializer.SpeciesData || constraint instanceof Class);
1313 }
1314
1315 Name(MethodHandle function, Object... arguments) {
1316 this(new NamedFunction(function), arguments);
1317 }
1318 Name(MethodType functionType, Object... arguments) {
1319 this(new NamedFunction(functionType), arguments);
1320 assert(arguments[0] instanceof Name name && name.type == L_TYPE);
1321 }
1322 Name(MemberName function, Object... arguments) {
1323 this(new NamedFunction(function), arguments);
1324 }
1325 Name(NamedFunction function) {
1326 this(-1, function.returnType(), function, EMPTY_ARGS, null);
1327 }
1328 Name(NamedFunction function, Object arg) {
1329 this(-1, function.returnType(), function, new Object[] { arg }, null);
1330 }
1331 Name(NamedFunction function, Object arg0, Object arg1) {
1332 this(-1, function.returnType(), function, new Object[] { arg0, arg1 }, null);
1333 }
1334 Name(NamedFunction function, Object... arguments) {
1335 this(-1, function.returnType(), function, Arrays.copyOf(arguments, arguments.length, Object[].class), null);
1336 }
1337 /** Create a raw parameter of the given type, with an expected index. */
1338 Name(int index, BasicType type) {
1339 this(index, type, null, null, null);
1340 }
1341 /** Create a raw parameter of the given type. */
1342 Name(BasicType type) { this(-1, type); }
1343
1344 BasicType type() { return type; }
1345 int index() { return index; }
1346
1347 char typeChar() {
1348 return type.btChar;
1349 }
1350
1351 Name withIndex(int i) {
1352 if (i == this.index) return this;
1353 return new Name(i, type, function, arguments, constraint);
1354 }
1355
1356 Name withConstraint(Object constraint) {
1357 if (constraint == this.constraint) return this;
1358 return new Name(index, type, function, arguments, constraint);
1359 }
1360
1361 Name replaceName(Name oldName, Name newName) { // FIXME: use replaceNames uniformly
1362 if (oldName == newName) return this;
1363 @SuppressWarnings("LocalVariableHidesMemberVariable")
1364 Object[] arguments = this.arguments;
1365 if (arguments == null) return this;
1366 boolean replaced = false;
1367 for (int j = 0; j < arguments.length; j++) {
1368 if (arguments[j] == oldName) {
1369 if (!replaced) {
1370 replaced = true;
1371 arguments = arguments.clone();
1372 }
1373 arguments[j] = newName;
1374 }
1375 }
1376 if (!replaced) return this;
1377 return new Name(function, arguments);
1378 }
1379 /** In the arguments of this Name, replace oldNames[i] pairwise by newNames[i].
1380 * Limit such replacements to {@code start<=i<end}. Return possibly changed self.
1381 */
1382 Name replaceNames(Name[] oldNames, Name[] newNames, int start, int end) {
1383 if (start >= end) return this;
1384 @SuppressWarnings("LocalVariableHidesMemberVariable")
1385 Object[] arguments = this.arguments;
1386 boolean replaced = false;
1387 eachArg:
1388 for (int j = 0; j < arguments.length; j++) {
1389 if (arguments[j] instanceof Name n) {
1390 int check = n.index;
1391 // harmless check to see if the thing is already in newNames:
1392 if (check >= 0 && check < newNames.length && n == newNames[check])
1393 continue eachArg;
1394 // n might not have the correct index: n != oldNames[n.index].
1395 for (int i = start; i < end; i++) {
1396 if (n == oldNames[i]) {
1397 if (n == newNames[i])
1398 continue eachArg;
1399 if (!replaced) {
1400 replaced = true;
1401 arguments = arguments.clone();
1402 }
1403 arguments[j] = newNames[i];
1404 continue eachArg;
1405 }
1406 }
1407 }
1408 }
1409 if (!replaced) return this;
1410 return new Name(function, arguments);
1411 }
1412 void internArguments() {
1413 @SuppressWarnings("LocalVariableHidesMemberVariable")
1414 Object[] arguments = this.arguments;
1415 for (int j = 0; j < arguments.length; j++) {
1416 if (arguments[j] instanceof Name n) {
1417 if (n.isParam() && n.index < INTERNED_ARGUMENT_LIMIT)
1418 arguments[j] = internArgument(n);
1419 }
1420 }
1421 }
1422 boolean isParam() {
1423 return function == null;
1424 }
1425
1426 boolean refersTo(Class<?> declaringClass, String methodName) {
1427 return function != null &&
1428 function.member() != null && function.member().refersTo(declaringClass, methodName);
1429 }
1430
1431 /**
1432 * Check if MemberName is a call to MethodHandle.invokeBasic.
1433 */
1434 boolean isInvokeBasic() {
1435 if (function == null)
1436 return false;
1437 if (arguments.length < 1)
1438 return false; // must have MH argument
1439 MemberName member = function.member();
1440 return member != null && member.refersTo(MethodHandle.class, "invokeBasic") &&
1441 !member.isPublic() && !member.isStatic();
1442 }
1443
1444 /**
1445 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
1446 */
1447 boolean isLinkerMethodInvoke() {
1448 if (function == null)
1449 return false;
1450 if (arguments.length < 1)
1451 return false; // must have MH argument
1452 MemberName member = function.member();
1453 return member != null &&
1454 member.getDeclaringClass() == MethodHandle.class &&
1455 !member.isPublic() && member.isStatic() &&
1456 member.getName().startsWith("linkTo");
1457 }
1458
1459 public String toString() {
1460 return (isParam()?"a":"t")+(index >= 0 ? index : System.identityHashCode(this))+":"+typeChar();
1461 }
1462 public String debugString() {
1463 String s = paramString();
1464 return (function == null) ? s : s + "=" + exprString();
1465 }
1466 public String paramString() {
1467 String s = toString();
1468 Object c = constraint;
1469 if (c == null)
1470 return s;
1471 if (c instanceof Class<?> cl) c = cl.getSimpleName();
1472 return s + "/" + c;
1473 }
1474 public String exprString() {
1475 if (function == null) return toString();
1476 StringBuilder buf = new StringBuilder(function.toString());
1477 buf.append("(");
1478 String cma = "";
1479 for (Object a : arguments) {
1480 buf.append(cma); cma = ",";
1481 if (a instanceof Name || a instanceof Integer)
1482 buf.append(a);
1483 else
1484 buf.append("(").append(a).append(")");
1485 }
1486 buf.append(")");
1487 return buf.toString();
1488 }
1489
1490 private boolean typesMatch(NamedFunction function, Object ... arguments) {
1491 if (arguments == null) {
1492 assert(function == null);
1493 return true;
1494 }
1495 assert(arguments.length == function.arity()) : "arity mismatch: arguments.length=" + arguments.length + " == function.arity()=" + function.arity() + " in " + debugString();
1496 for (int i = 0; i < arguments.length; i++) {
1497 assert (typesMatch(function.parameterType(i), arguments[i])) : "types don't match: function.parameterType(" + i + ")=" + function.parameterType(i) + ", arguments[" + i + "]=" + arguments[i] + " in " + debugString();
1498 }
1499 return true;
1500 }
1501
1502 private static boolean typesMatch(BasicType parameterType, Object object) {
1503 if (object instanceof Name name) {
1504 return name.type == parameterType;
1505 }
1506 switch (parameterType) {
1507 case I_TYPE: return object instanceof Integer;
1508 case J_TYPE: return object instanceof Long;
1509 case F_TYPE: return object instanceof Float;
1510 case D_TYPE: return object instanceof Double;
1511 }
1512 assert(parameterType == L_TYPE);
1513 return true;
1514 }
1515
1516 /** Return the index of the last occurrence of n in the argument array.
1517 * Return -1 if the name is not used.
1518 */
1519 int lastUseIndex(Name n) {
1520 Object[] arguments = this.arguments;
1521 if (arguments == null) return -1;
1522 for (int i = arguments.length; --i >= 0; ) {
1523 if (arguments[i] == n) return i;
1524 }
1525 return -1;
1526 }
1527
1528 public boolean equals(Name that) {
1529 if (this == that) return true;
1530 if (isParam())
1531 // each parameter is a unique atom
1532 return false; // this != that
1533 return
1534 //this.index == that.index &&
1535 this.type == that.type &&
1536 this.function.equals(that.function) &&
1537 Arrays.equals(this.arguments, that.arguments);
1538 }
1539 @Override
1540 public boolean equals(Object x) {
1541 return x instanceof Name n && equals(n);
1542 }
1543 @Override
1544 public int hashCode() {
1545 if (isParam())
1546 return index | (type.ordinal() << 8);
1547 return function.hashCode() ^ Arrays.hashCode(arguments);
1548 }
1549 }
1550
1551 /** Return the index of the last name which contains n as an argument.
1552 * Return -1 if the name is not used. Return names.length if it is the return value.
1553 */
1554 int lastUseIndex(Name n) {
1555 int ni = n.index, nmax = names.length;
1556 assert(names[ni] == n);
1557 if (result == ni) return nmax; // live all the way beyond the end
1558 for (int i = nmax; --i > ni; ) {
1559 if (names[i].lastUseIndex(n) >= 0)
1560 return i;
1561 }
1562 return -1;
1563 }
1564
1565 /** Return the number of times n is used as an argument or return value. */
1566 int useCount(Name n) {
1567 int count = (result == n.index) ? 1 : 0;
1568 int i = Math.max(n.index + 1, arity);
1569 Name[] names = this.names;
1570 while (i < names.length) {
1571 Object[] arguments = names[i++].arguments;
1572 if (arguments != null) {
1573 for (Object argument : arguments) {
1574 if (argument == n) {
1575 count++;
1576 }
1577 }
1578 }
1579 }
1580 return count;
1581 }
1582
1583 static Name argument(int which, BasicType type) {
1584 if (which >= INTERNED_ARGUMENT_LIMIT)
1585 return new Name(which, type);
1586 return INTERNED_ARGUMENTS[type.ordinal()][which];
1587 }
1588 static Name internArgument(Name n) {
1589 assert(n.isParam()) : "not param: " + n;
1590 assert(n.index < INTERNED_ARGUMENT_LIMIT);
1591 if (n.constraint != null) return n;
1592 return argument(n.index, n.type);
1593 }
1594 static Name[] arguments(int extra, MethodType types) {
1595 int length = types.parameterCount();
1596 Name[] names = new Name[length + extra];
1597 for (int i = 0; i < length; i++)
1598 names[i] = argument(i, basicType(types.parameterType(i)));
1599 return names;
1600 }
1601
1602 static Name[] invokeArguments(int extra, MethodType types) {
1603 int length = types.parameterCount();
1604 Name[] names = new Name[length + extra + 1];
1605 names[0] = argument(0, L_TYPE);
1606 for (int i = 0; i < length; i++)
1607 names[i + 1] = argument(i + 1, basicType(types.parameterType(i)));
1608 return names;
1609 }
1610
1611 static final int INTERNED_ARGUMENT_LIMIT = 10;
1612 private static final Name[][] INTERNED_ARGUMENTS
1613 = new Name[ARG_TYPE_LIMIT][INTERNED_ARGUMENT_LIMIT];
1614 static {
1615 for (BasicType type : BasicType.ARG_TYPES) {
1616 int ord = type.ordinal();
1617 for (int i = 0; i < INTERNED_ARGUMENTS[ord].length; i++) {
1618 INTERNED_ARGUMENTS[ord][i] = new Name(i, type);
1619 }
1620 }
1621 }
1622
1623 private static final MemberName.Factory IMPL_NAMES = MemberName.getFactory();
1624
1625 static LambdaForm identityForm(BasicType type) {
1626 int ord = type.ordinal();
1627 LambdaForm form = LF_identity[ord];
1628 if (form != null) {
1629 return form;
1630 }
1631 createIdentityForm(type);
1632 return LF_identity[ord];
1633 }
1634
1635 static NamedFunction identity(BasicType type) {
1636 int ord = type.ordinal();
1637 NamedFunction function = NF_identity[ord];
1638 if (function != null) {
1639 return function;
1640 }
1641 createIdentityForm(type);
1642 return NF_identity[ord];
1643 }
1644
1645 static LambdaForm constantForm(BasicType type) {
1646 assert type != null && type != V_TYPE : type;
1647 var cached = LF_constant[type.ordinal()];
1648 if (cached != null)
1649 return cached;
1650 return createConstantForm(type);
1651 }
1652
1653 private static LambdaForm createConstantForm(BasicType type) {
1654 UNSAFE.ensureClassInitialized(BoundMethodHandle.class); // defend access to SimpleMethodHandle
1655 var species = SimpleMethodHandle.BMH_SPECIES.extendWith(type);
1656 var carrier = argument(0, L_TYPE).withConstraint(species); // BMH bound with data
1657 Name[] constNames = new Name[] { carrier, new Name(species.getterFunction(0), carrier) };
1658 return LF_constant[type.ordinal()] = create(1, constNames, Kind.CONSTANT);
1659 }
1660
1661 private static final @Stable LambdaForm[] LF_identity = new LambdaForm[TYPE_LIMIT];
1662 private static final @Stable NamedFunction[] NF_identity = new NamedFunction[TYPE_LIMIT];
1663 private static final @Stable LambdaForm[] LF_constant = new LambdaForm[ARG_TYPE_LIMIT]; // no void
1664
1665 private static final Object createIdentityFormLock = new Object();
1666 private static void createIdentityForm(BasicType type) {
1667 // Avoid racy initialization during bootstrap
1668 UNSAFE.ensureClassInitialized(BoundMethodHandle.class);
1669 synchronized (createIdentityFormLock) {
1670 final int ord = type.ordinal();
1671 LambdaForm idForm = LF_identity[ord];
1672 if (idForm != null) {
1673 return;
1674 }
1675 char btChar = type.basicTypeChar();
1676 boolean isVoid = (type == V_TYPE);
1677 Class<?> btClass = type.btClass;
1678 MethodType idType = (isVoid) ? MethodType.methodType(btClass) : MethodType.methodType(btClass, btClass);
1679
1680 // Look up symbolic names. It might not be necessary to have these,
1681 // but if we need to emit direct references to bytecodes, it helps.
1682 MemberName idMem = new MemberName(LambdaForm.class, "identity_"+btChar, idType, REF_invokeStatic);
1683 try {
1684 idMem = IMPL_NAMES.resolveOrFail(REF_invokeStatic, idMem, null, LM_TRUSTED, NoSuchMethodException.class);
1685 } catch (IllegalAccessException|NoSuchMethodException ex) {
1686 throw newInternalError(ex);
1687 }
1688
1689 NamedFunction idFun;
1690
1691 // Create the LFs and NamedFunctions. Precompiling LFs to byte code is needed to break circular
1692 // bootstrap dependency on this method in case we're interpreting LFs
1693 if (isVoid) {
1694 Name[] idNames = new Name[] { argument(0, L_TYPE) };
1695 idForm = LambdaForm.create(1, idNames, VOID_RESULT, Kind.IDENTITY);
1696 idForm.compileToBytecode();
1697 idFun = new NamedFunction(idMem, SimpleMethodHandle.make(idMem.getInvocationType(), idForm));
1698 } else {
1699 Name[] idNames = new Name[] { argument(0, L_TYPE), argument(1, type) };
1700 idForm = LambdaForm.create(2, idNames, 1, Kind.IDENTITY);
1701 idForm.compileToBytecode();
1702 idFun = new NamedFunction(idMem, MethodHandleImpl.makeIntrinsic(idMem.getInvocationType(), idForm,
1703 MethodHandleImpl.Intrinsic.IDENTITY));
1704 }
1705
1706 LF_identity[ord] = idForm;
1707 NF_identity[ord] = idFun;
1708
1709 assert(idFun.isIdentity());
1710 }
1711 }
1712
1713 // Avoid appealing to ValueConversions at bootstrap time:
1714 private static int identity_I(int x) { return x; }
1715 private static long identity_J(long x) { return x; }
1716 private static float identity_F(float x) { return x; }
1717 private static double identity_D(double x) { return x; }
1718 private static Object identity_L(Object x) { return x; }
1719 private static void identity_V() { return; }
1720 /**
1721 * Internal marker for byte-compiled LambdaForms.
1722 */
1723 /*non-public*/
1724 @Target(ElementType.METHOD)
1725 @Retention(RetentionPolicy.RUNTIME)
1726 @interface Compiled {
1727 }
1728
1729 private static final HashMap<String,Integer> DEBUG_NAME_COUNTERS;
1730 private static final HashMap<LambdaForm,String> DEBUG_NAMES;
1731 static {
1732 if (debugEnabled()) {
1733 DEBUG_NAME_COUNTERS = new HashMap<>();
1734 DEBUG_NAMES = new HashMap<>();
1735 } else {
1736 DEBUG_NAME_COUNTERS = null;
1737 DEBUG_NAMES = null;
1738 }
1739 }
1740
1741 static {
1742 // The Holder class will contain pre-generated forms resolved
1743 // using MemberName.getFactory(). However, that doesn't initialize the
1744 // class, which subtly breaks inlining etc. By forcing
1745 // initialization of the Holder class we avoid these issues.
1746 UNSAFE.ensureClassInitialized(Holder.class);
1747 }
1748
1749 /* Placeholder class for identity and constant forms generated ahead of time */
1750 final class Holder {}
1751
1752 // The following hack is necessary in order to suppress TRACE_INTERPRETER
1753 // during execution of the static initializes of this class.
1754 // Turning on TRACE_INTERPRETER too early will cause
1755 // stack overflows and other misbehavior during attempts to trace events
1756 // that occur during LambdaForm.<clinit>.
1757 // Therefore, do not move this line higher in this file, and do not remove.
1758 private static final boolean TRACE_INTERPRETER = MethodHandleStatics.TRACE_INTERPRETER;
1759 }