1 /*
2 * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import jdk.internal.org.objectweb.asm.ClassWriter;
29 import jdk.internal.org.objectweb.asm.FieldVisitor;
30 import jdk.internal.org.objectweb.asm.Label;
31 import jdk.internal.org.objectweb.asm.MethodVisitor;
32 import jdk.internal.org.objectweb.asm.Opcodes;
33 import jdk.internal.org.objectweb.asm.Type;
34 import sun.invoke.util.VerifyAccess;
35 import sun.invoke.util.VerifyType;
36 import sun.invoke.util.Wrapper;
37 import sun.reflect.misc.ReflectUtil;
38
39 import java.io.File;
40 import java.io.FileOutputStream;
41 import java.io.IOException;
42 import java.lang.reflect.Modifier;
43 import java.util.ArrayList;
44 import java.util.Arrays;
45 import java.util.HashMap;
46 import java.util.List;
47 import java.util.stream.Stream;
48
49 import static java.lang.invoke.LambdaForm.BasicType;
50 import static java.lang.invoke.LambdaForm.BasicType.*;
51 import static java.lang.invoke.LambdaForm.*;
52 import static java.lang.invoke.MethodHandleNatives.Constants.*;
53 import static java.lang.invoke.MethodHandleStatics.*;
54 import static java.lang.invoke.MethodHandles.Lookup.*;
55
56 /**
57 * Code generation backend for LambdaForm.
58 * <p>
59 * @author John Rose, JSR 292 EG
60 */
61 class InvokerBytecodeGenerator {
62 /** Define class names for convenience. */
63 private static final String MH = "java/lang/invoke/MethodHandle";
64 private static final String MHI = "java/lang/invoke/MethodHandleImpl";
65 private static final String LF = "java/lang/invoke/LambdaForm";
66 private static final String LFN = "java/lang/invoke/LambdaForm$Name";
67 private static final String CLS = "java/lang/Class";
68 private static final String OBJ = "java/lang/Object";
69 private static final String OBJARY = "[Ljava/lang/Object;";
70
71 private static final String LOOP_CLAUSES = MHI + "$LoopClauses";
72 private static final String MHARY2 = "[[L" + MH + ";";
73 private static final String MH_SIG = "L" + MH + ";";
74
75
76 private static final String LF_SIG = "L" + LF + ";";
77 private static final String LFN_SIG = "L" + LFN + ";";
78 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
79 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V";
80 private static final String CLASS_PREFIX = LF + "$";
81 private static final String SOURCE_PREFIX = "LambdaForm$";
82
83 /** Name of its super class*/
84 static final String INVOKER_SUPER_NAME = OBJ;
85
86 /** Name of new class */
87 private final String className;
88
89 private final LambdaForm lambdaForm;
90 private final String invokerName;
91 private final MethodType invokerType;
92
93 /** Info about local variables in compiled lambda form */
94 private int[] localsMap; // index
95 private Class<?>[] localClasses; // type
96
97 /** ASM bytecode generation. */
98 private ClassWriter cw;
99 private MethodVisitor mv;
100 private final List<ClassData> classData = new ArrayList<>();
101
102 /** Single element internal class name lookup cache. */
103 private Class<?> lastClass;
104 private String lastInternalName;
105
106 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
107 private static final Class<?> HOST_CLASS = LambdaForm.class;
108 private static final MethodHandles.Lookup LOOKUP = lookup();
109
110 private static MethodHandles.Lookup lookup() {
111 try {
112 return MethodHandles.privateLookupIn(HOST_CLASS, IMPL_LOOKUP);
113 } catch (IllegalAccessException e) {
114 throw newInternalError(e);
115 }
116 }
117
118 /** Main constructor; other constructors delegate to this one. */
119 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
120 String className, String invokerName, MethodType invokerType) {
121 int p = invokerName.indexOf('.');
122 if (p > -1) {
123 className = invokerName.substring(0, p);
124 invokerName = invokerName.substring(p + 1);
125 }
126 if (DUMP_CLASS_FILES) {
127 className = makeDumpableClassName(className);
128 }
129 this.className = className;
130 this.lambdaForm = lambdaForm;
131 this.invokerName = invokerName;
132 this.invokerType = invokerType;
133 this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots
134 this.localClasses = new Class<?>[localsMapSize+1];
135 }
136
137 /** For generating LambdaForm interpreter entry points. */
138 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
139 this(null, invokerType.parameterCount(),
140 className, invokerName, invokerType);
141 MethodType mt = invokerType.erase();
142 // Create an array to map name indexes to locals indexes.
143 localsMap[0] = 0; // localsMap has at least one element
144 for (int i = 1, index = 0; i < localsMap.length; i++) {
145 Wrapper w = Wrapper.forBasicType(mt.parameterType(i - 1));
146 index += w.stackSlots();
147 localsMap[i] = index;
148 }
149 }
150
151 /** For generating customized code for a single LambdaForm. */
152 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
153 this(className, form.lambdaName(), form, invokerType);
154 }
155
156 /** For generating customized code for a single LambdaForm. */
157 InvokerBytecodeGenerator(String className, String invokerName,
158 LambdaForm form, MethodType invokerType) {
159 this(form, form.names.length,
160 className, invokerName, invokerType);
161 // Create an array to map name indexes to locals indexes.
162 Name[] names = form.names;
163 for (int i = 0, index = 0; i < localsMap.length; i++) {
164 localsMap[i] = index;
165 if (i < names.length) {
166 BasicType type = names[i].type();
167 index += type.basicTypeSlots();
168 }
169 }
170 }
171
172 /** instance counters for dumped classes */
173 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
174 /** debugging flag for saving generated class files */
175 private static final File DUMP_CLASS_FILES_DIR;
176
177 static {
178 if (DUMP_CLASS_FILES) {
179 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
180 try {
181 File dumpDir = new File("DUMP_CLASS_FILES");
182 if (!dumpDir.exists()) {
183 dumpDir.mkdirs();
184 }
185 DUMP_CLASS_FILES_DIR = dumpDir;
186 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
187 } catch (Exception e) {
188 throw newInternalError(e);
189 }
190 } else {
191 DUMP_CLASS_FILES_COUNTERS = null;
192 DUMP_CLASS_FILES_DIR = null;
193 }
194 }
195
196 private void maybeDump(final byte[] classFile) {
197 if (DUMP_CLASS_FILES) {
198 maybeDump(CLASS_PREFIX + className, classFile);
199 }
200 }
201
202 // Also used from BoundMethodHandle
203 static void maybeDump(final String className, final byte[] classFile) {
204 if (DUMP_CLASS_FILES) {
205 java.security.AccessController.doPrivileged(
206 new java.security.PrivilegedAction<>() {
207 public Void run() {
208 try {
209 String dumpName = className.replace('.','/');
210 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
211 System.out.println("dump: " + dumpFile);
212 dumpFile.getParentFile().mkdirs();
213 FileOutputStream file = new FileOutputStream(dumpFile);
214 file.write(classFile);
215 file.close();
216 return null;
217 } catch (IOException ex) {
218 throw newInternalError(ex);
219 }
220 }
221 });
222 }
223 }
224
225 private static String makeDumpableClassName(String className) {
226 Integer ctr;
227 synchronized (DUMP_CLASS_FILES_COUNTERS) {
228 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
229 if (ctr == null) ctr = 0;
230 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
231 }
232 String sfx = ctr.toString();
233 while (sfx.length() < 3)
234 sfx = "0"+sfx;
235 className += sfx;
236 return className;
237 }
238
239 public static class ClassData {
240 final String name;
241 final String desc;
242 final Object value;
243
244 ClassData(String name, String desc, Object value) {
245 this.name = name;
246 this.desc = desc;
247 this.value = value;
248 }
249
250 public String name() { return name; }
251 public String toString() {
252 return name + ",value="+value;
253 }
254 }
255
256 String classData(Object arg) {
257 String desc;
258 if (arg instanceof Class) {
259 desc = "Ljava/lang/Class;";
260 } else if (arg instanceof MethodHandle) {
261 desc = MH_SIG;
262 } else if (arg instanceof LambdaForm) {
263 desc = LF_SIG;
264 } else {
265 desc = "Ljava/lang/Object;";
266 }
267
268 Class<?> c = arg.getClass();
269 while (c.isArray()) {
270 c = c.getComponentType();
271 }
272 // unique static variable name
273 String name = "_DATA_" + c.getSimpleName() + "_" + classData.size();
274 ClassData cd = new ClassData(name, desc, arg);
275 classData.add(cd);
276 return cd.name();
277 }
278
279 List<Object> classDataValues() {
280 Object[] data = new Object[classData.size()];
281 for (int i = 0; i < classData.size(); i++) {
282 data[i] = classData.get(i).value;
283 }
284 return List.of(data);
285 }
286
287 private static String debugString(Object arg) {
288 if (arg instanceof MethodHandle) {
289 MethodHandle mh = (MethodHandle) arg;
290 MemberName member = mh.internalMemberName();
291 if (member != null)
292 return member.toString();
293 return mh.debugString();
294 }
295 return arg.toString();
296 }
297
298 /**
299 * Extract the number of constant pool entries from a given class file.
300 *
301 * @param classFile the bytes of the class file in question.
302 * @return the number of entries in the constant pool.
303 */
304 private static int getConstantPoolSize(byte[] classFile) {
305 // The first few bytes:
306 // u4 magic;
307 // u2 minor_version;
308 // u2 major_version;
309 // u2 constant_pool_count;
310 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
311 }
312
313 /**
314 * Extract the MemberName of a newly-defined method.
315 */
316 private MemberName loadMethod(byte[] classFile) {
317 Class<?> invokerClass = LOOKUP.makeHiddenClassDefiner(classFile)
318 .defineClass(true, classDataValues());
319 return resolveInvokerMember(invokerClass, invokerName, invokerType);
320 }
321
322 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
323 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
324 try {
325 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
326 } catch (ReflectiveOperationException e) {
327 throw newInternalError(e);
328 }
329 return member;
330 }
331
332 /**
333 * Set up class file generation.
334 */
335 private ClassWriter classFilePrologue() {
336 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
337 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
338 setClassWriter(cw);
339 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
340 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null);
341 cw.visitSource(SOURCE_PREFIX + className, null);
342 return cw;
343 }
344
345 private void methodPrologue() {
346 String invokerDesc = invokerType.toMethodDescriptorString();
347 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
348 }
349
350 /**
351 * Tear down class file generation.
352 */
353 private void methodEpilogue() {
354 mv.visitMaxs(0, 0);
355 mv.visitEnd();
356 }
357
358 private String className() {
359 return CLASS_PREFIX + className;
360 }
361
362 private void clinit() {
363 clinit(cw, className(), classData);
364 }
365
366 static void clinit(ClassWriter cw, String className, List<ClassData> classData) {
367 if (classData.isEmpty())
368 return;
369
370 for (ClassData p : classData) {
371 // add the static field
372 FieldVisitor fv = cw.visitField(Opcodes.ACC_STATIC|Opcodes.ACC_FINAL, p.name, p.desc, null, null);
373 fv.visitEnd();
374 }
375
376 MethodVisitor mv = cw.visitMethod(Opcodes.ACC_STATIC, "<clinit>", "()V", null, null);
377 mv.visitCode();
378 // bootstrapping issue if using condy
379 mv.visitLdcInsn(Type.getType("L" + className + ";"));
380 mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/invoke/MethodHandleNatives",
381 "classData", "(Ljava/lang/Class;)Ljava/lang/Object;", false);
382 // we should optimize one single element case that does not need to create a List
383 mv.visitTypeInsn(Opcodes.CHECKCAST, "java/util/List");
384 mv.visitVarInsn(Opcodes.ASTORE, 0);
385 int index = 0;
386 for (ClassData p : classData) {
387 // initialize the static field
388 mv.visitVarInsn(Opcodes.ALOAD, 0);
389 emitIconstInsn(mv, index++);
390 mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/List",
391 "get", "(I)Ljava/lang/Object;", true);
392 mv.visitTypeInsn(Opcodes.CHECKCAST, p.desc.substring(1, p.desc.length()-1));
393 mv.visitFieldInsn(Opcodes.PUTSTATIC, className, p.name, p.desc);
394 }
395 mv.visitInsn(Opcodes.RETURN);
396 mv.visitMaxs(2, 1);
397 mv.visitEnd();
398 }
399
400 /*
401 * Low-level emit helpers.
402 */
403 private void emitConst(Object con) {
404 if (con == null) {
405 mv.visitInsn(Opcodes.ACONST_NULL);
406 return;
407 }
408 if (con instanceof Integer) {
409 emitIconstInsn((int) con);
410 return;
411 }
412 if (con instanceof Byte) {
413 emitIconstInsn((byte)con);
414 return;
415 }
416 if (con instanceof Short) {
417 emitIconstInsn((short)con);
418 return;
419 }
420 if (con instanceof Character) {
421 emitIconstInsn((char)con);
422 return;
423 }
424 if (con instanceof Long) {
425 long x = (long) con;
426 short sx = (short)x;
427 if (x == sx) {
428 if (sx >= 0 && sx <= 1) {
429 mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
430 } else {
431 emitIconstInsn((int) x);
432 mv.visitInsn(Opcodes.I2L);
433 }
434 return;
435 }
436 }
437 if (con instanceof Float) {
438 float x = (float) con;
439 short sx = (short)x;
440 if (x == sx) {
441 if (sx >= 0 && sx <= 2) {
442 mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
443 } else {
444 emitIconstInsn((int) x);
445 mv.visitInsn(Opcodes.I2F);
446 }
447 return;
448 }
449 }
450 if (con instanceof Double) {
451 double x = (double) con;
452 short sx = (short)x;
453 if (x == sx) {
454 if (sx >= 0 && sx <= 1) {
455 mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
456 } else {
457 emitIconstInsn((int) x);
458 mv.visitInsn(Opcodes.I2D);
459 }
460 return;
461 }
462 }
463 if (con instanceof Boolean) {
464 emitIconstInsn((boolean) con ? 1 : 0);
465 return;
466 }
467 // fall through:
468 mv.visitLdcInsn(con);
469 }
470
471 private void emitIconstInsn(final int cst) {
472 emitIconstInsn(mv, cst);
473 }
474
475 private static void emitIconstInsn(MethodVisitor mv, int cst) {
476 if (cst >= -1 && cst <= 5) {
477 mv.visitInsn(Opcodes.ICONST_0 + cst);
478 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
479 mv.visitIntInsn(Opcodes.BIPUSH, cst);
480 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
481 mv.visitIntInsn(Opcodes.SIPUSH, cst);
482 } else {
483 mv.visitLdcInsn(cst);
484 }
485 }
486
487 /*
488 * NOTE: These load/store methods use the localsMap to find the correct index!
489 */
490 private void emitLoadInsn(BasicType type, int index) {
491 int opcode = loadInsnOpcode(type);
492 mv.visitVarInsn(opcode, localsMap[index]);
493 }
494
495 private int loadInsnOpcode(BasicType type) throws InternalError {
496 switch (type) {
497 case I_TYPE: return Opcodes.ILOAD;
498 case J_TYPE: return Opcodes.LLOAD;
499 case F_TYPE: return Opcodes.FLOAD;
500 case D_TYPE: return Opcodes.DLOAD;
501 case L_TYPE: return Opcodes.ALOAD;
502 default:
503 throw new InternalError("unknown type: " + type);
504 }
505 }
506 private void emitAloadInsn(int index) {
507 emitLoadInsn(L_TYPE, index);
508 }
509
510 private void emitStoreInsn(BasicType type, int index) {
511 int opcode = storeInsnOpcode(type);
512 mv.visitVarInsn(opcode, localsMap[index]);
513 }
514
515 private int storeInsnOpcode(BasicType type) throws InternalError {
516 switch (type) {
517 case I_TYPE: return Opcodes.ISTORE;
518 case J_TYPE: return Opcodes.LSTORE;
519 case F_TYPE: return Opcodes.FSTORE;
520 case D_TYPE: return Opcodes.DSTORE;
521 case L_TYPE: return Opcodes.ASTORE;
522 default:
523 throw new InternalError("unknown type: " + type);
524 }
525 }
526 private void emitAstoreInsn(int index) {
527 emitStoreInsn(L_TYPE, index);
528 }
529
530 private byte arrayTypeCode(Wrapper elementType) {
531 switch (elementType) {
532 case BOOLEAN: return Opcodes.T_BOOLEAN;
533 case BYTE: return Opcodes.T_BYTE;
534 case CHAR: return Opcodes.T_CHAR;
535 case SHORT: return Opcodes.T_SHORT;
536 case INT: return Opcodes.T_INT;
537 case LONG: return Opcodes.T_LONG;
538 case FLOAT: return Opcodes.T_FLOAT;
539 case DOUBLE: return Opcodes.T_DOUBLE;
540 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
541 default: throw new InternalError();
542 }
543 }
544
545 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
546 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
547 int xas;
548 switch (tcode) {
549 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
550 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
551 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
552 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
553 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
554 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
555 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
556 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
557 case 0: xas = Opcodes.AASTORE; break;
558 default: throw new InternalError();
559 }
560 return xas - Opcodes.AASTORE + aaop;
561 }
562
563 /**
564 * Emit a boxing call.
565 *
566 * @param wrapper primitive type class to box.
567 */
568 private void emitBoxing(Wrapper wrapper) {
569 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
570 String name = "valueOf";
571 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
572 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
573 }
574
575 /**
576 * Emit an unboxing call (plus preceding checkcast).
577 *
578 * @param wrapper wrapper type class to unbox.
579 */
580 private void emitUnboxing(Wrapper wrapper) {
581 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
582 String name = wrapper.primitiveSimpleName() + "Value";
583 String desc = "()" + wrapper.basicTypeChar();
584 emitReferenceCast(wrapper.wrapperType(), null);
585 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
586 }
587
588 /**
589 * Emit an implicit conversion for an argument which must be of the given pclass.
590 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
591 *
592 * @param ptype type of value present on stack
593 * @param pclass type of value required on stack
594 * @param arg compile-time representation of value on stack (Node, constant) or null if none
595 */
596 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
597 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
598 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
599 return; // nothing to do
600 switch (ptype) {
601 case L_TYPE:
602 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
603 if (PROFILE_LEVEL > 0)
604 emitReferenceCast(Object.class, arg);
605 return;
606 }
607 emitReferenceCast(pclass, arg);
608 return;
609 case I_TYPE:
610 if (!VerifyType.isNullConversion(int.class, pclass, false))
611 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
612 return;
613 }
614 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
615 }
616
617 /** Update localClasses type map. Return true if the information is already present. */
618 private boolean assertStaticType(Class<?> cls, Name n) {
619 int local = n.index();
620 Class<?> aclass = localClasses[local];
621 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
622 return true; // type info is already present
623 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
624 localClasses[local] = cls; // type info can be improved
625 }
626 return false;
627 }
628
629 private void emitReferenceCast(Class<?> cls, Object arg) {
630 Name writeBack = null; // local to write back result
631 if (arg instanceof Name) {
632 Name n = (Name) arg;
633 if (lambdaForm.useCount(n) > 1) {
634 // This guy gets used more than once.
635 writeBack = n;
636 if (assertStaticType(cls, n)) {
637 return; // this cast was already performed
638 }
639 }
640 }
641 if (isStaticallyNameable(cls)) {
642 String sig = getInternalName(cls);
643 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
644 } else {
645 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(cls), "Ljava/lang/Class;");
646 mv.visitInsn(Opcodes.SWAP);
647 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
648 if (Object[].class.isAssignableFrom(cls))
649 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
650 else if (PROFILE_LEVEL > 0)
651 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
652 }
653 if (writeBack != null) {
654 mv.visitInsn(Opcodes.DUP);
655 emitAstoreInsn(writeBack.index());
656 }
657 }
658
659 /**
660 * Emits an actual return instruction conforming to the given return type.
661 */
662 private void emitReturnInsn(BasicType type) {
663 int opcode;
664 switch (type) {
665 case I_TYPE: opcode = Opcodes.IRETURN; break;
666 case J_TYPE: opcode = Opcodes.LRETURN; break;
667 case F_TYPE: opcode = Opcodes.FRETURN; break;
668 case D_TYPE: opcode = Opcodes.DRETURN; break;
669 case L_TYPE: opcode = Opcodes.ARETURN; break;
670 case V_TYPE: opcode = Opcodes.RETURN; break;
671 default:
672 throw new InternalError("unknown return type: " + type);
673 }
674 mv.visitInsn(opcode);
675 }
676
677 private String getInternalName(Class<?> c) {
678 if (c == Object.class) return OBJ;
679 else if (c == Object[].class) return OBJARY;
680 else if (c == Class.class) return CLS;
681 else if (c == MethodHandle.class) return MH;
682 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
683
684 if (c == lastClass) {
685 return lastInternalName;
686 }
687 lastClass = c;
688 return lastInternalName = c.getName().replace('.', '/');
689 }
690
691 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
692 MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
693 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
694 if (TRACE_RESOLVE) {
695 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
696 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
697 }
698 return resolvedMember;
699 }
700
701 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
702 if (form.customized != null) {
703 // No pre-generated version for customized LF
704 return null;
705 }
706 String name = form.kind.methodName;
707 switch (form.kind) {
708 case BOUND_REINVOKER: {
709 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key();
710 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
711 }
712 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
713 case ZERO: // fall-through
714 case IDENTITY: {
715 name = name + "_" + form.returnType().basicTypeChar();
716 return resolveFrom(name, invokerType, LambdaForm.Holder.class);
717 }
718 case EXACT_INVOKER: // fall-through
719 case EXACT_LINKER: // fall-through
720 case LINK_TO_CALL_SITE: // fall-through
721 case LINK_TO_TARGET_METHOD: // fall-through
722 case GENERIC_INVOKER: // fall-through
723 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
724 case GET_REFERENCE: // fall-through
725 case GET_BOOLEAN: // fall-through
726 case GET_BYTE: // fall-through
727 case GET_CHAR: // fall-through
728 case GET_SHORT: // fall-through
729 case GET_INT: // fall-through
730 case GET_LONG: // fall-through
731 case GET_FLOAT: // fall-through
732 case GET_DOUBLE: // fall-through
733 case PUT_REFERENCE: // fall-through
734 case PUT_BOOLEAN: // fall-through
735 case PUT_BYTE: // fall-through
736 case PUT_CHAR: // fall-through
737 case PUT_SHORT: // fall-through
738 case PUT_INT: // fall-through
739 case PUT_LONG: // fall-through
740 case PUT_FLOAT: // fall-through
741 case PUT_DOUBLE: // fall-through
742 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through
743 case DIRECT_INVOKE_INTERFACE: // fall-through
744 case DIRECT_INVOKE_SPECIAL: // fall-through
745 case DIRECT_INVOKE_SPECIAL_IFC: // fall-through
746 case DIRECT_INVOKE_STATIC: // fall-through
747 case DIRECT_INVOKE_STATIC_INIT: // fall-through
748 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
749 }
750 return null;
751 }
752
753 /**
754 * Generate customized bytecode for a given LambdaForm.
755 */
756 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
757 MemberName pregenerated = lookupPregenerated(form, invokerType);
758 if (pregenerated != null) return pregenerated; // pre-generated bytecode
759
760 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
761 return g.loadMethod(g.generateCustomizedCodeBytes());
762 }
763
764 /** Generates code to check that actual receiver and LambdaForm matches */
765 private boolean checkActualReceiver() {
766 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
767 mv.visitInsn(Opcodes.DUP);
768 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
769 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
770 return true;
771 }
772
773 static String className(String cn) {
774 assert checkClassName(cn): "Class not found: " + cn;
775 return cn;
776 }
777
778 static boolean checkClassName(String cn) {
779 Type tp = Type.getType(cn);
780 // additional sanity so only valid "L;" descriptors work
781 if (tp.getSort() != Type.OBJECT) {
782 return false;
783 }
784 try {
785 Class<?> c = Class.forName(tp.getClassName(), false, null);
786 return true;
787 } catch (ClassNotFoundException e) {
788 return false;
789 }
790 }
791
792 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
793 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
794 static final String HIDDEN_SIG = className("Ljdk/internal/vm/annotation/Hidden;");
795 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
796 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
797
798 /**
799 * Generate an invoker method for the passed {@link LambdaForm}.
800 */
801 private byte[] generateCustomizedCodeBytes() {
802 classFilePrologue();
803 addMethod();
804 clinit();
805 bogusMethod(lambdaForm);
806
807 final byte[] classFile = toByteArray();
808 maybeDump(classFile);
809 return classFile;
810 }
811
812 void setClassWriter(ClassWriter cw) {
813 this.cw = cw;
814 }
815
816 void addMethod() {
817 methodPrologue();
818
819 // Suppress this method in backtraces displayed to the user.
820 mv.visitAnnotation(HIDDEN_SIG, true);
821
822 // Mark this method as a compiled LambdaForm
823 mv.visitAnnotation(LF_COMPILED_SIG, true);
824
825 if (lambdaForm.forceInline) {
826 // Force inlining of this invoker method.
827 mv.visitAnnotation(FORCEINLINE_SIG, true);
828 } else {
829 mv.visitAnnotation(DONTINLINE_SIG, true);
830 }
831
832 classData(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
833
834 if (lambdaForm.customized != null) {
835 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
836 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
837 // It enables more efficient code generation in some situations, since embedded constants
838 // are compile-time constants for JIT compiler.
839 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(lambdaForm.customized), MH_SIG);
840 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
841 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
842 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
843 }
844
845 // iterate over the form's names, generating bytecode instructions for each
846 // start iterating at the first name following the arguments
847 Name onStack = null;
848 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
849 Name name = lambdaForm.names[i];
850
851 emitStoreResult(onStack);
852 onStack = name; // unless otherwise modified below
853 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
854 switch (intr) {
855 case SELECT_ALTERNATIVE:
856 assert lambdaForm.isSelectAlternative(i);
857 if (PROFILE_GWT) {
858 assert(name.arguments[0] instanceof Name &&
859 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
860 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
861 }
862 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
863 i++; // skip MH.invokeBasic of the selectAlternative result
864 continue;
865 case GUARD_WITH_CATCH:
866 assert lambdaForm.isGuardWithCatch(i);
867 onStack = emitGuardWithCatch(i);
868 i += 2; // jump to the end of GWC idiom
869 continue;
870 case TRY_FINALLY:
871 assert lambdaForm.isTryFinally(i);
872 onStack = emitTryFinally(i);
873 i += 2; // jump to the end of the TF idiom
874 continue;
875 case LOOP:
876 assert lambdaForm.isLoop(i);
877 onStack = emitLoop(i);
878 i += 2; // jump to the end of the LOOP idiom
879 continue;
880 case NEW_ARRAY:
881 Class<?> rtype = name.function.methodType().returnType();
882 if (isStaticallyNameable(rtype)) {
883 emitNewArray(name);
884 continue;
885 }
886 break;
887 case ARRAY_LOAD:
888 emitArrayLoad(name);
889 continue;
890 case ARRAY_STORE:
891 emitArrayStore(name);
892 continue;
893 case ARRAY_LENGTH:
894 emitArrayLength(name);
895 continue;
896 case IDENTITY:
897 assert(name.arguments.length == 1);
898 emitPushArguments(name, 0);
899 continue;
900 case ZERO:
901 assert(name.arguments.length == 0);
902 emitConst(name.type.basicTypeWrapper().zero());
903 continue;
904 case NONE:
905 // no intrinsic associated
906 break;
907 default:
908 throw newInternalError("Unknown intrinsic: "+intr);
909 }
910
911 MemberName member = name.function.member();
912 if (isStaticallyInvocable(member)) {
913 emitStaticInvoke(member, name);
914 } else {
915 emitInvoke(name);
916 }
917 }
918
919 // return statement
920 emitReturn(onStack);
921
922 methodEpilogue();
923 }
924
925 /*
926 * @throws BytecodeGenerationException if something goes wrong when
927 * generating the byte code
928 */
929 private byte[] toByteArray() {
930 try {
931 return cw.toByteArray();
932 } catch (RuntimeException e) {
933 throw new BytecodeGenerationException(e);
934 }
935 }
936
937 @SuppressWarnings("serial")
938 static final class BytecodeGenerationException extends RuntimeException {
939 BytecodeGenerationException(Exception cause) {
940 super(cause);
941 }
942 }
943
944 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
945 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
946 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
947
948 void emitArrayOp(Name name, int arrayOpcode) {
949 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
950 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
951 assert elementType != null;
952 emitPushArguments(name, 0);
953 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
954 Wrapper w = Wrapper.forPrimitiveType(elementType);
955 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
956 }
957 mv.visitInsn(arrayOpcode);
958 }
959
960 /**
961 * Emit an invoke for the given name.
962 */
963 void emitInvoke(Name name) {
964 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
965 if (true) {
966 // push receiver
967 MethodHandle target = name.function.resolvedHandle();
968 assert(target != null) : name.exprString();
969 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(target), MH_SIG);
970 emitReferenceCast(MethodHandle.class, target);
971 } else {
972 // load receiver
973 emitAloadInsn(0);
974 emitReferenceCast(MethodHandle.class, null);
975 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
976 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
977 // TODO more to come
978 }
979
980 // push arguments
981 emitPushArguments(name, 0);
982
983 // invocation
984 MethodType type = name.function.methodType();
985 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
986 }
987
988 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
989 // Sample classes from each package we are willing to bind to statically:
990 java.lang.Object.class,
991 java.util.Arrays.class,
992 jdk.internal.misc.Unsafe.class
993 //MethodHandle.class already covered
994 };
995
996 static boolean isStaticallyInvocable(NamedFunction ... functions) {
997 for (NamedFunction nf : functions) {
998 if (!isStaticallyInvocable(nf.member())) {
999 return false;
1000 }
1001 }
1002 return true;
1003 }
1004
1005 static boolean isStaticallyInvocable(Name name) {
1006 return isStaticallyInvocable(name.function.member());
1007 }
1008
1009 static boolean isStaticallyInvocable(MemberName member) {
1010 if (member == null) return false;
1011 if (member.isConstructor()) return false;
1012 Class<?> cls = member.getDeclaringClass();
1013 // Fast-path non-private members declared by MethodHandles, which is a common
1014 // case
1015 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
1016 assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
1017 return true;
1018 }
1019 if (cls.isArray() || cls.isPrimitive())
1020 return false; // FIXME
1021 if (cls.isAnonymousClass() || cls.isLocalClass())
1022 return false; // inner class of some sort
1023 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
1024 return false; // not on BCP
1025 if (cls.isHiddenClass())
1026 return false;
1027 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: Unsafe::defineAnonymousClass to be removed
1028 return false;
1029 if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
1030 return false;
1031 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
1032 return true; // in java.lang.invoke package
1033 if (member.isPublic() && isStaticallyNameable(cls))
1034 return true;
1035 return false;
1036 }
1037
1038 private static boolean isStaticallyInvocableType(MethodType mtype) {
1039 if (!isStaticallyNameable(mtype.returnType()))
1040 return false;
1041 for (Class<?> ptype : mtype.parameterArray())
1042 if (!isStaticallyNameable(ptype))
1043 return false;
1044 return true;
1045 }
1046
1047 static boolean isStaticallyNameable(Class<?> cls) {
1048 if (cls == Object.class)
1049 return true;
1050 if (MethodHandle.class.isAssignableFrom(cls)) {
1051 assert(!cls.isHiddenClass());
1052 return true;
1053 }
1054 while (cls.isArray())
1055 cls = cls.getComponentType();
1056 if (cls.isPrimitive())
1057 return true; // int[].class, for example
1058 if (cls.isHiddenClass())
1059 return false;
1060 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: Unsafe::defineAnonymousClass to be removed
1061 return false;
1062 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
1063 if (cls.getClassLoader() != Object.class.getClassLoader())
1064 return false;
1065 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
1066 return true;
1067 if (!Modifier.isPublic(cls.getModifiers()))
1068 return false;
1069 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
1070 if (VerifyAccess.isSamePackage(pkgcls, cls))
1071 return true;
1072 }
1073 return false;
1074 }
1075
1076 void emitStaticInvoke(Name name) {
1077 emitStaticInvoke(name.function.member(), name);
1078 }
1079
1080 /**
1081 * Emit an invoke for the given name, using the MemberName directly.
1082 */
1083 void emitStaticInvoke(MemberName member, Name name) {
1084 assert(member.equals(name.function.member()));
1085 Class<?> defc = member.getDeclaringClass();
1086 String cname = getInternalName(defc);
1087 String mname = member.getName();
1088 String mtype;
1089 byte refKind = member.getReferenceKind();
1090 if (refKind == REF_invokeSpecial) {
1091 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1092 assert(member.canBeStaticallyBound()) : member;
1093 refKind = REF_invokeVirtual;
1094 }
1095
1096 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
1097
1098 // push arguments
1099 emitPushArguments(name, 0);
1100
1101 // invocation
1102 if (member.isMethod()) {
1103 mtype = member.getMethodType().toMethodDescriptorString();
1104 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1105 member.getDeclaringClass().isInterface());
1106 } else {
1107 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1108 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1109 }
1110 // Issue a type assertion for the result, so we can avoid casts later.
1111 if (name.type == L_TYPE) {
1112 Class<?> rtype = member.getInvocationType().returnType();
1113 assert(!rtype.isPrimitive());
1114 if (rtype != Object.class && !rtype.isInterface()) {
1115 assertStaticType(rtype, name);
1116 }
1117 }
1118 }
1119
1120 void emitNewArray(Name name) throws InternalError {
1121 Class<?> rtype = name.function.methodType().returnType();
1122 if (name.arguments.length == 0) {
1123 // The array will be a constant.
1124 Object emptyArray;
1125 try {
1126 emptyArray = name.function.resolvedHandle().invoke();
1127 } catch (Throwable ex) {
1128 throw uncaughtException(ex);
1129 }
1130 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1131 assert(emptyArray.getClass() == rtype); // exact typing
1132 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(emptyArray), "Ljava/lang/Object;");
1133 emitReferenceCast(rtype, emptyArray);
1134 return;
1135 }
1136 Class<?> arrayElementType = rtype.getComponentType();
1137 assert(arrayElementType != null);
1138 emitIconstInsn(name.arguments.length);
1139 int xas = Opcodes.AASTORE;
1140 if (!arrayElementType.isPrimitive()) {
1141 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1142 } else {
1143 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1144 xas = arrayInsnOpcode(tc, xas);
1145 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1146 }
1147 // store arguments
1148 for (int i = 0; i < name.arguments.length; i++) {
1149 mv.visitInsn(Opcodes.DUP);
1150 emitIconstInsn(i);
1151 emitPushArgument(name, i);
1152 mv.visitInsn(xas);
1153 }
1154 // the array is left on the stack
1155 assertStaticType(rtype, name);
1156 }
1157 int refKindOpcode(byte refKind) {
1158 switch (refKind) {
1159 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1160 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1161 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1162 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1163 case REF_getField: return Opcodes.GETFIELD;
1164 case REF_putField: return Opcodes.PUTFIELD;
1165 case REF_getStatic: return Opcodes.GETSTATIC;
1166 case REF_putStatic: return Opcodes.PUTSTATIC;
1167 }
1168 throw new InternalError("refKind="+refKind);
1169 }
1170
1171 /**
1172 * Emit bytecode for the selectAlternative idiom.
1173 *
1174 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1175 * <blockquote><pre>{@code
1176 * Lambda(a0:L,a1:I)=>{
1177 * t2:I=foo.test(a1:I);
1178 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1179 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1180 * }</pre></blockquote>
1181 */
1182 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1183 assert isStaticallyInvocable(invokeBasicName);
1184
1185 Name receiver = (Name) invokeBasicName.arguments[0];
1186
1187 Label L_fallback = new Label();
1188 Label L_done = new Label();
1189
1190 // load test result
1191 emitPushArgument(selectAlternativeName, 0);
1192
1193 // if_icmpne L_fallback
1194 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1195
1196 // invoke selectAlternativeName.arguments[1]
1197 Class<?>[] preForkClasses = localClasses.clone();
1198 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1199 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1200 emitStaticInvoke(invokeBasicName);
1201
1202 // goto L_done
1203 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1204
1205 // L_fallback:
1206 mv.visitLabel(L_fallback);
1207
1208 // invoke selectAlternativeName.arguments[2]
1209 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1210 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1211 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1212 emitStaticInvoke(invokeBasicName);
1213
1214 // L_done:
1215 mv.visitLabel(L_done);
1216 // for now do not bother to merge typestate; just reset to the dominator state
1217 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1218
1219 return invokeBasicName; // return what's on stack
1220 }
1221
1222 /**
1223 * Emit bytecode for the guardWithCatch idiom.
1224 *
1225 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1226 * <blockquote><pre>{@code
1227 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1228 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1229 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1230 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1231 * }</pre></blockquote>
1232 *
1233 * It is compiled into bytecode equivalent of the following code:
1234 * <blockquote><pre>{@code
1235 * try {
1236 * return a1.invokeBasic(a6, a7);
1237 * } catch (Throwable e) {
1238 * if (!a2.isInstance(e)) throw e;
1239 * return a3.invokeBasic(ex, a6, a7);
1240 * }}</pre></blockquote>
1241 */
1242 private Name emitGuardWithCatch(int pos) {
1243 Name args = lambdaForm.names[pos];
1244 Name invoker = lambdaForm.names[pos+1];
1245 Name result = lambdaForm.names[pos+2];
1246
1247 Label L_startBlock = new Label();
1248 Label L_endBlock = new Label();
1249 Label L_handler = new Label();
1250 Label L_done = new Label();
1251
1252 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1253 MethodType type = args.function.resolvedHandle().type()
1254 .dropParameterTypes(0,1)
1255 .changeReturnType(returnType);
1256
1257 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1258
1259 // Normal case
1260 mv.visitLabel(L_startBlock);
1261 // load target
1262 emitPushArgument(invoker, 0);
1263 emitPushArguments(args, 1); // skip 1st argument: method handle
1264 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1265 mv.visitLabel(L_endBlock);
1266 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1267
1268 // Exceptional case
1269 mv.visitLabel(L_handler);
1270
1271 // Check exception's type
1272 mv.visitInsn(Opcodes.DUP);
1273 // load exception class
1274 emitPushArgument(invoker, 1);
1275 mv.visitInsn(Opcodes.SWAP);
1276 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1277 Label L_rethrow = new Label();
1278 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1279
1280 // Invoke catcher
1281 // load catcher
1282 emitPushArgument(invoker, 2);
1283 mv.visitInsn(Opcodes.SWAP);
1284 emitPushArguments(args, 1); // skip 1st argument: method handle
1285 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1286 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1287 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1288
1289 mv.visitLabel(L_rethrow);
1290 mv.visitInsn(Opcodes.ATHROW);
1291
1292 mv.visitLabel(L_done);
1293
1294 return result;
1295 }
1296
1297 /**
1298 * Emit bytecode for the tryFinally idiom.
1299 * <p>
1300 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1301 * <blockquote><pre>{@code
1302 * // a0: BMH
1303 * // a1: target, a2: cleanup
1304 * // a3: box, a4: unbox
1305 * // a5 (and following): arguments
1306 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1307 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1308 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1309 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1310 * }</pre></blockquote>
1311 * <p>
1312 * It is compiled into bytecode equivalent to the following code:
1313 * <blockquote><pre>{@code
1314 * Throwable t;
1315 * Object r;
1316 * try {
1317 * r = a1.invokeBasic(a5);
1318 * } catch (Throwable thrown) {
1319 * t = thrown;
1320 * throw t;
1321 * } finally {
1322 * r = a2.invokeBasic(t, r, a5);
1323 * }
1324 * return r;
1325 * }</pre></blockquote>
1326 * <p>
1327 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1328 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1329 * shape if the return type is {@code void}):
1330 * <blockquote><pre>{@code
1331 * TRY: (--)
1332 * load target (-- target)
1333 * load args (-- args... target)
1334 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1335 * FINALLY_NORMAL: (-- r_2nd* r)
1336 * store returned value (--)
1337 * load cleanup (-- cleanup)
1338 * ACONST_NULL (-- t cleanup)
1339 * load returned value (-- r_2nd* r t cleanup)
1340 * load args (-- args... r_2nd* r t cleanup)
1341 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r)
1342 * GOTO DONE
1343 * CATCH: (-- t)
1344 * DUP (-- t t)
1345 * FINALLY_EXCEPTIONAL: (-- t t)
1346 * load cleanup (-- cleanup t t)
1347 * SWAP (-- t cleanup t)
1348 * load default for r (-- r_2nd* r t cleanup t)
1349 * load args (-- args... r_2nd* r t cleanup t)
1350 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r t)
1351 * POP/POP2* (-- t)
1352 * ATHROW
1353 * DONE: (-- r)
1354 * }</pre></blockquote>
1355 * * = depends on whether the return type takes up 2 stack slots.
1356 */
1357 private Name emitTryFinally(int pos) {
1358 Name args = lambdaForm.names[pos];
1359 Name invoker = lambdaForm.names[pos+1];
1360 Name result = lambdaForm.names[pos+2];
1361
1362 Label lFrom = new Label();
1363 Label lTo = new Label();
1364 Label lCatch = new Label();
1365 Label lDone = new Label();
1366
1367 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1368 BasicType basicReturnType = BasicType.basicType(returnType);
1369 boolean isNonVoid = returnType != void.class;
1370
1371 MethodType type = args.function.resolvedHandle().type()
1372 .dropParameterTypes(0,1)
1373 .changeReturnType(returnType);
1374 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1375 if (isNonVoid) {
1376 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1377 }
1378 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1379
1380 // exception handler table
1381 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1382
1383 // TRY:
1384 mv.visitLabel(lFrom);
1385 emitPushArgument(invoker, 0); // load target
1386 emitPushArguments(args, 1); // load args (skip 0: method handle)
1387 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1388 mv.visitLabel(lTo);
1389
1390 // FINALLY_NORMAL:
1391 int index = extendLocalsMap(new Class<?>[]{ returnType });
1392 if (isNonVoid) {
1393 emitStoreInsn(basicReturnType, index);
1394 }
1395 emitPushArgument(invoker, 1); // load cleanup
1396 mv.visitInsn(Opcodes.ACONST_NULL);
1397 if (isNonVoid) {
1398 emitLoadInsn(basicReturnType, index);
1399 }
1400 emitPushArguments(args, 1); // load args (skip 0: method handle)
1401 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1402 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1403
1404 // CATCH:
1405 mv.visitLabel(lCatch);
1406 mv.visitInsn(Opcodes.DUP);
1407
1408 // FINALLY_EXCEPTIONAL:
1409 emitPushArgument(invoker, 1); // load cleanup
1410 mv.visitInsn(Opcodes.SWAP);
1411 if (isNonVoid) {
1412 emitZero(BasicType.basicType(returnType)); // load default for result
1413 }
1414 emitPushArguments(args, 1); // load args (skip 0: method handle)
1415 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1416 if (isNonVoid) {
1417 emitPopInsn(basicReturnType);
1418 }
1419 mv.visitInsn(Opcodes.ATHROW);
1420
1421 // DONE:
1422 mv.visitLabel(lDone);
1423
1424 return result;
1425 }
1426
1427 private void emitPopInsn(BasicType type) {
1428 mv.visitInsn(popInsnOpcode(type));
1429 }
1430
1431 private static int popInsnOpcode(BasicType type) {
1432 switch (type) {
1433 case I_TYPE:
1434 case F_TYPE:
1435 case L_TYPE:
1436 return Opcodes.POP;
1437 case J_TYPE:
1438 case D_TYPE:
1439 return Opcodes.POP2;
1440 default:
1441 throw new InternalError("unknown type: " + type);
1442 }
1443 }
1444
1445 /**
1446 * Emit bytecode for the loop idiom.
1447 * <p>
1448 * The pattern looks like (Cf. MethodHandleImpl.loop):
1449 * <blockquote><pre>{@code
1450 * // a0: BMH
1451 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1452 * // a2: box, a3: unbox
1453 * // a4 (and following): arguments
1454 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1455 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1456 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1457 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1458 * }</pre></blockquote>
1459 * <p>
1460 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1461 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1462 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1463 * <p>
1464 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1465 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1466 * Assume there are {@code C} clauses in the loop.
1467 * <blockquote><pre>{@code
1468 * PREINIT: ALOAD_1
1469 * CHECKCAST LoopClauses
1470 * GETFIELD LoopClauses.clauses
1471 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1472 * INIT: (INIT_SEQ for clause 1)
1473 * ...
1474 * (INIT_SEQ for clause C)
1475 * LOOP: (LOOP_SEQ for clause 1)
1476 * ...
1477 * (LOOP_SEQ for clause C)
1478 * GOTO LOOP
1479 * DONE: ...
1480 * }</pre></blockquote>
1481 * <p>
1482 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1483 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1484 * <blockquote><pre>{@code
1485 * INIT_SEQ_x: ALOAD clauseDataIndex
1486 * ICONST_0
1487 * AALOAD // load the inits array
1488 * ICONST x
1489 * AALOAD // load the init handle for clause x
1490 * load args
1491 * INVOKEVIRTUAL MethodHandle.invokeBasic
1492 * store vx
1493 * }</pre></blockquote>
1494 * <p>
1495 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1496 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1497 * <blockquote><pre>{@code
1498 * LOOP_SEQ_x: ALOAD clauseDataIndex
1499 * ICONST_1
1500 * AALOAD // load the steps array
1501 * ICONST x
1502 * AALOAD // load the step handle for clause x
1503 * load locals
1504 * load args
1505 * INVOKEVIRTUAL MethodHandle.invokeBasic
1506 * store vx
1507 * ALOAD clauseDataIndex
1508 * ICONST_2
1509 * AALOAD // load the preds array
1510 * ICONST x
1511 * AALOAD // load the pred handle for clause x
1512 * load locals
1513 * load args
1514 * INVOKEVIRTUAL MethodHandle.invokeBasic
1515 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1516 * ALOAD clauseDataIndex
1517 * ICONST_3
1518 * AALOAD // load the finis array
1519 * ICONST x
1520 * AALOAD // load the fini handle for clause x
1521 * load locals
1522 * load args
1523 * INVOKEVIRTUAL MethodHandle.invokeBasic
1524 * GOTO DONE // jump beyond end of clauses to return from loop
1525 * }</pre></blockquote>
1526 */
1527 private Name emitLoop(int pos) {
1528 Name args = lambdaForm.names[pos];
1529 Name invoker = lambdaForm.names[pos+1];
1530 Name result = lambdaForm.names[pos+2];
1531
1532 // extract clause and loop-local state types
1533 // find the type info in the loop invocation
1534 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1535 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1536 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1537 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1538 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1539 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1540
1541 final int clauseDataIndex = extendLocalsMap(localTypes);
1542 final int firstLoopStateIndex = clauseDataIndex + 1;
1543
1544 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1545 MethodType loopType = args.function.resolvedHandle().type()
1546 .dropParameterTypes(0,1)
1547 .changeReturnType(returnType);
1548 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1549 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1550 MethodType finiType = loopHandleType;
1551
1552 final int nClauses = loopClauseTypes.length;
1553
1554 // indices to invoker arguments to load method handle arrays
1555 final int inits = 1;
1556 final int steps = 2;
1557 final int preds = 3;
1558 final int finis = 4;
1559
1560 Label lLoop = new Label();
1561 Label lDone = new Label();
1562 Label lNext;
1563
1564 // PREINIT:
1565 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1566 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1567 emitAstoreInsn(clauseDataIndex);
1568
1569 // INIT:
1570 for (int c = 0, state = 0; c < nClauses; ++c) {
1571 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1572 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1573 firstLoopStateIndex);
1574 if (cInitType.returnType() != void.class) {
1575 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1576 ++state;
1577 }
1578 }
1579
1580 // LOOP:
1581 mv.visitLabel(lLoop);
1582
1583 for (int c = 0, state = 0; c < nClauses; ++c) {
1584 lNext = new Label();
1585
1586 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1587 boolean isVoid = stepType.returnType() == void.class;
1588
1589 // invoke loop step
1590 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1591 firstLoopStateIndex);
1592 if (!isVoid) {
1593 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1594 ++state;
1595 }
1596
1597 // invoke loop predicate
1598 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1599 firstLoopStateIndex);
1600 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1601
1602 // invoke fini
1603 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1604 firstLoopStateIndex);
1605 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1606
1607 // this is the beginning of the next loop clause
1608 mv.visitLabel(lNext);
1609 }
1610
1611 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1612
1613 // DONE:
1614 mv.visitLabel(lDone);
1615
1616 return result;
1617 }
1618
1619 private int extendLocalsMap(Class<?>[] types) {
1620 int firstSlot = localsMap.length - 1;
1621 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1622 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1623 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1624 int index = localsMap[firstSlot - 1] + 1;
1625 int lastSlots = 0;
1626 for (int i = 0; i < types.length; ++i) {
1627 localsMap[firstSlot + i] = index;
1628 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1629 index += lastSlots;
1630 }
1631 localsMap[localsMap.length - 1] = index - lastSlots;
1632 return firstSlot;
1633 }
1634
1635 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1636 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1637 int firstLoopStateSlot) {
1638 // load handle for clause
1639 emitPushClauseArray(clauseDataSlot, handles);
1640 emitIconstInsn(clause);
1641 mv.visitInsn(Opcodes.AALOAD);
1642 // load loop state (preceding the other arguments)
1643 if (pushLocalState) {
1644 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1645 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1646 }
1647 }
1648 // load loop args (skip 0: method handle)
1649 emitPushArguments(args, 1);
1650 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1651 }
1652
1653 private void emitPushClauseArray(int clauseDataSlot, int which) {
1654 emitAloadInsn(clauseDataSlot);
1655 emitIconstInsn(which - 1);
1656 mv.visitInsn(Opcodes.AALOAD);
1657 }
1658
1659 private void emitZero(BasicType type) {
1660 switch (type) {
1661 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1662 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1663 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1664 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1665 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1666 default: throw new InternalError("unknown type: " + type);
1667 }
1668 }
1669
1670 private void emitPushArguments(Name args, int start) {
1671 MethodType type = args.function.methodType();
1672 for (int i = start; i < args.arguments.length; i++) {
1673 emitPushArgument(type.parameterType(i), args.arguments[i]);
1674 }
1675 }
1676
1677 private void emitPushArgument(Name name, int paramIndex) {
1678 Object arg = name.arguments[paramIndex];
1679 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1680 emitPushArgument(ptype, arg);
1681 }
1682
1683 private void emitPushArgument(Class<?> ptype, Object arg) {
1684 BasicType bptype = basicType(ptype);
1685 if (arg instanceof Name) {
1686 Name n = (Name) arg;
1687 emitLoadInsn(n.type, n.index());
1688 emitImplicitConversion(n.type, ptype, n);
1689 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1690 emitConst(arg);
1691 } else {
1692 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1693 emitConst(arg);
1694 } else {
1695 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(arg), "Ljava/lang/Object;");
1696 emitImplicitConversion(L_TYPE, ptype, arg);
1697 }
1698 }
1699 }
1700
1701 /**
1702 * Store the name to its local, if necessary.
1703 */
1704 private void emitStoreResult(Name name) {
1705 if (name != null && name.type != V_TYPE) {
1706 // non-void: actually assign
1707 emitStoreInsn(name.type, name.index());
1708 }
1709 }
1710
1711 /**
1712 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1713 */
1714 private void emitReturn(Name onStack) {
1715 // return statement
1716 Class<?> rclass = invokerType.returnType();
1717 BasicType rtype = lambdaForm.returnType();
1718 assert(rtype == basicType(rclass)); // must agree
1719 if (rtype == V_TYPE) {
1720 // void
1721 mv.visitInsn(Opcodes.RETURN);
1722 // it doesn't matter what rclass is; the JVM will discard any value
1723 } else {
1724 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1725
1726 // put return value on the stack if it is not already there
1727 if (rn != onStack) {
1728 emitLoadInsn(rtype, lambdaForm.result);
1729 }
1730
1731 emitImplicitConversion(rtype, rclass, rn);
1732
1733 // generate actual return statement
1734 emitReturnInsn(rtype);
1735 }
1736 }
1737
1738 /**
1739 * Emit a type conversion bytecode casting from "from" to "to".
1740 */
1741 private void emitPrimCast(Wrapper from, Wrapper to) {
1742 // Here's how.
1743 // - indicates forbidden
1744 // <-> indicates implicit
1745 // to ----> boolean byte short char int long float double
1746 // from boolean <-> - - - - - - -
1747 // byte - <-> i2s i2c <-> i2l i2f i2d
1748 // short - i2b <-> i2c <-> i2l i2f i2d
1749 // char - i2b i2s <-> <-> i2l i2f i2d
1750 // int - i2b i2s i2c <-> i2l i2f i2d
1751 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1752 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1753 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1754 if (from == to) {
1755 // no cast required, should be dead code anyway
1756 return;
1757 }
1758 if (from.isSubwordOrInt()) {
1759 // cast from {byte,short,char,int} to anything
1760 emitI2X(to);
1761 } else {
1762 // cast from {long,float,double} to anything
1763 if (to.isSubwordOrInt()) {
1764 // cast to {byte,short,char,int}
1765 emitX2I(from);
1766 if (to.bitWidth() < 32) {
1767 // targets other than int require another conversion
1768 emitI2X(to);
1769 }
1770 } else {
1771 // cast to {long,float,double} - this is verbose
1772 boolean error = false;
1773 switch (from) {
1774 case LONG:
1775 switch (to) {
1776 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1777 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1778 default: error = true; break;
1779 }
1780 break;
1781 case FLOAT:
1782 switch (to) {
1783 case LONG : mv.visitInsn(Opcodes.F2L); break;
1784 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1785 default: error = true; break;
1786 }
1787 break;
1788 case DOUBLE:
1789 switch (to) {
1790 case LONG : mv.visitInsn(Opcodes.D2L); break;
1791 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1792 default: error = true; break;
1793 }
1794 break;
1795 default:
1796 error = true;
1797 break;
1798 }
1799 if (error) {
1800 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1801 }
1802 }
1803 }
1804 }
1805
1806 private void emitI2X(Wrapper type) {
1807 switch (type) {
1808 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1809 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1810 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1811 case INT: /* naught */ break;
1812 case LONG: mv.visitInsn(Opcodes.I2L); break;
1813 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1814 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1815 case BOOLEAN:
1816 // For compatibility with ValueConversions and explicitCastArguments:
1817 mv.visitInsn(Opcodes.ICONST_1);
1818 mv.visitInsn(Opcodes.IAND);
1819 break;
1820 default: throw new InternalError("unknown type: " + type);
1821 }
1822 }
1823
1824 private void emitX2I(Wrapper type) {
1825 switch (type) {
1826 case LONG: mv.visitInsn(Opcodes.L2I); break;
1827 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1828 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1829 default: throw new InternalError("unknown type: " + type);
1830 }
1831 }
1832
1833 /**
1834 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1835 */
1836 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1837 assert(isValidSignature(basicTypeSignature(mt)));
1838 String name = "interpret_"+basicTypeChar(mt.returnType());
1839 MethodType type = mt; // includes leading argument
1840 type = type.changeParameterType(0, MethodHandle.class);
1841 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1842 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1843 }
1844
1845 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1846 classFilePrologue();
1847 methodPrologue();
1848
1849 // Suppress this method in backtraces displayed to the user.
1850 mv.visitAnnotation(HIDDEN_SIG, true);
1851
1852 // Don't inline the interpreter entry.
1853 mv.visitAnnotation(DONTINLINE_SIG, true);
1854
1855 // create parameter array
1856 emitIconstInsn(invokerType.parameterCount());
1857 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1858
1859 // fill parameter array
1860 for (int i = 0; i < invokerType.parameterCount(); i++) {
1861 Class<?> ptype = invokerType.parameterType(i);
1862 mv.visitInsn(Opcodes.DUP);
1863 emitIconstInsn(i);
1864 emitLoadInsn(basicType(ptype), i);
1865 // box if primitive type
1866 if (ptype.isPrimitive()) {
1867 emitBoxing(Wrapper.forPrimitiveType(ptype));
1868 }
1869 mv.visitInsn(Opcodes.AASTORE);
1870 }
1871 // invoke
1872 emitAloadInsn(0);
1873 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1874 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1875 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1876
1877 // maybe unbox
1878 Class<?> rtype = invokerType.returnType();
1879 if (rtype.isPrimitive() && rtype != void.class) {
1880 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1881 }
1882
1883 // return statement
1884 emitReturnInsn(basicType(rtype));
1885
1886 methodEpilogue();
1887 clinit();
1888 bogusMethod(invokerType);
1889
1890 final byte[] classFile = cw.toByteArray();
1891 maybeDump(classFile);
1892 return classFile;
1893 }
1894
1895 /**
1896 * Generate bytecode for a NamedFunction invoker.
1897 */
1898 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1899 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1900 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1901 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1902 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1903 }
1904
1905 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1906 MethodType dstType = typeForm.erasedType();
1907 classFilePrologue();
1908 methodPrologue();
1909
1910 // Suppress this method in backtraces displayed to the user.
1911 mv.visitAnnotation(HIDDEN_SIG, true);
1912
1913 // Force inlining of this invoker method.
1914 mv.visitAnnotation(FORCEINLINE_SIG, true);
1915
1916 // Load receiver
1917 emitAloadInsn(0);
1918
1919 // Load arguments from array
1920 for (int i = 0; i < dstType.parameterCount(); i++) {
1921 emitAloadInsn(1);
1922 emitIconstInsn(i);
1923 mv.visitInsn(Opcodes.AALOAD);
1924
1925 // Maybe unbox
1926 Class<?> dptype = dstType.parameterType(i);
1927 if (dptype.isPrimitive()) {
1928 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1929 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1930 emitUnboxing(srcWrapper);
1931 emitPrimCast(srcWrapper, dstWrapper);
1932 }
1933 }
1934
1935 // Invoke
1936 String targetDesc = dstType.basicType().toMethodDescriptorString();
1937 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1938
1939 // Box primitive types
1940 Class<?> rtype = dstType.returnType();
1941 if (rtype != void.class && rtype.isPrimitive()) {
1942 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1943 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1944 // boolean casts not allowed
1945 emitPrimCast(srcWrapper, dstWrapper);
1946 emitBoxing(dstWrapper);
1947 }
1948
1949 // If the return type is void we return a null reference.
1950 if (rtype == void.class) {
1951 mv.visitInsn(Opcodes.ACONST_NULL);
1952 }
1953 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1954
1955 methodEpilogue();
1956 clinit();
1957 bogusMethod(dstType);
1958
1959 final byte[] classFile = cw.toByteArray();
1960 maybeDump(classFile);
1961 return classFile;
1962 }
1963
1964 /**
1965 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1966 * for debugging purposes.
1967 */
1968 private void bogusMethod(Object os) {
1969 if (DUMP_CLASS_FILES) {
1970 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1971 mv.visitLdcInsn(os.toString());
1972 mv.visitInsn(Opcodes.POP);
1973 mv.visitInsn(Opcodes.RETURN);
1974 mv.visitMaxs(0, 0);
1975 mv.visitEnd();
1976 }
1977 }
1978 }