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 /*
367 * <clinit> to initialize the static final fields with the live class data
368 * LambdaForms can't use condy due to bootstrapping issue.
369 */
370 static void clinit(ClassWriter cw, String className, List<ClassData> classData) {
371 if (classData.isEmpty())
372 return;
373
374 for (ClassData p : classData) {
375 // add the static field
376 FieldVisitor fv = cw.visitField(Opcodes.ACC_STATIC|Opcodes.ACC_FINAL, p.name, p.desc, null, null);
377 fv.visitEnd();
378 }
379
380 MethodVisitor mv = cw.visitMethod(Opcodes.ACC_STATIC, "<clinit>", "()V", null, null);
381 mv.visitCode();
382 mv.visitLdcInsn(Type.getType("L" + className + ";"));
383 mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/invoke/MethodHandleNatives",
384 "classData", "(Ljava/lang/Class;)Ljava/lang/Object;", false);
385 // we should optimize one single element case that does not need to create a List
386 mv.visitTypeInsn(Opcodes.CHECKCAST, "java/util/List");
387 mv.visitVarInsn(Opcodes.ASTORE, 0);
388 int index = 0;
389 for (ClassData p : classData) {
390 // initialize the static field
391 mv.visitVarInsn(Opcodes.ALOAD, 0);
392 emitIconstInsn(mv, index++);
393 mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/List",
394 "get", "(I)Ljava/lang/Object;", true);
395 mv.visitTypeInsn(Opcodes.CHECKCAST, p.desc.substring(1, p.desc.length()-1));
396 mv.visitFieldInsn(Opcodes.PUTSTATIC, className, p.name, p.desc);
397 }
398 mv.visitInsn(Opcodes.RETURN);
399 mv.visitMaxs(2, 1);
400 mv.visitEnd();
401 }
402
403 /*
404 * Low-level emit helpers.
405 */
406 private void emitConst(Object con) {
407 if (con == null) {
408 mv.visitInsn(Opcodes.ACONST_NULL);
409 return;
410 }
411 if (con instanceof Integer) {
412 emitIconstInsn((int) con);
413 return;
414 }
415 if (con instanceof Byte) {
416 emitIconstInsn((byte)con);
417 return;
418 }
419 if (con instanceof Short) {
420 emitIconstInsn((short)con);
421 return;
422 }
423 if (con instanceof Character) {
424 emitIconstInsn((char)con);
425 return;
426 }
427 if (con instanceof Long) {
428 long x = (long) con;
429 short sx = (short)x;
430 if (x == sx) {
431 if (sx >= 0 && sx <= 1) {
432 mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
433 } else {
434 emitIconstInsn((int) x);
435 mv.visitInsn(Opcodes.I2L);
436 }
437 return;
438 }
439 }
440 if (con instanceof Float) {
441 float x = (float) con;
442 short sx = (short)x;
443 if (x == sx) {
444 if (sx >= 0 && sx <= 2) {
445 mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
446 } else {
447 emitIconstInsn((int) x);
448 mv.visitInsn(Opcodes.I2F);
449 }
450 return;
451 }
452 }
453 if (con instanceof Double) {
454 double x = (double) con;
455 short sx = (short)x;
456 if (x == sx) {
457 if (sx >= 0 && sx <= 1) {
458 mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
459 } else {
460 emitIconstInsn((int) x);
461 mv.visitInsn(Opcodes.I2D);
462 }
463 return;
464 }
465 }
466 if (con instanceof Boolean) {
467 emitIconstInsn((boolean) con ? 1 : 0);
468 return;
469 }
470 // fall through:
471 mv.visitLdcInsn(con);
472 }
473
474 private void emitIconstInsn(final int cst) {
475 emitIconstInsn(mv, cst);
476 }
477
478 private static void emitIconstInsn(MethodVisitor mv, int cst) {
479 if (cst >= -1 && cst <= 5) {
480 mv.visitInsn(Opcodes.ICONST_0 + cst);
481 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
482 mv.visitIntInsn(Opcodes.BIPUSH, cst);
483 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
484 mv.visitIntInsn(Opcodes.SIPUSH, cst);
485 } else {
486 mv.visitLdcInsn(cst);
487 }
488 }
489
490 /*
491 * NOTE: These load/store methods use the localsMap to find the correct index!
492 */
493 private void emitLoadInsn(BasicType type, int index) {
494 int opcode = loadInsnOpcode(type);
495 mv.visitVarInsn(opcode, localsMap[index]);
496 }
497
498 private int loadInsnOpcode(BasicType type) throws InternalError {
499 switch (type) {
500 case I_TYPE: return Opcodes.ILOAD;
501 case J_TYPE: return Opcodes.LLOAD;
502 case F_TYPE: return Opcodes.FLOAD;
503 case D_TYPE: return Opcodes.DLOAD;
504 case L_TYPE: return Opcodes.ALOAD;
505 default:
506 throw new InternalError("unknown type: " + type);
507 }
508 }
509 private void emitAloadInsn(int index) {
510 emitLoadInsn(L_TYPE, index);
511 }
512
513 private void emitStoreInsn(BasicType type, int index) {
514 int opcode = storeInsnOpcode(type);
515 mv.visitVarInsn(opcode, localsMap[index]);
516 }
517
518 private int storeInsnOpcode(BasicType type) throws InternalError {
519 switch (type) {
520 case I_TYPE: return Opcodes.ISTORE;
521 case J_TYPE: return Opcodes.LSTORE;
522 case F_TYPE: return Opcodes.FSTORE;
523 case D_TYPE: return Opcodes.DSTORE;
524 case L_TYPE: return Opcodes.ASTORE;
525 default:
526 throw new InternalError("unknown type: " + type);
527 }
528 }
529 private void emitAstoreInsn(int index) {
530 emitStoreInsn(L_TYPE, index);
531 }
532
533 private byte arrayTypeCode(Wrapper elementType) {
534 switch (elementType) {
535 case BOOLEAN: return Opcodes.T_BOOLEAN;
536 case BYTE: return Opcodes.T_BYTE;
537 case CHAR: return Opcodes.T_CHAR;
538 case SHORT: return Opcodes.T_SHORT;
539 case INT: return Opcodes.T_INT;
540 case LONG: return Opcodes.T_LONG;
541 case FLOAT: return Opcodes.T_FLOAT;
542 case DOUBLE: return Opcodes.T_DOUBLE;
543 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
544 default: throw new InternalError();
545 }
546 }
547
548 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
549 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
550 int xas;
551 switch (tcode) {
552 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
553 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
554 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
555 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
556 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
557 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
558 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
559 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
560 case 0: xas = Opcodes.AASTORE; break;
561 default: throw new InternalError();
562 }
563 return xas - Opcodes.AASTORE + aaop;
564 }
565
566 /**
567 * Emit a boxing call.
568 *
569 * @param wrapper primitive type class to box.
570 */
571 private void emitBoxing(Wrapper wrapper) {
572 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
573 String name = "valueOf";
574 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
575 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
576 }
577
578 /**
579 * Emit an unboxing call (plus preceding checkcast).
580 *
581 * @param wrapper wrapper type class to unbox.
582 */
583 private void emitUnboxing(Wrapper wrapper) {
584 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
585 String name = wrapper.primitiveSimpleName() + "Value";
586 String desc = "()" + wrapper.basicTypeChar();
587 emitReferenceCast(wrapper.wrapperType(), null);
588 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
589 }
590
591 /**
592 * Emit an implicit conversion for an argument which must be of the given pclass.
593 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
594 *
595 * @param ptype type of value present on stack
596 * @param pclass type of value required on stack
597 * @param arg compile-time representation of value on stack (Node, constant) or null if none
598 */
599 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
600 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
601 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
602 return; // nothing to do
603 switch (ptype) {
604 case L_TYPE:
605 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
606 if (PROFILE_LEVEL > 0)
607 emitReferenceCast(Object.class, arg);
608 return;
609 }
610 emitReferenceCast(pclass, arg);
611 return;
612 case I_TYPE:
613 if (!VerifyType.isNullConversion(int.class, pclass, false))
614 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
615 return;
616 }
617 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
618 }
619
620 /** Update localClasses type map. Return true if the information is already present. */
621 private boolean assertStaticType(Class<?> cls, Name n) {
622 int local = n.index();
623 Class<?> aclass = localClasses[local];
624 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
625 return true; // type info is already present
626 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
627 localClasses[local] = cls; // type info can be improved
628 }
629 return false;
630 }
631
632 private void emitReferenceCast(Class<?> cls, Object arg) {
633 Name writeBack = null; // local to write back result
634 if (arg instanceof Name) {
635 Name n = (Name) arg;
636 if (lambdaForm.useCount(n) > 1) {
637 // This guy gets used more than once.
638 writeBack = n;
639 if (assertStaticType(cls, n)) {
640 return; // this cast was already performed
641 }
642 }
643 }
644 if (isStaticallyNameable(cls)) {
645 String sig = getInternalName(cls);
646 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
647 } else {
648 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(cls), "Ljava/lang/Class;");
649 mv.visitInsn(Opcodes.SWAP);
650 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
651 if (Object[].class.isAssignableFrom(cls))
652 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
653 else if (PROFILE_LEVEL > 0)
654 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
655 }
656 if (writeBack != null) {
657 mv.visitInsn(Opcodes.DUP);
658 emitAstoreInsn(writeBack.index());
659 }
660 }
661
662 /**
663 * Emits an actual return instruction conforming to the given return type.
664 */
665 private void emitReturnInsn(BasicType type) {
666 int opcode;
667 switch (type) {
668 case I_TYPE: opcode = Opcodes.IRETURN; break;
669 case J_TYPE: opcode = Opcodes.LRETURN; break;
670 case F_TYPE: opcode = Opcodes.FRETURN; break;
671 case D_TYPE: opcode = Opcodes.DRETURN; break;
672 case L_TYPE: opcode = Opcodes.ARETURN; break;
673 case V_TYPE: opcode = Opcodes.RETURN; break;
674 default:
675 throw new InternalError("unknown return type: " + type);
676 }
677 mv.visitInsn(opcode);
678 }
679
680 private String getInternalName(Class<?> c) {
681 if (c == Object.class) return OBJ;
682 else if (c == Object[].class) return OBJARY;
683 else if (c == Class.class) return CLS;
684 else if (c == MethodHandle.class) return MH;
685 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
686
687 if (c == lastClass) {
688 return lastInternalName;
689 }
690 lastClass = c;
691 return lastInternalName = c.getName().replace('.', '/');
692 }
693
694 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
695 MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
696 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
697 if (TRACE_RESOLVE) {
698 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
699 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
700 }
701 return resolvedMember;
702 }
703
704 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
705 if (form.customized != null) {
706 // No pre-generated version for customized LF
707 return null;
708 }
709 String name = form.kind.methodName;
710 switch (form.kind) {
711 case BOUND_REINVOKER: {
712 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key();
713 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
714 }
715 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
716 case ZERO: // fall-through
717 case IDENTITY: {
718 name = name + "_" + form.returnType().basicTypeChar();
719 return resolveFrom(name, invokerType, LambdaForm.Holder.class);
720 }
721 case EXACT_INVOKER: // fall-through
722 case EXACT_LINKER: // fall-through
723 case LINK_TO_CALL_SITE: // fall-through
724 case LINK_TO_TARGET_METHOD: // fall-through
725 case GENERIC_INVOKER: // fall-through
726 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
727 case GET_REFERENCE: // fall-through
728 case GET_BOOLEAN: // fall-through
729 case GET_BYTE: // fall-through
730 case GET_CHAR: // fall-through
731 case GET_SHORT: // fall-through
732 case GET_INT: // fall-through
733 case GET_LONG: // fall-through
734 case GET_FLOAT: // fall-through
735 case GET_DOUBLE: // fall-through
736 case PUT_REFERENCE: // fall-through
737 case PUT_BOOLEAN: // fall-through
738 case PUT_BYTE: // fall-through
739 case PUT_CHAR: // fall-through
740 case PUT_SHORT: // fall-through
741 case PUT_INT: // fall-through
742 case PUT_LONG: // fall-through
743 case PUT_FLOAT: // fall-through
744 case PUT_DOUBLE: // fall-through
745 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through
746 case DIRECT_INVOKE_INTERFACE: // fall-through
747 case DIRECT_INVOKE_SPECIAL: // fall-through
748 case DIRECT_INVOKE_SPECIAL_IFC: // fall-through
749 case DIRECT_INVOKE_STATIC: // fall-through
750 case DIRECT_INVOKE_STATIC_INIT: // fall-through
751 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
752 }
753 return null;
754 }
755
756 /**
757 * Generate customized bytecode for a given LambdaForm.
758 */
759 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
760 MemberName pregenerated = lookupPregenerated(form, invokerType);
761 if (pregenerated != null) return pregenerated; // pre-generated bytecode
762
763 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
764 return g.loadMethod(g.generateCustomizedCodeBytes());
765 }
766
767 /** Generates code to check that actual receiver and LambdaForm matches */
768 private boolean checkActualReceiver() {
769 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
770 mv.visitInsn(Opcodes.DUP);
771 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
772 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
773 return true;
774 }
775
776 static String className(String cn) {
777 assert checkClassName(cn): "Class not found: " + cn;
778 return cn;
779 }
780
781 static boolean checkClassName(String cn) {
782 Type tp = Type.getType(cn);
783 // additional sanity so only valid "L;" descriptors work
784 if (tp.getSort() != Type.OBJECT) {
785 return false;
786 }
787 try {
788 Class<?> c = Class.forName(tp.getClassName(), false, null);
789 return true;
790 } catch (ClassNotFoundException e) {
791 return false;
792 }
793 }
794
795 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
796 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
797 static final String HIDDEN_SIG = className("Ljdk/internal/vm/annotation/Hidden;");
798 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
799 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
800
801 /**
802 * Generate an invoker method for the passed {@link LambdaForm}.
803 */
804 private byte[] generateCustomizedCodeBytes() {
805 classFilePrologue();
806 addMethod();
807 clinit();
808 bogusMethod(lambdaForm);
809
810 final byte[] classFile = toByteArray();
811 maybeDump(classFile);
812 return classFile;
813 }
814
815 void setClassWriter(ClassWriter cw) {
816 this.cw = cw;
817 }
818
819 void addMethod() {
820 methodPrologue();
821
822 // Suppress this method in backtraces displayed to the user.
823 mv.visitAnnotation(HIDDEN_SIG, true);
824
825 // Mark this method as a compiled LambdaForm
826 mv.visitAnnotation(LF_COMPILED_SIG, true);
827
828 if (lambdaForm.forceInline) {
829 // Force inlining of this invoker method.
830 mv.visitAnnotation(FORCEINLINE_SIG, true);
831 } else {
832 mv.visitAnnotation(DONTINLINE_SIG, true);
833 }
834
835 classData(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
836
837 if (lambdaForm.customized != null) {
838 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
839 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
840 // It enables more efficient code generation in some situations, since embedded constants
841 // are compile-time constants for JIT compiler.
842 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(lambdaForm.customized), MH_SIG);
843 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
844 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
845 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
846 }
847
848 // iterate over the form's names, generating bytecode instructions for each
849 // start iterating at the first name following the arguments
850 Name onStack = null;
851 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
852 Name name = lambdaForm.names[i];
853
854 emitStoreResult(onStack);
855 onStack = name; // unless otherwise modified below
856 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
857 switch (intr) {
858 case SELECT_ALTERNATIVE:
859 assert lambdaForm.isSelectAlternative(i);
860 if (PROFILE_GWT) {
861 assert(name.arguments[0] instanceof Name &&
862 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
863 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
864 }
865 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
866 i++; // skip MH.invokeBasic of the selectAlternative result
867 continue;
868 case GUARD_WITH_CATCH:
869 assert lambdaForm.isGuardWithCatch(i);
870 onStack = emitGuardWithCatch(i);
871 i += 2; // jump to the end of GWC idiom
872 continue;
873 case TRY_FINALLY:
874 assert lambdaForm.isTryFinally(i);
875 onStack = emitTryFinally(i);
876 i += 2; // jump to the end of the TF idiom
877 continue;
878 case LOOP:
879 assert lambdaForm.isLoop(i);
880 onStack = emitLoop(i);
881 i += 2; // jump to the end of the LOOP idiom
882 continue;
883 case NEW_ARRAY:
884 Class<?> rtype = name.function.methodType().returnType();
885 if (isStaticallyNameable(rtype)) {
886 emitNewArray(name);
887 continue;
888 }
889 break;
890 case ARRAY_LOAD:
891 emitArrayLoad(name);
892 continue;
893 case ARRAY_STORE:
894 emitArrayStore(name);
895 continue;
896 case ARRAY_LENGTH:
897 emitArrayLength(name);
898 continue;
899 case IDENTITY:
900 assert(name.arguments.length == 1);
901 emitPushArguments(name, 0);
902 continue;
903 case ZERO:
904 assert(name.arguments.length == 0);
905 emitConst(name.type.basicTypeWrapper().zero());
906 continue;
907 case NONE:
908 // no intrinsic associated
909 break;
910 default:
911 throw newInternalError("Unknown intrinsic: "+intr);
912 }
913
914 MemberName member = name.function.member();
915 if (isStaticallyInvocable(member)) {
916 emitStaticInvoke(member, name);
917 } else {
918 emitInvoke(name);
919 }
920 }
921
922 // return statement
923 emitReturn(onStack);
924
925 methodEpilogue();
926 }
927
928 /*
929 * @throws BytecodeGenerationException if something goes wrong when
930 * generating the byte code
931 */
932 private byte[] toByteArray() {
933 try {
934 return cw.toByteArray();
935 } catch (RuntimeException e) {
936 throw new BytecodeGenerationException(e);
937 }
938 }
939
940 @SuppressWarnings("serial")
941 static final class BytecodeGenerationException extends RuntimeException {
942 BytecodeGenerationException(Exception cause) {
943 super(cause);
944 }
945 }
946
947 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
948 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
949 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
950
951 void emitArrayOp(Name name, int arrayOpcode) {
952 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
953 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
954 assert elementType != null;
955 emitPushArguments(name, 0);
956 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
957 Wrapper w = Wrapper.forPrimitiveType(elementType);
958 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
959 }
960 mv.visitInsn(arrayOpcode);
961 }
962
963 /**
964 * Emit an invoke for the given name.
965 */
966 void emitInvoke(Name name) {
967 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
968 if (true) {
969 // push receiver
970 MethodHandle target = name.function.resolvedHandle();
971 assert(target != null) : name.exprString();
972 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(target), MH_SIG);
973 emitReferenceCast(MethodHandle.class, target);
974 } else {
975 // load receiver
976 emitAloadInsn(0);
977 emitReferenceCast(MethodHandle.class, null);
978 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
979 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
980 // TODO more to come
981 }
982
983 // push arguments
984 emitPushArguments(name, 0);
985
986 // invocation
987 MethodType type = name.function.methodType();
988 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
989 }
990
991 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
992 // Sample classes from each package we are willing to bind to statically:
993 java.lang.Object.class,
994 java.util.Arrays.class,
995 jdk.internal.misc.Unsafe.class
996 //MethodHandle.class already covered
997 };
998
999 static boolean isStaticallyInvocable(NamedFunction ... functions) {
1000 for (NamedFunction nf : functions) {
1001 if (!isStaticallyInvocable(nf.member())) {
1002 return false;
1003 }
1004 }
1005 return true;
1006 }
1007
1008 static boolean isStaticallyInvocable(Name name) {
1009 return isStaticallyInvocable(name.function.member());
1010 }
1011
1012 static boolean isStaticallyInvocable(MemberName member) {
1013 if (member == null) return false;
1014 if (member.isConstructor()) return false;
1015 Class<?> cls = member.getDeclaringClass();
1016 // Fast-path non-private members declared by MethodHandles, which is a common
1017 // case
1018 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
1019 assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
1020 return true;
1021 }
1022 if (cls.isArray() || cls.isPrimitive())
1023 return false; // FIXME
1024 if (cls.isAnonymousClass() || cls.isLocalClass())
1025 return false; // inner class of some sort
1026 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
1027 return false; // not on BCP
1028 if (cls.isHidden())
1029 return false;
1030 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: Unsafe::defineAnonymousClass to be removed
1031 return false;
1032 if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
1033 return false;
1034 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
1035 return true; // in java.lang.invoke package
1036 if (member.isPublic() && isStaticallyNameable(cls))
1037 return true;
1038 return false;
1039 }
1040
1041 private static boolean isStaticallyInvocableType(MethodType mtype) {
1042 if (!isStaticallyNameable(mtype.returnType()))
1043 return false;
1044 for (Class<?> ptype : mtype.parameterArray())
1045 if (!isStaticallyNameable(ptype))
1046 return false;
1047 return true;
1048 }
1049
1050 static boolean isStaticallyNameable(Class<?> cls) {
1051 if (cls == Object.class)
1052 return true;
1053 if (MethodHandle.class.isAssignableFrom(cls)) {
1054 assert(!cls.isHidden());
1055 return true;
1056 }
1057 while (cls.isArray())
1058 cls = cls.getComponentType();
1059 if (cls.isPrimitive())
1060 return true; // int[].class, for example
1061 if (cls.isHidden())
1062 return false;
1063 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: Unsafe::defineAnonymousClass to be removed
1064 return false;
1065 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
1066 if (cls.getClassLoader() != Object.class.getClassLoader())
1067 return false;
1068 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
1069 return true;
1070 if (!Modifier.isPublic(cls.getModifiers()))
1071 return false;
1072 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
1073 if (VerifyAccess.isSamePackage(pkgcls, cls))
1074 return true;
1075 }
1076 return false;
1077 }
1078
1079 void emitStaticInvoke(Name name) {
1080 emitStaticInvoke(name.function.member(), name);
1081 }
1082
1083 /**
1084 * Emit an invoke for the given name, using the MemberName directly.
1085 */
1086 void emitStaticInvoke(MemberName member, Name name) {
1087 assert(member.equals(name.function.member()));
1088 Class<?> defc = member.getDeclaringClass();
1089 String cname = getInternalName(defc);
1090 String mname = member.getName();
1091 String mtype;
1092 byte refKind = member.getReferenceKind();
1093 if (refKind == REF_invokeSpecial) {
1094 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1095 assert(member.canBeStaticallyBound()) : member;
1096 refKind = REF_invokeVirtual;
1097 }
1098
1099 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
1100
1101 // push arguments
1102 emitPushArguments(name, 0);
1103
1104 // invocation
1105 if (member.isMethod()) {
1106 mtype = member.getMethodType().toMethodDescriptorString();
1107 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1108 member.getDeclaringClass().isInterface());
1109 } else {
1110 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1111 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1112 }
1113 // Issue a type assertion for the result, so we can avoid casts later.
1114 if (name.type == L_TYPE) {
1115 Class<?> rtype = member.getInvocationType().returnType();
1116 assert(!rtype.isPrimitive());
1117 if (rtype != Object.class && !rtype.isInterface()) {
1118 assertStaticType(rtype, name);
1119 }
1120 }
1121 }
1122
1123 void emitNewArray(Name name) throws InternalError {
1124 Class<?> rtype = name.function.methodType().returnType();
1125 if (name.arguments.length == 0) {
1126 // The array will be a constant.
1127 Object emptyArray;
1128 try {
1129 emptyArray = name.function.resolvedHandle().invoke();
1130 } catch (Throwable ex) {
1131 throw uncaughtException(ex);
1132 }
1133 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1134 assert(emptyArray.getClass() == rtype); // exact typing
1135 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(emptyArray), "Ljava/lang/Object;");
1136 emitReferenceCast(rtype, emptyArray);
1137 return;
1138 }
1139 Class<?> arrayElementType = rtype.getComponentType();
1140 assert(arrayElementType != null);
1141 emitIconstInsn(name.arguments.length);
1142 int xas = Opcodes.AASTORE;
1143 if (!arrayElementType.isPrimitive()) {
1144 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1145 } else {
1146 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1147 xas = arrayInsnOpcode(tc, xas);
1148 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1149 }
1150 // store arguments
1151 for (int i = 0; i < name.arguments.length; i++) {
1152 mv.visitInsn(Opcodes.DUP);
1153 emitIconstInsn(i);
1154 emitPushArgument(name, i);
1155 mv.visitInsn(xas);
1156 }
1157 // the array is left on the stack
1158 assertStaticType(rtype, name);
1159 }
1160 int refKindOpcode(byte refKind) {
1161 switch (refKind) {
1162 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1163 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1164 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1165 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1166 case REF_getField: return Opcodes.GETFIELD;
1167 case REF_putField: return Opcodes.PUTFIELD;
1168 case REF_getStatic: return Opcodes.GETSTATIC;
1169 case REF_putStatic: return Opcodes.PUTSTATIC;
1170 }
1171 throw new InternalError("refKind="+refKind);
1172 }
1173
1174 /**
1175 * Emit bytecode for the selectAlternative idiom.
1176 *
1177 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1178 * <blockquote><pre>{@code
1179 * Lambda(a0:L,a1:I)=>{
1180 * t2:I=foo.test(a1:I);
1181 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1182 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1183 * }</pre></blockquote>
1184 */
1185 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1186 assert isStaticallyInvocable(invokeBasicName);
1187
1188 Name receiver = (Name) invokeBasicName.arguments[0];
1189
1190 Label L_fallback = new Label();
1191 Label L_done = new Label();
1192
1193 // load test result
1194 emitPushArgument(selectAlternativeName, 0);
1195
1196 // if_icmpne L_fallback
1197 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1198
1199 // invoke selectAlternativeName.arguments[1]
1200 Class<?>[] preForkClasses = localClasses.clone();
1201 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1202 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1203 emitStaticInvoke(invokeBasicName);
1204
1205 // goto L_done
1206 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1207
1208 // L_fallback:
1209 mv.visitLabel(L_fallback);
1210
1211 // invoke selectAlternativeName.arguments[2]
1212 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1213 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1214 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1215 emitStaticInvoke(invokeBasicName);
1216
1217 // L_done:
1218 mv.visitLabel(L_done);
1219 // for now do not bother to merge typestate; just reset to the dominator state
1220 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1221
1222 return invokeBasicName; // return what's on stack
1223 }
1224
1225 /**
1226 * Emit bytecode for the guardWithCatch idiom.
1227 *
1228 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1229 * <blockquote><pre>{@code
1230 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1231 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1232 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1233 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1234 * }</pre></blockquote>
1235 *
1236 * It is compiled into bytecode equivalent of the following code:
1237 * <blockquote><pre>{@code
1238 * try {
1239 * return a1.invokeBasic(a6, a7);
1240 * } catch (Throwable e) {
1241 * if (!a2.isInstance(e)) throw e;
1242 * return a3.invokeBasic(ex, a6, a7);
1243 * }}</pre></blockquote>
1244 */
1245 private Name emitGuardWithCatch(int pos) {
1246 Name args = lambdaForm.names[pos];
1247 Name invoker = lambdaForm.names[pos+1];
1248 Name result = lambdaForm.names[pos+2];
1249
1250 Label L_startBlock = new Label();
1251 Label L_endBlock = new Label();
1252 Label L_handler = new Label();
1253 Label L_done = new Label();
1254
1255 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1256 MethodType type = args.function.resolvedHandle().type()
1257 .dropParameterTypes(0,1)
1258 .changeReturnType(returnType);
1259
1260 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1261
1262 // Normal case
1263 mv.visitLabel(L_startBlock);
1264 // load target
1265 emitPushArgument(invoker, 0);
1266 emitPushArguments(args, 1); // skip 1st argument: method handle
1267 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1268 mv.visitLabel(L_endBlock);
1269 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1270
1271 // Exceptional case
1272 mv.visitLabel(L_handler);
1273
1274 // Check exception's type
1275 mv.visitInsn(Opcodes.DUP);
1276 // load exception class
1277 emitPushArgument(invoker, 1);
1278 mv.visitInsn(Opcodes.SWAP);
1279 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1280 Label L_rethrow = new Label();
1281 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1282
1283 // Invoke catcher
1284 // load catcher
1285 emitPushArgument(invoker, 2);
1286 mv.visitInsn(Opcodes.SWAP);
1287 emitPushArguments(args, 1); // skip 1st argument: method handle
1288 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1289 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1290 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1291
1292 mv.visitLabel(L_rethrow);
1293 mv.visitInsn(Opcodes.ATHROW);
1294
1295 mv.visitLabel(L_done);
1296
1297 return result;
1298 }
1299
1300 /**
1301 * Emit bytecode for the tryFinally idiom.
1302 * <p>
1303 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1304 * <blockquote><pre>{@code
1305 * // a0: BMH
1306 * // a1: target, a2: cleanup
1307 * // a3: box, a4: unbox
1308 * // a5 (and following): arguments
1309 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1310 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1311 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1312 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1313 * }</pre></blockquote>
1314 * <p>
1315 * It is compiled into bytecode equivalent to the following code:
1316 * <blockquote><pre>{@code
1317 * Throwable t;
1318 * Object r;
1319 * try {
1320 * r = a1.invokeBasic(a5);
1321 * } catch (Throwable thrown) {
1322 * t = thrown;
1323 * throw t;
1324 * } finally {
1325 * r = a2.invokeBasic(t, r, a5);
1326 * }
1327 * return r;
1328 * }</pre></blockquote>
1329 * <p>
1330 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1331 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1332 * shape if the return type is {@code void}):
1333 * <blockquote><pre>{@code
1334 * TRY: (--)
1335 * load target (-- target)
1336 * load args (-- args... target)
1337 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1338 * FINALLY_NORMAL: (-- r_2nd* r)
1339 * store returned value (--)
1340 * load cleanup (-- cleanup)
1341 * ACONST_NULL (-- t cleanup)
1342 * load returned value (-- r_2nd* r t cleanup)
1343 * load args (-- args... r_2nd* r t cleanup)
1344 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r)
1345 * GOTO DONE
1346 * CATCH: (-- t)
1347 * DUP (-- t t)
1348 * FINALLY_EXCEPTIONAL: (-- t t)
1349 * load cleanup (-- cleanup t t)
1350 * SWAP (-- t cleanup t)
1351 * load default for r (-- r_2nd* r t cleanup t)
1352 * load args (-- args... r_2nd* r t cleanup t)
1353 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r t)
1354 * POP/POP2* (-- t)
1355 * ATHROW
1356 * DONE: (-- r)
1357 * }</pre></blockquote>
1358 * * = depends on whether the return type takes up 2 stack slots.
1359 */
1360 private Name emitTryFinally(int pos) {
1361 Name args = lambdaForm.names[pos];
1362 Name invoker = lambdaForm.names[pos+1];
1363 Name result = lambdaForm.names[pos+2];
1364
1365 Label lFrom = new Label();
1366 Label lTo = new Label();
1367 Label lCatch = new Label();
1368 Label lDone = new Label();
1369
1370 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1371 BasicType basicReturnType = BasicType.basicType(returnType);
1372 boolean isNonVoid = returnType != void.class;
1373
1374 MethodType type = args.function.resolvedHandle().type()
1375 .dropParameterTypes(0,1)
1376 .changeReturnType(returnType);
1377 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1378 if (isNonVoid) {
1379 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1380 }
1381 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1382
1383 // exception handler table
1384 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1385
1386 // TRY:
1387 mv.visitLabel(lFrom);
1388 emitPushArgument(invoker, 0); // load target
1389 emitPushArguments(args, 1); // load args (skip 0: method handle)
1390 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1391 mv.visitLabel(lTo);
1392
1393 // FINALLY_NORMAL:
1394 int index = extendLocalsMap(new Class<?>[]{ returnType });
1395 if (isNonVoid) {
1396 emitStoreInsn(basicReturnType, index);
1397 }
1398 emitPushArgument(invoker, 1); // load cleanup
1399 mv.visitInsn(Opcodes.ACONST_NULL);
1400 if (isNonVoid) {
1401 emitLoadInsn(basicReturnType, index);
1402 }
1403 emitPushArguments(args, 1); // load args (skip 0: method handle)
1404 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1405 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1406
1407 // CATCH:
1408 mv.visitLabel(lCatch);
1409 mv.visitInsn(Opcodes.DUP);
1410
1411 // FINALLY_EXCEPTIONAL:
1412 emitPushArgument(invoker, 1); // load cleanup
1413 mv.visitInsn(Opcodes.SWAP);
1414 if (isNonVoid) {
1415 emitZero(BasicType.basicType(returnType)); // load default for result
1416 }
1417 emitPushArguments(args, 1); // load args (skip 0: method handle)
1418 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1419 if (isNonVoid) {
1420 emitPopInsn(basicReturnType);
1421 }
1422 mv.visitInsn(Opcodes.ATHROW);
1423
1424 // DONE:
1425 mv.visitLabel(lDone);
1426
1427 return result;
1428 }
1429
1430 private void emitPopInsn(BasicType type) {
1431 mv.visitInsn(popInsnOpcode(type));
1432 }
1433
1434 private static int popInsnOpcode(BasicType type) {
1435 switch (type) {
1436 case I_TYPE:
1437 case F_TYPE:
1438 case L_TYPE:
1439 return Opcodes.POP;
1440 case J_TYPE:
1441 case D_TYPE:
1442 return Opcodes.POP2;
1443 default:
1444 throw new InternalError("unknown type: " + type);
1445 }
1446 }
1447
1448 /**
1449 * Emit bytecode for the loop idiom.
1450 * <p>
1451 * The pattern looks like (Cf. MethodHandleImpl.loop):
1452 * <blockquote><pre>{@code
1453 * // a0: BMH
1454 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1455 * // a2: box, a3: unbox
1456 * // a4 (and following): arguments
1457 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1458 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1459 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1460 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1461 * }</pre></blockquote>
1462 * <p>
1463 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1464 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1465 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1466 * <p>
1467 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1468 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1469 * Assume there are {@code C} clauses in the loop.
1470 * <blockquote><pre>{@code
1471 * PREINIT: ALOAD_1
1472 * CHECKCAST LoopClauses
1473 * GETFIELD LoopClauses.clauses
1474 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1475 * INIT: (INIT_SEQ for clause 1)
1476 * ...
1477 * (INIT_SEQ for clause C)
1478 * LOOP: (LOOP_SEQ for clause 1)
1479 * ...
1480 * (LOOP_SEQ for clause C)
1481 * GOTO LOOP
1482 * DONE: ...
1483 * }</pre></blockquote>
1484 * <p>
1485 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1486 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1487 * <blockquote><pre>{@code
1488 * INIT_SEQ_x: ALOAD clauseDataIndex
1489 * ICONST_0
1490 * AALOAD // load the inits array
1491 * ICONST x
1492 * AALOAD // load the init handle for clause x
1493 * load args
1494 * INVOKEVIRTUAL MethodHandle.invokeBasic
1495 * store vx
1496 * }</pre></blockquote>
1497 * <p>
1498 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1499 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1500 * <blockquote><pre>{@code
1501 * LOOP_SEQ_x: ALOAD clauseDataIndex
1502 * ICONST_1
1503 * AALOAD // load the steps array
1504 * ICONST x
1505 * AALOAD // load the step handle for clause x
1506 * load locals
1507 * load args
1508 * INVOKEVIRTUAL MethodHandle.invokeBasic
1509 * store vx
1510 * ALOAD clauseDataIndex
1511 * ICONST_2
1512 * AALOAD // load the preds array
1513 * ICONST x
1514 * AALOAD // load the pred handle for clause x
1515 * load locals
1516 * load args
1517 * INVOKEVIRTUAL MethodHandle.invokeBasic
1518 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1519 * ALOAD clauseDataIndex
1520 * ICONST_3
1521 * AALOAD // load the finis array
1522 * ICONST x
1523 * AALOAD // load the fini handle for clause x
1524 * load locals
1525 * load args
1526 * INVOKEVIRTUAL MethodHandle.invokeBasic
1527 * GOTO DONE // jump beyond end of clauses to return from loop
1528 * }</pre></blockquote>
1529 */
1530 private Name emitLoop(int pos) {
1531 Name args = lambdaForm.names[pos];
1532 Name invoker = lambdaForm.names[pos+1];
1533 Name result = lambdaForm.names[pos+2];
1534
1535 // extract clause and loop-local state types
1536 // find the type info in the loop invocation
1537 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1538 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1539 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1540 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1541 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1542 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1543
1544 final int clauseDataIndex = extendLocalsMap(localTypes);
1545 final int firstLoopStateIndex = clauseDataIndex + 1;
1546
1547 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1548 MethodType loopType = args.function.resolvedHandle().type()
1549 .dropParameterTypes(0,1)
1550 .changeReturnType(returnType);
1551 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1552 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1553 MethodType finiType = loopHandleType;
1554
1555 final int nClauses = loopClauseTypes.length;
1556
1557 // indices to invoker arguments to load method handle arrays
1558 final int inits = 1;
1559 final int steps = 2;
1560 final int preds = 3;
1561 final int finis = 4;
1562
1563 Label lLoop = new Label();
1564 Label lDone = new Label();
1565 Label lNext;
1566
1567 // PREINIT:
1568 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1569 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1570 emitAstoreInsn(clauseDataIndex);
1571
1572 // INIT:
1573 for (int c = 0, state = 0; c < nClauses; ++c) {
1574 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1575 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1576 firstLoopStateIndex);
1577 if (cInitType.returnType() != void.class) {
1578 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1579 ++state;
1580 }
1581 }
1582
1583 // LOOP:
1584 mv.visitLabel(lLoop);
1585
1586 for (int c = 0, state = 0; c < nClauses; ++c) {
1587 lNext = new Label();
1588
1589 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1590 boolean isVoid = stepType.returnType() == void.class;
1591
1592 // invoke loop step
1593 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1594 firstLoopStateIndex);
1595 if (!isVoid) {
1596 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1597 ++state;
1598 }
1599
1600 // invoke loop predicate
1601 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1602 firstLoopStateIndex);
1603 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1604
1605 // invoke fini
1606 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1607 firstLoopStateIndex);
1608 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1609
1610 // this is the beginning of the next loop clause
1611 mv.visitLabel(lNext);
1612 }
1613
1614 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1615
1616 // DONE:
1617 mv.visitLabel(lDone);
1618
1619 return result;
1620 }
1621
1622 private int extendLocalsMap(Class<?>[] types) {
1623 int firstSlot = localsMap.length - 1;
1624 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1625 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1626 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1627 int index = localsMap[firstSlot - 1] + 1;
1628 int lastSlots = 0;
1629 for (int i = 0; i < types.length; ++i) {
1630 localsMap[firstSlot + i] = index;
1631 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1632 index += lastSlots;
1633 }
1634 localsMap[localsMap.length - 1] = index - lastSlots;
1635 return firstSlot;
1636 }
1637
1638 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1639 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1640 int firstLoopStateSlot) {
1641 // load handle for clause
1642 emitPushClauseArray(clauseDataSlot, handles);
1643 emitIconstInsn(clause);
1644 mv.visitInsn(Opcodes.AALOAD);
1645 // load loop state (preceding the other arguments)
1646 if (pushLocalState) {
1647 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1648 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1649 }
1650 }
1651 // load loop args (skip 0: method handle)
1652 emitPushArguments(args, 1);
1653 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1654 }
1655
1656 private void emitPushClauseArray(int clauseDataSlot, int which) {
1657 emitAloadInsn(clauseDataSlot);
1658 emitIconstInsn(which - 1);
1659 mv.visitInsn(Opcodes.AALOAD);
1660 }
1661
1662 private void emitZero(BasicType type) {
1663 switch (type) {
1664 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1665 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1666 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1667 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1668 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1669 default: throw new InternalError("unknown type: " + type);
1670 }
1671 }
1672
1673 private void emitPushArguments(Name args, int start) {
1674 MethodType type = args.function.methodType();
1675 for (int i = start; i < args.arguments.length; i++) {
1676 emitPushArgument(type.parameterType(i), args.arguments[i]);
1677 }
1678 }
1679
1680 private void emitPushArgument(Name name, int paramIndex) {
1681 Object arg = name.arguments[paramIndex];
1682 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1683 emitPushArgument(ptype, arg);
1684 }
1685
1686 private void emitPushArgument(Class<?> ptype, Object arg) {
1687 BasicType bptype = basicType(ptype);
1688 if (arg instanceof Name) {
1689 Name n = (Name) arg;
1690 emitLoadInsn(n.type, n.index());
1691 emitImplicitConversion(n.type, ptype, n);
1692 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1693 emitConst(arg);
1694 } else {
1695 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1696 emitConst(arg);
1697 } else {
1698 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(arg), "Ljava/lang/Object;");
1699 emitImplicitConversion(L_TYPE, ptype, arg);
1700 }
1701 }
1702 }
1703
1704 /**
1705 * Store the name to its local, if necessary.
1706 */
1707 private void emitStoreResult(Name name) {
1708 if (name != null && name.type != V_TYPE) {
1709 // non-void: actually assign
1710 emitStoreInsn(name.type, name.index());
1711 }
1712 }
1713
1714 /**
1715 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1716 */
1717 private void emitReturn(Name onStack) {
1718 // return statement
1719 Class<?> rclass = invokerType.returnType();
1720 BasicType rtype = lambdaForm.returnType();
1721 assert(rtype == basicType(rclass)); // must agree
1722 if (rtype == V_TYPE) {
1723 // void
1724 mv.visitInsn(Opcodes.RETURN);
1725 // it doesn't matter what rclass is; the JVM will discard any value
1726 } else {
1727 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1728
1729 // put return value on the stack if it is not already there
1730 if (rn != onStack) {
1731 emitLoadInsn(rtype, lambdaForm.result);
1732 }
1733
1734 emitImplicitConversion(rtype, rclass, rn);
1735
1736 // generate actual return statement
1737 emitReturnInsn(rtype);
1738 }
1739 }
1740
1741 /**
1742 * Emit a type conversion bytecode casting from "from" to "to".
1743 */
1744 private void emitPrimCast(Wrapper from, Wrapper to) {
1745 // Here's how.
1746 // - indicates forbidden
1747 // <-> indicates implicit
1748 // to ----> boolean byte short char int long float double
1749 // from boolean <-> - - - - - - -
1750 // byte - <-> i2s i2c <-> i2l i2f i2d
1751 // short - i2b <-> i2c <-> i2l i2f i2d
1752 // char - i2b i2s <-> <-> i2l i2f i2d
1753 // int - i2b i2s i2c <-> i2l i2f i2d
1754 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1755 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1756 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1757 if (from == to) {
1758 // no cast required, should be dead code anyway
1759 return;
1760 }
1761 if (from.isSubwordOrInt()) {
1762 // cast from {byte,short,char,int} to anything
1763 emitI2X(to);
1764 } else {
1765 // cast from {long,float,double} to anything
1766 if (to.isSubwordOrInt()) {
1767 // cast to {byte,short,char,int}
1768 emitX2I(from);
1769 if (to.bitWidth() < 32) {
1770 // targets other than int require another conversion
1771 emitI2X(to);
1772 }
1773 } else {
1774 // cast to {long,float,double} - this is verbose
1775 boolean error = false;
1776 switch (from) {
1777 case LONG:
1778 switch (to) {
1779 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1780 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1781 default: error = true; break;
1782 }
1783 break;
1784 case FLOAT:
1785 switch (to) {
1786 case LONG : mv.visitInsn(Opcodes.F2L); break;
1787 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1788 default: error = true; break;
1789 }
1790 break;
1791 case DOUBLE:
1792 switch (to) {
1793 case LONG : mv.visitInsn(Opcodes.D2L); break;
1794 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1795 default: error = true; break;
1796 }
1797 break;
1798 default:
1799 error = true;
1800 break;
1801 }
1802 if (error) {
1803 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1804 }
1805 }
1806 }
1807 }
1808
1809 private void emitI2X(Wrapper type) {
1810 switch (type) {
1811 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1812 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1813 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1814 case INT: /* naught */ break;
1815 case LONG: mv.visitInsn(Opcodes.I2L); break;
1816 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1817 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1818 case BOOLEAN:
1819 // For compatibility with ValueConversions and explicitCastArguments:
1820 mv.visitInsn(Opcodes.ICONST_1);
1821 mv.visitInsn(Opcodes.IAND);
1822 break;
1823 default: throw new InternalError("unknown type: " + type);
1824 }
1825 }
1826
1827 private void emitX2I(Wrapper type) {
1828 switch (type) {
1829 case LONG: mv.visitInsn(Opcodes.L2I); break;
1830 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1831 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1832 default: throw new InternalError("unknown type: " + type);
1833 }
1834 }
1835
1836 /**
1837 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1838 */
1839 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1840 assert(isValidSignature(basicTypeSignature(mt)));
1841 String name = "interpret_"+basicTypeChar(mt.returnType());
1842 MethodType type = mt; // includes leading argument
1843 type = type.changeParameterType(0, MethodHandle.class);
1844 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1845 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1846 }
1847
1848 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1849 classFilePrologue();
1850 methodPrologue();
1851
1852 // Suppress this method in backtraces displayed to the user.
1853 mv.visitAnnotation(HIDDEN_SIG, true);
1854
1855 // Don't inline the interpreter entry.
1856 mv.visitAnnotation(DONTINLINE_SIG, true);
1857
1858 // create parameter array
1859 emitIconstInsn(invokerType.parameterCount());
1860 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1861
1862 // fill parameter array
1863 for (int i = 0; i < invokerType.parameterCount(); i++) {
1864 Class<?> ptype = invokerType.parameterType(i);
1865 mv.visitInsn(Opcodes.DUP);
1866 emitIconstInsn(i);
1867 emitLoadInsn(basicType(ptype), i);
1868 // box if primitive type
1869 if (ptype.isPrimitive()) {
1870 emitBoxing(Wrapper.forPrimitiveType(ptype));
1871 }
1872 mv.visitInsn(Opcodes.AASTORE);
1873 }
1874 // invoke
1875 emitAloadInsn(0);
1876 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1877 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1878 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1879
1880 // maybe unbox
1881 Class<?> rtype = invokerType.returnType();
1882 if (rtype.isPrimitive() && rtype != void.class) {
1883 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1884 }
1885
1886 // return statement
1887 emitReturnInsn(basicType(rtype));
1888
1889 methodEpilogue();
1890 clinit();
1891 bogusMethod(invokerType);
1892
1893 final byte[] classFile = cw.toByteArray();
1894 maybeDump(classFile);
1895 return classFile;
1896 }
1897
1898 /**
1899 * Generate bytecode for a NamedFunction invoker.
1900 */
1901 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1902 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1903 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1904 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1905 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1906 }
1907
1908 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1909 MethodType dstType = typeForm.erasedType();
1910 classFilePrologue();
1911 methodPrologue();
1912
1913 // Suppress this method in backtraces displayed to the user.
1914 mv.visitAnnotation(HIDDEN_SIG, true);
1915
1916 // Force inlining of this invoker method.
1917 mv.visitAnnotation(FORCEINLINE_SIG, true);
1918
1919 // Load receiver
1920 emitAloadInsn(0);
1921
1922 // Load arguments from array
1923 for (int i = 0; i < dstType.parameterCount(); i++) {
1924 emitAloadInsn(1);
1925 emitIconstInsn(i);
1926 mv.visitInsn(Opcodes.AALOAD);
1927
1928 // Maybe unbox
1929 Class<?> dptype = dstType.parameterType(i);
1930 if (dptype.isPrimitive()) {
1931 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1932 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1933 emitUnboxing(srcWrapper);
1934 emitPrimCast(srcWrapper, dstWrapper);
1935 }
1936 }
1937
1938 // Invoke
1939 String targetDesc = dstType.basicType().toMethodDescriptorString();
1940 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1941
1942 // Box primitive types
1943 Class<?> rtype = dstType.returnType();
1944 if (rtype != void.class && rtype.isPrimitive()) {
1945 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1946 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1947 // boolean casts not allowed
1948 emitPrimCast(srcWrapper, dstWrapper);
1949 emitBoxing(dstWrapper);
1950 }
1951
1952 // If the return type is void we return a null reference.
1953 if (rtype == void.class) {
1954 mv.visitInsn(Opcodes.ACONST_NULL);
1955 }
1956 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1957
1958 methodEpilogue();
1959 clinit();
1960 bogusMethod(dstType);
1961
1962 final byte[] classFile = cw.toByteArray();
1963 maybeDump(classFile);
1964 return classFile;
1965 }
1966
1967 /**
1968 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1969 * for debugging purposes.
1970 */
1971 private void bogusMethod(Object os) {
1972 if (DUMP_CLASS_FILES) {
1973 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1974 mv.visitLdcInsn(os.toString());
1975 mv.visitInsn(Opcodes.POP);
1976 mv.visitInsn(Opcodes.RETURN);
1977 mv.visitMaxs(0, 0);
1978 mv.visitEnd();
1979 }
1980 }
1981 }