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.Set;
48 import java.util.stream.Stream;
49
50 import static java.lang.invoke.LambdaForm.BasicType;
51 import static java.lang.invoke.LambdaForm.BasicType.*;
52 import static java.lang.invoke.LambdaForm.*;
53 import static java.lang.invoke.MethodHandleNatives.Constants.*;
54 import static java.lang.invoke.MethodHandleStatics.*;
55 import static java.lang.invoke.MethodHandles.Lookup.*;
56
57 /**
58 * Code generation backend for LambdaForm.
59 * <p>
60 * @author John Rose, JSR 292 EG
61 */
62 class InvokerBytecodeGenerator {
63 /** Define class names for convenience. */
64 private static final String MH = "java/lang/invoke/MethodHandle";
65 private static final String MHI = "java/lang/invoke/MethodHandleImpl";
66 private static final String LF = "java/lang/invoke/LambdaForm";
67 private static final String LFN = "java/lang/invoke/LambdaForm$Name";
68 private static final String CLS = "java/lang/Class";
69 private static final String OBJ = "java/lang/Object";
70 private static final String OBJARY = "[Ljava/lang/Object;";
71
72 private static final String LOOP_CLAUSES = MHI + "$LoopClauses";
73 private static final String MHARY2 = "[[L" + MH + ";";
74 private static final String MH_SIG = "L" + MH + ";";
75
76
77 private static final String LF_SIG = "L" + LF + ";";
78 private static final String LFN_SIG = "L" + LFN + ";";
79 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
80 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V";
81 private static final String CLASS_PREFIX = LF + "$";
82 private static final String SOURCE_PREFIX = "LambdaForm$";
83
84 /** Name of its super class*/
85 static final String INVOKER_SUPER_NAME = OBJ;
86
87 /** Name of new class */
88 private final String className;
89
90 private final LambdaForm lambdaForm;
91 private final String invokerName;
92 private final MethodType invokerType;
93
94 /** Info about local variables in compiled lambda form */
95 private int[] localsMap; // index
96 private Class<?>[] localClasses; // type
97
98 /** ASM bytecode generation. */
99 private ClassWriter cw;
100 private MethodVisitor mv;
101 private final List<ClassData> classData = new ArrayList<>();
102
103 /** Single element internal class name lookup cache. */
104 private Class<?> lastClass;
105 private String lastInternalName;
106
107 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
108 private static final Class<?> HOST_CLASS = LambdaForm.class;
109 private static final MethodHandles.Lookup LOOKUP = lookup();
110
111 private static MethodHandles.Lookup lookup() {
112 try {
113 return MethodHandles.privateLookupIn(HOST_CLASS, IMPL_LOOKUP);
114 } catch (IllegalAccessException e) {
115 throw newInternalError(e);
116 }
117 }
118
119 /** Main constructor; other constructors delegate to this one. */
120 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
121 String className, String invokerName, MethodType invokerType) {
122 int p = invokerName.indexOf('.');
123 if (p > -1) {
124 className = invokerName.substring(0, p);
125 invokerName = invokerName.substring(p + 1);
126 }
127 if (DUMP_CLASS_FILES) {
128 className = makeDumpableClassName(className);
129 }
130 this.className = className;
131 this.lambdaForm = lambdaForm;
132 this.invokerName = invokerName;
133 this.invokerType = invokerType;
134 this.localsMap = new int[localsMapSize+1]; // last entry of localsMap is count of allocated local slots
135 this.localClasses = new Class<?>[localsMapSize+1];
136 }
137
138 /** For generating LambdaForm interpreter entry points. */
139 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
140 this(null, invokerType.parameterCount(),
141 className, invokerName, invokerType);
142 MethodType mt = invokerType.erase();
143 // Create an array to map name indexes to locals indexes.
144 localsMap[0] = 0; // localsMap has at least one element
145 for (int i = 1, index = 0; i < localsMap.length; i++) {
146 Wrapper w = Wrapper.forBasicType(mt.parameterType(i - 1));
147 index += w.stackSlots();
148 localsMap[i] = index;
149 }
150 }
151
152 /** For generating customized code for a single LambdaForm. */
153 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
154 this(className, form.lambdaName(), form, invokerType);
155 }
156
157 /** For generating customized code for a single LambdaForm. */
158 InvokerBytecodeGenerator(String className, String invokerName,
159 LambdaForm form, MethodType invokerType) {
160 this(form, form.names.length,
161 className, invokerName, invokerType);
162 // Create an array to map name indexes to locals indexes.
163 Name[] names = form.names;
164 for (int i = 0, index = 0; i < localsMap.length; i++) {
165 localsMap[i] = index;
166 if (i < names.length) {
167 BasicType type = names[i].type();
168 index += type.basicTypeSlots();
169 }
170 }
171 }
172
173 /** instance counters for dumped classes */
174 private static final HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
175 /** debugging flag for saving generated class files */
176 private static final File DUMP_CLASS_FILES_DIR;
177
178 static {
179 if (DUMP_CLASS_FILES) {
180 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
181 try {
182 File dumpDir = new File("DUMP_CLASS_FILES");
183 if (!dumpDir.exists()) {
184 dumpDir.mkdirs();
185 }
186 DUMP_CLASS_FILES_DIR = dumpDir;
187 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
188 } catch (Exception e) {
189 throw newInternalError(e);
190 }
191 } else {
192 DUMP_CLASS_FILES_COUNTERS = null;
193 DUMP_CLASS_FILES_DIR = null;
194 }
195 }
196
197 private void maybeDump(final byte[] classFile) {
198 if (DUMP_CLASS_FILES) {
199 maybeDump(CLASS_PREFIX + className, classFile);
200 }
201 }
202
203 // Also used from BoundMethodHandle
204 static void maybeDump(final String className, final byte[] classFile) {
205 if (DUMP_CLASS_FILES) {
206 java.security.AccessController.doPrivileged(
207 new java.security.PrivilegedAction<>() {
208 public Void run() {
209 try {
210 String dumpName = className.replace('.','/');
211 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
212 System.out.println("dump: " + dumpFile);
213 dumpFile.getParentFile().mkdirs();
214 FileOutputStream file = new FileOutputStream(dumpFile);
215 file.write(classFile);
216 file.close();
217 return null;
218 } catch (IOException ex) {
219 throw newInternalError(ex);
220 }
221 }
222 });
223 }
224 }
225
226 private static String makeDumpableClassName(String className) {
227 Integer ctr;
228 synchronized (DUMP_CLASS_FILES_COUNTERS) {
229 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
230 if (ctr == null) ctr = 0;
231 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
232 }
233 String sfx = ctr.toString();
234 while (sfx.length() < 3)
235 sfx = "0"+sfx;
236 className += sfx;
237 return className;
238 }
239
240 public static class ClassData {
241 final String name;
242 final String desc;
243 final Object value;
244
245 ClassData(String name, String desc, Object value) {
246 this.name = name;
247 this.desc = desc;
248 this.value = value;
249 }
250
251 public String name() { return name; }
252 public String toString() {
253 return name + ",value="+value;
254 }
255 }
256
257 String classData(Object arg) {
258 String desc;
259 if (arg instanceof Class) {
260 desc = "Ljava/lang/Class;";
261 } else if (arg instanceof MethodHandle) {
262 desc = MH_SIG;
263 } else if (arg instanceof LambdaForm) {
264 desc = LF_SIG;
265 } else {
266 desc = "Ljava/lang/Object;";
267 }
268
269 Class<?> c = arg.getClass();
270 while (c.isArray()) {
271 c = c.getComponentType();
272 }
273 // unique static variable name
274 String name = "_DATA_" + c.getSimpleName() + "_" + classData.size();
275 ClassData cd = new ClassData(name, desc, arg);
276 classData.add(cd);
277 return cd.name();
278 }
279
280 List<Object> classDataValues() {
281 Object[] data = new Object[classData.size()];
282 for (int i = 0; i < classData.size(); i++) {
283 data[i] = classData.get(i).value;
284 }
285 return List.of(data);
286 }
287
288 private static String debugString(Object arg) {
289 if (arg instanceof MethodHandle) {
290 MethodHandle mh = (MethodHandle) arg;
291 MemberName member = mh.internalMemberName();
292 if (member != null)
293 return member.toString();
294 return mh.debugString();
295 }
296 return arg.toString();
297 }
298
299 /**
300 * Extract the number of constant pool entries from a given class file.
301 *
302 * @param classFile the bytes of the class file in question.
303 * @return the number of entries in the constant pool.
304 */
305 private static int getConstantPoolSize(byte[] classFile) {
306 // The first few bytes:
307 // u4 magic;
308 // u2 minor_version;
309 // u2 major_version;
310 // u2 constant_pool_count;
311 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
312 }
313
314 /**
315 * Extract the MemberName of a newly-defined method.
316 */
317 private MemberName loadMethod(byte[] classFile) {
318 Class<?> invokerClass = LOOKUP.makeHiddenClassDefiner(classFile, Set.of(ClassOption.WEAK))
319 .defineClass(true, classDataValues());
320 return resolveInvokerMember(invokerClass, invokerName, invokerType);
321 }
322
323 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
324 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
325 try {
326 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
327 } catch (ReflectiveOperationException e) {
328 throw newInternalError(e);
329 }
330 return member;
331 }
332
333 /**
334 * Set up class file generation.
335 */
336 private ClassWriter classFilePrologue() {
337 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
338 ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
339 setClassWriter(cw);
340 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER,
341 CLASS_PREFIX + className, null, INVOKER_SUPER_NAME, null);
342 cw.visitSource(SOURCE_PREFIX + className, null);
343 return cw;
344 }
345
346 private void methodPrologue() {
347 String invokerDesc = invokerType.toMethodDescriptorString();
348 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
349 }
350
351 /**
352 * Tear down class file generation.
353 */
354 private void methodEpilogue() {
355 mv.visitMaxs(0, 0);
356 mv.visitEnd();
357 }
358
359 private String className() {
360 return CLASS_PREFIX + className;
361 }
362
363 private void clinit() {
364 clinit(cw, className(), classData);
365 }
366
367 static void clinit(ClassWriter cw, String className, List<ClassData> classData) {
368 if (classData.isEmpty())
369 return;
370
371 for (ClassData p : classData) {
372 // add the static field
373 FieldVisitor fv = cw.visitField(Opcodes.ACC_STATIC|Opcodes.ACC_FINAL, p.name, p.desc, null, null);
374 fv.visitEnd();
375 }
376
377 MethodVisitor mv = cw.visitMethod(Opcodes.ACC_STATIC, "<clinit>", "()V", null, null);
378 mv.visitCode();
379 // bootstrapping issue if using condy
380 mv.visitLdcInsn(Type.getType("L" + className + ";"));
381 mv.visitMethodInsn(Opcodes.INVOKESTATIC, "java/lang/invoke/MethodHandleNatives",
382 "classData", "(Ljava/lang/Class;)Ljava/lang/Object;", false);
383 // we should optimize one single element case that does not need to create a List
384 mv.visitTypeInsn(Opcodes.CHECKCAST, "java/util/List");
385 mv.visitVarInsn(Opcodes.ASTORE, 0);
386 int index = 0;
387 for (ClassData p : classData) {
388 // initialize the static field
389 mv.visitVarInsn(Opcodes.ALOAD, 0);
390 emitIconstInsn(mv, index++);
391 mv.visitMethodInsn(Opcodes.INVOKEINTERFACE, "java/util/List",
392 "get", "(I)Ljava/lang/Object;", true);
393 mv.visitTypeInsn(Opcodes.CHECKCAST, p.desc.substring(1, p.desc.length()-1));
394 mv.visitFieldInsn(Opcodes.PUTSTATIC, className, p.name, p.desc);
395 }
396 mv.visitInsn(Opcodes.RETURN);
397 mv.visitMaxs(2, 1);
398 mv.visitEnd();
399 }
400
401 /*
402 * Low-level emit helpers.
403 */
404 private void emitConst(Object con) {
405 if (con == null) {
406 mv.visitInsn(Opcodes.ACONST_NULL);
407 return;
408 }
409 if (con instanceof Integer) {
410 emitIconstInsn((int) con);
411 return;
412 }
413 if (con instanceof Byte) {
414 emitIconstInsn((byte)con);
415 return;
416 }
417 if (con instanceof Short) {
418 emitIconstInsn((short)con);
419 return;
420 }
421 if (con instanceof Character) {
422 emitIconstInsn((char)con);
423 return;
424 }
425 if (con instanceof Long) {
426 long x = (long) con;
427 short sx = (short)x;
428 if (x == sx) {
429 if (sx >= 0 && sx <= 1) {
430 mv.visitInsn(Opcodes.LCONST_0 + (int) sx);
431 } else {
432 emitIconstInsn((int) x);
433 mv.visitInsn(Opcodes.I2L);
434 }
435 return;
436 }
437 }
438 if (con instanceof Float) {
439 float x = (float) con;
440 short sx = (short)x;
441 if (x == sx) {
442 if (sx >= 0 && sx <= 2) {
443 mv.visitInsn(Opcodes.FCONST_0 + (int) sx);
444 } else {
445 emitIconstInsn((int) x);
446 mv.visitInsn(Opcodes.I2F);
447 }
448 return;
449 }
450 }
451 if (con instanceof Double) {
452 double x = (double) con;
453 short sx = (short)x;
454 if (x == sx) {
455 if (sx >= 0 && sx <= 1) {
456 mv.visitInsn(Opcodes.DCONST_0 + (int) sx);
457 } else {
458 emitIconstInsn((int) x);
459 mv.visitInsn(Opcodes.I2D);
460 }
461 return;
462 }
463 }
464 if (con instanceof Boolean) {
465 emitIconstInsn((boolean) con ? 1 : 0);
466 return;
467 }
468 // fall through:
469 mv.visitLdcInsn(con);
470 }
471
472 private void emitIconstInsn(final int cst) {
473 emitIconstInsn(mv, cst);
474 }
475
476 private static void emitIconstInsn(MethodVisitor mv, int cst) {
477 if (cst >= -1 && cst <= 5) {
478 mv.visitInsn(Opcodes.ICONST_0 + cst);
479 } else if (cst >= Byte.MIN_VALUE && cst <= Byte.MAX_VALUE) {
480 mv.visitIntInsn(Opcodes.BIPUSH, cst);
481 } else if (cst >= Short.MIN_VALUE && cst <= Short.MAX_VALUE) {
482 mv.visitIntInsn(Opcodes.SIPUSH, cst);
483 } else {
484 mv.visitLdcInsn(cst);
485 }
486 }
487
488 /*
489 * NOTE: These load/store methods use the localsMap to find the correct index!
490 */
491 private void emitLoadInsn(BasicType type, int index) {
492 int opcode = loadInsnOpcode(type);
493 mv.visitVarInsn(opcode, localsMap[index]);
494 }
495
496 private int loadInsnOpcode(BasicType type) throws InternalError {
497 switch (type) {
498 case I_TYPE: return Opcodes.ILOAD;
499 case J_TYPE: return Opcodes.LLOAD;
500 case F_TYPE: return Opcodes.FLOAD;
501 case D_TYPE: return Opcodes.DLOAD;
502 case L_TYPE: return Opcodes.ALOAD;
503 default:
504 throw new InternalError("unknown type: " + type);
505 }
506 }
507 private void emitAloadInsn(int index) {
508 emitLoadInsn(L_TYPE, index);
509 }
510
511 private void emitStoreInsn(BasicType type, int index) {
512 int opcode = storeInsnOpcode(type);
513 mv.visitVarInsn(opcode, localsMap[index]);
514 }
515
516 private int storeInsnOpcode(BasicType type) throws InternalError {
517 switch (type) {
518 case I_TYPE: return Opcodes.ISTORE;
519 case J_TYPE: return Opcodes.LSTORE;
520 case F_TYPE: return Opcodes.FSTORE;
521 case D_TYPE: return Opcodes.DSTORE;
522 case L_TYPE: return Opcodes.ASTORE;
523 default:
524 throw new InternalError("unknown type: " + type);
525 }
526 }
527 private void emitAstoreInsn(int index) {
528 emitStoreInsn(L_TYPE, index);
529 }
530
531 private byte arrayTypeCode(Wrapper elementType) {
532 switch (elementType) {
533 case BOOLEAN: return Opcodes.T_BOOLEAN;
534 case BYTE: return Opcodes.T_BYTE;
535 case CHAR: return Opcodes.T_CHAR;
536 case SHORT: return Opcodes.T_SHORT;
537 case INT: return Opcodes.T_INT;
538 case LONG: return Opcodes.T_LONG;
539 case FLOAT: return Opcodes.T_FLOAT;
540 case DOUBLE: return Opcodes.T_DOUBLE;
541 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
542 default: throw new InternalError();
543 }
544 }
545
546 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
547 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
548 int xas;
549 switch (tcode) {
550 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
551 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
552 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
553 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
554 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
555 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
556 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
557 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
558 case 0: xas = Opcodes.AASTORE; break;
559 default: throw new InternalError();
560 }
561 return xas - Opcodes.AASTORE + aaop;
562 }
563
564 /**
565 * Emit a boxing call.
566 *
567 * @param wrapper primitive type class to box.
568 */
569 private void emitBoxing(Wrapper wrapper) {
570 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
571 String name = "valueOf";
572 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
573 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
574 }
575
576 /**
577 * Emit an unboxing call (plus preceding checkcast).
578 *
579 * @param wrapper wrapper type class to unbox.
580 */
581 private void emitUnboxing(Wrapper wrapper) {
582 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
583 String name = wrapper.primitiveSimpleName() + "Value";
584 String desc = "()" + wrapper.basicTypeChar();
585 emitReferenceCast(wrapper.wrapperType(), null);
586 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
587 }
588
589 /**
590 * Emit an implicit conversion for an argument which must be of the given pclass.
591 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
592 *
593 * @param ptype type of value present on stack
594 * @param pclass type of value required on stack
595 * @param arg compile-time representation of value on stack (Node, constant) or null if none
596 */
597 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
598 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
599 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
600 return; // nothing to do
601 switch (ptype) {
602 case L_TYPE:
603 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
604 if (PROFILE_LEVEL > 0)
605 emitReferenceCast(Object.class, arg);
606 return;
607 }
608 emitReferenceCast(pclass, arg);
609 return;
610 case I_TYPE:
611 if (!VerifyType.isNullConversion(int.class, pclass, false))
612 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
613 return;
614 }
615 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
616 }
617
618 /** Update localClasses type map. Return true if the information is already present. */
619 private boolean assertStaticType(Class<?> cls, Name n) {
620 int local = n.index();
621 Class<?> aclass = localClasses[local];
622 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
623 return true; // type info is already present
624 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
625 localClasses[local] = cls; // type info can be improved
626 }
627 return false;
628 }
629
630 private void emitReferenceCast(Class<?> cls, Object arg) {
631 Name writeBack = null; // local to write back result
632 if (arg instanceof Name) {
633 Name n = (Name) arg;
634 if (lambdaForm.useCount(n) > 1) {
635 // This guy gets used more than once.
636 writeBack = n;
637 if (assertStaticType(cls, n)) {
638 return; // this cast was already performed
639 }
640 }
641 }
642 if (isStaticallyNameable(cls)) {
643 String sig = getInternalName(cls);
644 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
645 } else {
646 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(cls), "Ljava/lang/Class;");
647 mv.visitInsn(Opcodes.SWAP);
648 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG, false);
649 if (Object[].class.isAssignableFrom(cls))
650 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
651 else if (PROFILE_LEVEL > 0)
652 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
653 }
654 if (writeBack != null) {
655 mv.visitInsn(Opcodes.DUP);
656 emitAstoreInsn(writeBack.index());
657 }
658 }
659
660 /**
661 * Emits an actual return instruction conforming to the given return type.
662 */
663 private void emitReturnInsn(BasicType type) {
664 int opcode;
665 switch (type) {
666 case I_TYPE: opcode = Opcodes.IRETURN; break;
667 case J_TYPE: opcode = Opcodes.LRETURN; break;
668 case F_TYPE: opcode = Opcodes.FRETURN; break;
669 case D_TYPE: opcode = Opcodes.DRETURN; break;
670 case L_TYPE: opcode = Opcodes.ARETURN; break;
671 case V_TYPE: opcode = Opcodes.RETURN; break;
672 default:
673 throw new InternalError("unknown return type: " + type);
674 }
675 mv.visitInsn(opcode);
676 }
677
678 private String getInternalName(Class<?> c) {
679 if (c == Object.class) return OBJ;
680 else if (c == Object[].class) return OBJARY;
681 else if (c == Class.class) return CLS;
682 else if (c == MethodHandle.class) return MH;
683 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
684
685 if (c == lastClass) {
686 return lastInternalName;
687 }
688 lastClass = c;
689 return lastInternalName = c.getName().replace('.', '/');
690 }
691
692 private static MemberName resolveFrom(String name, MethodType type, Class<?> holder) {
693 MemberName member = new MemberName(holder, name, type, REF_invokeStatic);
694 MemberName resolvedMember = MemberName.getFactory().resolveOrNull(REF_invokeStatic, member, holder);
695 if (TRACE_RESOLVE) {
696 System.out.println("[LF_RESOLVE] " + holder.getName() + " " + name + " " +
697 shortenSignature(basicTypeSignature(type)) + (resolvedMember != null ? " (success)" : " (fail)") );
698 }
699 return resolvedMember;
700 }
701
702 private static MemberName lookupPregenerated(LambdaForm form, MethodType invokerType) {
703 if (form.customized != null) {
704 // No pre-generated version for customized LF
705 return null;
706 }
707 String name = form.kind.methodName;
708 switch (form.kind) {
709 case BOUND_REINVOKER: {
710 name = name + "_" + BoundMethodHandle.speciesDataFor(form).key();
711 return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
712 }
713 case DELEGATE: return resolveFrom(name, invokerType, DelegatingMethodHandle.Holder.class);
714 case ZERO: // fall-through
715 case IDENTITY: {
716 name = name + "_" + form.returnType().basicTypeChar();
717 return resolveFrom(name, invokerType, LambdaForm.Holder.class);
718 }
719 case EXACT_INVOKER: // fall-through
720 case EXACT_LINKER: // fall-through
721 case LINK_TO_CALL_SITE: // fall-through
722 case LINK_TO_TARGET_METHOD: // fall-through
723 case GENERIC_INVOKER: // fall-through
724 case GENERIC_LINKER: return resolveFrom(name, invokerType.basicType(), Invokers.Holder.class);
725 case GET_REFERENCE: // fall-through
726 case GET_BOOLEAN: // fall-through
727 case GET_BYTE: // fall-through
728 case GET_CHAR: // fall-through
729 case GET_SHORT: // fall-through
730 case GET_INT: // fall-through
731 case GET_LONG: // fall-through
732 case GET_FLOAT: // fall-through
733 case GET_DOUBLE: // fall-through
734 case PUT_REFERENCE: // fall-through
735 case PUT_BOOLEAN: // fall-through
736 case PUT_BYTE: // fall-through
737 case PUT_CHAR: // fall-through
738 case PUT_SHORT: // fall-through
739 case PUT_INT: // fall-through
740 case PUT_LONG: // fall-through
741 case PUT_FLOAT: // fall-through
742 case PUT_DOUBLE: // fall-through
743 case DIRECT_NEW_INVOKE_SPECIAL: // fall-through
744 case DIRECT_INVOKE_INTERFACE: // fall-through
745 case DIRECT_INVOKE_SPECIAL: // fall-through
746 case DIRECT_INVOKE_SPECIAL_IFC: // fall-through
747 case DIRECT_INVOKE_STATIC: // fall-through
748 case DIRECT_INVOKE_STATIC_INIT: // fall-through
749 case DIRECT_INVOKE_VIRTUAL: return resolveFrom(name, invokerType, DirectMethodHandle.Holder.class);
750 }
751 return null;
752 }
753
754 /**
755 * Generate customized bytecode for a given LambdaForm.
756 */
757 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
758 MemberName pregenerated = lookupPregenerated(form, invokerType);
759 if (pregenerated != null) return pregenerated; // pre-generated bytecode
760
761 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
762 return g.loadMethod(g.generateCustomizedCodeBytes());
763 }
764
765 /** Generates code to check that actual receiver and LambdaForm matches */
766 private boolean checkActualReceiver() {
767 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
768 mv.visitInsn(Opcodes.DUP);
769 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
770 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
771 return true;
772 }
773
774 static String className(String cn) {
775 assert checkClassName(cn): "Class not found: " + cn;
776 return cn;
777 }
778
779 static boolean checkClassName(String cn) {
780 Type tp = Type.getType(cn);
781 // additional sanity so only valid "L;" descriptors work
782 if (tp.getSort() != Type.OBJECT) {
783 return false;
784 }
785 try {
786 Class<?> c = Class.forName(tp.getClassName(), false, null);
787 return true;
788 } catch (ClassNotFoundException e) {
789 return false;
790 }
791 }
792
793 static final String DONTINLINE_SIG = className("Ljdk/internal/vm/annotation/DontInline;");
794 static final String FORCEINLINE_SIG = className("Ljdk/internal/vm/annotation/ForceInline;");
795 static final String HIDDEN_SIG = className("Ljdk/internal/vm/annotation/Hidden;");
796 static final String INJECTEDPROFILE_SIG = className("Ljava/lang/invoke/InjectedProfile;");
797 static final String LF_COMPILED_SIG = className("Ljava/lang/invoke/LambdaForm$Compiled;");
798
799 /**
800 * Generate an invoker method for the passed {@link LambdaForm}.
801 */
802 private byte[] generateCustomizedCodeBytes() {
803 classFilePrologue();
804 addMethod();
805 clinit();
806 bogusMethod(lambdaForm);
807
808 final byte[] classFile = toByteArray();
809 maybeDump(classFile);
810 return classFile;
811 }
812
813 void setClassWriter(ClassWriter cw) {
814 this.cw = cw;
815 }
816
817 void addMethod() {
818 methodPrologue();
819
820 // Suppress this method in backtraces displayed to the user.
821 mv.visitAnnotation(HIDDEN_SIG, true);
822
823 // Mark this method as a compiled LambdaForm
824 mv.visitAnnotation(LF_COMPILED_SIG, true);
825
826 if (lambdaForm.forceInline) {
827 // Force inlining of this invoker method.
828 mv.visitAnnotation(FORCEINLINE_SIG, true);
829 } else {
830 mv.visitAnnotation(DONTINLINE_SIG, true);
831 }
832
833 classData(lambdaForm); // keep LambdaForm instance & its compiled form lifetime tightly coupled.
834
835 if (lambdaForm.customized != null) {
836 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
837 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
838 // It enables more efficient code generation in some situations, since embedded constants
839 // are compile-time constants for JIT compiler.
840 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(lambdaForm.customized), MH_SIG);
841 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
842 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
843 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
844 }
845
846 // iterate over the form's names, generating bytecode instructions for each
847 // start iterating at the first name following the arguments
848 Name onStack = null;
849 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
850 Name name = lambdaForm.names[i];
851
852 emitStoreResult(onStack);
853 onStack = name; // unless otherwise modified below
854 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
855 switch (intr) {
856 case SELECT_ALTERNATIVE:
857 assert lambdaForm.isSelectAlternative(i);
858 if (PROFILE_GWT) {
859 assert(name.arguments[0] instanceof Name &&
860 ((Name)name.arguments[0]).refersTo(MethodHandleImpl.class, "profileBoolean"));
861 mv.visitAnnotation(INJECTEDPROFILE_SIG, true);
862 }
863 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
864 i++; // skip MH.invokeBasic of the selectAlternative result
865 continue;
866 case GUARD_WITH_CATCH:
867 assert lambdaForm.isGuardWithCatch(i);
868 onStack = emitGuardWithCatch(i);
869 i += 2; // jump to the end of GWC idiom
870 continue;
871 case TRY_FINALLY:
872 assert lambdaForm.isTryFinally(i);
873 onStack = emitTryFinally(i);
874 i += 2; // jump to the end of the TF idiom
875 continue;
876 case LOOP:
877 assert lambdaForm.isLoop(i);
878 onStack = emitLoop(i);
879 i += 2; // jump to the end of the LOOP idiom
880 continue;
881 case NEW_ARRAY:
882 Class<?> rtype = name.function.methodType().returnType();
883 if (isStaticallyNameable(rtype)) {
884 emitNewArray(name);
885 continue;
886 }
887 break;
888 case ARRAY_LOAD:
889 emitArrayLoad(name);
890 continue;
891 case ARRAY_STORE:
892 emitArrayStore(name);
893 continue;
894 case ARRAY_LENGTH:
895 emitArrayLength(name);
896 continue;
897 case IDENTITY:
898 assert(name.arguments.length == 1);
899 emitPushArguments(name, 0);
900 continue;
901 case ZERO:
902 assert(name.arguments.length == 0);
903 emitConst(name.type.basicTypeWrapper().zero());
904 continue;
905 case NONE:
906 // no intrinsic associated
907 break;
908 default:
909 throw newInternalError("Unknown intrinsic: "+intr);
910 }
911
912 MemberName member = name.function.member();
913 if (isStaticallyInvocable(member)) {
914 emitStaticInvoke(member, name);
915 } else {
916 emitInvoke(name);
917 }
918 }
919
920 // return statement
921 emitReturn(onStack);
922
923 methodEpilogue();
924 }
925
926 /*
927 * @throws BytecodeGenerationException if something goes wrong when
928 * generating the byte code
929 */
930 private byte[] toByteArray() {
931 try {
932 return cw.toByteArray();
933 } catch (RuntimeException e) {
934 throw new BytecodeGenerationException(e);
935 }
936 }
937
938 @SuppressWarnings("serial")
939 static final class BytecodeGenerationException extends RuntimeException {
940 BytecodeGenerationException(Exception cause) {
941 super(cause);
942 }
943 }
944
945 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
946 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
947 void emitArrayLength(Name name) { emitArrayOp(name, Opcodes.ARRAYLENGTH); }
948
949 void emitArrayOp(Name name, int arrayOpcode) {
950 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE || arrayOpcode == Opcodes.ARRAYLENGTH;
951 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
952 assert elementType != null;
953 emitPushArguments(name, 0);
954 if (arrayOpcode != Opcodes.ARRAYLENGTH && elementType.isPrimitive()) {
955 Wrapper w = Wrapper.forPrimitiveType(elementType);
956 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
957 }
958 mv.visitInsn(arrayOpcode);
959 }
960
961 /**
962 * Emit an invoke for the given name.
963 */
964 void emitInvoke(Name name) {
965 assert(!name.isLinkerMethodInvoke()); // should use the static path for these
966 if (true) {
967 // push receiver
968 MethodHandle target = name.function.resolvedHandle();
969 assert(target != null) : name.exprString();
970 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(target), MH_SIG);
971 emitReferenceCast(MethodHandle.class, target);
972 } else {
973 // load receiver
974 emitAloadInsn(0);
975 emitReferenceCast(MethodHandle.class, null);
976 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
977 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
978 // TODO more to come
979 }
980
981 // push arguments
982 emitPushArguments(name, 0);
983
984 // invocation
985 MethodType type = name.function.methodType();
986 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
987 }
988
989 private static Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
990 // Sample classes from each package we are willing to bind to statically:
991 java.lang.Object.class,
992 java.util.Arrays.class,
993 jdk.internal.misc.Unsafe.class
994 //MethodHandle.class already covered
995 };
996
997 static boolean isStaticallyInvocable(NamedFunction ... functions) {
998 for (NamedFunction nf : functions) {
999 if (!isStaticallyInvocable(nf.member())) {
1000 return false;
1001 }
1002 }
1003 return true;
1004 }
1005
1006 static boolean isStaticallyInvocable(Name name) {
1007 return isStaticallyInvocable(name.function.member());
1008 }
1009
1010 static boolean isStaticallyInvocable(MemberName member) {
1011 if (member == null) return false;
1012 if (member.isConstructor()) return false;
1013 Class<?> cls = member.getDeclaringClass();
1014 // Fast-path non-private members declared by MethodHandles, which is a common
1015 // case
1016 if (MethodHandle.class.isAssignableFrom(cls) && !member.isPrivate()) {
1017 assert(isStaticallyInvocableType(member.getMethodOrFieldType()));
1018 return true;
1019 }
1020 if (cls.isArray() || cls.isPrimitive())
1021 return false; // FIXME
1022 if (cls.isAnonymousClass() || cls.isLocalClass())
1023 return false; // inner class of some sort
1024 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
1025 return false; // not on BCP
1026 if (cls.isHiddenClass())
1027 return false;
1028 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: Unsafe::defineAnonymousClass to be removed
1029 return false;
1030 if (!isStaticallyInvocableType(member.getMethodOrFieldType()))
1031 return false;
1032 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
1033 return true; // in java.lang.invoke package
1034 if (member.isPublic() && isStaticallyNameable(cls))
1035 return true;
1036 return false;
1037 }
1038
1039 private static boolean isStaticallyInvocableType(MethodType mtype) {
1040 if (!isStaticallyNameable(mtype.returnType()))
1041 return false;
1042 for (Class<?> ptype : mtype.parameterArray())
1043 if (!isStaticallyNameable(ptype))
1044 return false;
1045 return true;
1046 }
1047
1048 static boolean isStaticallyNameable(Class<?> cls) {
1049 if (cls == Object.class)
1050 return true;
1051 if (MethodHandle.class.isAssignableFrom(cls)) {
1052 assert(!cls.isHiddenClass());
1053 return true;
1054 }
1055 while (cls.isArray())
1056 cls = cls.getComponentType();
1057 if (cls.isPrimitive())
1058 return true; // int[].class, for example
1059 if (cls.isHiddenClass())
1060 return false;
1061 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: Unsafe::defineAnonymousClass to be removed
1062 return false;
1063 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
1064 if (cls.getClassLoader() != Object.class.getClassLoader())
1065 return false;
1066 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
1067 return true;
1068 if (!Modifier.isPublic(cls.getModifiers()))
1069 return false;
1070 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
1071 if (VerifyAccess.isSamePackage(pkgcls, cls))
1072 return true;
1073 }
1074 return false;
1075 }
1076
1077 void emitStaticInvoke(Name name) {
1078 emitStaticInvoke(name.function.member(), name);
1079 }
1080
1081 /**
1082 * Emit an invoke for the given name, using the MemberName directly.
1083 */
1084 void emitStaticInvoke(MemberName member, Name name) {
1085 assert(member.equals(name.function.member()));
1086 Class<?> defc = member.getDeclaringClass();
1087 String cname = getInternalName(defc);
1088 String mname = member.getName();
1089 String mtype;
1090 byte refKind = member.getReferenceKind();
1091 if (refKind == REF_invokeSpecial) {
1092 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1093 assert(member.canBeStaticallyBound()) : member;
1094 refKind = REF_invokeVirtual;
1095 }
1096
1097 assert(!(member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual));
1098
1099 // push arguments
1100 emitPushArguments(name, 0);
1101
1102 // invocation
1103 if (member.isMethod()) {
1104 mtype = member.getMethodType().toMethodDescriptorString();
1105 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1106 member.getDeclaringClass().isInterface());
1107 } else {
1108 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1109 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1110 }
1111 // Issue a type assertion for the result, so we can avoid casts later.
1112 if (name.type == L_TYPE) {
1113 Class<?> rtype = member.getInvocationType().returnType();
1114 assert(!rtype.isPrimitive());
1115 if (rtype != Object.class && !rtype.isInterface()) {
1116 assertStaticType(rtype, name);
1117 }
1118 }
1119 }
1120
1121 void emitNewArray(Name name) throws InternalError {
1122 Class<?> rtype = name.function.methodType().returnType();
1123 if (name.arguments.length == 0) {
1124 // The array will be a constant.
1125 Object emptyArray;
1126 try {
1127 emptyArray = name.function.resolvedHandle().invoke();
1128 } catch (Throwable ex) {
1129 throw uncaughtException(ex);
1130 }
1131 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
1132 assert(emptyArray.getClass() == rtype); // exact typing
1133 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(emptyArray), "Ljava/lang/Object;");
1134 emitReferenceCast(rtype, emptyArray);
1135 return;
1136 }
1137 Class<?> arrayElementType = rtype.getComponentType();
1138 assert(arrayElementType != null);
1139 emitIconstInsn(name.arguments.length);
1140 int xas = Opcodes.AASTORE;
1141 if (!arrayElementType.isPrimitive()) {
1142 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
1143 } else {
1144 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
1145 xas = arrayInsnOpcode(tc, xas);
1146 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
1147 }
1148 // store arguments
1149 for (int i = 0; i < name.arguments.length; i++) {
1150 mv.visitInsn(Opcodes.DUP);
1151 emitIconstInsn(i);
1152 emitPushArgument(name, i);
1153 mv.visitInsn(xas);
1154 }
1155 // the array is left on the stack
1156 assertStaticType(rtype, name);
1157 }
1158 int refKindOpcode(byte refKind) {
1159 switch (refKind) {
1160 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1161 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1162 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1163 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1164 case REF_getField: return Opcodes.GETFIELD;
1165 case REF_putField: return Opcodes.PUTFIELD;
1166 case REF_getStatic: return Opcodes.GETSTATIC;
1167 case REF_putStatic: return Opcodes.PUTSTATIC;
1168 }
1169 throw new InternalError("refKind="+refKind);
1170 }
1171
1172 /**
1173 * Emit bytecode for the selectAlternative idiom.
1174 *
1175 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1176 * <blockquote><pre>{@code
1177 * Lambda(a0:L,a1:I)=>{
1178 * t2:I=foo.test(a1:I);
1179 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1180 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1181 * }</pre></blockquote>
1182 */
1183 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1184 assert isStaticallyInvocable(invokeBasicName);
1185
1186 Name receiver = (Name) invokeBasicName.arguments[0];
1187
1188 Label L_fallback = new Label();
1189 Label L_done = new Label();
1190
1191 // load test result
1192 emitPushArgument(selectAlternativeName, 0);
1193
1194 // if_icmpne L_fallback
1195 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1196
1197 // invoke selectAlternativeName.arguments[1]
1198 Class<?>[] preForkClasses = localClasses.clone();
1199 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1200 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1201 emitStaticInvoke(invokeBasicName);
1202
1203 // goto L_done
1204 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1205
1206 // L_fallback:
1207 mv.visitLabel(L_fallback);
1208
1209 // invoke selectAlternativeName.arguments[2]
1210 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1211 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1212 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1213 emitStaticInvoke(invokeBasicName);
1214
1215 // L_done:
1216 mv.visitLabel(L_done);
1217 // for now do not bother to merge typestate; just reset to the dominator state
1218 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1219
1220 return invokeBasicName; // return what's on stack
1221 }
1222
1223 /**
1224 * Emit bytecode for the guardWithCatch idiom.
1225 *
1226 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1227 * <blockquote><pre>{@code
1228 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1229 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1230 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1231 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1232 * }</pre></blockquote>
1233 *
1234 * It is compiled into bytecode equivalent of the following code:
1235 * <blockquote><pre>{@code
1236 * try {
1237 * return a1.invokeBasic(a6, a7);
1238 * } catch (Throwable e) {
1239 * if (!a2.isInstance(e)) throw e;
1240 * return a3.invokeBasic(ex, a6, a7);
1241 * }}</pre></blockquote>
1242 */
1243 private Name emitGuardWithCatch(int pos) {
1244 Name args = lambdaForm.names[pos];
1245 Name invoker = lambdaForm.names[pos+1];
1246 Name result = lambdaForm.names[pos+2];
1247
1248 Label L_startBlock = new Label();
1249 Label L_endBlock = new Label();
1250 Label L_handler = new Label();
1251 Label L_done = new Label();
1252
1253 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1254 MethodType type = args.function.resolvedHandle().type()
1255 .dropParameterTypes(0,1)
1256 .changeReturnType(returnType);
1257
1258 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1259
1260 // Normal case
1261 mv.visitLabel(L_startBlock);
1262 // load target
1263 emitPushArgument(invoker, 0);
1264 emitPushArguments(args, 1); // skip 1st argument: method handle
1265 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1266 mv.visitLabel(L_endBlock);
1267 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1268
1269 // Exceptional case
1270 mv.visitLabel(L_handler);
1271
1272 // Check exception's type
1273 mv.visitInsn(Opcodes.DUP);
1274 // load exception class
1275 emitPushArgument(invoker, 1);
1276 mv.visitInsn(Opcodes.SWAP);
1277 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1278 Label L_rethrow = new Label();
1279 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1280
1281 // Invoke catcher
1282 // load catcher
1283 emitPushArgument(invoker, 2);
1284 mv.visitInsn(Opcodes.SWAP);
1285 emitPushArguments(args, 1); // skip 1st argument: method handle
1286 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1287 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1288 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1289
1290 mv.visitLabel(L_rethrow);
1291 mv.visitInsn(Opcodes.ATHROW);
1292
1293 mv.visitLabel(L_done);
1294
1295 return result;
1296 }
1297
1298 /**
1299 * Emit bytecode for the tryFinally idiom.
1300 * <p>
1301 * The pattern looks like (Cf. MethodHandleImpl.makeTryFinally):
1302 * <blockquote><pre>{@code
1303 * // a0: BMH
1304 * // a1: target, a2: cleanup
1305 * // a3: box, a4: unbox
1306 * // a5 (and following): arguments
1307 * tryFinally=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L)=>{
1308 * t6:L=MethodHandle.invokeBasic(a3:L,a5:L); // box the arguments into an Object[]
1309 * t7:L=MethodHandleImpl.tryFinally(a1:L,a2:L,t6:L); // call the tryFinally executor
1310 * t8:L=MethodHandle.invokeBasic(a4:L,t7:L);t8:L} // unbox the result; return the result
1311 * }</pre></blockquote>
1312 * <p>
1313 * It is compiled into bytecode equivalent to the following code:
1314 * <blockquote><pre>{@code
1315 * Throwable t;
1316 * Object r;
1317 * try {
1318 * r = a1.invokeBasic(a5);
1319 * } catch (Throwable thrown) {
1320 * t = thrown;
1321 * throw t;
1322 * } finally {
1323 * r = a2.invokeBasic(t, r, a5);
1324 * }
1325 * return r;
1326 * }</pre></blockquote>
1327 * <p>
1328 * Specifically, the bytecode will have the following form (the stack effects are given for the beginnings of
1329 * blocks, and for the situations after executing the given instruction - the code will have a slightly different
1330 * shape if the return type is {@code void}):
1331 * <blockquote><pre>{@code
1332 * TRY: (--)
1333 * load target (-- target)
1334 * load args (-- args... target)
1335 * INVOKEVIRTUAL MethodHandle.invokeBasic (depends)
1336 * FINALLY_NORMAL: (-- r_2nd* r)
1337 * store returned value (--)
1338 * load cleanup (-- cleanup)
1339 * ACONST_NULL (-- t cleanup)
1340 * load returned value (-- r_2nd* r t cleanup)
1341 * load args (-- args... r_2nd* r t cleanup)
1342 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r)
1343 * GOTO DONE
1344 * CATCH: (-- t)
1345 * DUP (-- t t)
1346 * FINALLY_EXCEPTIONAL: (-- t t)
1347 * load cleanup (-- cleanup t t)
1348 * SWAP (-- t cleanup t)
1349 * load default for r (-- r_2nd* r t cleanup t)
1350 * load args (-- args... r_2nd* r t cleanup t)
1351 * INVOKEVIRTUAL MethodHandle.invokeBasic (-- r_2nd* r t)
1352 * POP/POP2* (-- t)
1353 * ATHROW
1354 * DONE: (-- r)
1355 * }</pre></blockquote>
1356 * * = depends on whether the return type takes up 2 stack slots.
1357 */
1358 private Name emitTryFinally(int pos) {
1359 Name args = lambdaForm.names[pos];
1360 Name invoker = lambdaForm.names[pos+1];
1361 Name result = lambdaForm.names[pos+2];
1362
1363 Label lFrom = new Label();
1364 Label lTo = new Label();
1365 Label lCatch = new Label();
1366 Label lDone = new Label();
1367
1368 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1369 BasicType basicReturnType = BasicType.basicType(returnType);
1370 boolean isNonVoid = returnType != void.class;
1371
1372 MethodType type = args.function.resolvedHandle().type()
1373 .dropParameterTypes(0,1)
1374 .changeReturnType(returnType);
1375 MethodType cleanupType = type.insertParameterTypes(0, Throwable.class);
1376 if (isNonVoid) {
1377 cleanupType = cleanupType.insertParameterTypes(1, returnType);
1378 }
1379 String cleanupDesc = cleanupType.basicType().toMethodDescriptorString();
1380
1381 // exception handler table
1382 mv.visitTryCatchBlock(lFrom, lTo, lCatch, "java/lang/Throwable");
1383
1384 // TRY:
1385 mv.visitLabel(lFrom);
1386 emitPushArgument(invoker, 0); // load target
1387 emitPushArguments(args, 1); // load args (skip 0: method handle)
1388 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1389 mv.visitLabel(lTo);
1390
1391 // FINALLY_NORMAL:
1392 int index = extendLocalsMap(new Class<?>[]{ returnType });
1393 if (isNonVoid) {
1394 emitStoreInsn(basicReturnType, index);
1395 }
1396 emitPushArgument(invoker, 1); // load cleanup
1397 mv.visitInsn(Opcodes.ACONST_NULL);
1398 if (isNonVoid) {
1399 emitLoadInsn(basicReturnType, index);
1400 }
1401 emitPushArguments(args, 1); // load args (skip 0: method handle)
1402 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1403 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1404
1405 // CATCH:
1406 mv.visitLabel(lCatch);
1407 mv.visitInsn(Opcodes.DUP);
1408
1409 // FINALLY_EXCEPTIONAL:
1410 emitPushArgument(invoker, 1); // load cleanup
1411 mv.visitInsn(Opcodes.SWAP);
1412 if (isNonVoid) {
1413 emitZero(BasicType.basicType(returnType)); // load default for result
1414 }
1415 emitPushArguments(args, 1); // load args (skip 0: method handle)
1416 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", cleanupDesc, false);
1417 if (isNonVoid) {
1418 emitPopInsn(basicReturnType);
1419 }
1420 mv.visitInsn(Opcodes.ATHROW);
1421
1422 // DONE:
1423 mv.visitLabel(lDone);
1424
1425 return result;
1426 }
1427
1428 private void emitPopInsn(BasicType type) {
1429 mv.visitInsn(popInsnOpcode(type));
1430 }
1431
1432 private static int popInsnOpcode(BasicType type) {
1433 switch (type) {
1434 case I_TYPE:
1435 case F_TYPE:
1436 case L_TYPE:
1437 return Opcodes.POP;
1438 case J_TYPE:
1439 case D_TYPE:
1440 return Opcodes.POP2;
1441 default:
1442 throw new InternalError("unknown type: " + type);
1443 }
1444 }
1445
1446 /**
1447 * Emit bytecode for the loop idiom.
1448 * <p>
1449 * The pattern looks like (Cf. MethodHandleImpl.loop):
1450 * <blockquote><pre>{@code
1451 * // a0: BMH
1452 * // a1: LoopClauses (containing an array of arrays: inits, steps, preds, finis)
1453 * // a2: box, a3: unbox
1454 * // a4 (and following): arguments
1455 * loop=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L)=>{
1456 * t5:L=MethodHandle.invokeBasic(a2:L,a4:L); // box the arguments into an Object[]
1457 * t6:L=MethodHandleImpl.loop(bt:L,a1:L,t5:L); // call the loop executor (with supplied types in bt)
1458 * t7:L=MethodHandle.invokeBasic(a3:L,t6:L);t7:L} // unbox the result; return the result
1459 * }</pre></blockquote>
1460 * <p>
1461 * It is compiled into bytecode equivalent to the code seen in {@link MethodHandleImpl#loop(BasicType[],
1462 * MethodHandleImpl.LoopClauses, Object...)}, with the difference that no arrays
1463 * will be used for local state storage. Instead, the local state will be mapped to actual stack slots.
1464 * <p>
1465 * Bytecode generation applies an unrolling scheme to enable better bytecode generation regarding local state type
1466 * handling. The generated bytecode will have the following form ({@code void} types are ignored for convenience).
1467 * Assume there are {@code C} clauses in the loop.
1468 * <blockquote><pre>{@code
1469 * PREINIT: ALOAD_1
1470 * CHECKCAST LoopClauses
1471 * GETFIELD LoopClauses.clauses
1472 * ASTORE clauseDataIndex // place the clauses 2-dimensional array on the stack
1473 * INIT: (INIT_SEQ for clause 1)
1474 * ...
1475 * (INIT_SEQ for clause C)
1476 * LOOP: (LOOP_SEQ for clause 1)
1477 * ...
1478 * (LOOP_SEQ for clause C)
1479 * GOTO LOOP
1480 * DONE: ...
1481 * }</pre></blockquote>
1482 * <p>
1483 * The {@code INIT_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1484 * the following shape. Assume slot {@code vx} is used to hold the state for clause {@code x}.
1485 * <blockquote><pre>{@code
1486 * INIT_SEQ_x: ALOAD clauseDataIndex
1487 * ICONST_0
1488 * AALOAD // load the inits array
1489 * ICONST x
1490 * AALOAD // load the init handle for clause x
1491 * load args
1492 * INVOKEVIRTUAL MethodHandle.invokeBasic
1493 * store vx
1494 * }</pre></blockquote>
1495 * <p>
1496 * The {@code LOOP_SEQ_x} sequence for clause {@code x} (with {@code x} ranging from {@code 0} to {@code C-1}) has
1497 * the following shape. Again, assume slot {@code vx} is used to hold the state for clause {@code x}.
1498 * <blockquote><pre>{@code
1499 * LOOP_SEQ_x: ALOAD clauseDataIndex
1500 * ICONST_1
1501 * AALOAD // load the steps array
1502 * ICONST x
1503 * AALOAD // load the step handle for clause x
1504 * load locals
1505 * load args
1506 * INVOKEVIRTUAL MethodHandle.invokeBasic
1507 * store vx
1508 * ALOAD clauseDataIndex
1509 * ICONST_2
1510 * AALOAD // load the preds array
1511 * ICONST x
1512 * AALOAD // load the pred handle for clause x
1513 * load locals
1514 * load args
1515 * INVOKEVIRTUAL MethodHandle.invokeBasic
1516 * IFNE LOOP_SEQ_x+1 // predicate returned false -> jump to next clause
1517 * ALOAD clauseDataIndex
1518 * ICONST_3
1519 * AALOAD // load the finis array
1520 * ICONST x
1521 * AALOAD // load the fini handle for clause x
1522 * load locals
1523 * load args
1524 * INVOKEVIRTUAL MethodHandle.invokeBasic
1525 * GOTO DONE // jump beyond end of clauses to return from loop
1526 * }</pre></blockquote>
1527 */
1528 private Name emitLoop(int pos) {
1529 Name args = lambdaForm.names[pos];
1530 Name invoker = lambdaForm.names[pos+1];
1531 Name result = lambdaForm.names[pos+2];
1532
1533 // extract clause and loop-local state types
1534 // find the type info in the loop invocation
1535 BasicType[] loopClauseTypes = (BasicType[]) invoker.arguments[0];
1536 Class<?>[] loopLocalStateTypes = Stream.of(loopClauseTypes).
1537 filter(bt -> bt != BasicType.V_TYPE).map(BasicType::basicTypeClass).toArray(Class<?>[]::new);
1538 Class<?>[] localTypes = new Class<?>[loopLocalStateTypes.length + 1];
1539 localTypes[0] = MethodHandleImpl.LoopClauses.class;
1540 System.arraycopy(loopLocalStateTypes, 0, localTypes, 1, loopLocalStateTypes.length);
1541
1542 final int clauseDataIndex = extendLocalsMap(localTypes);
1543 final int firstLoopStateIndex = clauseDataIndex + 1;
1544
1545 Class<?> returnType = result.function.resolvedHandle().type().returnType();
1546 MethodType loopType = args.function.resolvedHandle().type()
1547 .dropParameterTypes(0,1)
1548 .changeReturnType(returnType);
1549 MethodType loopHandleType = loopType.insertParameterTypes(0, loopLocalStateTypes);
1550 MethodType predType = loopHandleType.changeReturnType(boolean.class);
1551 MethodType finiType = loopHandleType;
1552
1553 final int nClauses = loopClauseTypes.length;
1554
1555 // indices to invoker arguments to load method handle arrays
1556 final int inits = 1;
1557 final int steps = 2;
1558 final int preds = 3;
1559 final int finis = 4;
1560
1561 Label lLoop = new Label();
1562 Label lDone = new Label();
1563 Label lNext;
1564
1565 // PREINIT:
1566 emitPushArgument(MethodHandleImpl.LoopClauses.class, invoker.arguments[1]);
1567 mv.visitFieldInsn(Opcodes.GETFIELD, LOOP_CLAUSES, "clauses", MHARY2);
1568 emitAstoreInsn(clauseDataIndex);
1569
1570 // INIT:
1571 for (int c = 0, state = 0; c < nClauses; ++c) {
1572 MethodType cInitType = loopType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1573 emitLoopHandleInvoke(invoker, inits, c, args, false, cInitType, loopLocalStateTypes, clauseDataIndex,
1574 firstLoopStateIndex);
1575 if (cInitType.returnType() != void.class) {
1576 emitStoreInsn(BasicType.basicType(cInitType.returnType()), firstLoopStateIndex + state);
1577 ++state;
1578 }
1579 }
1580
1581 // LOOP:
1582 mv.visitLabel(lLoop);
1583
1584 for (int c = 0, state = 0; c < nClauses; ++c) {
1585 lNext = new Label();
1586
1587 MethodType stepType = loopHandleType.changeReturnType(loopClauseTypes[c].basicTypeClass());
1588 boolean isVoid = stepType.returnType() == void.class;
1589
1590 // invoke loop step
1591 emitLoopHandleInvoke(invoker, steps, c, args, true, stepType, loopLocalStateTypes, clauseDataIndex,
1592 firstLoopStateIndex);
1593 if (!isVoid) {
1594 emitStoreInsn(BasicType.basicType(stepType.returnType()), firstLoopStateIndex + state);
1595 ++state;
1596 }
1597
1598 // invoke loop predicate
1599 emitLoopHandleInvoke(invoker, preds, c, args, true, predType, loopLocalStateTypes, clauseDataIndex,
1600 firstLoopStateIndex);
1601 mv.visitJumpInsn(Opcodes.IFNE, lNext);
1602
1603 // invoke fini
1604 emitLoopHandleInvoke(invoker, finis, c, args, true, finiType, loopLocalStateTypes, clauseDataIndex,
1605 firstLoopStateIndex);
1606 mv.visitJumpInsn(Opcodes.GOTO, lDone);
1607
1608 // this is the beginning of the next loop clause
1609 mv.visitLabel(lNext);
1610 }
1611
1612 mv.visitJumpInsn(Opcodes.GOTO, lLoop);
1613
1614 // DONE:
1615 mv.visitLabel(lDone);
1616
1617 return result;
1618 }
1619
1620 private int extendLocalsMap(Class<?>[] types) {
1621 int firstSlot = localsMap.length - 1;
1622 localsMap = Arrays.copyOf(localsMap, localsMap.length + types.length);
1623 localClasses = Arrays.copyOf(localClasses, localClasses.length + types.length);
1624 System.arraycopy(types, 0, localClasses, firstSlot, types.length);
1625 int index = localsMap[firstSlot - 1] + 1;
1626 int lastSlots = 0;
1627 for (int i = 0; i < types.length; ++i) {
1628 localsMap[firstSlot + i] = index;
1629 lastSlots = BasicType.basicType(localClasses[firstSlot + i]).basicTypeSlots();
1630 index += lastSlots;
1631 }
1632 localsMap[localsMap.length - 1] = index - lastSlots;
1633 return firstSlot;
1634 }
1635
1636 private void emitLoopHandleInvoke(Name holder, int handles, int clause, Name args, boolean pushLocalState,
1637 MethodType type, Class<?>[] loopLocalStateTypes, int clauseDataSlot,
1638 int firstLoopStateSlot) {
1639 // load handle for clause
1640 emitPushClauseArray(clauseDataSlot, handles);
1641 emitIconstInsn(clause);
1642 mv.visitInsn(Opcodes.AALOAD);
1643 // load loop state (preceding the other arguments)
1644 if (pushLocalState) {
1645 for (int s = 0; s < loopLocalStateTypes.length; ++s) {
1646 emitLoadInsn(BasicType.basicType(loopLocalStateTypes[s]), firstLoopStateSlot + s);
1647 }
1648 }
1649 // load loop args (skip 0: method handle)
1650 emitPushArguments(args, 1);
1651 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.toMethodDescriptorString(), false);
1652 }
1653
1654 private void emitPushClauseArray(int clauseDataSlot, int which) {
1655 emitAloadInsn(clauseDataSlot);
1656 emitIconstInsn(which - 1);
1657 mv.visitInsn(Opcodes.AALOAD);
1658 }
1659
1660 private void emitZero(BasicType type) {
1661 switch (type) {
1662 case I_TYPE: mv.visitInsn(Opcodes.ICONST_0); break;
1663 case J_TYPE: mv.visitInsn(Opcodes.LCONST_0); break;
1664 case F_TYPE: mv.visitInsn(Opcodes.FCONST_0); break;
1665 case D_TYPE: mv.visitInsn(Opcodes.DCONST_0); break;
1666 case L_TYPE: mv.visitInsn(Opcodes.ACONST_NULL); break;
1667 default: throw new InternalError("unknown type: " + type);
1668 }
1669 }
1670
1671 private void emitPushArguments(Name args, int start) {
1672 MethodType type = args.function.methodType();
1673 for (int i = start; i < args.arguments.length; i++) {
1674 emitPushArgument(type.parameterType(i), args.arguments[i]);
1675 }
1676 }
1677
1678 private void emitPushArgument(Name name, int paramIndex) {
1679 Object arg = name.arguments[paramIndex];
1680 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1681 emitPushArgument(ptype, arg);
1682 }
1683
1684 private void emitPushArgument(Class<?> ptype, Object arg) {
1685 BasicType bptype = basicType(ptype);
1686 if (arg instanceof Name) {
1687 Name n = (Name) arg;
1688 emitLoadInsn(n.type, n.index());
1689 emitImplicitConversion(n.type, ptype, n);
1690 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1691 emitConst(arg);
1692 } else {
1693 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1694 emitConst(arg);
1695 } else {
1696 mv.visitFieldInsn(Opcodes.GETSTATIC, className(), classData(arg), "Ljava/lang/Object;");
1697 emitImplicitConversion(L_TYPE, ptype, arg);
1698 }
1699 }
1700 }
1701
1702 /**
1703 * Store the name to its local, if necessary.
1704 */
1705 private void emitStoreResult(Name name) {
1706 if (name != null && name.type != V_TYPE) {
1707 // non-void: actually assign
1708 emitStoreInsn(name.type, name.index());
1709 }
1710 }
1711
1712 /**
1713 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1714 */
1715 private void emitReturn(Name onStack) {
1716 // return statement
1717 Class<?> rclass = invokerType.returnType();
1718 BasicType rtype = lambdaForm.returnType();
1719 assert(rtype == basicType(rclass)); // must agree
1720 if (rtype == V_TYPE) {
1721 // void
1722 mv.visitInsn(Opcodes.RETURN);
1723 // it doesn't matter what rclass is; the JVM will discard any value
1724 } else {
1725 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1726
1727 // put return value on the stack if it is not already there
1728 if (rn != onStack) {
1729 emitLoadInsn(rtype, lambdaForm.result);
1730 }
1731
1732 emitImplicitConversion(rtype, rclass, rn);
1733
1734 // generate actual return statement
1735 emitReturnInsn(rtype);
1736 }
1737 }
1738
1739 /**
1740 * Emit a type conversion bytecode casting from "from" to "to".
1741 */
1742 private void emitPrimCast(Wrapper from, Wrapper to) {
1743 // Here's how.
1744 // - indicates forbidden
1745 // <-> indicates implicit
1746 // to ----> boolean byte short char int long float double
1747 // from boolean <-> - - - - - - -
1748 // byte - <-> i2s i2c <-> i2l i2f i2d
1749 // short - i2b <-> i2c <-> i2l i2f i2d
1750 // char - i2b i2s <-> <-> i2l i2f i2d
1751 // int - i2b i2s i2c <-> i2l i2f i2d
1752 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1753 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1754 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1755 if (from == to) {
1756 // no cast required, should be dead code anyway
1757 return;
1758 }
1759 if (from.isSubwordOrInt()) {
1760 // cast from {byte,short,char,int} to anything
1761 emitI2X(to);
1762 } else {
1763 // cast from {long,float,double} to anything
1764 if (to.isSubwordOrInt()) {
1765 // cast to {byte,short,char,int}
1766 emitX2I(from);
1767 if (to.bitWidth() < 32) {
1768 // targets other than int require another conversion
1769 emitI2X(to);
1770 }
1771 } else {
1772 // cast to {long,float,double} - this is verbose
1773 boolean error = false;
1774 switch (from) {
1775 case LONG:
1776 switch (to) {
1777 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1778 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1779 default: error = true; break;
1780 }
1781 break;
1782 case FLOAT:
1783 switch (to) {
1784 case LONG : mv.visitInsn(Opcodes.F2L); break;
1785 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1786 default: error = true; break;
1787 }
1788 break;
1789 case DOUBLE:
1790 switch (to) {
1791 case LONG : mv.visitInsn(Opcodes.D2L); break;
1792 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1793 default: error = true; break;
1794 }
1795 break;
1796 default:
1797 error = true;
1798 break;
1799 }
1800 if (error) {
1801 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1802 }
1803 }
1804 }
1805 }
1806
1807 private void emitI2X(Wrapper type) {
1808 switch (type) {
1809 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1810 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1811 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1812 case INT: /* naught */ break;
1813 case LONG: mv.visitInsn(Opcodes.I2L); break;
1814 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1815 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1816 case BOOLEAN:
1817 // For compatibility with ValueConversions and explicitCastArguments:
1818 mv.visitInsn(Opcodes.ICONST_1);
1819 mv.visitInsn(Opcodes.IAND);
1820 break;
1821 default: throw new InternalError("unknown type: " + type);
1822 }
1823 }
1824
1825 private void emitX2I(Wrapper type) {
1826 switch (type) {
1827 case LONG: mv.visitInsn(Opcodes.L2I); break;
1828 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1829 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1830 default: throw new InternalError("unknown type: " + type);
1831 }
1832 }
1833
1834 /**
1835 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1836 */
1837 static MemberName generateLambdaFormInterpreterEntryPoint(MethodType mt) {
1838 assert(isValidSignature(basicTypeSignature(mt)));
1839 String name = "interpret_"+basicTypeChar(mt.returnType());
1840 MethodType type = mt; // includes leading argument
1841 type = type.changeParameterType(0, MethodHandle.class);
1842 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1843 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1844 }
1845
1846 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1847 classFilePrologue();
1848 methodPrologue();
1849
1850 // Suppress this method in backtraces displayed to the user.
1851 mv.visitAnnotation(HIDDEN_SIG, true);
1852
1853 // Don't inline the interpreter entry.
1854 mv.visitAnnotation(DONTINLINE_SIG, true);
1855
1856 // create parameter array
1857 emitIconstInsn(invokerType.parameterCount());
1858 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1859
1860 // fill parameter array
1861 for (int i = 0; i < invokerType.parameterCount(); i++) {
1862 Class<?> ptype = invokerType.parameterType(i);
1863 mv.visitInsn(Opcodes.DUP);
1864 emitIconstInsn(i);
1865 emitLoadInsn(basicType(ptype), i);
1866 // box if primitive type
1867 if (ptype.isPrimitive()) {
1868 emitBoxing(Wrapper.forPrimitiveType(ptype));
1869 }
1870 mv.visitInsn(Opcodes.AASTORE);
1871 }
1872 // invoke
1873 emitAloadInsn(0);
1874 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1875 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1876 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1877
1878 // maybe unbox
1879 Class<?> rtype = invokerType.returnType();
1880 if (rtype.isPrimitive() && rtype != void.class) {
1881 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1882 }
1883
1884 // return statement
1885 emitReturnInsn(basicType(rtype));
1886
1887 methodEpilogue();
1888 clinit();
1889 bogusMethod(invokerType);
1890
1891 final byte[] classFile = cw.toByteArray();
1892 maybeDump(classFile);
1893 return classFile;
1894 }
1895
1896 /**
1897 * Generate bytecode for a NamedFunction invoker.
1898 */
1899 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1900 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1901 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1902 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1903 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1904 }
1905
1906 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1907 MethodType dstType = typeForm.erasedType();
1908 classFilePrologue();
1909 methodPrologue();
1910
1911 // Suppress this method in backtraces displayed to the user.
1912 mv.visitAnnotation(HIDDEN_SIG, true);
1913
1914 // Force inlining of this invoker method.
1915 mv.visitAnnotation(FORCEINLINE_SIG, true);
1916
1917 // Load receiver
1918 emitAloadInsn(0);
1919
1920 // Load arguments from array
1921 for (int i = 0; i < dstType.parameterCount(); i++) {
1922 emitAloadInsn(1);
1923 emitIconstInsn(i);
1924 mv.visitInsn(Opcodes.AALOAD);
1925
1926 // Maybe unbox
1927 Class<?> dptype = dstType.parameterType(i);
1928 if (dptype.isPrimitive()) {
1929 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1930 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1931 emitUnboxing(srcWrapper);
1932 emitPrimCast(srcWrapper, dstWrapper);
1933 }
1934 }
1935
1936 // Invoke
1937 String targetDesc = dstType.basicType().toMethodDescriptorString();
1938 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1939
1940 // Box primitive types
1941 Class<?> rtype = dstType.returnType();
1942 if (rtype != void.class && rtype.isPrimitive()) {
1943 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1944 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1945 // boolean casts not allowed
1946 emitPrimCast(srcWrapper, dstWrapper);
1947 emitBoxing(dstWrapper);
1948 }
1949
1950 // If the return type is void we return a null reference.
1951 if (rtype == void.class) {
1952 mv.visitInsn(Opcodes.ACONST_NULL);
1953 }
1954 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1955
1956 methodEpilogue();
1957 clinit();
1958 bogusMethod(dstType);
1959
1960 final byte[] classFile = cw.toByteArray();
1961 maybeDump(classFile);
1962 return classFile;
1963 }
1964
1965 /**
1966 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1967 * for debugging purposes.
1968 */
1969 private void bogusMethod(Object os) {
1970 if (DUMP_CLASS_FILES) {
1971 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1972 mv.visitLdcInsn(os.toString());
1973 mv.visitInsn(Opcodes.POP);
1974 mv.visitInsn(Opcodes.RETURN);
1975 mv.visitMaxs(0, 0);
1976 mv.visitEnd();
1977 }
1978 }
1979 }