1 /*
2 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang.invoke;
27
28 import java.io.*;
29 import java.util.*;
30 import java.lang.reflect.Modifier;
31
32 import jdk.internal.org.objectweb.asm.*;
33
34 import static java.lang.invoke.LambdaForm.*;
35 import static java.lang.invoke.LambdaForm.BasicType.*;
36 import static java.lang.invoke.MethodHandleStatics.*;
37 import static java.lang.invoke.MethodHandleNatives.Constants.*;
38
39 import sun.invoke.util.VerifyAccess;
40 import sun.invoke.util.VerifyType;
41 import sun.invoke.util.Wrapper;
42 import sun.reflect.misc.ReflectUtil;
43
44 /**
45 * Code generation backend for LambdaForm.
46 * <p>
47 * @author John Rose, JSR 292 EG
48 */
49 class InvokerBytecodeGenerator {
50 /** Define class names for convenience. */
51 private static final String MH = "java/lang/invoke/MethodHandle";
52 private static final String MHI = "java/lang/invoke/MethodHandleImpl";
53 private static final String LF = "java/lang/invoke/LambdaForm";
54 private static final String LFN = "java/lang/invoke/LambdaForm$Name";
55 private static final String CLS = "java/lang/Class";
56 private static final String OBJ = "java/lang/Object";
57 private static final String OBJARY = "[Ljava/lang/Object;";
58
59 private static final String LF_SIG = "L" + LF + ";";
60 private static final String LFN_SIG = "L" + LFN + ";";
61 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
62 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";";
63
64 /** Name of its super class*/
65 private static final String superName = OBJ;
66
67 /** Name of new class */
68 private final String className;
69
70 /** Name of the source file (for stack trace printing). */
71 private final String sourceFile;
72
73 private final LambdaForm lambdaForm;
74 private final String invokerName;
75 private final MethodType invokerType;
76
77 /** Info about local variables in compiled lambda form */
78 private final int[] localsMap; // index
79 private final BasicType[] localTypes; // basic type
80 private final Class<?>[] localClasses; // type
81
82 /** ASM bytecode generation. */
83 private ClassWriter cw;
84 private MethodVisitor mv;
85
86 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
87 private static final Class<?> HOST_CLASS = LambdaForm.class;
88
89 /** Main constructor; other constructors delegate to this one. */
90 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
91 String className, String invokerName, MethodType invokerType) {
92 if (invokerName.contains(".")) {
93 int p = invokerName.indexOf('.');
94 className = invokerName.substring(0, p);
95 invokerName = invokerName.substring(p+1);
96 }
97 if (DUMP_CLASS_FILES) {
98 className = makeDumpableClassName(className);
99 }
100 this.className = LF + "$" + className;
101 this.sourceFile = "LambdaForm$" + className;
102 this.lambdaForm = lambdaForm;
103 this.invokerName = invokerName;
104 this.invokerType = invokerType;
105 this.localsMap = new int[localsMapSize+1];
106 // last entry of localsMap is count of allocated local slots
107 this.localTypes = new BasicType[localsMapSize+1];
108 this.localClasses = new Class<?>[localsMapSize+1];
109 }
110
111 /** For generating LambdaForm interpreter entry points. */
112 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
113 this(null, invokerType.parameterCount(),
114 className, invokerName, invokerType);
115 // Create an array to map name indexes to locals indexes.
116 localTypes[localTypes.length - 1] = V_TYPE;
117 for (int i = 0; i < localsMap.length; i++) {
118 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
119 if (i < invokerType.parameterCount())
120 localTypes[i] = basicType(invokerType.parameterType(i));
121 }
122 }
123
124 /** For generating customized code for a single LambdaForm. */
125 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
126 this(form, form.names.length,
127 className, form.debugName, invokerType);
128 // Create an array to map name indexes to locals indexes.
129 Name[] names = form.names;
130 for (int i = 0, index = 0; i < localsMap.length; i++) {
131 localsMap[i] = index;
132 if (i < names.length) {
133 BasicType type = names[i].type();
134 index += type.basicTypeSlots();
135 localTypes[i] = type;
136 }
137 }
138 }
139
140
141 /** instance counters for dumped classes */
142 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
143 /** debugging flag for saving generated class files */
144 private final static File DUMP_CLASS_FILES_DIR;
145
146 static {
147 if (DUMP_CLASS_FILES) {
148 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
149 try {
150 File dumpDir = new File("DUMP_CLASS_FILES");
151 if (!dumpDir.exists()) {
152 dumpDir.mkdirs();
153 }
154 DUMP_CLASS_FILES_DIR = dumpDir;
155 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
156 } catch (Exception e) {
157 throw newInternalError(e);
158 }
159 } else {
160 DUMP_CLASS_FILES_COUNTERS = null;
161 DUMP_CLASS_FILES_DIR = null;
162 }
163 }
164
165 static void maybeDump(final String className, final byte[] classFile) {
166 if (DUMP_CLASS_FILES) {
167 java.security.AccessController.doPrivileged(
168 new java.security.PrivilegedAction<Void>() {
169 public Void run() {
170 try {
171 String dumpName = className;
172 //dumpName = dumpName.replace('/', '-');
173 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
174 System.out.println("dump: " + dumpFile);
175 dumpFile.getParentFile().mkdirs();
176 FileOutputStream file = new FileOutputStream(dumpFile);
177 file.write(classFile);
178 file.close();
179 return null;
180 } catch (IOException ex) {
181 throw newInternalError(ex);
182 }
183 }
184 });
185 }
186
187 }
188
189 private static String makeDumpableClassName(String className) {
190 Integer ctr;
191 synchronized (DUMP_CLASS_FILES_COUNTERS) {
192 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
193 if (ctr == null) ctr = 0;
194 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
195 }
196 String sfx = ctr.toString();
197 while (sfx.length() < 3)
198 sfx = "0"+sfx;
199 className += sfx;
200 return className;
201 }
202
203 class CpPatch {
204 final int index;
205 final String placeholder;
206 final Object value;
207 CpPatch(int index, String placeholder, Object value) {
208 this.index = index;
209 this.placeholder = placeholder;
210 this.value = value;
211 }
212 public String toString() {
213 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
214 }
215 }
216
217 Map<Object, CpPatch> cpPatches = new HashMap<>();
218
219 int cph = 0; // for counting constant placeholders
220
221 String constantPlaceholder(Object arg) {
222 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
223 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid
224 if (cpPatches.containsKey(cpPlaceholder)) {
225 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
226 }
227 // insert placeholder in CP and remember the patch
228 int index = cw.newConst((Object) cpPlaceholder); // TODO check if already in the constant pool
229 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
230 return cpPlaceholder;
231 }
232
233 Object[] cpPatches(byte[] classFile) {
234 int size = getConstantPoolSize(classFile);
235 Object[] res = new Object[size];
236 for (CpPatch p : cpPatches.values()) {
237 if (p.index >= size)
238 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
239 res[p.index] = p.value;
240 }
241 return res;
242 }
243
244 private static String debugString(Object arg) {
245 if (arg instanceof MethodHandle) {
246 MethodHandle mh = (MethodHandle) arg;
247 MemberName member = mh.internalMemberName();
248 if (member != null)
249 return member.toString();
250 return mh.debugString();
251 }
252 return arg.toString();
253 }
254
255 /**
256 * Extract the number of constant pool entries from a given class file.
257 *
258 * @param classFile the bytes of the class file in question.
259 * @return the number of entries in the constant pool.
260 */
261 private static int getConstantPoolSize(byte[] classFile) {
262 // The first few bytes:
263 // u4 magic;
264 // u2 minor_version;
265 // u2 major_version;
266 // u2 constant_pool_count;
267 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
268 }
269
270 /**
271 * Extract the MemberName of a newly-defined method.
272 */
273 private MemberName loadMethod(byte[] classFile) {
274 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
275 return resolveInvokerMember(invokerClass, invokerName, invokerType);
276 }
277
278 /**
279 * Define a given class as anonymous class in the runtime system.
280 */
281 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
282 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
283 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
284 return invokerClass;
285 }
286
287 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
288 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
289 //System.out.println("resolveInvokerMember => "+member);
290 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
291 try {
292 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
293 } catch (ReflectiveOperationException e) {
294 throw newInternalError(e);
295 }
296 //System.out.println("resolveInvokerMember => "+member);
297 return member;
298 }
299
300 /**
301 * Set up class file generation.
302 */
303 private void classFilePrologue() {
304 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
305 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
306 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
307 cw.visitSource(sourceFile, null);
308
309 String invokerDesc = invokerType.toMethodDescriptorString();
310 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
311 }
312
313 /**
314 * Tear down class file generation.
315 */
316 private void classFileEpilogue() {
317 mv.visitMaxs(0, 0);
318 mv.visitEnd();
319 }
320
321 /*
322 * Low-level emit helpers.
323 */
324 private void emitConst(Object con) {
325 if (con == null) {
326 mv.visitInsn(Opcodes.ACONST_NULL);
327 return;
328 }
329 if (con instanceof Integer) {
330 emitIconstInsn((int) con);
331 return;
332 }
333 if (con instanceof Long) {
334 long x = (long) con;
335 if (x == (short) x) {
336 emitIconstInsn((int) x);
337 mv.visitInsn(Opcodes.I2L);
338 return;
339 }
340 }
341 if (con instanceof Float) {
342 float x = (float) con;
343 if (x == (short) x) {
344 emitIconstInsn((int) x);
345 mv.visitInsn(Opcodes.I2F);
346 return;
347 }
348 }
349 if (con instanceof Double) {
350 double x = (double) con;
351 if (x == (short) x) {
352 emitIconstInsn((int) x);
353 mv.visitInsn(Opcodes.I2D);
354 return;
355 }
356 }
357 if (con instanceof Boolean) {
358 emitIconstInsn((boolean) con ? 1 : 0);
359 return;
360 }
361 // fall through:
362 mv.visitLdcInsn(con);
363 }
364
365 private void emitIconstInsn(int i) {
366 int opcode;
367 switch (i) {
368 case 0: opcode = Opcodes.ICONST_0; break;
369 case 1: opcode = Opcodes.ICONST_1; break;
370 case 2: opcode = Opcodes.ICONST_2; break;
371 case 3: opcode = Opcodes.ICONST_3; break;
372 case 4: opcode = Opcodes.ICONST_4; break;
373 case 5: opcode = Opcodes.ICONST_5; break;
374 default:
375 if (i == (byte) i) {
376 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
377 } else if (i == (short) i) {
378 mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
379 } else {
380 mv.visitLdcInsn(i);
381 }
382 return;
383 }
384 mv.visitInsn(opcode);
385 }
386
387 /*
388 * NOTE: These load/store methods use the localsMap to find the correct index!
389 */
390 private void emitLoadInsn(BasicType type, int index) {
391 int opcode = loadInsnOpcode(type);
392 mv.visitVarInsn(opcode, localsMap[index]);
393 }
394
395 private int loadInsnOpcode(BasicType type) throws InternalError {
396 switch (type) {
397 case I_TYPE: return Opcodes.ILOAD;
398 case J_TYPE: return Opcodes.LLOAD;
399 case F_TYPE: return Opcodes.FLOAD;
400 case D_TYPE: return Opcodes.DLOAD;
401 case L_TYPE: return Opcodes.ALOAD;
402 default:
403 throw new InternalError("unknown type: " + type);
404 }
405 }
406 private void emitAloadInsn(int index) {
407 emitLoadInsn(L_TYPE, index);
408 }
409
410 private void emitStoreInsn(BasicType type, int index) {
411 int opcode = storeInsnOpcode(type);
412 mv.visitVarInsn(opcode, localsMap[index]);
413 }
414
415 private int storeInsnOpcode(BasicType type) throws InternalError {
416 switch (type) {
417 case I_TYPE: return Opcodes.ISTORE;
418 case J_TYPE: return Opcodes.LSTORE;
419 case F_TYPE: return Opcodes.FSTORE;
420 case D_TYPE: return Opcodes.DSTORE;
421 case L_TYPE: return Opcodes.ASTORE;
422 default:
423 throw new InternalError("unknown type: " + type);
424 }
425 }
426 private void emitAstoreInsn(int index) {
427 emitStoreInsn(L_TYPE, index);
428 }
429
430 private byte arrayTypeCode(Wrapper elementType) {
431 switch (elementType) {
432 case BOOLEAN: return Opcodes.T_BOOLEAN;
433 case BYTE: return Opcodes.T_BYTE;
434 case CHAR: return Opcodes.T_CHAR;
435 case SHORT: return Opcodes.T_SHORT;
436 case INT: return Opcodes.T_INT;
437 case LONG: return Opcodes.T_LONG;
438 case FLOAT: return Opcodes.T_FLOAT;
439 case DOUBLE: return Opcodes.T_DOUBLE;
440 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
441 default: throw new InternalError();
442 }
443 }
444
445 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
446 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
447 int xas;
448 switch (tcode) {
449 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
450 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
451 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
452 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
453 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
454 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
455 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
456 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
457 case 0: xas = Opcodes.AASTORE; break;
458 default: throw new InternalError();
459 }
460 return xas - Opcodes.AASTORE + aaop;
461 }
462
463
464 private void freeFrameLocal(int oldFrameLocal) {
465 int i = indexForFrameLocal(oldFrameLocal);
466 if (i < 0) return;
467 BasicType type = localTypes[i];
468 int newFrameLocal = makeLocalTemp(type);
469 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal);
470 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal);
471 assert(localsMap[i] == oldFrameLocal);
472 localsMap[i] = newFrameLocal;
473 assert(indexForFrameLocal(oldFrameLocal) < 0);
474 }
475 private int indexForFrameLocal(int frameLocal) {
476 for (int i = 0; i < localsMap.length; i++) {
477 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE)
478 return i;
479 }
480 return -1;
481 }
482 private int makeLocalTemp(BasicType type) {
483 int frameLocal = localsMap[localsMap.length - 1];
484 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots();
485 return frameLocal;
486 }
487
488 /**
489 * Emit a boxing call.
490 *
491 * @param wrapper primitive type class to box.
492 */
493 private void emitBoxing(Wrapper wrapper) {
494 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
495 String name = "valueOf";
496 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
497 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
498 }
499
500 /**
501 * Emit an unboxing call (plus preceding checkcast).
502 *
503 * @param wrapper wrapper type class to unbox.
504 */
505 private void emitUnboxing(Wrapper wrapper) {
506 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
507 String name = wrapper.primitiveSimpleName() + "Value";
508 String desc = "()" + wrapper.basicTypeChar();
509 emitReferenceCast(wrapper.wrapperType(), null);
510 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
511 }
512
513 /**
514 * Emit an implicit conversion for an argument which must be of the given pclass.
515 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
516 *
517 * @param ptype type of value present on stack
518 * @param pclass type of value required on stack
519 * @param arg compile-time representation of value on stack (Node, constant) or null if none
520 */
521 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
522 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
523 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
524 return; // nothing to do
525 switch (ptype) {
526 case L_TYPE:
527 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
528 if (PROFILE_LEVEL > 0)
529 emitReferenceCast(Object.class, arg);
530 return;
531 }
532 emitReferenceCast(pclass, arg);
533 return;
534 case I_TYPE:
535 if (!VerifyType.isNullConversion(int.class, pclass, false))
536 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
537 return;
538 }
539 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
540 }
541
542 /** Update localClasses type map. Return true if the information is already present. */
543 private boolean assertStaticType(Class<?> cls, Name n) {
544 int local = n.index();
545 Class<?> aclass = localClasses[local];
546 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
547 return true; // type info is already present
548 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
549 localClasses[local] = cls; // type info can be improved
550 }
551 return false;
552 }
553
554 private void emitReferenceCast(Class<?> cls, Object arg) {
555 Name writeBack = null; // local to write back result
556 if (arg instanceof Name) {
557 Name n = (Name) arg;
558 if (assertStaticType(cls, n))
559 return; // this cast was already performed
560 if (lambdaForm.useCount(n) > 1) {
561 // This guy gets used more than once.
562 writeBack = n;
563 }
564 }
565 if (isStaticallyNameable(cls)) {
566 String sig = getInternalName(cls);
567 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
568 } else {
569 mv.visitLdcInsn(constantPlaceholder(cls));
570 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
571 mv.visitInsn(Opcodes.SWAP);
572 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false);
573 if (Object[].class.isAssignableFrom(cls))
574 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
575 else if (PROFILE_LEVEL > 0)
576 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
577 }
578 if (writeBack != null) {
579 mv.visitInsn(Opcodes.DUP);
580 emitAstoreInsn(writeBack.index());
581 }
582 }
583
584 /**
585 * Emits an actual return instruction conforming to the given return type.
586 */
587 private void emitReturnInsn(BasicType type) {
588 int opcode;
589 switch (type) {
590 case I_TYPE: opcode = Opcodes.IRETURN; break;
591 case J_TYPE: opcode = Opcodes.LRETURN; break;
592 case F_TYPE: opcode = Opcodes.FRETURN; break;
593 case D_TYPE: opcode = Opcodes.DRETURN; break;
594 case L_TYPE: opcode = Opcodes.ARETURN; break;
595 case V_TYPE: opcode = Opcodes.RETURN; break;
596 default:
597 throw new InternalError("unknown return type: " + type);
598 }
599 mv.visitInsn(opcode);
600 }
601
602 private static String getInternalName(Class<?> c) {
603 if (c == Object.class) return OBJ;
604 else if (c == Object[].class) return OBJARY;
605 else if (c == Class.class) return CLS;
606 else if (c == MethodHandle.class) return MH;
607 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
608 return c.getName().replace('.', '/');
609 }
610
611 /**
612 * Generate customized bytecode for a given LambdaForm.
613 */
614 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
615 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
616 return g.loadMethod(g.generateCustomizedCodeBytes());
617 }
618
619 /**
620 * Generate an invoker method for the passed {@link LambdaForm}.
621 */
622 private byte[] generateCustomizedCodeBytes() {
623 classFilePrologue();
624
625 // Suppress this method in backtraces displayed to the user.
626 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
627
628 // Mark this method as a compiled LambdaForm
629 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
630
631 if (lambdaForm.forceInline) {
632 // Force inlining of this invoker method.
633 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
634 } else {
635 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
636 }
637
638
639 // iterate over the form's names, generating bytecode instructions for each
640 // start iterating at the first name following the arguments
641 Name onStack = null;
642 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
643 Name name = lambdaForm.names[i];
644
645 emitStoreResult(onStack);
646 onStack = name; // unless otherwise modified below
647 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
648 switch (intr) {
649 case SELECT_ALTERNATIVE:
650 assert isSelectAlternative(i);
651 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
652 i++; // skip MH.invokeBasic of the selectAlternative result
653 continue;
654 case GUARD_WITH_CATCH:
655 assert isGuardWithCatch(i);
656 onStack = emitGuardWithCatch(i);
657 i = i+2; // Jump to the end of GWC idiom
658 continue;
659 case NEW_ARRAY:
660 Class<?> rtype = name.function.methodType().returnType();
661 if (isStaticallyNameable(rtype)) {
662 emitNewArray(name);
663 continue;
664 }
665 break;
666 case ARRAY_LOAD:
667 emitArrayLoad(name);
668 continue;
669 case ARRAY_STORE:
670 emitArrayStore(name);
671 continue;
672 case IDENTITY:
673 assert(name.arguments.length == 1);
674 emitPushArguments(name);
675 continue;
676 case ZERO:
677 assert(name.arguments.length == 0);
678 emitConst(name.type.basicTypeWrapper().zero());
679 continue;
680 case NONE:
681 // no intrinsic associated
682 break;
683 default:
684 throw newInternalError("Unknown intrinsic: "+intr);
685 }
686
687 MemberName member = name.function.member();
688 if (isStaticallyInvocable(member)) {
689 emitStaticInvoke(member, name);
690 } else {
691 emitInvoke(name);
692 }
693 }
694
695 // return statement
696 emitReturn(onStack);
697
698 classFileEpilogue();
699 bogusMethod(lambdaForm);
700
701 final byte[] classFile = cw.toByteArray();
702 maybeDump(className, classFile);
703 return classFile;
704 }
705
706 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
707 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
708
709 void emitArrayOp(Name name, int arrayOpcode) {
710 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE;
711 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
712 assert elementType != null;
713 emitPushArguments(name);
714 if (elementType.isPrimitive()) {
715 Wrapper w = Wrapper.forPrimitiveType(elementType);
716 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
717 }
718 mv.visitInsn(arrayOpcode);
719 }
720
721 /**
722 * Emit an invoke for the given name.
723 */
724 void emitInvoke(Name name) {
725 assert(!isLinkerMethodInvoke(name)); // should use the static path for these
726 if (true) {
727 // push receiver
728 MethodHandle target = name.function.resolvedHandle;
729 assert(target != null) : name.exprString();
730 mv.visitLdcInsn(constantPlaceholder(target));
731 emitReferenceCast(MethodHandle.class, target);
732 } else {
733 // load receiver
734 emitAloadInsn(0);
735 emitReferenceCast(MethodHandle.class, null);
736 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
737 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
738 // TODO more to come
739 }
740
741 // push arguments
742 emitPushArguments(name);
743
744 // invocation
745 MethodType type = name.function.methodType();
746 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
747 }
748
749 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
750 // Sample classes from each package we are willing to bind to statically:
751 java.lang.Object.class,
752 java.util.Arrays.class,
753 sun.misc.Unsafe.class
754 //MethodHandle.class already covered
755 };
756
757 static boolean isStaticallyInvocable(Name name) {
758 return isStaticallyInvocable(name.function.member());
759 }
760
761 static boolean isStaticallyInvocable(MemberName member) {
762 if (member == null) return false;
763 if (member.isConstructor()) return false;
764 Class<?> cls = member.getDeclaringClass();
765 if (cls.isArray() || cls.isPrimitive())
766 return false; // FIXME
767 if (cls.isAnonymousClass() || cls.isLocalClass())
768 return false; // inner class of some sort
769 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
770 return false; // not on BCP
771 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
772 return false;
773 MethodType mtype = member.getMethodOrFieldType();
774 if (!isStaticallyNameable(mtype.returnType()))
775 return false;
776 for (Class<?> ptype : mtype.parameterArray())
777 if (!isStaticallyNameable(ptype))
778 return false;
779 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
780 return true; // in java.lang.invoke package
781 if (member.isPublic() && isStaticallyNameable(cls))
782 return true;
783 return false;
784 }
785
786 static boolean isStaticallyNameable(Class<?> cls) {
787 if (cls == Object.class)
788 return true;
789 while (cls.isArray())
790 cls = cls.getComponentType();
791 if (cls.isPrimitive())
792 return true; // int[].class, for example
793 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
794 return false;
795 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
796 if (cls.getClassLoader() != Object.class.getClassLoader())
797 return false;
798 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
799 return true;
800 if (!Modifier.isPublic(cls.getModifiers()))
801 return false;
802 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
803 if (VerifyAccess.isSamePackage(pkgcls, cls))
804 return true;
805 }
806 return false;
807 }
808
809 void emitStaticInvoke(Name name) {
810 emitStaticInvoke(name.function.member(), name);
811 }
812
813 /**
814 * Emit an invoke for the given name, using the MemberName directly.
815 */
816 void emitStaticInvoke(MemberName member, Name name) {
817 assert(member.equals(name.function.member()));
818 Class<?> defc = member.getDeclaringClass();
819 String cname = getInternalName(defc);
820 String mname = member.getName();
821 String mtype;
822 byte refKind = member.getReferenceKind();
823 if (refKind == REF_invokeSpecial) {
824 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
825 assert(member.canBeStaticallyBound()) : member;
826 refKind = REF_invokeVirtual;
827 }
828
829 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
830 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
831 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
832 refKind = REF_invokeInterface;
833 }
834
835 // push arguments
836 emitPushArguments(name);
837
838 // invocation
839 if (member.isMethod()) {
840 mtype = member.getMethodType().toMethodDescriptorString();
841 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
842 member.getDeclaringClass().isInterface());
843 } else {
844 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
845 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
846 }
847 // Issue a type assertion for the result, so we can avoid casts later.
848 if (name.type == L_TYPE) {
849 Class<?> rtype = member.getInvocationType().returnType();
850 assert(!rtype.isPrimitive());
851 if (rtype != Object.class && !rtype.isInterface()) {
852 assertStaticType(rtype, name);
853 }
854 }
855 }
856
857 void emitNewArray(Name name) throws InternalError {
858 Class<?> rtype = name.function.methodType().returnType();
859 if (name.arguments.length == 0) {
860 // The array will be a constant.
861 Object emptyArray;
862 try {
863 emptyArray = name.function.resolvedHandle.invoke();
864 } catch (Throwable ex) {
865 throw newInternalError(ex);
866 }
867 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
868 assert(emptyArray.getClass() == rtype); // exact typing
869 mv.visitLdcInsn(constantPlaceholder(emptyArray));
870 emitReferenceCast(rtype, emptyArray);
871 return;
872 }
873 Class<?> arrayElementType = rtype.getComponentType();
874 assert(arrayElementType != null);
875 emitIconstInsn(name.arguments.length);
876 int xas = Opcodes.AASTORE;
877 if (!arrayElementType.isPrimitive()) {
878 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
879 } else {
880 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
881 xas = arrayInsnOpcode(tc, xas);
882 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
883 }
884 // store arguments
885 for (int i = 0; i < name.arguments.length; i++) {
886 mv.visitInsn(Opcodes.DUP);
887 emitIconstInsn(i);
888 emitPushArgument(name, i);
889 mv.visitInsn(xas);
890 }
891 // the array is left on the stack
892 assertStaticType(rtype, name);
893 }
894 int refKindOpcode(byte refKind) {
895 switch (refKind) {
896 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
897 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
898 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
899 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
900 case REF_getField: return Opcodes.GETFIELD;
901 case REF_putField: return Opcodes.PUTFIELD;
902 case REF_getStatic: return Opcodes.GETSTATIC;
903 case REF_putStatic: return Opcodes.PUTSTATIC;
904 }
905 throw new InternalError("refKind="+refKind);
906 }
907
908 /**
909 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
910 */
911 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) {
912 return member != null &&
913 member.getDeclaringClass() == declaringClass &&
914 member.getName().equals(name);
915 }
916 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) {
917 return name.function != null &&
918 memberRefersTo(name.function.member(), declaringClass, methodName);
919 }
920
921 /**
922 * Check if MemberName is a call to MethodHandle.invokeBasic.
923 */
924 private boolean isInvokeBasic(Name name) {
925 if (name.function == null)
926 return false;
927 if (name.arguments.length < 1)
928 return false; // must have MH argument
929 MemberName member = name.function.member();
930 return memberRefersTo(member, MethodHandle.class, "invokeBasic") &&
931 !member.isPublic() && !member.isStatic();
932 }
933
934 /**
935 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
936 */
937 private boolean isLinkerMethodInvoke(Name name) {
938 if (name.function == null)
939 return false;
940 if (name.arguments.length < 1)
941 return false; // must have MH argument
942 MemberName member = name.function.member();
943 return member != null &&
944 member.getDeclaringClass() == MethodHandle.class &&
945 !member.isPublic() && member.isStatic() &&
946 member.getName().startsWith("linkTo");
947 }
948
949 /**
950 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
951 */
952 private boolean isSelectAlternative(int pos) {
953 // selectAlternative idiom:
954 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
955 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
956 if (pos+1 >= lambdaForm.names.length) return false;
957 Name name0 = lambdaForm.names[pos];
958 Name name1 = lambdaForm.names[pos+1];
959 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") &&
960 isInvokeBasic(name1) &&
961 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
962 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
963 }
964
965 /**
966 * Check if i-th name is a start of GuardWithCatch idiom.
967 */
968 private boolean isGuardWithCatch(int pos) {
969 // GuardWithCatch idiom:
970 // t_{n}:L=MethodHandle.invokeBasic(...)
971 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
972 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
973 if (pos+2 >= lambdaForm.names.length) return false;
974 Name name0 = lambdaForm.names[pos];
975 Name name1 = lambdaForm.names[pos+1];
976 Name name2 = lambdaForm.names[pos+2];
977 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") &&
978 isInvokeBasic(name0) &&
979 isInvokeBasic(name2) &&
980 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
981 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
982 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
983 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
984 }
985
986 /**
987 * Emit bytecode for the selectAlternative idiom.
988 *
989 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
990 * <blockquote><pre>{@code
991 * Lambda(a0:L,a1:I)=>{
992 * t2:I=foo.test(a1:I);
993 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
994 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
995 * }</pre></blockquote>
996 */
997 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
998 assert isStaticallyInvocable(invokeBasicName);
999
1000 Name receiver = (Name) invokeBasicName.arguments[0];
1001
1002 Label L_fallback = new Label();
1003 Label L_done = new Label();
1004
1005 // load test result
1006 emitPushArgument(selectAlternativeName, 0);
1007
1008 // if_icmpne L_fallback
1009 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1010
1011 // invoke selectAlternativeName.arguments[1]
1012 Class<?>[] preForkClasses = localClasses.clone();
1013 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1014 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1015 emitStaticInvoke(invokeBasicName);
1016
1017 // goto L_done
1018 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1019
1020 // L_fallback:
1021 mv.visitLabel(L_fallback);
1022
1023 // invoke selectAlternativeName.arguments[2]
1024 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1025 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1026 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1027 emitStaticInvoke(invokeBasicName);
1028
1029 // L_done:
1030 mv.visitLabel(L_done);
1031 // for now do not bother to merge typestate; just reset to the dominator state
1032 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1033
1034 return invokeBasicName; // return what's on stack
1035 }
1036
1037 /**
1038 * Emit bytecode for the guardWithCatch idiom.
1039 *
1040 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1041 * <blockquote><pre>{@code
1042 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1043 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1044 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1045 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1046 * }</pre></blockquote>
1047 *
1048 * It is compiled into bytecode equivalent of the following code:
1049 * <blockquote><pre>{@code
1050 * try {
1051 * return a1.invokeBasic(a6, a7);
1052 * } catch (Throwable e) {
1053 * if (!a2.isInstance(e)) throw e;
1054 * return a3.invokeBasic(ex, a6, a7);
1055 * }}
1056 */
1057 private Name emitGuardWithCatch(int pos) {
1058 Name args = lambdaForm.names[pos];
1059 Name invoker = lambdaForm.names[pos+1];
1060 Name result = lambdaForm.names[pos+2];
1061
1062 Label L_startBlock = new Label();
1063 Label L_endBlock = new Label();
1064 Label L_handler = new Label();
1065 Label L_done = new Label();
1066
1067 Class<?> returnType = result.function.resolvedHandle.type().returnType();
1068 MethodType type = args.function.resolvedHandle.type()
1069 .dropParameterTypes(0,1)
1070 .changeReturnType(returnType);
1071
1072 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1073
1074 // Normal case
1075 mv.visitLabel(L_startBlock);
1076 // load target
1077 emitPushArgument(invoker, 0);
1078 emitPushArguments(args, 1); // skip 1st argument: method handle
1079 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1080 mv.visitLabel(L_endBlock);
1081 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1082
1083 // Exceptional case
1084 mv.visitLabel(L_handler);
1085
1086 // Check exception's type
1087 mv.visitInsn(Opcodes.DUP);
1088 // load exception class
1089 emitPushArgument(invoker, 1);
1090 mv.visitInsn(Opcodes.SWAP);
1091 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1092 Label L_rethrow = new Label();
1093 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1094
1095 // Invoke catcher
1096 // load catcher
1097 emitPushArgument(invoker, 2);
1098 mv.visitInsn(Opcodes.SWAP);
1099 emitPushArguments(args, 1); // skip 1st argument: method handle
1100 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1101 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1102 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1103
1104 mv.visitLabel(L_rethrow);
1105 mv.visitInsn(Opcodes.ATHROW);
1106
1107 mv.visitLabel(L_done);
1108
1109 return result;
1110 }
1111
1112 private void emitPushArguments(Name args) {
1113 emitPushArguments(args, 0);
1114 }
1115
1116 private void emitPushArguments(Name args, int start) {
1117 for (int i = start; i < args.arguments.length; i++) {
1118 emitPushArgument(args, i);
1119 }
1120 }
1121
1122 private void emitPushArgument(Name name, int paramIndex) {
1123 Object arg = name.arguments[paramIndex];
1124 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1125 emitPushArgument(ptype, arg);
1126 }
1127
1128 private void emitPushArgument(Class<?> ptype, Object arg) {
1129 BasicType bptype = basicType(ptype);
1130 if (arg instanceof Name) {
1131 Name n = (Name) arg;
1132 emitLoadInsn(n.type, n.index());
1133 emitImplicitConversion(n.type, ptype, n);
1134 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1135 emitConst(arg);
1136 } else {
1137 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1138 emitConst(arg);
1139 } else {
1140 mv.visitLdcInsn(constantPlaceholder(arg));
1141 emitImplicitConversion(L_TYPE, ptype, arg);
1142 }
1143 }
1144 }
1145
1146 /**
1147 * Store the name to its local, if necessary.
1148 */
1149 private void emitStoreResult(Name name) {
1150 if (name != null && name.type != V_TYPE) {
1151 // non-void: actually assign
1152 emitStoreInsn(name.type, name.index());
1153 }
1154 }
1155
1156 /**
1157 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1158 */
1159 private void emitReturn(Name onStack) {
1160 // return statement
1161 Class<?> rclass = invokerType.returnType();
1162 BasicType rtype = lambdaForm.returnType();
1163 assert(rtype == basicType(rclass)); // must agree
1164 if (rtype == V_TYPE) {
1165 // void
1166 mv.visitInsn(Opcodes.RETURN);
1167 // it doesn't matter what rclass is; the JVM will discard any value
1168 } else {
1169 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1170
1171 // put return value on the stack if it is not already there
1172 if (rn != onStack) {
1173 emitLoadInsn(rtype, lambdaForm.result);
1174 }
1175
1176 emitImplicitConversion(rtype, rclass, rn);
1177
1178 // generate actual return statement
1179 emitReturnInsn(rtype);
1180 }
1181 }
1182
1183 /**
1184 * Emit a type conversion bytecode casting from "from" to "to".
1185 */
1186 private void emitPrimCast(Wrapper from, Wrapper to) {
1187 // Here's how.
1188 // - indicates forbidden
1189 // <-> indicates implicit
1190 // to ----> boolean byte short char int long float double
1191 // from boolean <-> - - - - - - -
1192 // byte - <-> i2s i2c <-> i2l i2f i2d
1193 // short - i2b <-> i2c <-> i2l i2f i2d
1194 // char - i2b i2s <-> <-> i2l i2f i2d
1195 // int - i2b i2s i2c <-> i2l i2f i2d
1196 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1197 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1198 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1199 if (from == to) {
1200 // no cast required, should be dead code anyway
1201 return;
1202 }
1203 if (from.isSubwordOrInt()) {
1204 // cast from {byte,short,char,int} to anything
1205 emitI2X(to);
1206 } else {
1207 // cast from {long,float,double} to anything
1208 if (to.isSubwordOrInt()) {
1209 // cast to {byte,short,char,int}
1210 emitX2I(from);
1211 if (to.bitWidth() < 32) {
1212 // targets other than int require another conversion
1213 emitI2X(to);
1214 }
1215 } else {
1216 // cast to {long,float,double} - this is verbose
1217 boolean error = false;
1218 switch (from) {
1219 case LONG:
1220 switch (to) {
1221 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1222 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1223 default: error = true; break;
1224 }
1225 break;
1226 case FLOAT:
1227 switch (to) {
1228 case LONG : mv.visitInsn(Opcodes.F2L); break;
1229 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1230 default: error = true; break;
1231 }
1232 break;
1233 case DOUBLE:
1234 switch (to) {
1235 case LONG : mv.visitInsn(Opcodes.D2L); break;
1236 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1237 default: error = true; break;
1238 }
1239 break;
1240 default:
1241 error = true;
1242 break;
1243 }
1244 if (error) {
1245 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1246 }
1247 }
1248 }
1249 }
1250
1251 private void emitI2X(Wrapper type) {
1252 switch (type) {
1253 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1254 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1255 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1256 case INT: /* naught */ break;
1257 case LONG: mv.visitInsn(Opcodes.I2L); break;
1258 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1259 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1260 case BOOLEAN:
1261 // For compatibility with ValueConversions and explicitCastArguments:
1262 mv.visitInsn(Opcodes.ICONST_1);
1263 mv.visitInsn(Opcodes.IAND);
1264 break;
1265 default: throw new InternalError("unknown type: " + type);
1266 }
1267 }
1268
1269 private void emitX2I(Wrapper type) {
1270 switch (type) {
1271 case LONG: mv.visitInsn(Opcodes.L2I); break;
1272 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1273 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1274 default: throw new InternalError("unknown type: " + type);
1275 }
1276 }
1277
1278 /**
1279 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1280 */
1281 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1282 assert(isValidSignature(sig));
1283 String name = "interpret_"+signatureReturn(sig).basicTypeChar();
1284 MethodType type = signatureType(sig); // sig includes leading argument
1285 type = type.changeParameterType(0, MethodHandle.class);
1286 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1287 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1288 }
1289
1290 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1291 classFilePrologue();
1292
1293 // Suppress this method in backtraces displayed to the user.
1294 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1295
1296 // Don't inline the interpreter entry.
1297 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1298
1299 // create parameter array
1300 emitIconstInsn(invokerType.parameterCount());
1301 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1302
1303 // fill parameter array
1304 for (int i = 0; i < invokerType.parameterCount(); i++) {
1305 Class<?> ptype = invokerType.parameterType(i);
1306 mv.visitInsn(Opcodes.DUP);
1307 emitIconstInsn(i);
1308 emitLoadInsn(basicType(ptype), i);
1309 // box if primitive type
1310 if (ptype.isPrimitive()) {
1311 emitBoxing(Wrapper.forPrimitiveType(ptype));
1312 }
1313 mv.visitInsn(Opcodes.AASTORE);
1314 }
1315 // invoke
1316 emitAloadInsn(0);
1317 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1318 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1319 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1320
1321 // maybe unbox
1322 Class<?> rtype = invokerType.returnType();
1323 if (rtype.isPrimitive() && rtype != void.class) {
1324 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1325 }
1326
1327 // return statement
1328 emitReturnInsn(basicType(rtype));
1329
1330 classFileEpilogue();
1331 bogusMethod(invokerType);
1332
1333 final byte[] classFile = cw.toByteArray();
1334 maybeDump(className, classFile);
1335 return classFile;
1336 }
1337
1338 /**
1339 * Generate bytecode for a NamedFunction invoker.
1340 */
1341 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1342 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1343 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1344 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1345 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1346 }
1347
1348 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1349 MethodType dstType = typeForm.erasedType();
1350 classFilePrologue();
1351
1352 // Suppress this method in backtraces displayed to the user.
1353 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1354
1355 // Force inlining of this invoker method.
1356 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1357
1358 // Load receiver
1359 emitAloadInsn(0);
1360
1361 // Load arguments from array
1362 for (int i = 0; i < dstType.parameterCount(); i++) {
1363 emitAloadInsn(1);
1364 emitIconstInsn(i);
1365 mv.visitInsn(Opcodes.AALOAD);
1366
1367 // Maybe unbox
1368 Class<?> dptype = dstType.parameterType(i);
1369 if (dptype.isPrimitive()) {
1370 Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1371 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1372 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1373 emitUnboxing(srcWrapper);
1374 emitPrimCast(srcWrapper, dstWrapper);
1375 }
1376 }
1377
1378 // Invoke
1379 String targetDesc = dstType.basicType().toMethodDescriptorString();
1380 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1381
1382 // Box primitive types
1383 Class<?> rtype = dstType.returnType();
1384 if (rtype != void.class && rtype.isPrimitive()) {
1385 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1386 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1387 // boolean casts not allowed
1388 emitPrimCast(srcWrapper, dstWrapper);
1389 emitBoxing(dstWrapper);
1390 }
1391
1392 // If the return type is void we return a null reference.
1393 if (rtype == void.class) {
1394 mv.visitInsn(Opcodes.ACONST_NULL);
1395 }
1396 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1397
1398 classFileEpilogue();
1399 bogusMethod(dstType);
1400
1401 final byte[] classFile = cw.toByteArray();
1402 maybeDump(className, classFile);
1403 return classFile;
1404 }
1405
1406 /**
1407 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1408 * for debugging purposes.
1409 */
1410 private void bogusMethod(Object... os) {
1411 if (DUMP_CLASS_FILES) {
1412 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1413 for (Object o : os) {
1414 mv.visitLdcInsn(o.toString());
1415 mv.visitInsn(Opcodes.POP);
1416 }
1417 mv.visitInsn(Opcodes.RETURN);
1418 mv.visitMaxs(0, 0);
1419 mv.visitEnd();
1420 }
1421 }
1422 }