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 import java.lang.invoke.MethodHandleImpl.ArrayAccessor;
39 import sun.invoke.util.ValueConversions;
40 import sun.invoke.util.VerifyAccess;
41 import sun.invoke.util.VerifyType;
42 import sun.invoke.util.Wrapper;
43 import sun.reflect.misc.ReflectUtil;
44
45 /**
46 * Code generation backend for LambdaForm.
47 * <p>
48 * @author John Rose, JSR 292 EG
49 */
50 class InvokerBytecodeGenerator {
51 /** Define class names for convenience. */
52 private static final String MH = "java/lang/invoke/MethodHandle";
53 private static final String MHI = "java/lang/invoke/MethodHandleImpl";
54 private static final String LF = "java/lang/invoke/LambdaForm";
55 private static final String LFN = "java/lang/invoke/LambdaForm$Name";
56 private static final String CLS = "java/lang/Class";
57 private static final String OBJ = "java/lang/Object";
58 private static final String OBJARY = "[Ljava/lang/Object;";
59
60 private static final String LF_SIG = "L" + LF + ";";
61 private static final String LFN_SIG = "L" + LFN + ";";
62 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
63 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";";
64
65 /** Name of its super class*/
66 private static final String superName = LF;
67
68 /** Name of new class */
69 private final String className;
70
71 /** Name of the source file (for stack trace printing). */
72 private final String sourceFile;
73
74 private final LambdaForm lambdaForm;
75 private final String invokerName;
76 private final MethodType invokerType;
77
78 /** Info about local variables in compiled lambda form */
79 private final int[] localsMap; // index
80 private final BasicType[] localTypes; // basic type
81 private final Class<?>[] localClasses; // type
82
83 /** ASM bytecode generation. */
84 private ClassWriter cw;
85 private MethodVisitor mv;
86
87 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
88 private static final Class<?> HOST_CLASS = LambdaForm.class;
89
90 /** Main constructor; other constructors delegate to this one. */
91 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
92 String className, String invokerName, MethodType invokerType) {
93 if (invokerName.contains(".")) {
94 int p = invokerName.indexOf('.');
95 className = invokerName.substring(0, p);
96 invokerName = invokerName.substring(p+1);
97 }
98 if (DUMP_CLASS_FILES) {
99 className = makeDumpableClassName(className);
100 }
101 this.className = superName + "$" + className;
102 this.sourceFile = "LambdaForm$" + className;
103 this.lambdaForm = lambdaForm;
104 this.invokerName = invokerName;
105 this.invokerType = invokerType;
106 this.localsMap = new int[localsMapSize+1];
107 // last entry of localsMap is count of allocated local slots
108 this.localTypes = new BasicType[localsMapSize+1];
109 this.localClasses = new Class<?>[localsMapSize+1];
110 }
111
112 /** For generating LambdaForm interpreter entry points. */
113 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
114 this(null, invokerType.parameterCount(),
115 className, invokerName, invokerType);
116 // Create an array to map name indexes to locals indexes.
117 localTypes[localTypes.length - 1] = V_TYPE;
118 for (int i = 0; i < localsMap.length; i++) {
119 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
120 if (i < invokerType.parameterCount())
121 localTypes[i] = basicType(invokerType.parameterType(i));
122 }
123 }
124
125 /** For generating customized code for a single LambdaForm. */
126 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
127 this(form, form.names.length,
128 className, form.debugName, invokerType);
129 // Create an array to map name indexes to locals indexes.
130 Name[] names = form.names;
131 for (int i = 0, index = 0; i < localsMap.length; i++) {
132 localsMap[i] = index;
133 if (i < names.length) {
134 BasicType type = names[i].type();
135 index += type.basicTypeSlots();
136 localTypes[i] = type;
137 }
138 }
139 }
140
141
142 /** instance counters for dumped classes */
143 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
144 /** debugging flag for saving generated class files */
145 private final static File DUMP_CLASS_FILES_DIR;
146
147 static {
148 if (DUMP_CLASS_FILES) {
149 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
150 try {
151 File dumpDir = new File("DUMP_CLASS_FILES");
152 if (!dumpDir.exists()) {
153 dumpDir.mkdirs();
154 }
155 DUMP_CLASS_FILES_DIR = dumpDir;
156 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
157 } catch (Exception e) {
158 throw newInternalError(e);
159 }
160 } else {
161 DUMP_CLASS_FILES_COUNTERS = null;
162 DUMP_CLASS_FILES_DIR = null;
163 }
164 }
165
166 static void maybeDump(final String className, final byte[] classFile) {
167 if (DUMP_CLASS_FILES) {
168 java.security.AccessController.doPrivileged(
169 new java.security.PrivilegedAction<Void>() {
170 public Void run() {
171 try {
172 String dumpName = className;
173 //dumpName = dumpName.replace('/', '-');
174 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
175 System.out.println("dump: " + dumpFile);
176 dumpFile.getParentFile().mkdirs();
177 FileOutputStream file = new FileOutputStream(dumpFile);
178 file.write(classFile);
179 file.close();
180 return null;
181 } catch (IOException ex) {
182 throw newInternalError(ex);
183 }
184 }
185 });
186 }
187
188 }
189
190 private static String makeDumpableClassName(String className) {
191 Integer ctr;
192 synchronized (DUMP_CLASS_FILES_COUNTERS) {
193 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
194 if (ctr == null) ctr = 0;
195 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
196 }
197 String sfx = ctr.toString();
198 while (sfx.length() < 3)
199 sfx = "0"+sfx;
200 className += sfx;
201 return className;
202 }
203
204 class CpPatch {
205 final int index;
206 final String placeholder;
207 final Object value;
208 CpPatch(int index, String placeholder, Object value) {
209 this.index = index;
210 this.placeholder = placeholder;
211 this.value = value;
212 }
213 public String toString() {
214 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
215 }
216 }
217
218 Map<Object, CpPatch> cpPatches = new HashMap<>();
219
220 int cph = 0; // for counting constant placeholders
221
222 String constantPlaceholder(Object arg) {
223 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
224 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid
225 if (cpPatches.containsKey(cpPlaceholder)) {
226 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
227 }
228 // insert placeholder in CP and remember the patch
229 int index = cw.newConst((Object) cpPlaceholder); // TODO check if aready in the constant pool
230 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
231 return cpPlaceholder;
232 }
233
234 Object[] cpPatches(byte[] classFile) {
235 int size = getConstantPoolSize(classFile);
236 Object[] res = new Object[size];
237 for (CpPatch p : cpPatches.values()) {
238 if (p.index >= size)
239 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
240 res[p.index] = p.value;
241 }
242 return res;
243 }
244
245 private static String debugString(Object arg) {
246 if (arg instanceof MethodHandle) {
247 MethodHandle mh = (MethodHandle) arg;
248 MemberName member = mh.internalMemberName();
249 if (member != null)
250 return member.toString();
251 return mh.debugString();
252 }
253 return arg.toString();
254 }
255
256 /**
257 * Extract the number of constant pool entries from a given class file.
258 *
259 * @param classFile the bytes of the class file in question.
260 * @return the number of entries in the constant pool.
261 */
262 private static int getConstantPoolSize(byte[] classFile) {
263 // The first few bytes:
264 // u4 magic;
265 // u2 minor_version;
266 // u2 major_version;
267 // u2 constant_pool_count;
268 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
269 }
270
271 /**
272 * Extract the MemberName of a newly-defined method.
273 */
274 private MemberName loadMethod(byte[] classFile) {
275 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
276 return resolveInvokerMember(invokerClass, invokerName, invokerType);
277 }
278
279 /**
280 * Define a given class as anonymous class in the runtime system.
281 */
282 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
283 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
284 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
285 return invokerClass;
286 }
287
288 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
289 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
290 //System.out.println("resolveInvokerMember => "+member);
291 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
292 try {
293 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
294 } catch (ReflectiveOperationException e) {
295 throw newInternalError(e);
296 }
297 //System.out.println("resolveInvokerMember => "+member);
298 return member;
299 }
300
301 /**
302 * Set up class file generation.
303 */
304 private void classFilePrologue() {
305 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
306 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
307 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
308 cw.visitSource(sourceFile, null);
309
310 String invokerDesc = invokerType.toMethodDescriptorString();
311 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
312 }
313
314 /**
315 * Tear down class file generation.
316 */
317 private void classFileEpilogue() {
318 mv.visitMaxs(0, 0);
319 mv.visitEnd();
320 }
321
322 /*
323 * Low-level emit helpers.
324 */
325 private void emitConst(Object con) {
326 if (con == null) {
327 mv.visitInsn(Opcodes.ACONST_NULL);
328 return;
329 }
330 if (con instanceof Integer) {
331 emitIconstInsn((int) con);
332 return;
333 }
334 if (con instanceof Long) {
335 long x = (long) con;
336 if (x == (short) x) {
337 emitIconstInsn((int) x);
338 mv.visitInsn(Opcodes.I2L);
339 return;
340 }
341 }
342 if (con instanceof Float) {
343 float x = (float) con;
344 if (x == (short) x) {
345 emitIconstInsn((int) x);
346 mv.visitInsn(Opcodes.I2F);
347 return;
348 }
349 }
350 if (con instanceof Double) {
351 double x = (double) con;
352 if (x == (short) x) {
353 emitIconstInsn((int) x);
354 mv.visitInsn(Opcodes.I2D);
355 return;
356 }
357 }
358 if (con instanceof Boolean) {
359 emitIconstInsn((boolean) con ? 1 : 0);
360 return;
361 }
362 // fall through:
363 mv.visitLdcInsn(con);
364 }
365
366 private void emitIconstInsn(int i) {
367 int opcode;
368 switch (i) {
369 case 0: opcode = Opcodes.ICONST_0; break;
370 case 1: opcode = Opcodes.ICONST_1; break;
371 case 2: opcode = Opcodes.ICONST_2; break;
372 case 3: opcode = Opcodes.ICONST_3; break;
373 case 4: opcode = Opcodes.ICONST_4; break;
374 case 5: opcode = Opcodes.ICONST_5; break;
375 default:
376 if (i == (byte) i) {
377 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
378 } else if (i == (short) i) {
379 mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
380 } else {
381 mv.visitLdcInsn(i);
382 }
383 return;
384 }
385 mv.visitInsn(opcode);
386 }
387
388 /*
389 * NOTE: These load/store methods use the localsMap to find the correct index!
390 */
391 private void emitLoadInsn(BasicType type, int index) {
392 int opcode = loadInsnOpcode(type);
393 mv.visitVarInsn(opcode, localsMap[index]);
394 }
395
396 private int loadInsnOpcode(BasicType type) throws InternalError {
397 switch (type) {
398 case I_TYPE: return Opcodes.ILOAD;
399 case J_TYPE: return Opcodes.LLOAD;
400 case F_TYPE: return Opcodes.FLOAD;
401 case D_TYPE: return Opcodes.DLOAD;
402 case L_TYPE: return Opcodes.ALOAD;
403 default:
404 throw new InternalError("unknown type: " + type);
405 }
406 }
407 private void emitAloadInsn(int index) {
408 emitLoadInsn(L_TYPE, index);
409 }
410
411 private void emitStoreInsn(BasicType type, int index) {
412 int opcode = storeInsnOpcode(type);
413 mv.visitVarInsn(opcode, localsMap[index]);
414 }
415
416 private int storeInsnOpcode(BasicType type) throws InternalError {
417 switch (type) {
418 case I_TYPE: return Opcodes.ISTORE;
419 case J_TYPE: return Opcodes.LSTORE;
420 case F_TYPE: return Opcodes.FSTORE;
421 case D_TYPE: return Opcodes.DSTORE;
422 case L_TYPE: return Opcodes.ASTORE;
423 default:
424 throw new InternalError("unknown type: " + type);
425 }
426 }
427 private void emitAstoreInsn(int index) {
428 emitStoreInsn(L_TYPE, index);
429 }
430
431 private byte arrayTypeCode(Wrapper elementType) {
432 switch (elementType) {
433 case BOOLEAN: return Opcodes.T_BOOLEAN;
434 case BYTE: return Opcodes.T_BYTE;
435 case CHAR: return Opcodes.T_CHAR;
436 case SHORT: return Opcodes.T_SHORT;
437 case INT: return Opcodes.T_INT;
438 case LONG: return Opcodes.T_LONG;
439 case FLOAT: return Opcodes.T_FLOAT;
440 case DOUBLE: return Opcodes.T_DOUBLE;
441 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
442 default: throw new InternalError();
443 }
444 }
445
446 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
447 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
448 int xas;
449 switch (tcode) {
450 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
451 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
452 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
453 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
454 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
455 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
456 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
457 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
458 case 0: xas = Opcodes.AASTORE; break;
459 default: throw new InternalError();
460 }
461 return xas - Opcodes.AASTORE + aaop;
462 }
463
464
465 private void freeFrameLocal(int oldFrameLocal) {
466 int i = indexForFrameLocal(oldFrameLocal);
467 if (i < 0) return;
468 BasicType type = localTypes[i];
469 int newFrameLocal = makeLocalTemp(type);
470 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal);
471 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal);
472 assert(localsMap[i] == oldFrameLocal);
473 localsMap[i] = newFrameLocal;
474 assert(indexForFrameLocal(oldFrameLocal) < 0);
475 }
476 private int indexForFrameLocal(int frameLocal) {
477 for (int i = 0; i < localsMap.length; i++) {
478 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE)
479 return i;
480 }
481 return -1;
482 }
483 private int makeLocalTemp(BasicType type) {
484 int frameLocal = localsMap[localsMap.length - 1];
485 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots();
486 return frameLocal;
487 }
488
489 /**
490 * Emit a boxing call.
491 *
492 * @param wrapper primitive type class to box.
493 */
494 private void emitBoxing(Wrapper wrapper) {
495 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
496 String name = "valueOf";
497 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
498 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
499 }
500
501 /**
502 * Emit an unboxing call (plus preceding checkcast).
503 *
504 * @param wrapper wrapper type class to unbox.
505 */
506 private void emitUnboxing(Wrapper wrapper) {
507 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
508 String name = wrapper.primitiveSimpleName() + "Value";
509 String desc = "()" + wrapper.basicTypeChar();
510 emitReferenceCast(wrapper.wrapperType(), null);
511 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
512 }
513
514 /**
515 * Emit an implicit conversion for an argument which must be of the given pclass.
516 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
517 *
518 * @param ptype type of value present on stack
519 * @param pclass type of value required on stack
520 * @param arg compile-time representation of value on stack (Node, constant) or null if none
521 */
522 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
523 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
524 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
525 return; // nothing to do
526 switch (ptype) {
527 case L_TYPE:
528 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
529 if (PROFILE_LEVEL > 0)
530 emitReferenceCast(Object.class, arg);
531 return;
532 }
533 emitReferenceCast(pclass, arg);
534 return;
535 case I_TYPE:
536 if (!VerifyType.isNullConversion(int.class, pclass, false))
537 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
538 return;
539 }
540 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
541 }
542
543 /** Update localClasses type map. Return true if the information is already present. */
544 private boolean assertStaticType(Class<?> cls, Name n) {
545 int local = n.index();
546 Class<?> aclass = localClasses[local];
547 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
548 return true; // type info is already present
549 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
550 localClasses[local] = cls; // type info can be improved
551 }
552 return false;
553 }
554
555 private void emitReferenceCast(Class<?> cls, Object arg) {
556 Name writeBack = null; // local to write back result
557 if (arg instanceof Name) {
558 Name n = (Name) arg;
559 if (assertStaticType(cls, n))
560 return; // this cast was already performed
561 if (lambdaForm.useCount(n) > 1) {
562 // This guy gets used more than once.
563 writeBack = n;
564 }
565 }
566 if (isStaticallyNameable(cls)) {
567 String sig = getInternalName(cls);
568 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
569 } else {
570 mv.visitLdcInsn(constantPlaceholder(cls));
571 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
572 mv.visitInsn(Opcodes.SWAP);
573 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false);
574 if (Object[].class.isAssignableFrom(cls))
575 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
576 else if (PROFILE_LEVEL > 0)
577 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
578 }
579 if (writeBack != null) {
580 mv.visitInsn(Opcodes.DUP);
581 emitAstoreInsn(writeBack.index());
582 }
583 }
584
585 /**
586 * Emits an actual return instruction conforming to the given return type.
587 */
588 private void emitReturnInsn(BasicType type) {
589 int opcode;
590 switch (type) {
591 case I_TYPE: opcode = Opcodes.IRETURN; break;
592 case J_TYPE: opcode = Opcodes.LRETURN; break;
593 case F_TYPE: opcode = Opcodes.FRETURN; break;
594 case D_TYPE: opcode = Opcodes.DRETURN; break;
595 case L_TYPE: opcode = Opcodes.ARETURN; break;
596 case V_TYPE: opcode = Opcodes.RETURN; break;
597 default:
598 throw new InternalError("unknown return type: " + type);
599 }
600 mv.visitInsn(opcode);
601 }
602
603 private static String getInternalName(Class<?> c) {
604 if (c == Object.class) return OBJ;
605 else if (c == Object[].class) return OBJARY;
606 else if (c == Class.class) return CLS;
607 else if (c == MethodHandle.class) return MH;
608 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
609 return c.getName().replace('.', '/');
610 }
611
612 /**
613 * Generate customized bytecode for a given LambdaForm.
614 */
615 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
616 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
617 return g.loadMethod(g.generateCustomizedCodeBytes());
618 }
619
620 /**
621 * Generate an invoker method for the passed {@link LambdaForm}.
622 */
623 private byte[] generateCustomizedCodeBytes() {
624 classFilePrologue();
625
626 // Suppress this method in backtraces displayed to the user.
627 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
628
629 // Mark this method as a compiled LambdaForm
630 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
631
632 // Force inlining of this invoker method.
633 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
634
635 // iterate over the form's names, generating bytecode instructions for each
636 // start iterating at the first name following the arguments
637 Name onStack = null;
638 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
639 Name name = lambdaForm.names[i];
640 MemberName member = name.function.member();
641 Class<?> rtype = name.function.methodType().returnType();
642
643 emitStoreResult(onStack);
644 onStack = name; // unless otherwise modified below
645
646 if (isSelectAlternative(i)) {
647 onStack = emitSelectAlternative(name, lambdaForm.names[i + 1]);
648 i++; // skip MH.invokeBasic of the selectAlternative result
649 } else if (isGuardWithCatch(i)) {
650 onStack = emitGuardWithCatch(i);
651 i = i+2; // Jump to the end of GWC idiom
652 } else if (isNewArray(rtype, name)) {
653 emitNewArray(rtype, name);
654 } else if (isArrayLoad(member)) {
655 emitArrayLoad(name);
656 } else if (isArrayStore(member)) {
657 emitArrayStore(name);
658 } else if (isStaticallyInvocable(member)) {
659 emitStaticInvoke(name);
660 } else {
661 emitInvoke(name);
662 }
663 }
664
665 // return statement
666 emitReturn(onStack);
667
668 classFileEpilogue();
669 bogusMethod(lambdaForm);
670
671 final byte[] classFile = cw.toByteArray();
672 maybeDump(className, classFile);
673 return classFile;
674 }
675
676 boolean isArrayLoad(MemberName member) {
677 return member != null &&
678 member.getDeclaringClass() == ArrayAccessor.class &&
679 member.getName() != null &&
680 member.getName().startsWith("getElement");
681 }
682
683 boolean isArrayStore(MemberName member) {
684 return member != null &&
685 member.getDeclaringClass() == ArrayAccessor.class &&
686 member.getName() != null &&
687 member.getName().startsWith("setElement");
688 }
689
690 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
691 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
692
693 void emitArrayOp(Name name, int arrayOpcode) {
694 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE;
695 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
696 assert elementType != null;
697 emitPushArguments(name);
698 if (elementType.isPrimitive()) {
699 Wrapper w = Wrapper.forPrimitiveType(elementType);
700 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
701 }
702 mv.visitInsn(arrayOpcode);
703 }
704
705 /**
706 * Emit an invoke for the given name.
707 */
708 void emitInvoke(Name name) {
709 assert(!isLinkerMethodInvoke(name)); // should use the static path for these
710 if (true) {
711 // push receiver
712 MethodHandle target = name.function.resolvedHandle;
713 assert(target != null) : name.exprString();
714 mv.visitLdcInsn(constantPlaceholder(target));
715 emitReferenceCast(MethodHandle.class, target);
716 } else {
717 // load receiver
718 emitAloadInsn(0);
719 emitReferenceCast(MethodHandle.class, null);
720 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
721 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
722 // TODO more to come
723 }
724
725 // push arguments
726 emitPushArguments(name);
727
728 // invocation
729 MethodType type = name.function.methodType();
730 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
731 }
732
733 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
734 // Sample classes from each package we are willing to bind to statically:
735 java.lang.Object.class,
736 java.util.Arrays.class,
737 sun.misc.Unsafe.class
738 //MethodHandle.class already covered
739 };
740
741 static boolean isStaticallyInvocable(Name name) {
742 return isStaticallyInvocable(name.function.member());
743 }
744
745 static boolean isStaticallyInvocable(MemberName member) {
746 if (member == null) return false;
747 if (member.isConstructor()) return false;
748 Class<?> cls = member.getDeclaringClass();
749 if (cls.isArray() || cls.isPrimitive())
750 return false; // FIXME
751 if (cls.isAnonymousClass() || cls.isLocalClass())
752 return false; // inner class of some sort
753 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
754 return false; // not on BCP
755 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
756 return false;
757 MethodType mtype = member.getMethodOrFieldType();
758 if (!isStaticallyNameable(mtype.returnType()))
759 return false;
760 for (Class<?> ptype : mtype.parameterArray())
761 if (!isStaticallyNameable(ptype))
762 return false;
763 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
764 return true; // in java.lang.invoke package
765 if (member.isPublic() && isStaticallyNameable(cls))
766 return true;
767 return false;
768 }
769
770 static boolean isStaticallyNameable(Class<?> cls) {
771 if (cls == Object.class)
772 return true;
773 while (cls.isArray())
774 cls = cls.getComponentType();
775 if (cls.isPrimitive())
776 return true; // int[].class, for example
777 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
778 return false;
779 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
780 if (cls.getClassLoader() != Object.class.getClassLoader())
781 return false;
782 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
783 return true;
784 if (!Modifier.isPublic(cls.getModifiers()))
785 return false;
786 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
787 if (VerifyAccess.isSamePackage(pkgcls, cls))
788 return true;
789 }
790 return false;
791 }
792
793 void emitStaticInvoke(Name name) {
794 emitStaticInvoke(name.function.member(), name);
795 }
796
797 /**
798 * Emit an invoke for the given name, using the MemberName directly.
799 */
800 void emitStaticInvoke(MemberName member, Name name) {
801 assert(member.equals(name.function.member()));
802 Class<?> defc = member.getDeclaringClass();
803 String cname = getInternalName(defc);
804 String mname = member.getName();
805 String mtype;
806 byte refKind = member.getReferenceKind();
807 if (refKind == REF_invokeSpecial) {
808 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
809 assert(member.canBeStaticallyBound()) : member;
810 refKind = REF_invokeVirtual;
811 }
812
813 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
814 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
815 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
816 refKind = REF_invokeInterface;
817 }
818
819 // push arguments
820 emitPushArguments(name);
821
822 // invocation
823 if (member.isMethod()) {
824 mtype = member.getMethodType().toMethodDescriptorString();
825 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
826 member.getDeclaringClass().isInterface());
827 } else {
828 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
829 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
830 }
831 // Issue a type assertion for the result, so we can avoid casts later.
832 if (name.type == L_TYPE) {
833 Class<?> rtype = member.getInvocationType().returnType();
834 assert(!rtype.isPrimitive());
835 if (rtype != Object.class && !rtype.isInterface()) {
836 assertStaticType(rtype, name);
837 }
838 }
839 }
840
841 boolean isNewArray(Class<?> rtype, Name name) {
842 return rtype.isArray() &&
843 isStaticallyNameable(rtype) &&
844 isArrayBuilder(name.function.resolvedHandle) &&
845 name.arguments.length > 0;
846 }
847
848 void emitNewArray(Class<?> rtype, Name name) throws InternalError {
849 Class<?> arrayElementType = rtype.getComponentType();
850 emitIconstInsn(name.arguments.length);
851 int xas;
852 if (!arrayElementType.isPrimitive()) {
853 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
854 xas = Opcodes.AASTORE;
855 } else {
856 int tc;
857 switch (Wrapper.forPrimitiveType(arrayElementType)) {
858 case BOOLEAN: tc = Opcodes.T_BOOLEAN; xas = Opcodes.BASTORE; break;
859 case BYTE: tc = Opcodes.T_BYTE; xas = Opcodes.BASTORE; break;
860 case CHAR: tc = Opcodes.T_CHAR; xas = Opcodes.CASTORE; break;
861 case SHORT: tc = Opcodes.T_SHORT; xas = Opcodes.SASTORE; break;
862 case INT: tc = Opcodes.T_INT; xas = Opcodes.IASTORE; break;
863 case LONG: tc = Opcodes.T_LONG; xas = Opcodes.LASTORE; break;
864 case FLOAT: tc = Opcodes.T_FLOAT; xas = Opcodes.FASTORE; break;
865 case DOUBLE: tc = Opcodes.T_DOUBLE; xas = Opcodes.DASTORE; break;
866 default: throw new InternalError(rtype.getName());
867 }
868 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
869 }
870 // store arguments
871 for (int i = 0; i < name.arguments.length; i++) {
872 mv.visitInsn(Opcodes.DUP);
873 emitIconstInsn(i);
874 emitPushArgument(name, i);
875 mv.visitInsn(xas);
876 }
877 // the array is left on the stack
878 assertStaticType(rtype, name);
879 }
880 int refKindOpcode(byte refKind) {
881 switch (refKind) {
882 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
883 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
884 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
885 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
886 case REF_getField: return Opcodes.GETFIELD;
887 case REF_putField: return Opcodes.PUTFIELD;
888 case REF_getStatic: return Opcodes.GETSTATIC;
889 case REF_putStatic: return Opcodes.PUTSTATIC;
890 }
891 throw new InternalError("refKind="+refKind);
892 }
893
894 static boolean isArrayBuilder(MethodHandle fn) {
895 if (fn == null)
896 return false;
897 MethodType mtype = fn.type();
898 Class<?> rtype = mtype.returnType();
899 Class<?> arrayElementType = rtype.getComponentType();
900 if (arrayElementType == null)
901 return false;
902 List<Class<?>> ptypes = mtype.parameterList();
903 int size = ptypes.size();
904 if (!ptypes.equals(Collections.nCopies(size, arrayElementType)))
905 return false;
906 // Assume varargsArray caches pointers.
907 if (fn != ValueConversions.varargsArray(rtype, size))
908 return false;
909 return true;
910 }
911
912 static boolean match(MemberName member, MethodHandle fn) {
913 if (member == null || fn == null) return false;
914 return member.equals(fn.internalMemberName());
915 }
916
917 /**
918 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
919 */
920 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) {
921 return member != null &&
922 member.getDeclaringClass() == declaringClass &&
923 member.getName().equals(name);
924 }
925 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) {
926 return name.function != null &&
927 memberRefersTo(name.function.member(), declaringClass, methodName);
928 }
929
930 /**
931 * Check if MemberName is a call to MethodHandle.invokeBasic.
932 */
933 private boolean isInvokeBasic(Name name) {
934 if (name.function == null)
935 return false;
936 if (name.arguments.length < 1)
937 return false; // must have MH argument
938 MemberName member = name.function.member();
939 return memberRefersTo(member, MethodHandle.class, "invokeBasic") &&
940 !member.isPublic() && !member.isStatic();
941 }
942
943 /**
944 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
945 */
946 private boolean isLinkerMethodInvoke(Name name) {
947 if (name.function == null)
948 return false;
949 if (name.arguments.length < 1)
950 return false; // must have MH argument
951 MemberName member = name.function.member();
952 return member != null &&
953 member.getDeclaringClass() == MethodHandle.class &&
954 !member.isPublic() && member.isStatic() &&
955 member.getName().startsWith("linkTo");
956 }
957
958 /**
959 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
960 */
961 private boolean isSelectAlternative(int pos) {
962 // selectAlternative idiom:
963 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
964 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
965 if (pos+1 >= lambdaForm.names.length) return false;
966 Name name0 = lambdaForm.names[pos];
967 Name name1 = lambdaForm.names[pos+1];
968 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") &&
969 isInvokeBasic(name1) &&
970 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
971 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
972 }
973
974 /**
975 * Check if i-th name is a start of GuardWithCatch idiom.
976 */
977 private boolean isGuardWithCatch(int pos) {
978 // GuardWithCatch idiom:
979 // t_{n}:L=MethodHandle.invokeBasic(...)
980 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
981 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
982 if (pos+2 >= lambdaForm.names.length) return false;
983 Name name0 = lambdaForm.names[pos];
984 Name name1 = lambdaForm.names[pos+1];
985 Name name2 = lambdaForm.names[pos+2];
986 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") &&
987 isInvokeBasic(name0) &&
988 isInvokeBasic(name2) &&
989 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
990 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
991 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
992 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
993 }
994
995 /**
996 * Emit bytecode for the selectAlternative idiom.
997 *
998 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
999 * <blockquote><pre>{@code
1000 * Lambda(a0:L,a1:I)=>{
1001 * t2:I=foo.test(a1:I);
1002 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1003 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1004 * }</pre></blockquote>
1005 */
1006 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1007 assert isStaticallyInvocable(invokeBasicName);
1008
1009 Name receiver = (Name) invokeBasicName.arguments[0];
1010
1011 Label L_fallback = new Label();
1012 Label L_done = new Label();
1013
1014 // load test result
1015 emitPushArgument(selectAlternativeName, 0);
1016
1017 // if_icmpne L_fallback
1018 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1019
1020 // invoke selectAlternativeName.arguments[1]
1021 Class<?>[] preForkClasses = localClasses.clone();
1022 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1023 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1024 emitStaticInvoke(invokeBasicName);
1025
1026 // goto L_done
1027 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1028
1029 // L_fallback:
1030 mv.visitLabel(L_fallback);
1031
1032 // invoke selectAlternativeName.arguments[2]
1033 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1034 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1035 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1036 emitStaticInvoke(invokeBasicName);
1037
1038 // L_done:
1039 mv.visitLabel(L_done);
1040 // for now do not bother to merge typestate; just reset to the dominator state
1041 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1042
1043 return invokeBasicName; // return what's on stack
1044 }
1045
1046 /**
1047 * Emit bytecode for the guardWithCatch idiom.
1048 *
1049 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1050 * <blockquote><pre>{@code
1051 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1052 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1053 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1054 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1055 * }</pre></blockquote>
1056 *
1057 * It is compiled into bytecode equivalent of the following code:
1058 * <blockquote><pre>{@code
1059 * try {
1060 * return a1.invokeBasic(a6, a7);
1061 * } catch (Throwable e) {
1062 * if (!a2.isInstance(e)) throw e;
1063 * return a3.invokeBasic(ex, a6, a7);
1064 * }}
1065 */
1066 private Name emitGuardWithCatch(int pos) {
1067 Name args = lambdaForm.names[pos];
1068 Name invoker = lambdaForm.names[pos+1];
1069 Name result = lambdaForm.names[pos+2];
1070
1071 Label L_startBlock = new Label();
1072 Label L_endBlock = new Label();
1073 Label L_handler = new Label();
1074 Label L_done = new Label();
1075
1076 Class<?> returnType = result.function.resolvedHandle.type().returnType();
1077 MethodType type = args.function.resolvedHandle.type()
1078 .dropParameterTypes(0,1)
1079 .changeReturnType(returnType);
1080
1081 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1082
1083 // Normal case
1084 mv.visitLabel(L_startBlock);
1085 // load target
1086 emitPushArgument(invoker, 0);
1087 emitPushArguments(args, 1); // skip 1st argument: method handle
1088 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1089 mv.visitLabel(L_endBlock);
1090 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1091
1092 // Exceptional case
1093 mv.visitLabel(L_handler);
1094
1095 // Check exception's type
1096 mv.visitInsn(Opcodes.DUP);
1097 // load exception class
1098 emitPushArgument(invoker, 1);
1099 mv.visitInsn(Opcodes.SWAP);
1100 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1101 Label L_rethrow = new Label();
1102 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1103
1104 // Invoke catcher
1105 // load catcher
1106 emitPushArgument(invoker, 2);
1107 mv.visitInsn(Opcodes.SWAP);
1108 emitPushArguments(args, 1); // skip 1st argument: method handle
1109 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1110 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1111 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1112
1113 mv.visitLabel(L_rethrow);
1114 mv.visitInsn(Opcodes.ATHROW);
1115
1116 mv.visitLabel(L_done);
1117
1118 return result;
1119 }
1120
1121 private void emitPushArguments(Name args) {
1122 emitPushArguments(args, 0);
1123 }
1124
1125 private void emitPushArguments(Name args, int start) {
1126 for (int i = start; i < args.arguments.length; i++) {
1127 emitPushArgument(args, i);
1128 }
1129 }
1130
1131 private void emitPushArgument(Name name, int paramIndex) {
1132 Object arg = name.arguments[paramIndex];
1133 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1134 emitPushArgument(ptype, arg);
1135 }
1136
1137 private void emitPushArgument(Class<?> ptype, Object arg) {
1138 BasicType bptype = basicType(ptype);
1139 if (arg instanceof Name) {
1140 Name n = (Name) arg;
1141 emitLoadInsn(n.type, n.index());
1142 emitImplicitConversion(n.type, ptype, n);
1143 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1144 emitConst(arg);
1145 } else {
1146 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1147 emitConst(arg);
1148 } else {
1149 mv.visitLdcInsn(constantPlaceholder(arg));
1150 emitImplicitConversion(L_TYPE, ptype, arg);
1151 }
1152 }
1153 }
1154
1155 /**
1156 * Store the name to its local, if necessary.
1157 */
1158 private void emitStoreResult(Name name) {
1159 if (name != null && name.type != V_TYPE) {
1160 // non-void: actually assign
1161 emitStoreInsn(name.type, name.index());
1162 }
1163 }
1164
1165 /**
1166 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1167 */
1168 private void emitReturn(Name onStack) {
1169 // return statement
1170 Class<?> rclass = invokerType.returnType();
1171 BasicType rtype = lambdaForm.returnType();
1172 assert(rtype == basicType(rclass)); // must agree
1173 if (rtype == V_TYPE) {
1174 // void
1175 mv.visitInsn(Opcodes.RETURN);
1176 // it doesn't matter what rclass is; the JVM will discard any value
1177 } else {
1178 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1179
1180 // put return value on the stack if it is not already there
1181 if (rn != onStack) {
1182 emitLoadInsn(rtype, lambdaForm.result);
1183 }
1184
1185 emitImplicitConversion(rtype, rclass, rn);
1186
1187 // generate actual return statement
1188 emitReturnInsn(rtype);
1189 }
1190 }
1191
1192 /**
1193 * Emit a type conversion bytecode casting from "from" to "to".
1194 */
1195 private void emitPrimCast(Wrapper from, Wrapper to) {
1196 // Here's how.
1197 // - indicates forbidden
1198 // <-> indicates implicit
1199 // to ----> boolean byte short char int long float double
1200 // from boolean <-> - - - - - - -
1201 // byte - <-> i2s i2c <-> i2l i2f i2d
1202 // short - i2b <-> i2c <-> i2l i2f i2d
1203 // char - i2b i2s <-> <-> i2l i2f i2d
1204 // int - i2b i2s i2c <-> i2l i2f i2d
1205 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1206 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1207 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1208 if (from == to) {
1209 // no cast required, should be dead code anyway
1210 return;
1211 }
1212 if (from.isSubwordOrInt()) {
1213 // cast from {byte,short,char,int} to anything
1214 emitI2X(to);
1215 } else {
1216 // cast from {long,float,double} to anything
1217 if (to.isSubwordOrInt()) {
1218 // cast to {byte,short,char,int}
1219 emitX2I(from);
1220 if (to.bitWidth() < 32) {
1221 // targets other than int require another conversion
1222 emitI2X(to);
1223 }
1224 } else {
1225 // cast to {long,float,double} - this is verbose
1226 boolean error = false;
1227 switch (from) {
1228 case LONG:
1229 switch (to) {
1230 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1231 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1232 default: error = true; break;
1233 }
1234 break;
1235 case FLOAT:
1236 switch (to) {
1237 case LONG : mv.visitInsn(Opcodes.F2L); break;
1238 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1239 default: error = true; break;
1240 }
1241 break;
1242 case DOUBLE:
1243 switch (to) {
1244 case LONG : mv.visitInsn(Opcodes.D2L); break;
1245 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1246 default: error = true; break;
1247 }
1248 break;
1249 default:
1250 error = true;
1251 break;
1252 }
1253 if (error) {
1254 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1255 }
1256 }
1257 }
1258 }
1259
1260 private void emitI2X(Wrapper type) {
1261 switch (type) {
1262 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1263 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1264 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1265 case INT: /* naught */ break;
1266 case LONG: mv.visitInsn(Opcodes.I2L); break;
1267 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1268 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1269 case BOOLEAN:
1270 // For compatibility with ValueConversions and explicitCastArguments:
1271 mv.visitInsn(Opcodes.ICONST_1);
1272 mv.visitInsn(Opcodes.IAND);
1273 break;
1274 default: throw new InternalError("unknown type: " + type);
1275 }
1276 }
1277
1278 private void emitX2I(Wrapper type) {
1279 switch (type) {
1280 case LONG: mv.visitInsn(Opcodes.L2I); break;
1281 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1282 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1283 default: throw new InternalError("unknown type: " + type);
1284 }
1285 }
1286
1287 /**
1288 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1289 */
1290 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1291 assert(isValidSignature(sig));
1292 String name = "interpret_"+signatureReturn(sig).basicTypeChar();
1293 MethodType type = signatureType(sig); // sig includes leading argument
1294 type = type.changeParameterType(0, MethodHandle.class);
1295 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1296 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1297 }
1298
1299 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1300 classFilePrologue();
1301
1302 // Suppress this method in backtraces displayed to the user.
1303 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1304
1305 // Don't inline the interpreter entry.
1306 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1307
1308 // create parameter array
1309 emitIconstInsn(invokerType.parameterCount());
1310 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1311
1312 // fill parameter array
1313 for (int i = 0; i < invokerType.parameterCount(); i++) {
1314 Class<?> ptype = invokerType.parameterType(i);
1315 mv.visitInsn(Opcodes.DUP);
1316 emitIconstInsn(i);
1317 emitLoadInsn(basicType(ptype), i);
1318 // box if primitive type
1319 if (ptype.isPrimitive()) {
1320 emitBoxing(Wrapper.forPrimitiveType(ptype));
1321 }
1322 mv.visitInsn(Opcodes.AASTORE);
1323 }
1324 // invoke
1325 emitAloadInsn(0);
1326 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1327 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1328 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1329
1330 // maybe unbox
1331 Class<?> rtype = invokerType.returnType();
1332 if (rtype.isPrimitive() && rtype != void.class) {
1333 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1334 }
1335
1336 // return statement
1337 emitReturnInsn(basicType(rtype));
1338
1339 classFileEpilogue();
1340 bogusMethod(invokerType);
1341
1342 final byte[] classFile = cw.toByteArray();
1343 maybeDump(className, classFile);
1344 return classFile;
1345 }
1346
1347 /**
1348 * Generate bytecode for a NamedFunction invoker.
1349 */
1350 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1351 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1352 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1353 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1354 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1355 }
1356
1357 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1358 MethodType dstType = typeForm.erasedType();
1359 classFilePrologue();
1360
1361 // Suppress this method in backtraces displayed to the user.
1362 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1363
1364 // Force inlining of this invoker method.
1365 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1366
1367 // Load receiver
1368 emitAloadInsn(0);
1369
1370 // Load arguments from array
1371 for (int i = 0; i < dstType.parameterCount(); i++) {
1372 emitAloadInsn(1);
1373 emitIconstInsn(i);
1374 mv.visitInsn(Opcodes.AALOAD);
1375
1376 // Maybe unbox
1377 Class<?> dptype = dstType.parameterType(i);
1378 if (dptype.isPrimitive()) {
1379 Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1380 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1381 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1382 emitUnboxing(srcWrapper);
1383 emitPrimCast(srcWrapper, dstWrapper);
1384 }
1385 }
1386
1387 // Invoke
1388 String targetDesc = dstType.basicType().toMethodDescriptorString();
1389 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1390
1391 // Box primitive types
1392 Class<?> rtype = dstType.returnType();
1393 if (rtype != void.class && rtype.isPrimitive()) {
1394 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1395 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1396 // boolean casts not allowed
1397 emitPrimCast(srcWrapper, dstWrapper);
1398 emitBoxing(dstWrapper);
1399 }
1400
1401 // If the return type is void we return a null reference.
1402 if (rtype == void.class) {
1403 mv.visitInsn(Opcodes.ACONST_NULL);
1404 }
1405 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1406
1407 classFileEpilogue();
1408 bogusMethod(dstType);
1409
1410 final byte[] classFile = cw.toByteArray();
1411 maybeDump(className, classFile);
1412 return classFile;
1413 }
1414
1415 /**
1416 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1417 * for debugging purposes.
1418 */
1419 private void bogusMethod(Object... os) {
1420 if (DUMP_CLASS_FILES) {
1421 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1422 for (Object o : os) {
1423 mv.visitLdcInsn(o.toString());
1424 mv.visitInsn(Opcodes.POP);
1425 }
1426 mv.visitInsn(Opcodes.RETURN);
1427 mv.visitMaxs(0, 0);
1428 mv.visitEnd();
1429 }
1430 }
1431 }