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$Name";
55 private static final String CLS = "java/lang/Class";
56 private static final String OBJ = "java/lang/Object";
57 private static final String OBJARY = "[Ljava/lang/Object;";
58
59 private static final String MH_SIG = "L" + MH + ";";
60 private static final String LF_SIG = "L" + LF + ";";
61 private static final String LFN_SIG = "L" + LFN + ";";
62 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
63 private static final String LLV_SIG = "(L" + OBJ + ";L" + OBJ + ";)V";
64 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";";
65
66 /** Name of its super class*/
67 private static final String superName = OBJ;
68
69 /** Name of new class */
70 private final String className;
71
72 /** Name of the source file (for stack trace printing). */
73 private final String sourceFile;
74
75 private final LambdaForm lambdaForm;
76 private final String invokerName;
77 private final MethodType invokerType;
78
79 /** Info about local variables in compiled lambda form */
80 private final int[] localsMap; // index
81 private final BasicType[] localTypes; // basic type
82 private final Class<?>[] localClasses; // type
83
84 /** ASM bytecode generation. */
85 private ClassWriter cw;
86 private MethodVisitor mv;
87
88 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
89 private static final Class<?> HOST_CLASS = LambdaForm.class;
90
91 /** Main constructor; other constructors delegate to this one. */
92 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
93 String className, String invokerName, MethodType invokerType) {
94 if (invokerName.contains(".")) {
95 int p = invokerName.indexOf('.');
96 className = invokerName.substring(0, p);
97 invokerName = invokerName.substring(p+1);
98 }
99 if (DUMP_CLASS_FILES) {
100 className = makeDumpableClassName(className);
101 }
102 this.className = LF + "$" + className;
103 this.sourceFile = "LambdaForm$" + className;
104 this.lambdaForm = lambdaForm;
105 this.invokerName = invokerName;
106 this.invokerType = invokerType;
107 this.localsMap = new int[localsMapSize+1];
108 // last entry of localsMap is count of allocated local slots
109 this.localTypes = new BasicType[localsMapSize+1];
110 this.localClasses = new Class<?>[localsMapSize+1];
111 }
112
113 /** For generating LambdaForm interpreter entry points. */
114 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
115 this(null, invokerType.parameterCount(),
116 className, invokerName, invokerType);
117 // Create an array to map name indexes to locals indexes.
118 localTypes[localTypes.length - 1] = V_TYPE;
119 for (int i = 0; i < localsMap.length; i++) {
120 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
121 if (i < invokerType.parameterCount())
122 localTypes[i] = basicType(invokerType.parameterType(i));
123 }
124 }
125
126 /** For generating customized code for a single LambdaForm. */
127 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
128 this(form, form.names.length,
129 className, form.debugName, invokerType);
130 // Create an array to map name indexes to locals indexes.
131 Name[] names = form.names;
132 for (int i = 0, index = 0; i < localsMap.length; i++) {
133 localsMap[i] = index;
134 if (i < names.length) {
135 BasicType type = names[i].type();
136 index += type.basicTypeSlots();
137 localTypes[i] = type;
138 }
139 }
140 }
141
142
143 /** instance counters for dumped classes */
144 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
145 /** debugging flag for saving generated class files */
146 private final static File DUMP_CLASS_FILES_DIR;
147
148 static {
149 if (DUMP_CLASS_FILES) {
150 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
151 try {
152 File dumpDir = new File("DUMP_CLASS_FILES");
153 if (!dumpDir.exists()) {
154 dumpDir.mkdirs();
155 }
156 DUMP_CLASS_FILES_DIR = dumpDir;
157 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
158 } catch (Exception e) {
159 throw newInternalError(e);
160 }
161 } else {
162 DUMP_CLASS_FILES_COUNTERS = null;
163 DUMP_CLASS_FILES_DIR = null;
164 }
165 }
166
167 static void maybeDump(final String className, final byte[] classFile) {
168 if (DUMP_CLASS_FILES) {
169 java.security.AccessController.doPrivileged(
170 new java.security.PrivilegedAction<Void>() {
171 public Void run() {
172 try {
173 String dumpName = className;
174 //dumpName = dumpName.replace('/', '-');
175 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
176 System.out.println("dump: " + dumpFile);
177 dumpFile.getParentFile().mkdirs();
178 FileOutputStream file = new FileOutputStream(dumpFile);
179 file.write(classFile);
180 file.close();
181 return null;
182 } catch (IOException ex) {
183 throw newInternalError(ex);
184 }
185 }
186 });
187 }
188
189 }
190
191 private static String makeDumpableClassName(String className) {
192 Integer ctr;
193 synchronized (DUMP_CLASS_FILES_COUNTERS) {
194 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
195 if (ctr == null) ctr = 0;
196 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
197 }
198 String sfx = ctr.toString();
199 while (sfx.length() < 3)
200 sfx = "0"+sfx;
201 className += sfx;
202 return className;
203 }
204
205 class CpPatch {
206 final int index;
207 final String placeholder;
208 final Object value;
209 CpPatch(int index, String placeholder, Object value) {
210 this.index = index;
211 this.placeholder = placeholder;
212 this.value = value;
213 }
214 public String toString() {
215 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
216 }
217 }
218
219 Map<Object, CpPatch> cpPatches = new HashMap<>();
220
221 int cph = 0; // for counting constant placeholders
222
223 String constantPlaceholder(Object arg) {
224 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
225 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid
226 if (cpPatches.containsKey(cpPlaceholder)) {
227 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
228 }
229 // insert placeholder in CP and remember the patch
230 int index = cw.newConst((Object) cpPlaceholder); // TODO check if already in the constant pool
231 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
232 return cpPlaceholder;
233 }
234
235 Object[] cpPatches(byte[] classFile) {
236 int size = getConstantPoolSize(classFile);
237 Object[] res = new Object[size];
238 for (CpPatch p : cpPatches.values()) {
239 if (p.index >= size)
240 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
241 res[p.index] = p.value;
242 }
243 return res;
244 }
245
246 private static String debugString(Object arg) {
247 if (arg instanceof MethodHandle) {
248 MethodHandle mh = (MethodHandle) arg;
249 MemberName member = mh.internalMemberName();
250 if (member != null)
251 return member.toString();
252 return mh.debugString();
253 }
254 return arg.toString();
255 }
256
257 /**
258 * Extract the number of constant pool entries from a given class file.
259 *
260 * @param classFile the bytes of the class file in question.
261 * @return the number of entries in the constant pool.
262 */
263 private static int getConstantPoolSize(byte[] classFile) {
264 // The first few bytes:
265 // u4 magic;
266 // u2 minor_version;
267 // u2 major_version;
268 // u2 constant_pool_count;
269 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
270 }
271
272 /**
273 * Extract the MemberName of a newly-defined method.
274 */
275 private MemberName loadMethod(byte[] classFile) {
276 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
277 return resolveInvokerMember(invokerClass, invokerName, invokerType);
278 }
279
280 /**
281 * Define a given class as anonymous class in the runtime system.
282 */
283 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
284 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
285 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
286 return invokerClass;
287 }
288
289 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
290 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
291 //System.out.println("resolveInvokerMember => "+member);
292 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
293 try {
294 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
295 } catch (ReflectiveOperationException e) {
296 throw newInternalError(e);
297 }
298 //System.out.println("resolveInvokerMember => "+member);
299 return member;
300 }
301
302 /**
303 * Set up class file generation.
304 */
305 private void classFilePrologue() {
306 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
307 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
308 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
309 cw.visitSource(sourceFile, null);
310
311 String invokerDesc = invokerType.toMethodDescriptorString();
312 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
313 }
314
315 /**
316 * Tear down class file generation.
317 */
318 private void classFileEpilogue() {
319 mv.visitMaxs(0, 0);
320 mv.visitEnd();
321 }
322
323 /*
324 * Low-level emit helpers.
325 */
326 private void emitConst(Object con) {
327 if (con == null) {
328 mv.visitInsn(Opcodes.ACONST_NULL);
329 return;
330 }
331 if (con instanceof Integer) {
332 emitIconstInsn((int) con);
333 return;
334 }
335 if (con instanceof Long) {
336 long x = (long) con;
337 if (x == (short) x) {
338 emitIconstInsn((int) x);
339 mv.visitInsn(Opcodes.I2L);
340 return;
341 }
342 }
343 if (con instanceof Float) {
344 float x = (float) con;
345 if (x == (short) x) {
346 emitIconstInsn((int) x);
347 mv.visitInsn(Opcodes.I2F);
348 return;
349 }
350 }
351 if (con instanceof Double) {
352 double x = (double) con;
353 if (x == (short) x) {
354 emitIconstInsn((int) x);
355 mv.visitInsn(Opcodes.I2D);
356 return;
357 }
358 }
359 if (con instanceof Boolean) {
360 emitIconstInsn((boolean) con ? 1 : 0);
361 return;
362 }
363 // fall through:
364 mv.visitLdcInsn(con);
365 }
366
367 private void emitIconstInsn(int i) {
368 int opcode;
369 switch (i) {
370 case 0: opcode = Opcodes.ICONST_0; break;
371 case 1: opcode = Opcodes.ICONST_1; break;
372 case 2: opcode = Opcodes.ICONST_2; break;
373 case 3: opcode = Opcodes.ICONST_3; break;
374 case 4: opcode = Opcodes.ICONST_4; break;
375 case 5: opcode = Opcodes.ICONST_5; break;
376 default:
377 if (i == (byte) i) {
378 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
379 } else if (i == (short) i) {
380 mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
381 } else {
382 mv.visitLdcInsn(i);
383 }
384 return;
385 }
386 mv.visitInsn(opcode);
387 }
388
389 /*
390 * NOTE: These load/store methods use the localsMap to find the correct index!
391 */
392 private void emitLoadInsn(BasicType type, int index) {
393 int opcode = loadInsnOpcode(type);
394 mv.visitVarInsn(opcode, localsMap[index]);
395 }
396
397 private int loadInsnOpcode(BasicType type) throws InternalError {
398 switch (type) {
399 case I_TYPE: return Opcodes.ILOAD;
400 case J_TYPE: return Opcodes.LLOAD;
401 case F_TYPE: return Opcodes.FLOAD;
402 case D_TYPE: return Opcodes.DLOAD;
403 case L_TYPE: return Opcodes.ALOAD;
404 default:
405 throw new InternalError("unknown type: " + type);
406 }
407 }
408 private void emitAloadInsn(int index) {
409 emitLoadInsn(L_TYPE, index);
410 }
411
412 private void emitStoreInsn(BasicType type, int index) {
413 int opcode = storeInsnOpcode(type);
414 mv.visitVarInsn(opcode, localsMap[index]);
415 }
416
417 private int storeInsnOpcode(BasicType type) throws InternalError {
418 switch (type) {
419 case I_TYPE: return Opcodes.ISTORE;
420 case J_TYPE: return Opcodes.LSTORE;
421 case F_TYPE: return Opcodes.FSTORE;
422 case D_TYPE: return Opcodes.DSTORE;
423 case L_TYPE: return Opcodes.ASTORE;
424 default:
425 throw new InternalError("unknown type: " + type);
426 }
427 }
428 private void emitAstoreInsn(int index) {
429 emitStoreInsn(L_TYPE, index);
430 }
431
432 private byte arrayTypeCode(Wrapper elementType) {
433 switch (elementType) {
434 case BOOLEAN: return Opcodes.T_BOOLEAN;
435 case BYTE: return Opcodes.T_BYTE;
436 case CHAR: return Opcodes.T_CHAR;
437 case SHORT: return Opcodes.T_SHORT;
438 case INT: return Opcodes.T_INT;
439 case LONG: return Opcodes.T_LONG;
440 case FLOAT: return Opcodes.T_FLOAT;
441 case DOUBLE: return Opcodes.T_DOUBLE;
442 case OBJECT: return 0; // in place of Opcodes.T_OBJECT
443 default: throw new InternalError();
444 }
445 }
446
447 private int arrayInsnOpcode(byte tcode, int aaop) throws InternalError {
448 assert(aaop == Opcodes.AASTORE || aaop == Opcodes.AALOAD);
449 int xas;
450 switch (tcode) {
451 case Opcodes.T_BOOLEAN: xas = Opcodes.BASTORE; break;
452 case Opcodes.T_BYTE: xas = Opcodes.BASTORE; break;
453 case Opcodes.T_CHAR: xas = Opcodes.CASTORE; break;
454 case Opcodes.T_SHORT: xas = Opcodes.SASTORE; break;
455 case Opcodes.T_INT: xas = Opcodes.IASTORE; break;
456 case Opcodes.T_LONG: xas = Opcodes.LASTORE; break;
457 case Opcodes.T_FLOAT: xas = Opcodes.FASTORE; break;
458 case Opcodes.T_DOUBLE: xas = Opcodes.DASTORE; break;
459 case 0: xas = Opcodes.AASTORE; break;
460 default: throw new InternalError();
461 }
462 return xas - Opcodes.AASTORE + aaop;
463 }
464
465
466 private void freeFrameLocal(int oldFrameLocal) {
467 int i = indexForFrameLocal(oldFrameLocal);
468 if (i < 0) return;
469 BasicType type = localTypes[i];
470 int newFrameLocal = makeLocalTemp(type);
471 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal);
472 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal);
473 assert(localsMap[i] == oldFrameLocal);
474 localsMap[i] = newFrameLocal;
475 assert(indexForFrameLocal(oldFrameLocal) < 0);
476 }
477 private int indexForFrameLocal(int frameLocal) {
478 for (int i = 0; i < localsMap.length; i++) {
479 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE)
480 return i;
481 }
482 return -1;
483 }
484 private int makeLocalTemp(BasicType type) {
485 int frameLocal = localsMap[localsMap.length - 1];
486 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots();
487 return frameLocal;
488 }
489
490 /**
491 * Emit a boxing call.
492 *
493 * @param wrapper primitive type class to box.
494 */
495 private void emitBoxing(Wrapper wrapper) {
496 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
497 String name = "valueOf";
498 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
499 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
500 }
501
502 /**
503 * Emit an unboxing call (plus preceding checkcast).
504 *
505 * @param wrapper wrapper type class to unbox.
506 */
507 private void emitUnboxing(Wrapper wrapper) {
508 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
509 String name = wrapper.primitiveSimpleName() + "Value";
510 String desc = "()" + wrapper.basicTypeChar();
511 emitReferenceCast(wrapper.wrapperType(), null);
512 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
513 }
514
515 /**
516 * Emit an implicit conversion for an argument which must be of the given pclass.
517 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
518 *
519 * @param ptype type of value present on stack
520 * @param pclass type of value required on stack
521 * @param arg compile-time representation of value on stack (Node, constant) or null if none
522 */
523 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
524 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
525 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
526 return; // nothing to do
527 switch (ptype) {
528 case L_TYPE:
529 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
530 if (PROFILE_LEVEL > 0)
531 emitReferenceCast(Object.class, arg);
532 return;
533 }
534 emitReferenceCast(pclass, arg);
535 return;
536 case I_TYPE:
537 if (!VerifyType.isNullConversion(int.class, pclass, false))
538 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
539 return;
540 }
541 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
542 }
543
544 /** Update localClasses type map. Return true if the information is already present. */
545 private boolean assertStaticType(Class<?> cls, Name n) {
546 int local = n.index();
547 Class<?> aclass = localClasses[local];
548 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
549 return true; // type info is already present
550 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
551 localClasses[local] = cls; // type info can be improved
552 }
553 return false;
554 }
555
556 private void emitReferenceCast(Class<?> cls, Object arg) {
557 Name writeBack = null; // local to write back result
558 if (arg instanceof Name) {
559 Name n = (Name) arg;
560 if (assertStaticType(cls, n))
561 return; // this cast was already performed
562 if (lambdaForm.useCount(n) > 1) {
563 // This guy gets used more than once.
564 writeBack = n;
565 }
566 }
567 if (isStaticallyNameable(cls)) {
568 String sig = getInternalName(cls);
569 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
570 } else {
571 mv.visitLdcInsn(constantPlaceholder(cls));
572 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
573 mv.visitInsn(Opcodes.SWAP);
574 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false);
575 if (Object[].class.isAssignableFrom(cls))
576 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
577 else if (PROFILE_LEVEL > 0)
578 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
579 }
580 if (writeBack != null) {
581 mv.visitInsn(Opcodes.DUP);
582 emitAstoreInsn(writeBack.index());
583 }
584 }
585
586 /**
587 * Emits an actual return instruction conforming to the given return type.
588 */
589 private void emitReturnInsn(BasicType type) {
590 int opcode;
591 switch (type) {
592 case I_TYPE: opcode = Opcodes.IRETURN; break;
593 case J_TYPE: opcode = Opcodes.LRETURN; break;
594 case F_TYPE: opcode = Opcodes.FRETURN; break;
595 case D_TYPE: opcode = Opcodes.DRETURN; break;
596 case L_TYPE: opcode = Opcodes.ARETURN; break;
597 case V_TYPE: opcode = Opcodes.RETURN; break;
598 default:
599 throw new InternalError("unknown return type: " + type);
600 }
601 mv.visitInsn(opcode);
602 }
603
604 private static String getInternalName(Class<?> c) {
605 if (c == Object.class) return OBJ;
606 else if (c == Object[].class) return OBJARY;
607 else if (c == Class.class) return CLS;
608 else if (c == MethodHandle.class) return MH;
609 assert(VerifyAccess.isTypeVisible(c, Object.class)) : c.getName();
610 return c.getName().replace('.', '/');
611 }
612
613 /**
614 * Generate customized bytecode for a given LambdaForm.
615 */
616 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
617 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
618 return g.loadMethod(g.generateCustomizedCodeBytes());
619 }
620
621 /** Determines whether a LambdaForm being compiled contains an intrinsic of some particular type. */
622 private boolean containsIntrinsic(MethodHandleImpl.Intrinsic intr) {
623 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
624 Name name = lambdaForm.names[i];
625 if (name.function.intrinsicName() == intr) {
626 return true;
627 }
628 }
629 return false;
630 }
631
632 /** Generates code to check that actual receiver and LambdaForm matches */
633 private boolean checkActualReceiver() {
634 // Expects MethodHandle on the stack and actual receiver MethodHandle in slot #0
635 mv.visitInsn(Opcodes.DUP);
636 mv.visitVarInsn(Opcodes.ALOAD, localsMap[0]);
637 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "assertSame", LLV_SIG, false);
638 return true;
639 }
640
641 /**
642 * Generate an invoker method for the passed {@link LambdaForm}.
643 */
644 private byte[] generateCustomizedCodeBytes() {
645 classFilePrologue();
646
647 // Suppress this method in backtraces displayed to the user.
648 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
649
650 // Mark this method as a compiled LambdaForm
651 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
652
653 if (PROFILE_GWT && containsIntrinsic(MethodHandleImpl.Intrinsic.SELECT_ALTERNATIVE)) {
654 // For now, mark only GWT LambdaForms as @Shared.
655 // TODO: consider marking other non-customized LambdaForms as @Shared
656 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Shared;", true);
657 }
658
659 if (lambdaForm.forceInline) {
660 // Force inlining of this invoker method.
661 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
662 } else {
663 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
664 }
665
666 if (lambdaForm.customized != null) {
667 // Since LambdaForm is customized for a particular MethodHandle, it's safe to substitute
668 // receiver MethodHandle (at slot #0) with an embedded constant and use it instead.
669 // It enables more efficient code generation in some situations, since embedded constants
670 // are compile-time constants for JIT compiler.
671 mv.visitLdcInsn(constantPlaceholder(lambdaForm.customized));
672 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
673 assert(checkActualReceiver()); // expects MethodHandle on top of the stack
674 mv.visitVarInsn(Opcodes.ASTORE, localsMap[0]);
675 }
676
677 // iterate over the form's names, generating bytecode instructions for each
678 // start iterating at the first name following the arguments
679 Name onStack = null;
680 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
681 Name name = lambdaForm.names[i];
682
683 emitStoreResult(onStack);
684 onStack = name; // unless otherwise modified below
685 MethodHandleImpl.Intrinsic intr = name.function.intrinsicName();
686 switch (intr) {
687 case SELECT_ALTERNATIVE:
688 assert isSelectAlternative(i);
689 onStack = emitSelectAlternative(name, lambdaForm.names[i+1]);
690 i++; // skip MH.invokeBasic of the selectAlternative result
691 continue;
692 case GUARD_WITH_CATCH:
693 assert isGuardWithCatch(i);
694 onStack = emitGuardWithCatch(i);
695 i = i+2; // Jump to the end of GWC idiom
696 continue;
697 case NEW_ARRAY:
698 Class<?> rtype = name.function.methodType().returnType();
699 if (isStaticallyNameable(rtype)) {
700 emitNewArray(name);
701 continue;
702 }
703 break;
704 case ARRAY_LOAD:
705 emitArrayLoad(name);
706 continue;
707 case ARRAY_STORE:
708 emitArrayStore(name);
709 continue;
710 case IDENTITY:
711 assert(name.arguments.length == 1);
712 emitPushArguments(name);
713 continue;
714 case ZERO:
715 assert(name.arguments.length == 0);
716 emitConst(name.type.basicTypeWrapper().zero());
717 continue;
718 case NONE:
719 // no intrinsic associated
720 break;
721 default:
722 throw newInternalError("Unknown intrinsic: "+intr);
723 }
724
725 MemberName member = name.function.member();
726 if (isStaticallyInvocable(member)) {
727 emitStaticInvoke(member, name);
728 } else {
729 emitInvoke(name);
730 }
731 }
732
733 // return statement
734 emitReturn(onStack);
735
736 classFileEpilogue();
737 bogusMethod(lambdaForm);
738
739 final byte[] classFile = cw.toByteArray();
740 maybeDump(className, classFile);
741 return classFile;
742 }
743
744 void emitArrayLoad(Name name) { emitArrayOp(name, Opcodes.AALOAD); }
745 void emitArrayStore(Name name) { emitArrayOp(name, Opcodes.AASTORE); }
746
747 void emitArrayOp(Name name, int arrayOpcode) {
748 assert arrayOpcode == Opcodes.AALOAD || arrayOpcode == Opcodes.AASTORE;
749 Class<?> elementType = name.function.methodType().parameterType(0).getComponentType();
750 assert elementType != null;
751 emitPushArguments(name);
752 if (elementType.isPrimitive()) {
753 Wrapper w = Wrapper.forPrimitiveType(elementType);
754 arrayOpcode = arrayInsnOpcode(arrayTypeCode(w), arrayOpcode);
755 }
756 mv.visitInsn(arrayOpcode);
757 }
758
759 /**
760 * Emit an invoke for the given name.
761 */
762 void emitInvoke(Name name) {
763 assert(!isLinkerMethodInvoke(name)); // should use the static path for these
764 if (true) {
765 // push receiver
766 MethodHandle target = name.function.resolvedHandle;
767 assert(target != null) : name.exprString();
768 mv.visitLdcInsn(constantPlaceholder(target));
769 emitReferenceCast(MethodHandle.class, target);
770 } else {
771 // load receiver
772 emitAloadInsn(0);
773 emitReferenceCast(MethodHandle.class, null);
774 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
775 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
776 // TODO more to come
777 }
778
779 // push arguments
780 emitPushArguments(name);
781
782 // invocation
783 MethodType type = name.function.methodType();
784 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
785 }
786
787 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
788 // Sample classes from each package we are willing to bind to statically:
789 java.lang.Object.class,
790 java.util.Arrays.class,
791 sun.misc.Unsafe.class
792 //MethodHandle.class already covered
793 };
794
795 static boolean isStaticallyInvocable(Name name) {
796 return isStaticallyInvocable(name.function.member());
797 }
798
799 static boolean isStaticallyInvocable(MemberName member) {
800 if (member == null) return false;
801 if (member.isConstructor()) return false;
802 Class<?> cls = member.getDeclaringClass();
803 if (cls.isArray() || cls.isPrimitive())
804 return false; // FIXME
805 if (cls.isAnonymousClass() || cls.isLocalClass())
806 return false; // inner class of some sort
807 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
808 return false; // not on BCP
809 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
810 return false;
811 MethodType mtype = member.getMethodOrFieldType();
812 if (!isStaticallyNameable(mtype.returnType()))
813 return false;
814 for (Class<?> ptype : mtype.parameterArray())
815 if (!isStaticallyNameable(ptype))
816 return false;
817 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
818 return true; // in java.lang.invoke package
819 if (member.isPublic() && isStaticallyNameable(cls))
820 return true;
821 return false;
822 }
823
824 static boolean isStaticallyNameable(Class<?> cls) {
825 if (cls == Object.class)
826 return true;
827 while (cls.isArray())
828 cls = cls.getComponentType();
829 if (cls.isPrimitive())
830 return true; // int[].class, for example
831 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
832 return false;
833 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
834 if (cls.getClassLoader() != Object.class.getClassLoader())
835 return false;
836 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
837 return true;
838 if (!Modifier.isPublic(cls.getModifiers()))
839 return false;
840 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
841 if (VerifyAccess.isSamePackage(pkgcls, cls))
842 return true;
843 }
844 return false;
845 }
846
847 void emitStaticInvoke(Name name) {
848 emitStaticInvoke(name.function.member(), name);
849 }
850
851 /**
852 * Emit an invoke for the given name, using the MemberName directly.
853 */
854 void emitStaticInvoke(MemberName member, Name name) {
855 assert(member.equals(name.function.member()));
856 Class<?> defc = member.getDeclaringClass();
857 String cname = getInternalName(defc);
858 String mname = member.getName();
859 String mtype;
860 byte refKind = member.getReferenceKind();
861 if (refKind == REF_invokeSpecial) {
862 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
863 assert(member.canBeStaticallyBound()) : member;
864 refKind = REF_invokeVirtual;
865 }
866
867 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
868 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
869 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
870 refKind = REF_invokeInterface;
871 }
872
873 // push arguments
874 emitPushArguments(name);
875
876 // invocation
877 if (member.isMethod()) {
878 mtype = member.getMethodType().toMethodDescriptorString();
879 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
880 member.getDeclaringClass().isInterface());
881 } else {
882 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
883 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
884 }
885 // Issue a type assertion for the result, so we can avoid casts later.
886 if (name.type == L_TYPE) {
887 Class<?> rtype = member.getInvocationType().returnType();
888 assert(!rtype.isPrimitive());
889 if (rtype != Object.class && !rtype.isInterface()) {
890 assertStaticType(rtype, name);
891 }
892 }
893 }
894
895 void emitNewArray(Name name) throws InternalError {
896 Class<?> rtype = name.function.methodType().returnType();
897 if (name.arguments.length == 0) {
898 // The array will be a constant.
899 Object emptyArray;
900 try {
901 emptyArray = name.function.resolvedHandle.invoke();
902 } catch (Throwable ex) {
903 throw newInternalError(ex);
904 }
905 assert(java.lang.reflect.Array.getLength(emptyArray) == 0);
906 assert(emptyArray.getClass() == rtype); // exact typing
907 mv.visitLdcInsn(constantPlaceholder(emptyArray));
908 emitReferenceCast(rtype, emptyArray);
909 return;
910 }
911 Class<?> arrayElementType = rtype.getComponentType();
912 assert(arrayElementType != null);
913 emitIconstInsn(name.arguments.length);
914 int xas = Opcodes.AASTORE;
915 if (!arrayElementType.isPrimitive()) {
916 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
917 } else {
918 byte tc = arrayTypeCode(Wrapper.forPrimitiveType(arrayElementType));
919 xas = arrayInsnOpcode(tc, xas);
920 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
921 }
922 // store arguments
923 for (int i = 0; i < name.arguments.length; i++) {
924 mv.visitInsn(Opcodes.DUP);
925 emitIconstInsn(i);
926 emitPushArgument(name, i);
927 mv.visitInsn(xas);
928 }
929 // the array is left on the stack
930 assertStaticType(rtype, name);
931 }
932 int refKindOpcode(byte refKind) {
933 switch (refKind) {
934 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
935 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
936 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
937 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
938 case REF_getField: return Opcodes.GETFIELD;
939 case REF_putField: return Opcodes.PUTFIELD;
940 case REF_getStatic: return Opcodes.GETSTATIC;
941 case REF_putStatic: return Opcodes.PUTSTATIC;
942 }
943 throw new InternalError("refKind="+refKind);
944 }
945
946 /**
947 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
948 */
949 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) {
950 return member != null &&
951 member.getDeclaringClass() == declaringClass &&
952 member.getName().equals(name);
953 }
954 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) {
955 return name.function != null &&
956 memberRefersTo(name.function.member(), declaringClass, methodName);
957 }
958
959 /**
960 * Check if MemberName is a call to MethodHandle.invokeBasic.
961 */
962 private boolean isInvokeBasic(Name name) {
963 if (name.function == null)
964 return false;
965 if (name.arguments.length < 1)
966 return false; // must have MH argument
967 MemberName member = name.function.member();
968 return memberRefersTo(member, MethodHandle.class, "invokeBasic") &&
969 !member.isPublic() && !member.isStatic();
970 }
971
972 /**
973 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
974 */
975 private boolean isLinkerMethodInvoke(Name name) {
976 if (name.function == null)
977 return false;
978 if (name.arguments.length < 1)
979 return false; // must have MH argument
980 MemberName member = name.function.member();
981 return member != null &&
982 member.getDeclaringClass() == MethodHandle.class &&
983 !member.isPublic() && member.isStatic() &&
984 member.getName().startsWith("linkTo");
985 }
986
987 /**
988 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
989 */
990 private boolean isSelectAlternative(int pos) {
991 // selectAlternative idiom:
992 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
993 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
994 if (pos+1 >= lambdaForm.names.length) return false;
995 Name name0 = lambdaForm.names[pos];
996 Name name1 = lambdaForm.names[pos+1];
997 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") &&
998 isInvokeBasic(name1) &&
999 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
1000 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
1001 }
1002
1003 /**
1004 * Check if i-th name is a start of GuardWithCatch idiom.
1005 */
1006 private boolean isGuardWithCatch(int pos) {
1007 // GuardWithCatch idiom:
1008 // t_{n}:L=MethodHandle.invokeBasic(...)
1009 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
1010 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
1011 if (pos+2 >= lambdaForm.names.length) return false;
1012 Name name0 = lambdaForm.names[pos];
1013 Name name1 = lambdaForm.names[pos+1];
1014 Name name2 = lambdaForm.names[pos+2];
1015 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") &&
1016 isInvokeBasic(name0) &&
1017 isInvokeBasic(name2) &&
1018 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
1019 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
1020 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
1021 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
1022 }
1023
1024 /**
1025 * Emit bytecode for the selectAlternative idiom.
1026 *
1027 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1028 * <blockquote><pre>{@code
1029 * Lambda(a0:L,a1:I)=>{
1030 * t2:I=foo.test(a1:I);
1031 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1032 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1033 * }</pre></blockquote>
1034 */
1035 private Name emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1036 assert isStaticallyInvocable(invokeBasicName);
1037
1038 Name receiver = (Name) invokeBasicName.arguments[0];
1039
1040 Label L_fallback = new Label();
1041 Label L_done = new Label();
1042
1043 // load test result
1044 emitPushArgument(selectAlternativeName, 0);
1045
1046 if (PROFILE_GWT) {
1047 emitPushArgument(selectAlternativeName, 3);
1048 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "profileBranch", "(Z[I)Z", false);
1049 }
1050
1051 // if_icmpne L_fallback
1052 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
1053
1054 // invoke selectAlternativeName.arguments[1]
1055 Class<?>[] preForkClasses = localClasses.clone();
1056 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1057 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1058 emitStaticInvoke(invokeBasicName);
1059
1060 // goto L_done
1061 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1062
1063 // L_fallback:
1064 mv.visitLabel(L_fallback);
1065
1066 // invoke selectAlternativeName.arguments[2]
1067 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1068 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1069 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1070 emitStaticInvoke(invokeBasicName);
1071
1072 // L_done:
1073 mv.visitLabel(L_done);
1074 // for now do not bother to merge typestate; just reset to the dominator state
1075 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1076
1077 return invokeBasicName; // return what's on stack
1078 }
1079
1080 /**
1081 * Emit bytecode for the guardWithCatch idiom.
1082 *
1083 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1084 * <blockquote><pre>{@code
1085 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1086 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1087 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1088 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1089 * }</pre></blockquote>
1090 *
1091 * It is compiled into bytecode equivalent of the following code:
1092 * <blockquote><pre>{@code
1093 * try {
1094 * return a1.invokeBasic(a6, a7);
1095 * } catch (Throwable e) {
1096 * if (!a2.isInstance(e)) throw e;
1097 * return a3.invokeBasic(ex, a6, a7);
1098 * }}
1099 */
1100 private Name emitGuardWithCatch(int pos) {
1101 Name args = lambdaForm.names[pos];
1102 Name invoker = lambdaForm.names[pos+1];
1103 Name result = lambdaForm.names[pos+2];
1104
1105 Label L_startBlock = new Label();
1106 Label L_endBlock = new Label();
1107 Label L_handler = new Label();
1108 Label L_done = new Label();
1109
1110 Class<?> returnType = result.function.resolvedHandle.type().returnType();
1111 MethodType type = args.function.resolvedHandle.type()
1112 .dropParameterTypes(0,1)
1113 .changeReturnType(returnType);
1114
1115 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1116
1117 // Normal case
1118 mv.visitLabel(L_startBlock);
1119 // load target
1120 emitPushArgument(invoker, 0);
1121 emitPushArguments(args, 1); // skip 1st argument: method handle
1122 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1123 mv.visitLabel(L_endBlock);
1124 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1125
1126 // Exceptional case
1127 mv.visitLabel(L_handler);
1128
1129 // Check exception's type
1130 mv.visitInsn(Opcodes.DUP);
1131 // load exception class
1132 emitPushArgument(invoker, 1);
1133 mv.visitInsn(Opcodes.SWAP);
1134 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1135 Label L_rethrow = new Label();
1136 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1137
1138 // Invoke catcher
1139 // load catcher
1140 emitPushArgument(invoker, 2);
1141 mv.visitInsn(Opcodes.SWAP);
1142 emitPushArguments(args, 1); // skip 1st argument: method handle
1143 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1144 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1145 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1146
1147 mv.visitLabel(L_rethrow);
1148 mv.visitInsn(Opcodes.ATHROW);
1149
1150 mv.visitLabel(L_done);
1151
1152 return result;
1153 }
1154
1155 private void emitPushArguments(Name args) {
1156 emitPushArguments(args, 0);
1157 }
1158
1159 private void emitPushArguments(Name args, int start) {
1160 for (int i = start; i < args.arguments.length; i++) {
1161 emitPushArgument(args, i);
1162 }
1163 }
1164
1165 private void emitPushArgument(Name name, int paramIndex) {
1166 Object arg = name.arguments[paramIndex];
1167 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1168 emitPushArgument(ptype, arg);
1169 }
1170
1171 private void emitPushArgument(Class<?> ptype, Object arg) {
1172 BasicType bptype = basicType(ptype);
1173 if (arg instanceof Name) {
1174 Name n = (Name) arg;
1175 emitLoadInsn(n.type, n.index());
1176 emitImplicitConversion(n.type, ptype, n);
1177 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1178 emitConst(arg);
1179 } else {
1180 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1181 emitConst(arg);
1182 } else {
1183 mv.visitLdcInsn(constantPlaceholder(arg));
1184 emitImplicitConversion(L_TYPE, ptype, arg);
1185 }
1186 }
1187 }
1188
1189 /**
1190 * Store the name to its local, if necessary.
1191 */
1192 private void emitStoreResult(Name name) {
1193 if (name != null && name.type != V_TYPE) {
1194 // non-void: actually assign
1195 emitStoreInsn(name.type, name.index());
1196 }
1197 }
1198
1199 /**
1200 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1201 */
1202 private void emitReturn(Name onStack) {
1203 // return statement
1204 Class<?> rclass = invokerType.returnType();
1205 BasicType rtype = lambdaForm.returnType();
1206 assert(rtype == basicType(rclass)); // must agree
1207 if (rtype == V_TYPE) {
1208 // void
1209 mv.visitInsn(Opcodes.RETURN);
1210 // it doesn't matter what rclass is; the JVM will discard any value
1211 } else {
1212 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1213
1214 // put return value on the stack if it is not already there
1215 if (rn != onStack) {
1216 emitLoadInsn(rtype, lambdaForm.result);
1217 }
1218
1219 emitImplicitConversion(rtype, rclass, rn);
1220
1221 // generate actual return statement
1222 emitReturnInsn(rtype);
1223 }
1224 }
1225
1226 /**
1227 * Emit a type conversion bytecode casting from "from" to "to".
1228 */
1229 private void emitPrimCast(Wrapper from, Wrapper to) {
1230 // Here's how.
1231 // - indicates forbidden
1232 // <-> indicates implicit
1233 // to ----> boolean byte short char int long float double
1234 // from boolean <-> - - - - - - -
1235 // byte - <-> i2s i2c <-> i2l i2f i2d
1236 // short - i2b <-> i2c <-> i2l i2f i2d
1237 // char - i2b i2s <-> <-> i2l i2f i2d
1238 // int - i2b i2s i2c <-> i2l i2f i2d
1239 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1240 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1241 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1242 if (from == to) {
1243 // no cast required, should be dead code anyway
1244 return;
1245 }
1246 if (from.isSubwordOrInt()) {
1247 // cast from {byte,short,char,int} to anything
1248 emitI2X(to);
1249 } else {
1250 // cast from {long,float,double} to anything
1251 if (to.isSubwordOrInt()) {
1252 // cast to {byte,short,char,int}
1253 emitX2I(from);
1254 if (to.bitWidth() < 32) {
1255 // targets other than int require another conversion
1256 emitI2X(to);
1257 }
1258 } else {
1259 // cast to {long,float,double} - this is verbose
1260 boolean error = false;
1261 switch (from) {
1262 case LONG:
1263 switch (to) {
1264 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1265 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1266 default: error = true; break;
1267 }
1268 break;
1269 case FLOAT:
1270 switch (to) {
1271 case LONG : mv.visitInsn(Opcodes.F2L); break;
1272 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1273 default: error = true; break;
1274 }
1275 break;
1276 case DOUBLE:
1277 switch (to) {
1278 case LONG : mv.visitInsn(Opcodes.D2L); break;
1279 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1280 default: error = true; break;
1281 }
1282 break;
1283 default:
1284 error = true;
1285 break;
1286 }
1287 if (error) {
1288 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1289 }
1290 }
1291 }
1292 }
1293
1294 private void emitI2X(Wrapper type) {
1295 switch (type) {
1296 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1297 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1298 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1299 case INT: /* naught */ break;
1300 case LONG: mv.visitInsn(Opcodes.I2L); break;
1301 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1302 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1303 case BOOLEAN:
1304 // For compatibility with ValueConversions and explicitCastArguments:
1305 mv.visitInsn(Opcodes.ICONST_1);
1306 mv.visitInsn(Opcodes.IAND);
1307 break;
1308 default: throw new InternalError("unknown type: " + type);
1309 }
1310 }
1311
1312 private void emitX2I(Wrapper type) {
1313 switch (type) {
1314 case LONG: mv.visitInsn(Opcodes.L2I); break;
1315 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1316 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1317 default: throw new InternalError("unknown type: " + type);
1318 }
1319 }
1320
1321 /**
1322 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1323 */
1324 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1325 assert(isValidSignature(sig));
1326 String name = "interpret_"+signatureReturn(sig).basicTypeChar();
1327 MethodType type = signatureType(sig); // sig includes leading argument
1328 type = type.changeParameterType(0, MethodHandle.class);
1329 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1330 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1331 }
1332
1333 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1334 classFilePrologue();
1335
1336 // Suppress this method in backtraces displayed to the user.
1337 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1338
1339 // Don't inline the interpreter entry.
1340 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1341
1342 // create parameter array
1343 emitIconstInsn(invokerType.parameterCount());
1344 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1345
1346 // fill parameter array
1347 for (int i = 0; i < invokerType.parameterCount(); i++) {
1348 Class<?> ptype = invokerType.parameterType(i);
1349 mv.visitInsn(Opcodes.DUP);
1350 emitIconstInsn(i);
1351 emitLoadInsn(basicType(ptype), i);
1352 // box if primitive type
1353 if (ptype.isPrimitive()) {
1354 emitBoxing(Wrapper.forPrimitiveType(ptype));
1355 }
1356 mv.visitInsn(Opcodes.AASTORE);
1357 }
1358 // invoke
1359 emitAloadInsn(0);
1360 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1361 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1362 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1363
1364 // maybe unbox
1365 Class<?> rtype = invokerType.returnType();
1366 if (rtype.isPrimitive() && rtype != void.class) {
1367 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1368 }
1369
1370 // return statement
1371 emitReturnInsn(basicType(rtype));
1372
1373 classFileEpilogue();
1374 bogusMethod(invokerType);
1375
1376 final byte[] classFile = cw.toByteArray();
1377 maybeDump(className, classFile);
1378 return classFile;
1379 }
1380
1381 /**
1382 * Generate bytecode for a NamedFunction invoker.
1383 */
1384 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1385 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1386 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1387 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1388 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1389 }
1390
1391 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1392 MethodType dstType = typeForm.erasedType();
1393 classFilePrologue();
1394
1395 // Suppress this method in backtraces displayed to the user.
1396 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1397
1398 // Force inlining of this invoker method.
1399 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1400
1401 // Load receiver
1402 emitAloadInsn(0);
1403
1404 // Load arguments from array
1405 for (int i = 0; i < dstType.parameterCount(); i++) {
1406 emitAloadInsn(1);
1407 emitIconstInsn(i);
1408 mv.visitInsn(Opcodes.AALOAD);
1409
1410 // Maybe unbox
1411 Class<?> dptype = dstType.parameterType(i);
1412 if (dptype.isPrimitive()) {
1413 Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1414 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1415 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1416 emitUnboxing(srcWrapper);
1417 emitPrimCast(srcWrapper, dstWrapper);
1418 }
1419 }
1420
1421 // Invoke
1422 String targetDesc = dstType.basicType().toMethodDescriptorString();
1423 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1424
1425 // Box primitive types
1426 Class<?> rtype = dstType.returnType();
1427 if (rtype != void.class && rtype.isPrimitive()) {
1428 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1429 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1430 // boolean casts not allowed
1431 emitPrimCast(srcWrapper, dstWrapper);
1432 emitBoxing(dstWrapper);
1433 }
1434
1435 // If the return type is void we return a null reference.
1436 if (rtype == void.class) {
1437 mv.visitInsn(Opcodes.ACONST_NULL);
1438 }
1439 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1440
1441 classFileEpilogue();
1442 bogusMethod(dstType);
1443
1444 final byte[] classFile = cw.toByteArray();
1445 maybeDump(className, classFile);
1446 return classFile;
1447 }
1448
1449 /**
1450 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1451 * for debugging purposes.
1452 */
1453 private void bogusMethod(Object... os) {
1454 if (DUMP_CLASS_FILES) {
1455 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1456 for (Object o : os) {
1457 mv.visitLdcInsn(o.toString());
1458 mv.visitInsn(Opcodes.POP);
1459 }
1460 mv.visitInsn(Opcodes.RETURN);
1461 mv.visitMaxs(0, 0);
1462 mv.visitEnd();
1463 }
1464 }
1465 }