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 sun.invoke.util.VerifyAccess;
29 import static java.lang.invoke.LambdaForm.*;
30
31 import sun.invoke.util.Wrapper;
32
33 import java.io.*;
34 import java.util.*;
35
36 import jdk.internal.org.objectweb.asm.*;
37
38 import java.lang.reflect.*;
39 import static java.lang.invoke.MethodHandleStatics.*;
40 import static java.lang.invoke.MethodHandleNatives.Constants.*;
41 import static java.lang.invoke.LambdaForm.BasicType.*;
42 import sun.invoke.util.VerifyType;
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$Name";
56 private static final String CLS = "java/lang/Class";
57 private static final String OBJ = "java/lang/Object";
58 private static final String OBJARY = "[Ljava/lang/Object;";
59
60 private static final String LF_SIG = "L" + LF + ";";
61 private static final String LFN_SIG = "L" + LFN + ";";
62 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
63 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";";
64
65 /** Name of its super class*/
66 private static final String superName = LF;
67
68 /** Name of new class */
69 private final String className;
70
71 /** Name of the source file (for stack trace printing). */
72 private final String sourceFile;
73
74 private final LambdaForm lambdaForm;
75 private final String invokerName;
76 private final MethodType invokerType;
77 private final int[] localsMap;
78
79 /** ASM bytecode generation. */
80 private ClassWriter cw;
81 private MethodVisitor mv;
82
83 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
84 private static final Class<?> HOST_CLASS = LambdaForm.class;
85
86 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
87 String className, String invokerName, MethodType invokerType) {
88 if (invokerName.contains(".")) {
89 int p = invokerName.indexOf('.');
90 className = invokerName.substring(0, p);
91 invokerName = invokerName.substring(p+1);
92 }
93 if (DUMP_CLASS_FILES) {
94 className = makeDumpableClassName(className);
95 }
96 this.className = superName + "$" + className;
97 this.sourceFile = "LambdaForm$" + className;
98 this.lambdaForm = lambdaForm;
99 this.invokerName = invokerName;
100 this.invokerType = invokerType;
101 this.localsMap = new int[localsMapSize];
102 }
103
104 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
105 this(null, invokerType.parameterCount(),
106 className, invokerName, invokerType);
107 // Create an array to map name indexes to locals indexes.
108 for (int i = 0; i < localsMap.length; i++) {
109 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
110 }
111 }
112
113 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
114 this(form, form.names.length,
115 className, form.debugName, invokerType);
116 // Create an array to map name indexes to locals indexes.
117 Name[] names = form.names;
118 for (int i = 0, index = 0; i < localsMap.length; i++) {
119 localsMap[i] = index;
120 index += names[i].type.basicTypeSlots();
121 }
122 }
123
124
125 /** instance counters for dumped classes */
126 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
127 /** debugging flag for saving generated class files */
128 private final static File DUMP_CLASS_FILES_DIR;
129
130 static {
131 if (DUMP_CLASS_FILES) {
132 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
133 try {
134 File dumpDir = new File("DUMP_CLASS_FILES");
135 if (!dumpDir.exists()) {
136 dumpDir.mkdirs();
137 }
138 DUMP_CLASS_FILES_DIR = dumpDir;
139 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
140 } catch (Exception e) {
141 throw newInternalError(e);
142 }
143 } else {
144 DUMP_CLASS_FILES_COUNTERS = null;
145 DUMP_CLASS_FILES_DIR = null;
146 }
147 }
148
149 static void maybeDump(final String className, final byte[] classFile) {
150 if (DUMP_CLASS_FILES) {
151 System.out.println("dump: " + className);
152 java.security.AccessController.doPrivileged(
153 new java.security.PrivilegedAction<Void>() {
154 public Void run() {
155 try {
156 String dumpName = className;
157 //dumpName = dumpName.replace('/', '-');
158 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
159 dumpFile.getParentFile().mkdirs();
160 FileOutputStream file = new FileOutputStream(dumpFile);
161 file.write(classFile);
162 file.close();
163 return null;
164 } catch (IOException ex) {
165 throw newInternalError(ex);
166 }
167 }
168 });
169 }
170
171 }
172
173 private static String makeDumpableClassName(String className) {
174 Integer ctr;
175 synchronized (DUMP_CLASS_FILES_COUNTERS) {
176 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
177 if (ctr == null) ctr = 0;
178 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
179 }
180 String sfx = ctr.toString();
181 while (sfx.length() < 3)
182 sfx = "0"+sfx;
183 className += sfx;
184 return className;
185 }
186
187 class CpPatch {
188 final int index;
189 final String placeholder;
190 final Object value;
191 CpPatch(int index, String placeholder, Object value) {
192 this.index = index;
193 this.placeholder = placeholder;
194 this.value = value;
195 }
196 public String toString() {
197 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
198 }
199 }
200
201 Map<Object, CpPatch> cpPatches = new HashMap<>();
202
203 int cph = 0; // for counting constant placeholders
204
205 String constantPlaceholder(Object arg) {
206 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
207 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + arg.toString() + ">>"; // debugging aid
208 if (cpPatches.containsKey(cpPlaceholder)) {
209 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
210 }
211 // insert placeholder in CP and remember the patch
212 int index = cw.newConst((Object) cpPlaceholder); // TODO check if aready in the constant pool
213 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
214 return cpPlaceholder;
215 }
216
217 Object[] cpPatches(byte[] classFile) {
218 int size = getConstantPoolSize(classFile);
219 Object[] res = new Object[size];
220 for (CpPatch p : cpPatches.values()) {
221 if (p.index >= size)
222 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
223 res[p.index] = p.value;
224 }
225 return res;
226 }
227
228 /**
229 * Extract the number of constant pool entries from a given class file.
230 *
231 * @param classFile the bytes of the class file in question.
232 * @return the number of entries in the constant pool.
233 */
234 private static int getConstantPoolSize(byte[] classFile) {
235 // The first few bytes:
236 // u4 magic;
237 // u2 minor_version;
238 // u2 major_version;
239 // u2 constant_pool_count;
240 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
241 }
242
243 /**
244 * Extract the MemberName of a newly-defined method.
245 */
246 private MemberName loadMethod(byte[] classFile) {
247 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
248 return resolveInvokerMember(invokerClass, invokerName, invokerType);
249 }
250
251 /**
252 * Define a given class as anonymous class in the runtime system.
253 */
254 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
255 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
256 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
257 return invokerClass;
258 }
259
260 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
261 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
262 //System.out.println("resolveInvokerMember => "+member);
263 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
264 try {
265 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
266 } catch (ReflectiveOperationException e) {
267 throw newInternalError(e);
268 }
269 //System.out.println("resolveInvokerMember => "+member);
270 return member;
271 }
272
273 /**
274 * Set up class file generation.
275 */
276 private void classFilePrologue() {
277 final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
278 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
279 cw.visit(Opcodes.V1_8, NOT_ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
280 cw.visitSource(sourceFile, null);
281
282 String invokerDesc = invokerType.toMethodDescriptorString();
283 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
284 }
285
286 /**
287 * Tear down class file generation.
288 */
289 private void classFileEpilogue() {
290 mv.visitMaxs(0, 0);
291 mv.visitEnd();
292 }
293
294 /*
295 * Low-level emit helpers.
296 */
297 private void emitConst(Object con) {
298 if (con == null) {
299 mv.visitInsn(Opcodes.ACONST_NULL);
300 return;
301 }
302 if (con instanceof Integer) {
303 emitIconstInsn((int) con);
304 return;
305 }
306 if (con instanceof Long) {
307 long x = (long) con;
308 if (x == (short) x) {
309 emitIconstInsn((int) x);
310 mv.visitInsn(Opcodes.I2L);
311 return;
312 }
313 }
314 if (con instanceof Float) {
315 float x = (float) con;
316 if (x == (short) x) {
317 emitIconstInsn((int) x);
318 mv.visitInsn(Opcodes.I2F);
319 return;
320 }
321 }
322 if (con instanceof Double) {
323 double x = (double) con;
324 if (x == (short) x) {
325 emitIconstInsn((int) x);
326 mv.visitInsn(Opcodes.I2D);
327 return;
328 }
329 }
330 if (con instanceof Boolean) {
331 emitIconstInsn((boolean) con ? 1 : 0);
332 return;
333 }
334 // fall through:
335 mv.visitLdcInsn(con);
336 }
337
338 private void emitIconstInsn(int i) {
339 int opcode;
340 switch (i) {
341 case 0: opcode = Opcodes.ICONST_0; break;
342 case 1: opcode = Opcodes.ICONST_1; break;
343 case 2: opcode = Opcodes.ICONST_2; break;
344 case 3: opcode = Opcodes.ICONST_3; break;
345 case 4: opcode = Opcodes.ICONST_4; break;
346 case 5: opcode = Opcodes.ICONST_5; break;
347 default:
348 if (i == (byte) i) {
349 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
350 } else if (i == (short) i) {
351 mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
352 } else {
353 mv.visitLdcInsn(i);
354 }
355 return;
356 }
357 mv.visitInsn(opcode);
358 }
359
360 /*
361 * NOTE: These load/store methods use the localsMap to find the correct index!
362 */
363 private void emitLoadInsn(BasicType type, int index) {
364 int opcode = loadInsnOpcode(type);
365 mv.visitVarInsn(opcode, localsMap[index]);
366 }
367
368 private int loadInsnOpcode(BasicType type) throws InternalError {
369 switch (type) {
370 case I_TYPE: return Opcodes.ILOAD;
371 case J_TYPE: return Opcodes.LLOAD;
372 case F_TYPE: return Opcodes.FLOAD;
373 case D_TYPE: return Opcodes.DLOAD;
374 case L_TYPE: return Opcodes.ALOAD;
375 default:
376 throw new InternalError("unknown type: " + type);
377 }
378 }
379 private void emitAloadInsn(int index) {
380 emitLoadInsn(L_TYPE, index);
381 }
382
383 private void emitStoreInsn(BasicType type, int index) {
384 int opcode = storeInsnOpcode(type);
385 mv.visitVarInsn(opcode, localsMap[index]);
386 }
387
388 private int storeInsnOpcode(BasicType type) throws InternalError {
389 switch (type) {
390 case I_TYPE: return Opcodes.ISTORE;
391 case J_TYPE: return Opcodes.LSTORE;
392 case F_TYPE: return Opcodes.FSTORE;
393 case D_TYPE: return Opcodes.DSTORE;
394 case L_TYPE: return Opcodes.ASTORE;
395 default:
396 throw new InternalError("unknown type: " + type);
397 }
398 }
399 private void emitAstoreInsn(int index) {
400 emitStoreInsn(L_TYPE, index);
401 }
402
403 /**
404 * Emit a boxing call.
405 *
406 * @param wrapper primitive type class to box.
407 */
408 private void emitBoxing(Wrapper wrapper) {
409 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
410 String name = "valueOf";
411 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
412 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
413 }
414
415 /**
416 * Emit an unboxing call (plus preceding checkcast).
417 *
418 * @param wrapper wrapper type class to unbox.
419 */
420 private void emitUnboxing(Wrapper wrapper) {
421 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
422 String name = wrapper.primitiveSimpleName() + "Value";
423 String desc = "()" + wrapper.basicTypeChar();
424 mv.visitTypeInsn(Opcodes.CHECKCAST, owner);
425 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
426 }
427
428 /**
429 * Emit an implicit conversion.
430 *
431 * @param ptype type of value present on stack
432 * @param pclass type of value required on stack
433 */
434 private void emitImplicitConversion(BasicType ptype, Class<?> pclass) {
435 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
436 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
437 return; // nothing to do
438 switch (ptype) {
439 case L_TYPE:
440 if (VerifyType.isNullConversion(Object.class, pclass))
441 return;
442 if (isStaticallyNameable(pclass)) {
443 mv.visitTypeInsn(Opcodes.CHECKCAST, getInternalName(pclass));
444 } else {
445 mv.visitLdcInsn(constantPlaceholder(pclass));
446 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
447 mv.visitInsn(Opcodes.SWAP);
448 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false);
449 if (pclass.isArray())
450 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
451 }
452 return;
453 case I_TYPE:
454 if (!VerifyType.isNullConversion(int.class, pclass))
455 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
456 return;
457 }
458 throw new InternalError("bad implicit conversion: tc="+ptype+": "+pclass);
459 }
460
461 /**
462 * Emits an actual return instruction conforming to the given return type.
463 */
464 private void emitReturnInsn(BasicType type) {
465 int opcode;
466 switch (type) {
467 case I_TYPE: opcode = Opcodes.IRETURN; break;
468 case J_TYPE: opcode = Opcodes.LRETURN; break;
469 case F_TYPE: opcode = Opcodes.FRETURN; break;
470 case D_TYPE: opcode = Opcodes.DRETURN; break;
471 case L_TYPE: opcode = Opcodes.ARETURN; break;
472 case V_TYPE: opcode = Opcodes.RETURN; break;
473 default:
474 throw new InternalError("unknown return type: " + type);
475 }
476 mv.visitInsn(opcode);
477 }
478
479 private static String getInternalName(Class<?> c) {
480 assert(VerifyAccess.isTypeVisible(c, Object.class));
481 return c.getName().replace('.', '/');
482 }
483
484 /**
485 * Generate customized bytecode for a given LambdaForm.
486 */
487 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
488 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
489 return g.loadMethod(g.generateCustomizedCodeBytes());
490 }
491
492 /**
493 * Generate an invoker method for the passed {@link LambdaForm}.
494 */
495 private byte[] generateCustomizedCodeBytes() {
496 classFilePrologue();
497
498 // Suppress this method in backtraces displayed to the user.
499 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
500
501 // Mark this method as a compiled LambdaForm
502 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
503
504 // Force inlining of this invoker method.
505 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
506
507 // iterate over the form's names, generating bytecode instructions for each
508 // start iterating at the first name following the arguments
509 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
510 Name name = lambdaForm.names[i];
511 MemberName member = name.function.member();
512
513 if (isSelectAlternative(i)) {
514 emitSelectAlternative(name, lambdaForm.names[i + 1]);
515 i++; // skip MH.invokeBasic of the selectAlternative result
516 } else if (isGuardWithCatch(i)) {
517 emitGuardWithCatch(i);
518 i = i+2; // Jump to the end of GWC idiom
519 } else if (isStaticallyInvocable(member)) {
520 emitStaticInvoke(member, name);
521 } else {
522 emitInvoke(name);
523 }
524
525 // Update cached form name's info in case an intrinsic spanning multiple names was encountered.
526 name = lambdaForm.names[i];
527 member = name.function.member();
528
529 // store the result from evaluating to the target name in a local if required
530 // (if this is the last value, i.e., the one that is going to be returned,
531 // avoid store/load/return and just return)
532 if (i == lambdaForm.names.length - 1 && i == lambdaForm.result) {
533 // return value - do nothing
534 } else if (name.type != V_TYPE) {
535 // non-void: actually assign
536 emitStoreInsn(name.type, name.index());
537 }
538 }
539
540 // return statement
541 emitReturn();
542
543 classFileEpilogue();
544 bogusMethod(lambdaForm);
545
546 final byte[] classFile = cw.toByteArray();
547 maybeDump(className, classFile);
548 return classFile;
549 }
550
551 /**
552 * Emit an invoke for the given name.
553 */
554 void emitInvoke(Name name) {
555 if (true) {
556 // push receiver
557 MethodHandle target = name.function.resolvedHandle;
558 assert(target != null) : name.exprString();
559 mv.visitLdcInsn(constantPlaceholder(target));
560 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
561 } else {
562 // load receiver
563 emitAloadInsn(0);
564 mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
565 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
566 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
567 // TODO more to come
568 }
569
570 // push arguments
571 for (int i = 0; i < name.arguments.length; i++) {
572 emitPushArgument(name, i);
573 }
574
575 // invocation
576 MethodType type = name.function.methodType();
577 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
578 }
579
580 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
581 // Sample classes from each package we are willing to bind to statically:
582 java.lang.Object.class,
583 java.util.Arrays.class,
584 sun.misc.Unsafe.class
585 //MethodHandle.class already covered
586 };
587
588 static boolean isStaticallyInvocable(MemberName member) {
589 if (member == null) return false;
590 if (member.isConstructor()) return false;
591 Class<?> cls = member.getDeclaringClass();
592 if (cls.isArray() || cls.isPrimitive())
593 return false; // FIXME
594 if (cls.isAnonymousClass() || cls.isLocalClass())
595 return false; // inner class of some sort
596 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
597 return false; // not on BCP
598 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
599 return false;
600 MethodType mtype = member.getMethodOrFieldType();
601 if (!isStaticallyNameable(mtype.returnType()))
602 return false;
603 for (Class<?> ptype : mtype.parameterArray())
604 if (!isStaticallyNameable(ptype))
605 return false;
606 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
607 return true; // in java.lang.invoke package
608 if (member.isPublic() && isStaticallyNameable(cls))
609 return true;
610 return false;
611 }
612
613 static boolean isStaticallyNameable(Class<?> cls) {
614 while (cls.isArray())
615 cls = cls.getComponentType();
616 if (cls.isPrimitive())
617 return true; // int[].class, for example
618 if (ReflectUtil.isVMAnonymousClass(cls)) // FIXME: switch to supported API once it is added
619 return false;
620 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
621 if (cls.getClassLoader() != Object.class.getClassLoader())
622 return false;
623 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
624 return true;
625 if (!Modifier.isPublic(cls.getModifiers()))
626 return false;
627 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
628 if (VerifyAccess.isSamePackage(pkgcls, cls))
629 return true;
630 }
631 return false;
632 }
633
634 /**
635 * Emit an invoke for the given name, using the MemberName directly.
636 */
637 void emitStaticInvoke(MemberName member, Name name) {
638 assert(member.equals(name.function.member()));
639 String cname = getInternalName(member.getDeclaringClass());
640 String mname = member.getName();
641 String mtype;
642 byte refKind = member.getReferenceKind();
643 if (refKind == REF_invokeSpecial) {
644 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
645 assert(member.canBeStaticallyBound()) : member;
646 refKind = REF_invokeVirtual;
647 }
648
649 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
650 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
651 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
652 refKind = REF_invokeInterface;
653 }
654
655 // push arguments
656 for (int i = 0; i < name.arguments.length; i++) {
657 emitPushArgument(name, i);
658 }
659
660 // invocation
661 if (member.isMethod()) {
662 mtype = member.getMethodType().toMethodDescriptorString();
663 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
664 member.getDeclaringClass().isInterface());
665 } else {
666 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
667 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
668 }
669 }
670 int refKindOpcode(byte refKind) {
671 switch (refKind) {
672 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
673 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
674 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
675 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
676 case REF_getField: return Opcodes.GETFIELD;
677 case REF_putField: return Opcodes.PUTFIELD;
678 case REF_getStatic: return Opcodes.GETSTATIC;
679 case REF_putStatic: return Opcodes.PUTSTATIC;
680 }
681 throw new InternalError("refKind="+refKind);
682 }
683
684 /**
685 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
686 */
687 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) {
688 return member != null &&
689 member.getDeclaringClass() == declaringClass &&
690 member.getName().equals(name);
691 }
692 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) {
693 return name.function != null &&
694 memberRefersTo(name.function.member(), declaringClass, methodName);
695 }
696
697 /**
698 * Check if MemberName is a call to MethodHandle.invokeBasic.
699 */
700 private boolean isInvokeBasic(Name name) {
701 if (name.function == null)
702 return false;
703 if (name.arguments.length < 1)
704 return false; // must have MH argument
705 MemberName member = name.function.member();
706 return memberRefersTo(member, MethodHandle.class, "invokeBasic") &&
707 !member.isPublic() && !member.isStatic();
708 }
709
710 /**
711 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
712 */
713 private boolean isSelectAlternative(int pos) {
714 // selectAlternative idiom:
715 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
716 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
717 if (pos+1 >= lambdaForm.names.length) return false;
718 Name name0 = lambdaForm.names[pos];
719 Name name1 = lambdaForm.names[pos+1];
720 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") &&
721 isInvokeBasic(name1) &&
722 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
723 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
724 }
725
726 /**
727 * Check if i-th name is a start of GuardWithCatch idiom.
728 */
729 private boolean isGuardWithCatch(int pos) {
730 // GuardWithCatch idiom:
731 // t_{n}:L=MethodHandle.invokeBasic(...)
732 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
733 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
734 if (pos+2 >= lambdaForm.names.length) return false;
735 Name name0 = lambdaForm.names[pos];
736 Name name1 = lambdaForm.names[pos+1];
737 Name name2 = lambdaForm.names[pos+2];
738 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") &&
739 isInvokeBasic(name0) &&
740 isInvokeBasic(name2) &&
741 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
742 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
743 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
744 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
745 }
746
747 /**
748 * Emit bytecode for the selectAlternative idiom.
749 *
750 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
751 * <blockquote><pre>{@code
752 * Lambda(a0:L,a1:I)=>{
753 * t2:I=foo.test(a1:I);
754 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
755 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
756 * }</pre></blockquote>
757 */
758 private void emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
759 Name receiver = (Name) invokeBasicName.arguments[0];
760
761 Label L_fallback = new Label();
762 Label L_done = new Label();
763
764 // load test result
765 emitPushArgument(selectAlternativeName, 0);
766 mv.visitInsn(Opcodes.ICONST_1);
767
768 // if_icmpne L_fallback
769 mv.visitJumpInsn(Opcodes.IF_ICMPNE, L_fallback);
770
771 // invoke selectAlternativeName.arguments[1]
772 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
773 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
774 emitInvoke(invokeBasicName);
775
776 // goto L_done
777 mv.visitJumpInsn(Opcodes.GOTO, L_done);
778
779 // L_fallback:
780 mv.visitLabel(L_fallback);
781
782 // invoke selectAlternativeName.arguments[2]
783 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
784 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
785 emitInvoke(invokeBasicName);
786
787 // L_done:
788 mv.visitLabel(L_done);
789 }
790
791 /**
792 * Emit bytecode for the guardWithCatch idiom.
793 *
794 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
795 * <blockquote><pre>{@code
796 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
797 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
798 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
799 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
800 * }</pre></blockquote>
801 *
802 * It is compiled into bytecode equivalent of the following code:
803 * <blockquote><pre>{@code
804 * try {
805 * return a1.invokeBasic(a6, a7);
806 * } catch (Throwable e) {
807 * if (!a2.isInstance(e)) throw e;
808 * return a3.invokeBasic(ex, a6, a7);
809 * }}
810 */
811 private void emitGuardWithCatch(int pos) {
812 Name args = lambdaForm.names[pos];
813 Name invoker = lambdaForm.names[pos+1];
814 Name result = lambdaForm.names[pos+2];
815
816 Label L_startBlock = new Label();
817 Label L_endBlock = new Label();
818 Label L_handler = new Label();
819 Label L_done = new Label();
820
821 Class<?> returnType = result.function.resolvedHandle.type().returnType();
822 MethodType type = args.function.resolvedHandle.type()
823 .dropParameterTypes(0,1)
824 .changeReturnType(returnType);
825
826 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
827
828 // Normal case
829 mv.visitLabel(L_startBlock);
830 // load target
831 emitPushArgument(invoker, 0);
832 emitPushArguments(args, 1); // skip 1st argument: method handle
833 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
834 mv.visitLabel(L_endBlock);
835 mv.visitJumpInsn(Opcodes.GOTO, L_done);
836
837 // Exceptional case
838 mv.visitLabel(L_handler);
839
840 // Check exception's type
841 mv.visitInsn(Opcodes.DUP);
842 // load exception class
843 emitPushArgument(invoker, 1);
844 mv.visitInsn(Opcodes.SWAP);
845 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
846 Label L_rethrow = new Label();
847 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
848
849 // Invoke catcher
850 // load catcher
851 emitPushArgument(invoker, 2);
852 mv.visitInsn(Opcodes.SWAP);
853 emitPushArguments(args, 1); // skip 1st argument: method handle
854 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
855 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
856 mv.visitJumpInsn(Opcodes.GOTO, L_done);
857
858 mv.visitLabel(L_rethrow);
859 mv.visitInsn(Opcodes.ATHROW);
860
861 mv.visitLabel(L_done);
862 }
863
864 private void emitPushArguments(Name args, int start) {
865 for (int i = start; i < args.arguments.length; i++) {
866 emitPushArgument(args, i);
867 }
868 }
869
870 private void emitPushArgument(Name name, int paramIndex) {
871 Object arg = name.arguments[paramIndex];
872 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
873 emitPushArgument(ptype, arg);
874 }
875
876 private void emitPushArgument(Class<?> ptype, Object arg) {
877 BasicType bptype = basicType(ptype);
878 if (arg instanceof Name) {
879 Name n = (Name) arg;
880 emitLoadInsn(n.type, n.index());
881 emitImplicitConversion(n.type, ptype);
882 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
883 emitConst(arg);
884 } else {
885 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
886 emitConst(arg);
887 } else {
888 mv.visitLdcInsn(constantPlaceholder(arg));
889 emitImplicitConversion(L_TYPE, ptype);
890 }
891 }
892 }
893
894 /**
895 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
896 */
897 private void emitReturn() {
898 // return statement
899 Class<?> rclass = invokerType.returnType();
900 BasicType rtype = lambdaForm.returnType();
901 assert(rtype == basicType(rclass)); // must agree
902 if (rtype == V_TYPE) {
903 // void
904 mv.visitInsn(Opcodes.RETURN);
905 // it doesn't matter what rclass is; the JVM will discard any value
906 } else {
907 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
908
909 // put return value on the stack if it is not already there
910 if (lambdaForm.result != lambdaForm.names.length - 1 ||
911 lambdaForm.result < lambdaForm.arity) {
912 emitLoadInsn(rn.type, lambdaForm.result);
913 }
914
915 emitImplicitConversion(rtype, rclass);
916
917 // generate actual return statement
918 emitReturnInsn(rtype);
919 }
920 }
921
922 /**
923 * Emit a type conversion bytecode casting from "from" to "to".
924 */
925 private void emitPrimCast(Wrapper from, Wrapper to) {
926 // Here's how.
927 // - indicates forbidden
928 // <-> indicates implicit
929 // to ----> boolean byte short char int long float double
930 // from boolean <-> - - - - - - -
931 // byte - <-> i2s i2c <-> i2l i2f i2d
932 // short - i2b <-> i2c <-> i2l i2f i2d
933 // char - i2b i2s <-> <-> i2l i2f i2d
934 // int - i2b i2s i2c <-> i2l i2f i2d
935 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
936 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
937 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
938 if (from == to) {
939 // no cast required, should be dead code anyway
940 return;
941 }
942 if (from.isSubwordOrInt()) {
943 // cast from {byte,short,char,int} to anything
944 emitI2X(to);
945 } else {
946 // cast from {long,float,double} to anything
947 if (to.isSubwordOrInt()) {
948 // cast to {byte,short,char,int}
949 emitX2I(from);
950 if (to.bitWidth() < 32) {
951 // targets other than int require another conversion
952 emitI2X(to);
953 }
954 } else {
955 // cast to {long,float,double} - this is verbose
956 boolean error = false;
957 switch (from) {
958 case LONG:
959 switch (to) {
960 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
961 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
962 default: error = true; break;
963 }
964 break;
965 case FLOAT:
966 switch (to) {
967 case LONG : mv.visitInsn(Opcodes.F2L); break;
968 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
969 default: error = true; break;
970 }
971 break;
972 case DOUBLE:
973 switch (to) {
974 case LONG : mv.visitInsn(Opcodes.D2L); break;
975 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
976 default: error = true; break;
977 }
978 break;
979 default:
980 error = true;
981 break;
982 }
983 if (error) {
984 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
985 }
986 }
987 }
988 }
989
990 private void emitI2X(Wrapper type) {
991 switch (type) {
992 case BYTE: mv.visitInsn(Opcodes.I2B); break;
993 case SHORT: mv.visitInsn(Opcodes.I2S); break;
994 case CHAR: mv.visitInsn(Opcodes.I2C); break;
995 case INT: /* naught */ break;
996 case LONG: mv.visitInsn(Opcodes.I2L); break;
997 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
998 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
999 case BOOLEAN:
1000 // For compatibility with ValueConversions and explicitCastArguments:
1001 mv.visitInsn(Opcodes.ICONST_1);
1002 mv.visitInsn(Opcodes.IAND);
1003 break;
1004 default: throw new InternalError("unknown type: " + type);
1005 }
1006 }
1007
1008 private void emitX2I(Wrapper type) {
1009 switch (type) {
1010 case LONG: mv.visitInsn(Opcodes.L2I); break;
1011 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1012 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1013 default: throw new InternalError("unknown type: " + type);
1014 }
1015 }
1016
1017 /**
1018 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1019 */
1020 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1021 assert(isValidSignature(sig));
1022 String name = "interpret_"+signatureReturn(sig).basicTypeChar();
1023 MethodType type = signatureType(sig); // sig includes leading argument
1024 type = type.changeParameterType(0, MethodHandle.class);
1025 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1026 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1027 }
1028
1029 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1030 classFilePrologue();
1031
1032 // Suppress this method in backtraces displayed to the user.
1033 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1034
1035 // Don't inline the interpreter entry.
1036 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1037
1038 // create parameter array
1039 emitIconstInsn(invokerType.parameterCount());
1040 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1041
1042 // fill parameter array
1043 for (int i = 0; i < invokerType.parameterCount(); i++) {
1044 Class<?> ptype = invokerType.parameterType(i);
1045 mv.visitInsn(Opcodes.DUP);
1046 emitIconstInsn(i);
1047 emitLoadInsn(basicType(ptype), i);
1048 // box if primitive type
1049 if (ptype.isPrimitive()) {
1050 emitBoxing(Wrapper.forPrimitiveType(ptype));
1051 }
1052 mv.visitInsn(Opcodes.AASTORE);
1053 }
1054 // invoke
1055 emitAloadInsn(0);
1056 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1057 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1058 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1059
1060 // maybe unbox
1061 Class<?> rtype = invokerType.returnType();
1062 if (rtype.isPrimitive() && rtype != void.class) {
1063 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1064 }
1065
1066 // return statement
1067 emitReturnInsn(basicType(rtype));
1068
1069 classFileEpilogue();
1070 bogusMethod(invokerType);
1071
1072 final byte[] classFile = cw.toByteArray();
1073 maybeDump(className, classFile);
1074 return classFile;
1075 }
1076
1077 /**
1078 * Generate bytecode for a NamedFunction invoker.
1079 */
1080 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1081 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1082 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1083 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1084 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1085 }
1086
1087 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1088 MethodType dstType = typeForm.erasedType();
1089 classFilePrologue();
1090
1091 // Suppress this method in backtraces displayed to the user.
1092 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1093
1094 // Force inlining of this invoker method.
1095 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1096
1097 // Load receiver
1098 emitAloadInsn(0);
1099
1100 // Load arguments from array
1101 for (int i = 0; i < dstType.parameterCount(); i++) {
1102 emitAloadInsn(1);
1103 emitIconstInsn(i);
1104 mv.visitInsn(Opcodes.AALOAD);
1105
1106 // Maybe unbox
1107 Class<?> dptype = dstType.parameterType(i);
1108 if (dptype.isPrimitive()) {
1109 Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1110 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1111 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1112 emitUnboxing(srcWrapper);
1113 emitPrimCast(srcWrapper, dstWrapper);
1114 }
1115 }
1116
1117 // Invoke
1118 String targetDesc = dstType.basicType().toMethodDescriptorString();
1119 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1120
1121 // Box primitive types
1122 Class<?> rtype = dstType.returnType();
1123 if (rtype != void.class && rtype.isPrimitive()) {
1124 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1125 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1126 // boolean casts not allowed
1127 emitPrimCast(srcWrapper, dstWrapper);
1128 emitBoxing(dstWrapper);
1129 }
1130
1131 // If the return type is void we return a null reference.
1132 if (rtype == void.class) {
1133 mv.visitInsn(Opcodes.ACONST_NULL);
1134 }
1135 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1136
1137 classFileEpilogue();
1138 bogusMethod(dstType);
1139
1140 final byte[] classFile = cw.toByteArray();
1141 maybeDump(className, classFile);
1142 return classFile;
1143 }
1144
1145 /**
1146 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1147 * for debugging purposes.
1148 */
1149 private void bogusMethod(Object... os) {
1150 if (DUMP_CLASS_FILES) {
1151 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1152 for (Object o : os) {
1153 mv.visitLdcInsn(o.toString());
1154 mv.visitInsn(Opcodes.POP);
1155 }
1156 mv.visitInsn(Opcodes.RETURN);
1157 mv.visitMaxs(0, 0);
1158 mv.visitEnd();
1159 }
1160 }
1161 }