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