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