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