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