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 java.io.*;
29 import java.util.*;
30 import java.lang.reflect.Modifier;
31
32 import jdk.internal.org.objectweb.asm.*;
33
34 import static java.lang.invoke.LambdaForm.*;
35 import static java.lang.invoke.LambdaForm.BasicType.*;
36 import static java.lang.invoke.MethodHandleStatics.*;
37 import static java.lang.invoke.MethodHandleNatives.Constants.*;
38 import sun.invoke.util.ValueConversions;
39 import sun.invoke.util.VerifyType;
40 import sun.invoke.util.VerifyAccess;
41 import sun.invoke.util.Wrapper;
42
43 /**
44 * Code generation backend for LambdaForm.
45 * <p>
46 * @author John Rose, JSR 292 EG
47 */
48 class InvokerBytecodeGenerator {
49 /** Define class names for convenience. */
50 private static final String MH = "java/lang/invoke/MethodHandle";
51 private static final String MHI = "java/lang/invoke/MethodHandleImpl";
52 private static final String LF = "java/lang/invoke/LambdaForm";
53 private static final String LFN = "java/lang/invoke/LambdaForm$Name";
54 private static final String CLS = "java/lang/Class";
55 private static final String OBJ = "java/lang/Object";
56 private static final String OBJARY = "[Ljava/lang/Object;";
57
58 private static final String LF_SIG = "L" + LF + ";";
59 private static final String LFN_SIG = "L" + LFN + ";";
60 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
61 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";";
62
63 /** Name of its super class*/
64 private static final String superName = LF;
65
66 /** Name of new class */
67 private final String className;
68
69 /** Name of the source file (for stack trace printing). */
70 private final String sourceFile;
71
72 private final LambdaForm lambdaForm;
73 private final String invokerName;
74 private final MethodType invokerType;
75
76 /** Info about local variables in compiled lambda form */
77 private final int[] localsMap; // index
78 private final BasicType[] localTypes; // basic type
79 private final Class<?>[] localClasses; // type
80
81 /** ASM bytecode generation. */
82 private ClassWriter cw;
83 private MethodVisitor mv;
84
85 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
86 private static final Class<?> HOST_CLASS = LambdaForm.class;
87
88 /** Main constructor; other constructors delegate to this one. */
89 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
90 String className, String invokerName, MethodType invokerType) {
91 if (invokerName.contains(".")) {
92 int p = invokerName.indexOf(".");
93 className = invokerName.substring(0, p);
94 invokerName = invokerName.substring(p+1);
95 }
96 if (DUMP_CLASS_FILES) {
97 className = makeDumpableClassName(className);
98 }
99 this.className = superName + "$" + className;
100 this.sourceFile = "LambdaForm$" + className;
101 this.lambdaForm = lambdaForm;
102 this.invokerName = invokerName;
103 this.invokerType = invokerType;
104 this.localsMap = new int[localsMapSize+1];
105 // last entry of localsMap is count of allocated local slots
106 this.localTypes = new BasicType[localsMapSize+1];
107 this.localClasses = new Class<?>[localsMapSize+1];
108 }
109
110 /** For generating LambdaForm interpreter entry points. */
111 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
112 this(null, invokerType.parameterCount(),
113 className, invokerName, invokerType);
114 // Create an array to map name indexes to locals indexes.
115 localTypes[localTypes.length - 1] = V_TYPE;
116 for (int i = 0; i < localsMap.length; i++) {
117 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
118 if (i < invokerType.parameterCount())
119 localTypes[i] = basicType(invokerType.parameterType(i));
120 }
121 }
122
123 /** For generating customized code for a single LambdaForm. */
124 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
125 this(form, form.names.length,
126 className, form.debugName, invokerType);
127 // Create an array to map name indexes to locals indexes.
128 Name[] names = form.names;
129 for (int i = 0, index = 0; i < localsMap.length; i++) {
130 localsMap[i] = index;
131 if (i < names.length) {
132 BasicType type = names[i].type();
133 index += type.basicTypeSlots();
134 localTypes[i] = type;
135 }
136 }
137 }
138
139
140 /** instance counters for dumped classes */
141 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
142 /** debugging flag for saving generated class files */
143 private final static File DUMP_CLASS_FILES_DIR;
144
145 static {
146 if (DUMP_CLASS_FILES) {
147 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
148 try {
149 File dumpDir = new File("DUMP_CLASS_FILES");
150 if (!dumpDir.exists()) {
151 dumpDir.mkdirs();
152 }
153 DUMP_CLASS_FILES_DIR = dumpDir;
154 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
155 } catch (Exception e) {
156 throw newInternalError(e);
157 }
158 } else {
159 DUMP_CLASS_FILES_COUNTERS = null;
160 DUMP_CLASS_FILES_DIR = null;
161 }
162 }
163
164 static void maybeDump(final String className, final byte[] classFile) {
165 if (DUMP_CLASS_FILES) {
166 java.security.AccessController.doPrivileged(
167 new java.security.PrivilegedAction<Void>() {
168 public Void run() {
169 try {
170 String dumpName = className;
171 //dumpName = dumpName.replace('/', '-');
172 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
173 System.out.println("dump: " + dumpFile);
174 dumpFile.getParentFile().mkdirs();
175 FileOutputStream file = new FileOutputStream(dumpFile);
176 file.write(classFile);
177 file.close();
178 return null;
179 } catch (IOException ex) {
180 throw newInternalError(ex);
181 }
182 }
183 });
184 }
185
186 }
187
188 private static String makeDumpableClassName(String className) {
189 Integer ctr;
190 synchronized (DUMP_CLASS_FILES_COUNTERS) {
191 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
192 if (ctr == null) ctr = 0;
193 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
194 }
195 String sfx = ctr.toString();
196 while (sfx.length() < 3)
197 sfx = "0"+sfx;
198 className += sfx;
199 return className;
200 }
201
202 class CpPatch {
203 final int index;
204 final String placeholder;
205 final Object value;
206 CpPatch(int index, String placeholder, Object value) {
207 this.index = index;
208 this.placeholder = placeholder;
209 this.value = value;
210 }
211 public String toString() {
212 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
213 }
214 }
215
216 Map<Object, CpPatch> cpPatches = new HashMap<>();
217
218 int cph = 0; // for counting constant placeholders
219
220 String constantPlaceholder(Object arg) {
221 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
222 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid
223 if (cpPatches.containsKey(cpPlaceholder)) {
224 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
225 }
226 // insert placeholder in CP and remember the patch
227 int index = cw.newConst((Object) cpPlaceholder); // TODO check if aready in the constant pool
228 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
229 return cpPlaceholder;
230 }
231
232 Object[] cpPatches(byte[] classFile) {
233 int size = getConstantPoolSize(classFile);
234 Object[] res = new Object[size];
235 for (CpPatch p : cpPatches.values()) {
236 if (p.index >= size)
237 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
238 res[p.index] = p.value;
239 }
240 return res;
241 }
242
243 private static String debugString(Object arg) {
244 if (arg instanceof MethodHandle) {
245 MethodHandle mh = (MethodHandle) arg;
246 MemberName member = mh.internalMemberName();
247 if (member != null)
248 return member.toString();
249 return mh.debugString();
250 }
251 return arg.toString();
252 }
253
254 /**
255 * Extract the number of constant pool entries from a given class file.
256 *
257 * @param classFile the bytes of the class file in question.
258 * @return the number of entries in the constant pool.
259 */
260 private static int getConstantPoolSize(byte[] classFile) {
261 // The first few bytes:
262 // u4 magic;
263 // u2 minor_version;
264 // u2 major_version;
265 // u2 constant_pool_count;
266 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
267 }
268
269 /**
270 * Extract the MemberName of a newly-defined method.
271 */
272 private MemberName loadMethod(byte[] classFile) {
273 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
274 return resolveInvokerMember(invokerClass, invokerName, invokerType);
275 }
276
277 /**
278 * Define a given class as anonymous class in the runtime system.
279 */
280 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
281 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
282 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
283 return invokerClass;
284 }
285
286 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
287 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
288 //System.out.println("resolveInvokerMember => "+member);
289 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
290 try {
291 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
292 } catch (ReflectiveOperationException e) {
293 throw newInternalError(e);
294 }
295 //System.out.println("resolveInvokerMember => "+member);
296 return member;
297 }
298
299 /**
300 * Set up class file generation.
301 */
302 private void classFilePrologue() {
303 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
304 cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
305 cw.visitSource(sourceFile, null);
306
307 String invokerDesc = invokerType.toMethodDescriptorString();
308 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
309 }
310
311 /**
312 * Tear down class file generation.
313 */
314 private void classFileEpilogue() {
315 mv.visitMaxs(0, 0);
316 mv.visitEnd();
317 }
318
319 /*
320 * Low-level emit helpers.
321 */
322 private void emitConst(Object con) {
323 if (con == null) {
324 mv.visitInsn(Opcodes.ACONST_NULL);
325 return;
326 }
327 if (con instanceof Integer) {
328 emitIconstInsn((int) con);
329 return;
330 }
331 if (con instanceof Long) {
332 long x = (long) con;
333 if (x == (short) x) {
334 emitIconstInsn((int) x);
335 mv.visitInsn(Opcodes.I2L);
336 return;
337 }
338 }
339 if (con instanceof Float) {
340 float x = (float) con;
341 if (x == (short) x) {
342 emitIconstInsn((int) x);
343 mv.visitInsn(Opcodes.I2F);
344 return;
345 }
346 }
347 if (con instanceof Double) {
348 double x = (double) con;
349 if (x == (short) x) {
350 emitIconstInsn((int) x);
351 mv.visitInsn(Opcodes.I2D);
352 return;
353 }
354 }
355 if (con instanceof Boolean) {
356 emitIconstInsn((boolean) con ? 1 : 0);
357 return;
358 }
359 // fall through:
360 mv.visitLdcInsn(con);
361 }
362
363 private void emitIconstInsn(int i) {
364 int opcode;
365 switch (i) {
366 case 0: opcode = Opcodes.ICONST_0; break;
367 case 1: opcode = Opcodes.ICONST_1; break;
368 case 2: opcode = Opcodes.ICONST_2; break;
369 case 3: opcode = Opcodes.ICONST_3; break;
370 case 4: opcode = Opcodes.ICONST_4; break;
371 case 5: opcode = Opcodes.ICONST_5; break;
372 default:
373 if (i == (byte) i) {
374 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
375 } else if (i == (short) i) {
376 mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
377 } else {
378 mv.visitLdcInsn(i);
379 }
380 return;
381 }
382 mv.visitInsn(opcode);
383 }
384
385 /*
386 * NOTE: These load/store methods use the localsMap to find the correct index!
387 */
388 private void emitLoadInsn(BasicType type, int index) {
389 int opcode = loadInsnOpcode(type);
390 mv.visitVarInsn(opcode, localsMap[index]);
391 }
392
393 private int loadInsnOpcode(BasicType type) throws InternalError {
394 int opcode;
395 switch (type) {
396 case I_TYPE: opcode = Opcodes.ILOAD; break;
397 case J_TYPE: opcode = Opcodes.LLOAD; break;
398 case F_TYPE: opcode = Opcodes.FLOAD; break;
399 case D_TYPE: opcode = Opcodes.DLOAD; break;
400 case L_TYPE: opcode = Opcodes.ALOAD; break;
401 default:
402 throw new InternalError("unknown type: " + type);
403 }
404 return opcode;
405 }
406 private void emitAloadInsn(int index) {
407 emitLoadInsn(L_TYPE, index);
408 }
409
410 private void emitStoreInsn(BasicType type, int index) {
411 int opcode = storeInsnOpcode(type);
412 mv.visitVarInsn(opcode, localsMap[index]);
413 }
414
415 private int storeInsnOpcode(BasicType type) throws InternalError {
416 int opcode;
417 switch (type) {
418 case I_TYPE: opcode = Opcodes.ISTORE; break;
419 case J_TYPE: opcode = Opcodes.LSTORE; break;
420 case F_TYPE: opcode = Opcodes.FSTORE; break;
421 case D_TYPE: opcode = Opcodes.DSTORE; break;
422 case L_TYPE: opcode = Opcodes.ASTORE; break;
423 default:
424 throw new InternalError("unknown type: " + type);
425 }
426 return opcode;
427 }
428 private void emitAstoreInsn(int index) {
429 emitStoreInsn(L_TYPE, index);
430 }
431
432 private void freeFrameLocal(int oldFrameLocal) {
433 int i = indexForFrameLocal(oldFrameLocal);
434 if (i < 0) return;
435 BasicType type = localTypes[i];
436 int newFrameLocal = makeLocalTemp(type);
437 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal);
438 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal);
439 assert(localsMap[i] == oldFrameLocal);
440 localsMap[i] = newFrameLocal;
441 assert(indexForFrameLocal(oldFrameLocal) < 0);
442 }
443 private int indexForFrameLocal(int frameLocal) {
444 for (int i = 0; i < localsMap.length; i++) {
445 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE)
446 return i;
447 }
448 return -1;
449 }
450 private int makeLocalTemp(BasicType type) {
451 int frameLocal = localsMap[localsMap.length - 1];
452 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots();
453 return frameLocal;
454 }
455
456 /**
457 * Emit a boxing call.
458 *
459 * @param wrapper primitive type class to box.
460 */
461 private void emitBoxing(Wrapper wrapper) {
462 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
463 String name = "valueOf";
464 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
465 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
466 }
467
468 /**
469 * Emit an unboxing call (plus preceding checkcast).
470 *
471 * @param wrapper wrapper type class to unbox.
472 */
473 private void emitUnboxing(Wrapper wrapper) {
474 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
475 String name = wrapper.primitiveSimpleName() + "Value";
476 String desc = "()" + wrapper.basicTypeChar();
477 emitReferenceCast(wrapper.wrapperType(), null);
478 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
479 }
480
481 /**
482 * Emit an implicit conversion for an argument which must be of the given pclass.
483 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
484 *
485 * @param ptype type of value present on stack
486 * @param pclass type of value required on stack
487 * @param arg compile-time representation of value on stack (Node, constant) or null if none
488 */
489 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
490 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
491 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
492 return; // nothing to do
493 switch (ptype) {
494 case L_TYPE:
495 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
496 if (PROFILE_LEVEL > 0)
497 emitReferenceCast(Object.class, arg);
498 return;
499 }
500 emitReferenceCast(pclass, arg);
501 return;
502 case I_TYPE:
503 if (!VerifyType.isNullConversion(int.class, pclass, false))
504 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
505 return;
506 }
507 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
508 }
509
510 /** Update localClasses type map. Return true if the information is already present. */
511 private boolean assertStaticType(Class<?> cls, Name n) {
512 int local = n.index();
513 Class<?> aclass = localClasses[local];
514 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
515 return true; // type info is already present
516 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
517 localClasses[local] = cls; // type info can be improved
518 }
519 return false;
520 }
521
522 private void emitReferenceCast(Class<?> cls, Object arg) {
523 Name writeBack = null; // local to write back result
524 if (arg instanceof Name) {
525 Name n = (Name) arg;
526 if (assertStaticType(cls, n))
527 return; // this cast was already performed
528 if (lambdaForm.useCount(n) > 1) {
529 // This guy gets used more than once.
530 writeBack = n;
531 }
532 }
533 if (isStaticallyNameable(cls)) {
534 String sig = getInternalName(cls);
535 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
536 } else {
537 mv.visitLdcInsn(constantPlaceholder(cls));
538 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
539 mv.visitInsn(Opcodes.SWAP);
540 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false);
541 if (Object[].class.isAssignableFrom(cls))
542 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
543 else if (PROFILE_LEVEL > 0)
544 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
545 }
546 if (writeBack != null) {
547 mv.visitInsn(Opcodes.DUP);
548 emitAstoreInsn(writeBack.index());
549 }
550 }
551
552 /**
553 * Emits an actual return instruction conforming to the given return type.
554 */
555 private void emitReturnInsn(BasicType type) {
556 int opcode;
557 switch (type) {
558 case I_TYPE: opcode = Opcodes.IRETURN; break;
559 case J_TYPE: opcode = Opcodes.LRETURN; break;
560 case F_TYPE: opcode = Opcodes.FRETURN; break;
561 case D_TYPE: opcode = Opcodes.DRETURN; break;
562 case L_TYPE: opcode = Opcodes.ARETURN; break;
563 case V_TYPE: opcode = Opcodes.RETURN; break;
564 default:
565 throw new InternalError("unknown return type: " + type);
566 }
567 mv.visitInsn(opcode);
568 }
569
570 private static String getInternalName(Class<?> c) {
571 if (c == Object.class) return OBJ;
572 else if (c == Object[].class) return OBJARY;
573 else if (c == Class.class) return CLS;
574 else if (c == MethodHandle.class) return MH;
575 assert(VerifyAccess.isTypeVisible(c, Object.class));
576 return c.getName().replace('.', '/');
577 }
578
579 /**
580 * Generate customized bytecode for a given LambdaForm.
581 */
582 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
583 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
584 return g.loadMethod(g.generateCustomizedCodeBytes());
585 }
586
587 /**
588 * Generate an invoker method for the passed {@link LambdaForm}.
589 */
590 private byte[] generateCustomizedCodeBytes() {
591 classFilePrologue();
592
593 // Suppress this method in backtraces displayed to the user.
594 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
595
596 // Mark this method as a compiled LambdaForm
597 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
598
599 // Force inlining of this invoker method.
600 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
601
602 // iterate over the form's names, generating bytecode instructions for each
603 // start iterating at the first name following the arguments
604 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
605 Name name = lambdaForm.names[i];
606 MemberName member = name.function.member();
607 Class<?> rtype = name.function.methodType().returnType();
608
609 if (isSelectAlternative(i)) {
610 emitSelectAlternative(name, lambdaForm.names[i + 1]);
611 i++; // skip MH.invokeBasic of the selectAlternative result
612 } else if (isGuardWithCatch(i)) {
613 emitGuardWithCatch(i);
614 i = i+2; // Jump to the end of GWC idiom
615 } else if (isNewArray(rtype, name)) {
616 emitNewArray(rtype, name);
617 } else if (isStaticallyInvocable(member)) {
618 if (isLinkerMethodInvoke(name))
619 preserveLinkerMethodTarget(name);
620 emitStaticInvoke(member, name);
621 } else {
622 emitInvoke(name);
623 }
624
625 // Update cached form name's info in case an intrinsic spanning multiple names was encountered.
626 name = lambdaForm.names[i];
627 member = name.function.member();
628 rtype = name.function.methodType().returnType();
629
630 // store the result from evaluating to the target name in a local if required
631 // (if this is the last value, i.e., the one that is going to be returned,
632 // avoid store/load/return and just return)
633 if (i == lambdaForm.names.length - 1 && i == lambdaForm.result) {
634 // return value - do nothing
635 } else if (name.type != V_TYPE) {
636 // non-void: actually assign
637 emitStoreInsn(name.type, name.index());
638 }
639 }
640
641 // return statement
642 emitReturn();
643
644 classFileEpilogue();
645 bogusMethod(lambdaForm);
646
647 final byte[] classFile = cw.toByteArray();
648 maybeDump(className, classFile);
649 return classFile;
650 }
651
652 /** Certain parts of the JVM expect that, when a call to linkToStatic is made,
653 * the DMH that produced its MN argument is in local #0.
654 * This is often true, since the lambda form of a DMH will start with
655 * the DMH 'l'in arg 0 (local #0) and will end with a call to its linker method.
656 * But if the DMH is transformed, a new lambda form may be created with
657 * the DMH placed elsewhere.
658 */
659 private void preserveLinkerMethodTarget(Name name) {
660 Object lastArg = name.arguments[name.arguments.length - 1];
661 Name targetMember = (Name) lastArg;
662 assert(targetMember.type() == L_TYPE &&
663 !targetMember.isParam() &&
664 isStaticallyInvocable(targetMember.function.member()) &&
665 targetMember.arguments.length == 1);
666 Object targetDMH = DirectMethodHandle.findDirectMethodHandle(targetMember);
667 assert(targetDMH != null);
668 if (!(targetDMH instanceof Name && ((Name)targetDMH).index() == 0)) {
669 // Oops, the DMH is not in a local #0, or is a constant.
670 int DMH_FRAME_INDEX = 0; // hardwired to local #0
671 BasicType DMH_TYPE = L_TYPE;
672 freeFrameLocal(DMH_FRAME_INDEX);
673 // Save it to local #0:
674 emitPushArgument(Object.class, targetDMH);
675 mv.visitVarInsn(storeInsnOpcode(DMH_TYPE), DMH_FRAME_INDEX);
676 }
677 }
678
679 /**
680 * Emit an invoke for the given name.
681 */
682 void emitInvoke(Name name) {
683 assert(!isLinkerMethodInvoke(name)); // should use the static path for these
684 if (true) {
685 // push receiver
686 MethodHandle target = name.function.resolvedHandle;
687 assert(target != null) : name.exprString();
688 mv.visitLdcInsn(constantPlaceholder(target));
689 emitReferenceCast(MethodHandle.class, target);
690 } else {
691 // load receiver
692 emitAloadInsn(0);
693 emitReferenceCast(MethodHandle.class, null);
694 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
695 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
696 // TODO more to come
697 }
698
699 // push arguments
700 for (int i = 0; i < name.arguments.length; i++) {
701 emitPushArgument(name, i);
702 }
703
704 // invocation
705 MethodType type = name.function.methodType();
706 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
707 }
708
709 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
710 // Sample classes from each package we are willing to bind to statically:
711 java.lang.Object.class,
712 java.util.Arrays.class,
713 sun.misc.Unsafe.class
714 //MethodHandle.class already covered
715 };
716
717 static boolean isStaticallyInvocable(MemberName member) {
718 if (member == null) return false;
719 if (member.isConstructor()) return false;
720 Class<?> cls = member.getDeclaringClass();
721 if (cls.isArray() || cls.isPrimitive())
722 return false; // FIXME
723 if (cls.isAnonymousClass() || cls.isLocalClass())
724 return false; // inner class of some sort
725 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
726 return false; // not on BCP
727 MethodType mtype = member.getMethodOrFieldType();
728 if (!isStaticallyNameable(mtype.returnType()))
729 return false;
730 for (Class<?> ptype : mtype.parameterArray())
731 if (!isStaticallyNameable(ptype))
732 return false;
733 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
734 return true; // in java.lang.invoke package
735 if (member.isPublic() && isStaticallyNameable(cls))
736 return true;
737 return false;
738 }
739
740 static boolean isStaticallyNameable(Class<?> cls) {
741 if (cls == Object.class)
742 return true;
743 while (cls.isArray())
744 cls = cls.getComponentType();
745 if (cls.isPrimitive())
746 return true; // int[].class, for example
747 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
748 if (cls.getClassLoader() != Object.class.getClassLoader())
749 return false;
750 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
751 return true;
752 if (!Modifier.isPublic(cls.getModifiers()))
753 return false;
754 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
755 if (VerifyAccess.isSamePackage(pkgcls, cls))
756 return true;
757 }
758 return false;
759 }
760
761 /**
762 * Emit an invoke for the given name, using the MemberName directly.
763 */
764 void emitStaticInvoke(MemberName member, Name name) {
765 assert(member.equals(name.function.member()));
766 Class<?> defc = member.getDeclaringClass();
767 String cname = getInternalName(defc);
768 String mname = member.getName();
769 String mtype;
770 byte refKind = member.getReferenceKind();
771 if (refKind == REF_invokeSpecial) {
772 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
773 assert(member.canBeStaticallyBound()) : member;
774 refKind = REF_invokeVirtual;
775 }
776
777 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
778 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
779 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
780 refKind = REF_invokeInterface;
781 }
782
783 // push arguments
784 for (int i = 0; i < name.arguments.length; i++) {
785 emitPushArgument(name, i);
786 }
787
788 // invocation
789 if (member.isMethod()) {
790 mtype = member.getMethodType().toMethodDescriptorString();
791 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
792 member.getDeclaringClass().isInterface());
793 } else {
794 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
795 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
796 }
797 // Issue a type assertion for the result, so we can avoid casts later.
798 if (name.type == L_TYPE) {
799 Class<?> rtype = member.getInvocationType().returnType();
800 assert(!rtype.isPrimitive());
801 if (rtype != Object.class && !rtype.isInterface()) {
802 assertStaticType(rtype, name);
803 }
804 }
805 }
806
807 boolean isNewArray(Class<?> rtype, Name name) {
808 return rtype.isArray() &&
809 isStaticallyNameable(rtype) &&
810 isArrayBuilder(name.function.resolvedHandle) &&
811 name.arguments.length > 0;
812 }
813
814 void emitNewArray(Class<?> rtype, Name name) throws InternalError {
815 Class<?> arrayElementType = rtype.getComponentType();
816 emitIconstInsn(name.arguments.length);
817 int xas;
818 if (!arrayElementType.isPrimitive()) {
819 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
820 xas = Opcodes.AASTORE;
821 } else {
822 int tc;
823 switch (Wrapper.forPrimitiveType(arrayElementType)) {
824 case BOOLEAN: tc = Opcodes.T_BOOLEAN; xas = Opcodes.BASTORE; break;
825 case BYTE: tc = Opcodes.T_BYTE; xas = Opcodes.BASTORE; break;
826 case CHAR: tc = Opcodes.T_CHAR; xas = Opcodes.CASTORE; break;
827 case SHORT: tc = Opcodes.T_SHORT; xas = Opcodes.SASTORE; break;
828 case INT: tc = Opcodes.T_INT; xas = Opcodes.IASTORE; break;
829 case LONG: tc = Opcodes.T_LONG; xas = Opcodes.LASTORE; break;
830 case FLOAT: tc = Opcodes.T_FLOAT; xas = Opcodes.FASTORE; break;
831 case DOUBLE: tc = Opcodes.T_DOUBLE; xas = Opcodes.DASTORE; break;
832 default: throw new InternalError(rtype.getName());
833 }
834 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
835 }
836 // store arguments
837 for (int i = 0; i < name.arguments.length; i++) {
838 mv.visitInsn(Opcodes.DUP);
839 emitIconstInsn(i);
840 emitPushArgument(name, i);
841 mv.visitInsn(xas);
842 }
843 // the array is left on the stack
844 assertStaticType(rtype, name);
845 }
846 int refKindOpcode(byte refKind) {
847 switch (refKind) {
848 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
849 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
850 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
851 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
852 case REF_getField: return Opcodes.GETFIELD;
853 case REF_putField: return Opcodes.PUTFIELD;
854 case REF_getStatic: return Opcodes.GETSTATIC;
855 case REF_putStatic: return Opcodes.PUTSTATIC;
856 }
857 throw new InternalError("refKind="+refKind);
858 }
859
860 static boolean isArrayBuilder(MethodHandle fn) {
861 if (fn == null)
862 return false;
863 MethodType mtype = fn.type();
864 Class<?> rtype = mtype.returnType();
865 Class<?> arrayElementType = rtype.getComponentType();
866 if (arrayElementType == null)
867 return false;
868 List<Class<?>> ptypes = mtype.parameterList();
869 int size = ptypes.size();
870 if (!ptypes.equals(Collections.nCopies(size, arrayElementType)))
871 return false;
872 // Assume varargsArray caches pointers.
873 if (fn != ValueConversions.varargsArray(rtype, size))
874 return false;
875 return true;
876 }
877
878 static boolean match(MemberName member, MethodHandle fn) {
879 if (member == null || fn == null) return false;
880 return member.equals(fn.internalMemberName());
881 }
882
883 /**
884 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
885 */
886 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) {
887 return member != null &&
888 member.getDeclaringClass() == declaringClass &&
889 member.getName().equals(name);
890 }
891 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) {
892 return name.function != null &&
893 memberRefersTo(name.function.member(), declaringClass, methodName);
894 }
895
896 /**
897 * Check if MemberName is a call to MethodHandle.invokeBasic.
898 */
899 private boolean isInvokeBasic(Name name) {
900 if (name.function == null)
901 return false;
902 if (name.arguments.length < 1)
903 return false; // must have MH argument
904 MemberName member = name.function.member();
905 return memberRefersTo(member, MethodHandle.class, "invokeBasic") &&
906 !member.isPublic() && !member.isStatic();
907 }
908
909 /**
910 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
911 */
912 private boolean isLinkerMethodInvoke(Name name) {
913 if (name.function == null)
914 return false;
915 if (name.arguments.length < 1)
916 return false; // must have MH argument
917 MemberName member = name.function.member();
918 return member != null &&
919 member.getDeclaringClass() == MethodHandle.class &&
920 !member.isPublic() && member.isStatic() &&
921 member.getName().startsWith("linkTo");
922 }
923
924 /**
925 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
926 */
927 private boolean isSelectAlternative(int pos) {
928 // selectAlternative idiom:
929 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
930 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
931 if (pos+1 >= lambdaForm.names.length) return false;
932 Name name0 = lambdaForm.names[pos];
933 Name name1 = lambdaForm.names[pos+1];
934 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") &&
935 isInvokeBasic(name1) &&
936 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
937 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
938 }
939
940 /**
941 * Check if i-th name is a start of GuardWithCatch idiom.
942 */
943 private boolean isGuardWithCatch(int pos) {
944 // GuardWithCatch idiom:
945 // t_{n}:L=MethodHandle.invokeBasic(...)
946 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
947 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
948 if (pos+2 >= lambdaForm.names.length) return false;
949 Name name0 = lambdaForm.names[pos];
950 Name name1 = lambdaForm.names[pos+1];
951 Name name2 = lambdaForm.names[pos+2];
952 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") &&
953 isInvokeBasic(name0) &&
954 isInvokeBasic(name2) &&
955 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
956 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
957 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
958 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
959 }
960
961 /**
962 * Emit bytecode for the selectAlternative idiom.
963 *
964 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
965 * <blockquote><pre>{@code
966 * Lambda(a0:L,a1:I)=>{
967 * t2:I=foo.test(a1:I);
968 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
969 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
970 * }</pre></blockquote>
971 */
972 private void emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
973 Name receiver = (Name) invokeBasicName.arguments[0];
974
975 Label L_fallback = new Label();
976 Label L_done = new Label();
977
978 // load test result
979 emitPushArgument(selectAlternativeName, 0);
980
981 // if_icmpne L_fallback
982 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
983
984 // invoke selectAlternativeName.arguments[1]
985 Class<?>[] preForkClasses = localClasses.clone();
986 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
987 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
988 emitInvoke(invokeBasicName);
989
990 // goto L_done
991 mv.visitJumpInsn(Opcodes.GOTO, L_done);
992
993 // L_fallback:
994 mv.visitLabel(L_fallback);
995
996 // invoke selectAlternativeName.arguments[2]
997 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
998 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
999 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1000 emitInvoke(invokeBasicName);
1001
1002 // L_done:
1003 mv.visitLabel(L_done);
1004 // for now do not bother to merge typestate; just reset to the dominator state
1005 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1006 }
1007
1008 /**
1009 * Emit bytecode for the guardWithCatch idiom.
1010 *
1011 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1012 * <blockquote><pre>{@code
1013 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1014 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1015 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1016 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1017 * }</pre></blockquote>
1018 *
1019 * It is compiled into bytecode equivalent of the following code:
1020 * <blockquote><pre>{@code
1021 * try {
1022 * return a1.invokeBasic(a6, a7);
1023 * } catch (Throwable e) {
1024 * if (!a2.isInstance(e)) throw e;
1025 * return a3.invokeBasic(ex, a6, a7);
1026 * }}
1027 */
1028 private void emitGuardWithCatch(int pos) {
1029 Name args = lambdaForm.names[pos];
1030 Name invoker = lambdaForm.names[pos+1];
1031 Name result = lambdaForm.names[pos+2];
1032
1033 Label L_startBlock = new Label();
1034 Label L_endBlock = new Label();
1035 Label L_handler = new Label();
1036 Label L_done = new Label();
1037
1038 Class<?> returnType = result.function.resolvedHandle.type().returnType();
1039 MethodType type = args.function.resolvedHandle.type()
1040 .dropParameterTypes(0,1)
1041 .changeReturnType(returnType);
1042
1043 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1044
1045 // Normal case
1046 mv.visitLabel(L_startBlock);
1047 // load target
1048 emitPushArgument(invoker, 0);
1049 emitPushArguments(args, 1); // skip 1st argument: method handle
1050 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1051 mv.visitLabel(L_endBlock);
1052 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1053
1054 // Exceptional case
1055 mv.visitLabel(L_handler);
1056
1057 // Check exception's type
1058 mv.visitInsn(Opcodes.DUP);
1059 // load exception class
1060 emitPushArgument(invoker, 1);
1061 mv.visitInsn(Opcodes.SWAP);
1062 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1063 Label L_rethrow = new Label();
1064 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1065
1066 // Invoke catcher
1067 // load catcher
1068 emitPushArgument(invoker, 2);
1069 mv.visitInsn(Opcodes.SWAP);
1070 emitPushArguments(args, 1); // skip 1st argument: method handle
1071 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1072 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1073 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1074
1075 mv.visitLabel(L_rethrow);
1076 mv.visitInsn(Opcodes.ATHROW);
1077
1078 mv.visitLabel(L_done);
1079 }
1080
1081 private void emitPushArguments(Name args, int start) {
1082 for (int i = start; i < args.arguments.length; i++) {
1083 emitPushArgument(args, i);
1084 }
1085 }
1086
1087 private void emitPushArgument(Name name, int paramIndex) {
1088 Object arg = name.arguments[paramIndex];
1089 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1090 emitPushArgument(ptype, arg);
1091 }
1092
1093 private void emitPushArgument(Class<?> ptype, Object arg) {
1094 BasicType bptype = basicType(ptype);
1095 if (arg instanceof Name) {
1096 Name n = (Name) arg;
1097 emitLoadInsn(n.type, n.index());
1098 emitImplicitConversion(n.type, ptype, n);
1099 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1100 emitConst(arg);
1101 } else {
1102 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1103 emitConst(arg);
1104 } else {
1105 mv.visitLdcInsn(constantPlaceholder(arg));
1106 emitImplicitConversion(L_TYPE, ptype, arg);
1107 }
1108 }
1109 }
1110
1111 /**
1112 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1113 */
1114 private void emitReturn() {
1115 // return statement
1116 Class<?> rclass = invokerType.returnType();
1117 BasicType rtype = lambdaForm.returnType();
1118 assert(rtype == basicType(rclass)); // must agree
1119 if (rtype == V_TYPE) {
1120 // void
1121 mv.visitInsn(Opcodes.RETURN);
1122 // it doesn't matter what rclass is; the JVM will discard any value
1123 } else {
1124 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1125
1126 // put return value on the stack if it is not already there
1127 if (lambdaForm.result != lambdaForm.names.length - 1 ||
1128 lambdaForm.result < lambdaForm.arity) {
1129 emitLoadInsn(rtype, lambdaForm.result);
1130 }
1131
1132 emitImplicitConversion(rtype, rclass, rn);
1133
1134 // generate actual return statement
1135 emitReturnInsn(rtype);
1136 }
1137 }
1138
1139 /**
1140 * Emit a type conversion bytecode casting from "from" to "to".
1141 */
1142 private void emitPrimCast(Wrapper from, Wrapper to) {
1143 // Here's how.
1144 // - indicates forbidden
1145 // <-> indicates implicit
1146 // to ----> boolean byte short char int long float double
1147 // from boolean <-> - - - - - - -
1148 // byte - <-> i2s i2c <-> i2l i2f i2d
1149 // short - i2b <-> i2c <-> i2l i2f i2d
1150 // char - i2b i2s <-> <-> i2l i2f i2d
1151 // int - i2b i2s i2c <-> i2l i2f i2d
1152 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1153 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1154 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1155 if (from == to) {
1156 // no cast required, should be dead code anyway
1157 return;
1158 }
1159 if (from.isSubwordOrInt()) {
1160 // cast from {byte,short,char,int} to anything
1161 emitI2X(to);
1162 } else {
1163 // cast from {long,float,double} to anything
1164 if (to.isSubwordOrInt()) {
1165 // cast to {byte,short,char,int}
1166 emitX2I(from);
1167 if (to.bitWidth() < 32) {
1168 // targets other than int require another conversion
1169 emitI2X(to);
1170 }
1171 } else {
1172 // cast to {long,float,double} - this is verbose
1173 boolean error = false;
1174 switch (from) {
1175 case LONG:
1176 switch (to) {
1177 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1178 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1179 default: error = true; break;
1180 }
1181 break;
1182 case FLOAT:
1183 switch (to) {
1184 case LONG : mv.visitInsn(Opcodes.F2L); break;
1185 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1186 default: error = true; break;
1187 }
1188 break;
1189 case DOUBLE:
1190 switch (to) {
1191 case LONG : mv.visitInsn(Opcodes.D2L); break;
1192 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1193 default: error = true; break;
1194 }
1195 break;
1196 default:
1197 error = true;
1198 break;
1199 }
1200 if (error) {
1201 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1202 }
1203 }
1204 }
1205 }
1206
1207 private void emitI2X(Wrapper type) {
1208 switch (type) {
1209 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1210 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1211 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1212 case INT: /* naught */ break;
1213 case LONG: mv.visitInsn(Opcodes.I2L); break;
1214 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1215 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1216 case BOOLEAN:
1217 // For compatibility with ValueConversions and explicitCastArguments:
1218 mv.visitInsn(Opcodes.ICONST_1);
1219 mv.visitInsn(Opcodes.IAND);
1220 break;
1221 default: throw new InternalError("unknown type: " + type);
1222 }
1223 }
1224
1225 private void emitX2I(Wrapper type) {
1226 switch (type) {
1227 case LONG: mv.visitInsn(Opcodes.L2I); break;
1228 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1229 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1230 default: throw new InternalError("unknown type: " + type);
1231 }
1232 }
1233
1234 /**
1235 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1236 */
1237 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1238 assert(isValidSignature(sig));
1239 String name = "interpret_"+signatureReturn(sig).basicTypeChar();
1240 MethodType type = signatureType(sig); // sig includes leading argument
1241 type = type.changeParameterType(0, MethodHandle.class);
1242 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1243 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1244 }
1245
1246 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1247 classFilePrologue();
1248
1249 // Suppress this method in backtraces displayed to the user.
1250 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1251
1252 // Don't inline the interpreter entry.
1253 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1254
1255 // create parameter array
1256 emitIconstInsn(invokerType.parameterCount());
1257 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1258
1259 // fill parameter array
1260 for (int i = 0; i < invokerType.parameterCount(); i++) {
1261 Class<?> ptype = invokerType.parameterType(i);
1262 mv.visitInsn(Opcodes.DUP);
1263 emitIconstInsn(i);
1264 emitLoadInsn(basicType(ptype), i);
1265 // box if primitive type
1266 if (ptype.isPrimitive()) {
1267 emitBoxing(Wrapper.forPrimitiveType(ptype));
1268 }
1269 mv.visitInsn(Opcodes.AASTORE);
1270 }
1271 // invoke
1272 emitAloadInsn(0);
1273 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1274 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1275 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1276
1277 // maybe unbox
1278 Class<?> rtype = invokerType.returnType();
1279 if (rtype.isPrimitive() && rtype != void.class) {
1280 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1281 }
1282
1283 // return statement
1284 emitReturnInsn(basicType(rtype));
1285
1286 classFileEpilogue();
1287 bogusMethod(invokerType);
1288
1289 final byte[] classFile = cw.toByteArray();
1290 maybeDump(className, classFile);
1291 return classFile;
1292 }
1293
1294 /**
1295 * Generate bytecode for a NamedFunction invoker.
1296 */
1297 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1298 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1299 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1300 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1301 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1302 }
1303
1304 static int nfi = 0;
1305
1306 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1307 MethodType dstType = typeForm.erasedType();
1308 classFilePrologue();
1309
1310 // Suppress this method in backtraces displayed to the user.
1311 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1312
1313 // Force inlining of this invoker method.
1314 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1315
1316 // Load receiver
1317 emitAloadInsn(0);
1318
1319 // Load arguments from array
1320 for (int i = 0; i < dstType.parameterCount(); i++) {
1321 emitAloadInsn(1);
1322 emitIconstInsn(i);
1323 mv.visitInsn(Opcodes.AALOAD);
1324
1325 // Maybe unbox
1326 Class<?> dptype = dstType.parameterType(i);
1327 if (dptype.isPrimitive()) {
1328 Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1329 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1330 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1331 emitUnboxing(srcWrapper);
1332 emitPrimCast(srcWrapper, dstWrapper);
1333 }
1334 }
1335
1336 // Invoke
1337 String targetDesc = dstType.basicType().toMethodDescriptorString();
1338 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1339
1340 // Box primitive types
1341 Class<?> rtype = dstType.returnType();
1342 if (rtype != void.class && rtype.isPrimitive()) {
1343 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1344 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1345 // boolean casts not allowed
1346 emitPrimCast(srcWrapper, dstWrapper);
1347 emitBoxing(dstWrapper);
1348 }
1349
1350 // If the return type is void we return a null reference.
1351 if (rtype == void.class) {
1352 mv.visitInsn(Opcodes.ACONST_NULL);
1353 }
1354 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1355
1356 classFileEpilogue();
1357 bogusMethod(dstType);
1358
1359 final byte[] classFile = cw.toByteArray();
1360 maybeDump(className, classFile);
1361 return classFile;
1362 }
1363
1364 /**
1365 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1366 * for debugging purposes.
1367 */
1368 private void bogusMethod(Object... os) {
1369 if (DUMP_CLASS_FILES) {
1370 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1371 for (Object o : os) {
1372 mv.visitLdcInsn(o.toString());
1373 mv.visitInsn(Opcodes.POP);
1374 }
1375 mv.visitInsn(Opcodes.RETURN);
1376 mv.visitMaxs(0, 0);
1377 mv.visitEnd();
1378 }
1379 }
1380 }