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 java.lang.invoke.MethodHandleImpl.ArrayAccessor;
39 import sun.invoke.util.ValueConversions;
40 import sun.invoke.util.VerifyType;
41 import sun.invoke.util.VerifyAccess;
42 import sun.invoke.util.Wrapper;
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$Name";
55 private static final String CLS = "java/lang/Class";
56 private static final String OBJ = "java/lang/Object";
57 private static final String OBJARY = "[Ljava/lang/Object;";
58
59 private static final String LF_SIG = "L" + LF + ";";
60 private static final String LFN_SIG = "L" + LFN + ";";
61 private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
62 private static final String CLL_SIG = "(L" + CLS + ";L" + OBJ + ";)L" + OBJ + ";";
63
64 /** Name of its super class*/
65 private static final String superName = LF;
66
67 /** Name of new class */
68 private final String className;
69
70 /** Name of the source file (for stack trace printing). */
71 private final String sourceFile;
72
73 private final LambdaForm lambdaForm;
74 private final String invokerName;
75 private final MethodType invokerType;
76
77 /** Info about local variables in compiled lambda form */
78 private final int[] localsMap; // index
79 private final BasicType[] localTypes; // basic type
80 private final Class<?>[] localClasses; // type
81
82 /** ASM bytecode generation. */
83 private ClassWriter cw;
84 private MethodVisitor mv;
85
86 private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
87 private static final Class<?> HOST_CLASS = LambdaForm.class;
88
89 /** Main constructor; other constructors delegate to this one. */
90 private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
91 String className, String invokerName, MethodType invokerType) {
92 if (invokerName.contains(".")) {
93 int p = invokerName.indexOf(".");
94 className = invokerName.substring(0, p);
95 invokerName = invokerName.substring(p+1);
96 }
97 if (DUMP_CLASS_FILES) {
98 className = makeDumpableClassName(className);
99 }
100 this.className = superName + "$" + className;
101 this.sourceFile = "LambdaForm$" + className;
102 this.lambdaForm = lambdaForm;
103 this.invokerName = invokerName;
104 this.invokerType = invokerType;
105 this.localsMap = new int[localsMapSize+1];
106 // last entry of localsMap is count of allocated local slots
107 this.localTypes = new BasicType[localsMapSize+1];
108 this.localClasses = new Class<?>[localsMapSize+1];
109 }
110
111 /** For generating LambdaForm interpreter entry points. */
112 private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
113 this(null, invokerType.parameterCount(),
114 className, invokerName, invokerType);
115 // Create an array to map name indexes to locals indexes.
116 localTypes[localTypes.length - 1] = V_TYPE;
117 for (int i = 0; i < localsMap.length; i++) {
118 localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
119 if (i < invokerType.parameterCount())
120 localTypes[i] = basicType(invokerType.parameterType(i));
121 }
122 }
123
124 /** For generating customized code for a single LambdaForm. */
125 private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
126 this(form, form.names.length,
127 className, form.debugName, invokerType);
128 // Create an array to map name indexes to locals indexes.
129 Name[] names = form.names;
130 for (int i = 0, index = 0; i < localsMap.length; i++) {
131 localsMap[i] = index;
132 if (i < names.length) {
133 BasicType type = names[i].type();
134 index += type.basicTypeSlots();
135 localTypes[i] = type;
136 }
137 }
138 }
139
140
141 /** instance counters for dumped classes */
142 private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
143 /** debugging flag for saving generated class files */
144 private final static File DUMP_CLASS_FILES_DIR;
145
146 static {
147 if (DUMP_CLASS_FILES) {
148 DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
149 try {
150 File dumpDir = new File("DUMP_CLASS_FILES");
151 if (!dumpDir.exists()) {
152 dumpDir.mkdirs();
153 }
154 DUMP_CLASS_FILES_DIR = dumpDir;
155 System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
156 } catch (Exception e) {
157 throw newInternalError(e);
158 }
159 } else {
160 DUMP_CLASS_FILES_COUNTERS = null;
161 DUMP_CLASS_FILES_DIR = null;
162 }
163 }
164
165 static void maybeDump(final String className, final byte[] classFile) {
166 if (DUMP_CLASS_FILES) {
167 java.security.AccessController.doPrivileged(
168 new java.security.PrivilegedAction<Void>() {
169 public Void run() {
170 try {
171 String dumpName = className;
172 //dumpName = dumpName.replace('/', '-');
173 File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
174 System.out.println("dump: " + dumpFile);
175 dumpFile.getParentFile().mkdirs();
176 FileOutputStream file = new FileOutputStream(dumpFile);
177 file.write(classFile);
178 file.close();
179 return null;
180 } catch (IOException ex) {
181 throw newInternalError(ex);
182 }
183 }
184 });
185 }
186
187 }
188
189 private static String makeDumpableClassName(String className) {
190 Integer ctr;
191 synchronized (DUMP_CLASS_FILES_COUNTERS) {
192 ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
193 if (ctr == null) ctr = 0;
194 DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
195 }
196 String sfx = ctr.toString();
197 while (sfx.length() < 3)
198 sfx = "0"+sfx;
199 className += sfx;
200 return className;
201 }
202
203 class CpPatch {
204 final int index;
205 final String placeholder;
206 final Object value;
207 CpPatch(int index, String placeholder, Object value) {
208 this.index = index;
209 this.placeholder = placeholder;
210 this.value = value;
211 }
212 public String toString() {
213 return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
214 }
215 }
216
217 Map<Object, CpPatch> cpPatches = new HashMap<>();
218
219 int cph = 0; // for counting constant placeholders
220
221 String constantPlaceholder(Object arg) {
222 String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
223 if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + debugString(arg) + ">>"; // debugging aid
224 if (cpPatches.containsKey(cpPlaceholder)) {
225 throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
226 }
227 // insert placeholder in CP and remember the patch
228 int index = cw.newConst((Object) cpPlaceholder); // TODO check if aready in the constant pool
229 cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
230 return cpPlaceholder;
231 }
232
233 Object[] cpPatches(byte[] classFile) {
234 int size = getConstantPoolSize(classFile);
235 Object[] res = new Object[size];
236 for (CpPatch p : cpPatches.values()) {
237 if (p.index >= size)
238 throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
239 res[p.index] = p.value;
240 }
241 return res;
242 }
243
244 private static String debugString(Object arg) {
245 if (arg instanceof MethodHandle) {
246 MethodHandle mh = (MethodHandle) arg;
247 MemberName member = mh.internalMemberName();
248 if (member != null)
249 return member.toString();
250 return mh.debugString();
251 }
252 return arg.toString();
253 }
254
255 /**
256 * Extract the number of constant pool entries from a given class file.
257 *
258 * @param classFile the bytes of the class file in question.
259 * @return the number of entries in the constant pool.
260 */
261 private static int getConstantPoolSize(byte[] classFile) {
262 // The first few bytes:
263 // u4 magic;
264 // u2 minor_version;
265 // u2 major_version;
266 // u2 constant_pool_count;
267 return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
268 }
269
270 /**
271 * Extract the MemberName of a newly-defined method.
272 */
273 private MemberName loadMethod(byte[] classFile) {
274 Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
275 return resolveInvokerMember(invokerClass, invokerName, invokerType);
276 }
277
278 /**
279 * Define a given class as anonymous class in the runtime system.
280 */
281 private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
282 Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
283 UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
284 return invokerClass;
285 }
286
287 private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
288 MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
289 //System.out.println("resolveInvokerMember => "+member);
290 //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
291 try {
292 member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
293 } catch (ReflectiveOperationException e) {
294 throw newInternalError(e);
295 }
296 //System.out.println("resolveInvokerMember => "+member);
297 return member;
298 }
299
300 /**
301 * Set up class file generation.
302 */
303 private void classFilePrologue() {
304 cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
305 cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
306 cw.visitSource(sourceFile, null);
307
308 String invokerDesc = invokerType.toMethodDescriptorString();
309 mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
310 }
311
312 /**
313 * Tear down class file generation.
314 */
315 private void classFileEpilogue() {
316 mv.visitMaxs(0, 0);
317 mv.visitEnd();
318 }
319
320 /*
321 * Low-level emit helpers.
322 */
323 private void emitConst(Object con) {
324 if (con == null) {
325 mv.visitInsn(Opcodes.ACONST_NULL);
326 return;
327 }
328 if (con instanceof Integer) {
329 emitIconstInsn((int) con);
330 return;
331 }
332 if (con instanceof Long) {
333 long x = (long) con;
334 if (x == (short) x) {
335 emitIconstInsn((int) x);
336 mv.visitInsn(Opcodes.I2L);
337 return;
338 }
339 }
340 if (con instanceof Float) {
341 float x = (float) con;
342 if (x == (short) x) {
343 emitIconstInsn((int) x);
344 mv.visitInsn(Opcodes.I2F);
345 return;
346 }
347 }
348 if (con instanceof Double) {
349 double x = (double) con;
350 if (x == (short) x) {
351 emitIconstInsn((int) x);
352 mv.visitInsn(Opcodes.I2D);
353 return;
354 }
355 }
356 if (con instanceof Boolean) {
357 emitIconstInsn((boolean) con ? 1 : 0);
358 return;
359 }
360 // fall through:
361 mv.visitLdcInsn(con);
362 }
363
364 private void emitIconstInsn(int i) {
365 int opcode;
366 switch (i) {
367 case 0: opcode = Opcodes.ICONST_0; break;
368 case 1: opcode = Opcodes.ICONST_1; break;
369 case 2: opcode = Opcodes.ICONST_2; break;
370 case 3: opcode = Opcodes.ICONST_3; break;
371 case 4: opcode = Opcodes.ICONST_4; break;
372 case 5: opcode = Opcodes.ICONST_5; break;
373 default:
374 if (i == (byte) i) {
375 mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
376 } else if (i == (short) i) {
377 mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
378 } else {
379 mv.visitLdcInsn(i);
380 }
381 return;
382 }
383 mv.visitInsn(opcode);
384 }
385
386 /*
387 * NOTE: These load/store methods use the localsMap to find the correct index!
388 */
389 private void emitLoadInsn(BasicType type, int index) {
390 int opcode = loadInsnOpcode(type);
391 mv.visitVarInsn(opcode, localsMap[index]);
392 }
393
394 private int loadInsnOpcode(BasicType type) throws InternalError {
395 int opcode;
396 switch (type) {
397 case I_TYPE: opcode = Opcodes.ILOAD; break;
398 case J_TYPE: opcode = Opcodes.LLOAD; break;
399 case F_TYPE: opcode = Opcodes.FLOAD; break;
400 case D_TYPE: opcode = Opcodes.DLOAD; break;
401 case L_TYPE: opcode = Opcodes.ALOAD; break;
402 default:
403 throw new InternalError("unknown type: " + type);
404 }
405 return opcode;
406 }
407 private void emitAloadInsn(int index) {
408 emitLoadInsn(L_TYPE, index);
409 }
410
411 private void emitStoreInsn(BasicType type, int index) {
412 int opcode = storeInsnOpcode(type);
413 mv.visitVarInsn(opcode, localsMap[index]);
414 }
415
416 private int storeInsnOpcode(BasicType type) throws InternalError {
417 int opcode;
418 switch (type) {
419 case I_TYPE: opcode = Opcodes.ISTORE; break;
420 case J_TYPE: opcode = Opcodes.LSTORE; break;
421 case F_TYPE: opcode = Opcodes.FSTORE; break;
422 case D_TYPE: opcode = Opcodes.DSTORE; break;
423 case L_TYPE: opcode = Opcodes.ASTORE; break;
424 default:
425 throw new InternalError("unknown type: " + type);
426 }
427 return opcode;
428 }
429 private void emitAstoreInsn(int index) {
430 emitStoreInsn(L_TYPE, index);
431 }
432
433 private void freeFrameLocal(int oldFrameLocal) {
434 int i = indexForFrameLocal(oldFrameLocal);
435 if (i < 0) return;
436 BasicType type = localTypes[i];
437 int newFrameLocal = makeLocalTemp(type);
438 mv.visitVarInsn(loadInsnOpcode(type), oldFrameLocal);
439 mv.visitVarInsn(storeInsnOpcode(type), newFrameLocal);
440 assert(localsMap[i] == oldFrameLocal);
441 localsMap[i] = newFrameLocal;
442 assert(indexForFrameLocal(oldFrameLocal) < 0);
443 }
444 private int indexForFrameLocal(int frameLocal) {
445 for (int i = 0; i < localsMap.length; i++) {
446 if (localsMap[i] == frameLocal && localTypes[i] != V_TYPE)
447 return i;
448 }
449 return -1;
450 }
451 private int makeLocalTemp(BasicType type) {
452 int frameLocal = localsMap[localsMap.length - 1];
453 localsMap[localsMap.length - 1] = frameLocal + type.basicTypeSlots();
454 return frameLocal;
455 }
456
457 /**
458 * Emit a boxing call.
459 *
460 * @param wrapper primitive type class to box.
461 */
462 private void emitBoxing(Wrapper wrapper) {
463 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
464 String name = "valueOf";
465 String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
466 mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc, false);
467 }
468
469 /**
470 * Emit an unboxing call (plus preceding checkcast).
471 *
472 * @param wrapper wrapper type class to unbox.
473 */
474 private void emitUnboxing(Wrapper wrapper) {
475 String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
476 String name = wrapper.primitiveSimpleName() + "Value";
477 String desc = "()" + wrapper.basicTypeChar();
478 emitReferenceCast(wrapper.wrapperType(), null);
479 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, false);
480 }
481
482 /**
483 * Emit an implicit conversion for an argument which must be of the given pclass.
484 * This is usually a no-op, except when pclass is a subword type or a reference other than Object or an interface.
485 *
486 * @param ptype type of value present on stack
487 * @param pclass type of value required on stack
488 * @param arg compile-time representation of value on stack (Node, constant) or null if none
489 */
490 private void emitImplicitConversion(BasicType ptype, Class<?> pclass, Object arg) {
491 assert(basicType(pclass) == ptype); // boxing/unboxing handled by caller
492 if (pclass == ptype.basicTypeClass() && ptype != L_TYPE)
493 return; // nothing to do
494 switch (ptype) {
495 case L_TYPE:
496 if (VerifyType.isNullConversion(Object.class, pclass, false)) {
497 if (PROFILE_LEVEL > 0)
498 emitReferenceCast(Object.class, arg);
499 return;
500 }
501 emitReferenceCast(pclass, arg);
502 return;
503 case I_TYPE:
504 if (!VerifyType.isNullConversion(int.class, pclass, false))
505 emitPrimCast(ptype.basicTypeWrapper(), Wrapper.forPrimitiveType(pclass));
506 return;
507 }
508 throw newInternalError("bad implicit conversion: tc="+ptype+": "+pclass);
509 }
510
511 /** Update localClasses type map. Return true if the information is already present. */
512 private boolean assertStaticType(Class<?> cls, Name n) {
513 int local = n.index();
514 Class<?> aclass = localClasses[local];
515 if (aclass != null && (aclass == cls || cls.isAssignableFrom(aclass))) {
516 return true; // type info is already present
517 } else if (aclass == null || aclass.isAssignableFrom(cls)) {
518 localClasses[local] = cls; // type info can be improved
519 }
520 return false;
521 }
522
523 private void emitReferenceCast(Class<?> cls, Object arg) {
524 Name writeBack = null; // local to write back result
525 if (arg instanceof Name) {
526 Name n = (Name) arg;
527 if (assertStaticType(cls, n))
528 return; // this cast was already performed
529 if (lambdaForm.useCount(n) > 1) {
530 // This guy gets used more than once.
531 writeBack = n;
532 }
533 }
534 if (isStaticallyNameable(cls)) {
535 String sig = getInternalName(cls);
536 mv.visitTypeInsn(Opcodes.CHECKCAST, sig);
537 } else {
538 mv.visitLdcInsn(constantPlaceholder(cls));
539 mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
540 mv.visitInsn(Opcodes.SWAP);
541 mv.visitMethodInsn(Opcodes.INVOKESTATIC, MHI, "castReference", CLL_SIG, false);
542 if (Object[].class.isAssignableFrom(cls))
543 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
544 else if (PROFILE_LEVEL > 0)
545 mv.visitTypeInsn(Opcodes.CHECKCAST, OBJ);
546 }
547 if (writeBack != null) {
548 mv.visitInsn(Opcodes.DUP);
549 emitAstoreInsn(writeBack.index());
550 }
551 }
552
553 /**
554 * Emits an actual return instruction conforming to the given return type.
555 */
556 private void emitReturnInsn(BasicType type) {
557 int opcode;
558 switch (type) {
559 case I_TYPE: opcode = Opcodes.IRETURN; break;
560 case J_TYPE: opcode = Opcodes.LRETURN; break;
561 case F_TYPE: opcode = Opcodes.FRETURN; break;
562 case D_TYPE: opcode = Opcodes.DRETURN; break;
563 case L_TYPE: opcode = Opcodes.ARETURN; break;
564 case V_TYPE: opcode = Opcodes.RETURN; break;
565 default:
566 throw new InternalError("unknown return type: " + type);
567 }
568 mv.visitInsn(opcode);
569 }
570
571 private static String getInternalName(Class<?> c) {
572 if (c == Object.class) return OBJ;
573 else if (c == Object[].class) return OBJARY;
574 else if (c == Class.class) return CLS;
575 else if (c == MethodHandle.class) return MH;
576 assert(VerifyAccess.isTypeVisible(c, Object.class));
577 return c.getName().replace('.', '/');
578 }
579
580 /**
581 * Generate customized bytecode for a given LambdaForm.
582 */
583 static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
584 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
585 return g.loadMethod(g.generateCustomizedCodeBytes());
586 }
587
588 /**
589 * Generate an invoker method for the passed {@link LambdaForm}.
590 */
591 private byte[] generateCustomizedCodeBytes() {
592 classFilePrologue();
593
594 // Suppress this method in backtraces displayed to the user.
595 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
596
597 // Mark this method as a compiled LambdaForm
598 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
599
600 // Force inlining of this invoker method.
601 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
602
603 // iterate over the form's names, generating bytecode instructions for each
604 // start iterating at the first name following the arguments
605 for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
606 Name name = lambdaForm.names[i];
607 MemberName member = name.function.member();
608 Class<?> rtype = name.function.methodType().returnType();
609
610 if (isSelectAlternative(i)) {
611 emitSelectAlternative(name, lambdaForm.names[i + 1]);
612 i++; // skip MH.invokeBasic of the selectAlternative result
613 } else if (isGuardWithCatch(i)) {
614 emitGuardWithCatch(i);
615 i = i+2; // Jump to the end of GWC idiom
616 } else if (isNewArray(rtype, name)) {
617 emitNewArray(rtype, name);
618 } else if (isStaticallyInvocable(member)) {
619 if (isLinkerMethodInvoke(name))
620 preserveLinkerMethodTarget(name);
621 emitStaticInvoke(member, name);
622 } else {
623 emitInvoke(name);
624 }
625
626 // Update cached form name's info in case an intrinsic spanning multiple names was encountered.
627 name = lambdaForm.names[i];
628 member = name.function.member();
629 rtype = name.function.methodType().returnType();
630
631 // store the result from evaluating to the target name in a local if required
632 // (if this is the last value, i.e., the one that is going to be returned,
633 // avoid store/load/return and just return)
634 if (i == lambdaForm.names.length - 1 && i == lambdaForm.result) {
635 // return value - do nothing
636 } else if (name.type != V_TYPE) {
637 // non-void: actually assign
638 emitStoreInsn(name.type, name.index());
639 }
640 }
641
642 // return statement
643 emitReturn();
644
645 classFileEpilogue();
646 bogusMethod(lambdaForm);
647
648 final byte[] classFile = cw.toByteArray();
649 maybeDump(className, classFile);
650 return classFile;
651 }
652
653 /** Certain parts of the JVM expect that, when a call to linkToStatic is made,
654 * the DMH that produced its MN argument is in local #0.
655 * This is often true, since the lambda form of a DMH will start with
656 * the DMH 'l'in arg 0 (local #0) and will end with a call to its linker method.
657 * But if the DMH is transformed, a new lambda form may be created with
658 * the DMH placed elsewhere.
659 */
660 private void preserveLinkerMethodTarget(Name name) {
661 Object lastArg = name.arguments[name.arguments.length - 1];
662 Name targetMember = (Name) lastArg;
663 assert(targetMember.type() == L_TYPE &&
664 !targetMember.isParam() &&
665 isStaticallyInvocable(targetMember.function.member()) &&
666 targetMember.arguments.length == 1);
667 Object targetDMH = DirectMethodHandle.findDirectMethodHandle(targetMember);
668 assert(targetDMH != null);
669 if (!(targetDMH instanceof Name && ((Name)targetDMH).index() == 0)) {
670 // Oops, the DMH is not in a local #0, or is a constant.
671 int DMH_FRAME_INDEX = 0; // hardwired to local #0
672 BasicType DMH_TYPE = L_TYPE;
673 freeFrameLocal(DMH_FRAME_INDEX);
674 // Save it to local #0:
675 emitPushArgument(Object.class, targetDMH);
676 mv.visitVarInsn(storeInsnOpcode(DMH_TYPE), DMH_FRAME_INDEX);
677 }
678 }
679
680 /**
681 * Emit an invoke for the given name.
682 */
683 void emitInvoke(Name name) {
684 assert(!isLinkerMethodInvoke(name)); // should use the static path for these
685 if (true) {
686 // push receiver
687 MethodHandle target = name.function.resolvedHandle;
688 assert(target != null) : name.exprString();
689 mv.visitLdcInsn(constantPlaceholder(target));
690 emitReferenceCast(MethodHandle.class, target);
691 } else {
692 // load receiver
693 emitAloadInsn(0);
694 emitReferenceCast(MethodHandle.class, null);
695 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
696 mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
697 // TODO more to come
698 }
699
700 // push arguments
701 for (int i = 0; i < name.arguments.length; i++) {
702 emitPushArgument(name, i);
703 }
704
705 // invocation
706 MethodType type = name.function.methodType();
707 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
708 }
709
710 static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
711 // Sample classes from each package we are willing to bind to statically:
712 java.lang.Object.class,
713 java.util.Arrays.class,
714 sun.misc.Unsafe.class
715 //MethodHandle.class already covered
716 };
717
718 static boolean isStaticallyInvocable(MemberName member) {
719 if (member == null) return false;
720 if (member.isConstructor()) return false;
721 Class<?> cls = member.getDeclaringClass();
722 if (cls.isArray() || cls.isPrimitive())
723 return false; // FIXME
724 if (cls.isAnonymousClass() || cls.isLocalClass())
725 return false; // inner class of some sort
726 if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
727 return false; // not on BCP
728 MethodType mtype = member.getMethodOrFieldType();
729 if (!isStaticallyNameable(mtype.returnType()))
730 return false;
731 for (Class<?> ptype : mtype.parameterArray())
732 if (!isStaticallyNameable(ptype))
733 return false;
734 if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
735 return true; // in java.lang.invoke package
736 if (member.isPublic() && isStaticallyNameable(cls))
737 return true;
738 return false;
739 }
740
741 static boolean isStaticallyNameable(Class<?> cls) {
742 if (cls == Object.class)
743 return true;
744 while (cls.isArray())
745 cls = cls.getComponentType();
746 if (cls.isPrimitive())
747 return true; // int[].class, for example
748 // could use VerifyAccess.isClassAccessible but the following is a safe approximation
749 if (cls.getClassLoader() != Object.class.getClassLoader())
750 return false;
751 if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
752 return true;
753 if (!Modifier.isPublic(cls.getModifiers()))
754 return false;
755 for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
756 if (VerifyAccess.isSamePackage(pkgcls, cls))
757 return true;
758 }
759 return false;
760 }
761
762 /**
763 * Emit an invoke for the given name, using the MemberName directly.
764 */
765 void emitStaticInvoke(MemberName member, Name name) {
766 assert(member.equals(name.function.member()));
767 Class<?> defc = member.getDeclaringClass();
768 String cname = getInternalName(defc);
769 String mname = member.getName();
770 String mtype;
771 byte refKind = member.getReferenceKind();
772 if (refKind == REF_invokeSpecial) {
773 // in order to pass the verifier, we need to convert this to invokevirtual in all cases
774 assert(member.canBeStaticallyBound()) : member;
775 refKind = REF_invokeVirtual;
776 }
777
778 if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
779 // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
780 // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
781 refKind = REF_invokeInterface;
782 }
783
784 // push arguments
785 for (int i = 0; i < name.arguments.length; i++) {
786 emitPushArgument(name, i);
787 }
788
789 // invocation
790 if (defc == ArrayAccessor.class &&
791 match(member, ArrayAccessor.OBJECT_ARRAY_GETTER)) {
792 mv.visitInsn(Opcodes.AALOAD);
793 } else if (defc == ArrayAccessor.class &&
794 match(member, ArrayAccessor.OBJECT_ARRAY_SETTER)) {
795 mv.visitInsn(Opcodes.AASTORE);
796 } else if (member.isMethod()) {
797 mtype = member.getMethodType().toMethodDescriptorString();
798 mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
799 member.getDeclaringClass().isInterface());
800 } else {
801 mtype = MethodType.toFieldDescriptorString(member.getFieldType());
802 mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
803 }
804 // Issue a type assertion for the result, so we can avoid casts later.
805 if (name.type == L_TYPE) {
806 Class<?> rtype = member.getInvocationType().returnType();
807 assert(!rtype.isPrimitive());
808 if (rtype != Object.class && !rtype.isInterface()) {
809 assertStaticType(rtype, name);
810 }
811 }
812 }
813
814 boolean isNewArray(Class<?> rtype, Name name) {
815 return rtype.isArray() &&
816 isStaticallyNameable(rtype) &&
817 isArrayBuilder(name.function.resolvedHandle) &&
818 name.arguments.length > 0;
819 }
820
821 void emitNewArray(Class<?> rtype, Name name) throws InternalError {
822 Class<?> arrayElementType = rtype.getComponentType();
823 emitIconstInsn(name.arguments.length);
824 int xas;
825 if (!arrayElementType.isPrimitive()) {
826 mv.visitTypeInsn(Opcodes.ANEWARRAY, getInternalName(arrayElementType));
827 xas = Opcodes.AASTORE;
828 } else {
829 int tc;
830 switch (Wrapper.forPrimitiveType(arrayElementType)) {
831 case BOOLEAN: tc = Opcodes.T_BOOLEAN; xas = Opcodes.BASTORE; break;
832 case BYTE: tc = Opcodes.T_BYTE; xas = Opcodes.BASTORE; break;
833 case CHAR: tc = Opcodes.T_CHAR; xas = Opcodes.CASTORE; break;
834 case SHORT: tc = Opcodes.T_SHORT; xas = Opcodes.SASTORE; break;
835 case INT: tc = Opcodes.T_INT; xas = Opcodes.IASTORE; break;
836 case LONG: tc = Opcodes.T_LONG; xas = Opcodes.LASTORE; break;
837 case FLOAT: tc = Opcodes.T_FLOAT; xas = Opcodes.FASTORE; break;
838 case DOUBLE: tc = Opcodes.T_DOUBLE; xas = Opcodes.DASTORE; break;
839 default: throw new InternalError(rtype.getName());
840 }
841 mv.visitIntInsn(Opcodes.NEWARRAY, tc);
842 }
843 // store arguments
844 for (int i = 0; i < name.arguments.length; i++) {
845 mv.visitInsn(Opcodes.DUP);
846 emitIconstInsn(i);
847 emitPushArgument(name, i);
848 mv.visitInsn(xas);
849 }
850 // the array is left on the stack
851 assertStaticType(rtype, name);
852 }
853 int refKindOpcode(byte refKind) {
854 switch (refKind) {
855 case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
856 case REF_invokeStatic: return Opcodes.INVOKESTATIC;
857 case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
858 case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
859 case REF_getField: return Opcodes.GETFIELD;
860 case REF_putField: return Opcodes.PUTFIELD;
861 case REF_getStatic: return Opcodes.GETSTATIC;
862 case REF_putStatic: return Opcodes.PUTSTATIC;
863 }
864 throw new InternalError("refKind="+refKind);
865 }
866
867 static boolean isArrayBuilder(MethodHandle fn) {
868 if (fn == null)
869 return false;
870 MethodType mtype = fn.type();
871 Class<?> rtype = mtype.returnType();
872 Class<?> arrayElementType = rtype.getComponentType();
873 if (arrayElementType == null)
874 return false;
875 List<Class<?>> ptypes = mtype.parameterList();
876 int size = ptypes.size();
877 if (!ptypes.equals(Collections.nCopies(size, arrayElementType)))
878 return false;
879 // Assume varargsArray caches pointers.
880 if (fn != ValueConversions.varargsArray(rtype, size))
881 return false;
882 return true;
883 }
884
885 static boolean match(MemberName member, MethodHandle fn) {
886 if (member == null || fn == null) return false;
887 return member.equals(fn.internalMemberName());
888 }
889
890 /**
891 * Check if MemberName is a call to a method named {@code name} in class {@code declaredClass}.
892 */
893 private boolean memberRefersTo(MemberName member, Class<?> declaringClass, String name) {
894 return member != null &&
895 member.getDeclaringClass() == declaringClass &&
896 member.getName().equals(name);
897 }
898 private boolean nameRefersTo(Name name, Class<?> declaringClass, String methodName) {
899 return name.function != null &&
900 memberRefersTo(name.function.member(), declaringClass, methodName);
901 }
902
903 /**
904 * Check if MemberName is a call to MethodHandle.invokeBasic.
905 */
906 private boolean isInvokeBasic(Name name) {
907 if (name.function == null)
908 return false;
909 if (name.arguments.length < 1)
910 return false; // must have MH argument
911 MemberName member = name.function.member();
912 return memberRefersTo(member, MethodHandle.class, "invokeBasic") &&
913 !member.isPublic() && !member.isStatic();
914 }
915
916 /**
917 * Check if MemberName is a call to MethodHandle.linkToStatic, etc.
918 */
919 private boolean isLinkerMethodInvoke(Name name) {
920 if (name.function == null)
921 return false;
922 if (name.arguments.length < 1)
923 return false; // must have MH argument
924 MemberName member = name.function.member();
925 return member != null &&
926 member.getDeclaringClass() == MethodHandle.class &&
927 !member.isPublic() && member.isStatic() &&
928 member.getName().startsWith("linkTo");
929 }
930
931 /**
932 * Check if i-th name is a call to MethodHandleImpl.selectAlternative.
933 */
934 private boolean isSelectAlternative(int pos) {
935 // selectAlternative idiom:
936 // t_{n}:L=MethodHandleImpl.selectAlternative(...)
937 // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
938 if (pos+1 >= lambdaForm.names.length) return false;
939 Name name0 = lambdaForm.names[pos];
940 Name name1 = lambdaForm.names[pos+1];
941 return nameRefersTo(name0, MethodHandleImpl.class, "selectAlternative") &&
942 isInvokeBasic(name1) &&
943 name1.lastUseIndex(name0) == 0 && // t_{n+1}:?=MethodHandle.invokeBasic(t_{n}, ...)
944 lambdaForm.lastUseIndex(name0) == pos+1; // t_{n} is local: used only in t_{n+1}
945 }
946
947 /**
948 * Check if i-th name is a start of GuardWithCatch idiom.
949 */
950 private boolean isGuardWithCatch(int pos) {
951 // GuardWithCatch idiom:
952 // t_{n}:L=MethodHandle.invokeBasic(...)
953 // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
954 // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
955 if (pos+2 >= lambdaForm.names.length) return false;
956 Name name0 = lambdaForm.names[pos];
957 Name name1 = lambdaForm.names[pos+1];
958 Name name2 = lambdaForm.names[pos+2];
959 return nameRefersTo(name1, MethodHandleImpl.class, "guardWithCatch") &&
960 isInvokeBasic(name0) &&
961 isInvokeBasic(name2) &&
962 name1.lastUseIndex(name0) == 3 && // t_{n+1}:L=MethodHandleImpl.guardWithCatch(*, *, *, t_{n});
963 lambdaForm.lastUseIndex(name0) == pos+1 && // t_{n} is local: used only in t_{n+1}
964 name2.lastUseIndex(name1) == 1 && // t_{n+2}:?=MethodHandle.invokeBasic(t_{n+1})
965 lambdaForm.lastUseIndex(name1) == pos+2; // t_{n+1} is local: used only in t_{n+2}
966 }
967
968 /**
969 * Emit bytecode for the selectAlternative idiom.
970 *
971 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
972 * <blockquote><pre>{@code
973 * Lambda(a0:L,a1:I)=>{
974 * t2:I=foo.test(a1:I);
975 * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
976 * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
977 * }</pre></blockquote>
978 */
979 private void emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
980 Name receiver = (Name) invokeBasicName.arguments[0];
981
982 Label L_fallback = new Label();
983 Label L_done = new Label();
984
985 // load test result
986 emitPushArgument(selectAlternativeName, 0);
987
988 // if_icmpne L_fallback
989 mv.visitJumpInsn(Opcodes.IFEQ, L_fallback);
990
991 // invoke selectAlternativeName.arguments[1]
992 Class<?>[] preForkClasses = localClasses.clone();
993 emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
994 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
995 emitInvoke(invokeBasicName);
996
997 // goto L_done
998 mv.visitJumpInsn(Opcodes.GOTO, L_done);
999
1000 // L_fallback:
1001 mv.visitLabel(L_fallback);
1002
1003 // invoke selectAlternativeName.arguments[2]
1004 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1005 emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1006 emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1007 emitInvoke(invokeBasicName);
1008
1009 // L_done:
1010 mv.visitLabel(L_done);
1011 // for now do not bother to merge typestate; just reset to the dominator state
1012 System.arraycopy(preForkClasses, 0, localClasses, 0, preForkClasses.length);
1013 }
1014
1015 /**
1016 * Emit bytecode for the guardWithCatch idiom.
1017 *
1018 * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithCatch):
1019 * <blockquote><pre>{@code
1020 * guardWithCatch=Lambda(a0:L,a1:L,a2:L,a3:L,a4:L,a5:L,a6:L,a7:L)=>{
1021 * t8:L=MethodHandle.invokeBasic(a4:L,a6:L,a7:L);
1022 * t9:L=MethodHandleImpl.guardWithCatch(a1:L,a2:L,a3:L,t8:L);
1023 * t10:I=MethodHandle.invokeBasic(a5:L,t9:L);t10:I}
1024 * }</pre></blockquote>
1025 *
1026 * It is compiled into bytecode equivalent of the following code:
1027 * <blockquote><pre>{@code
1028 * try {
1029 * return a1.invokeBasic(a6, a7);
1030 * } catch (Throwable e) {
1031 * if (!a2.isInstance(e)) throw e;
1032 * return a3.invokeBasic(ex, a6, a7);
1033 * }}
1034 */
1035 private void emitGuardWithCatch(int pos) {
1036 Name args = lambdaForm.names[pos];
1037 Name invoker = lambdaForm.names[pos+1];
1038 Name result = lambdaForm.names[pos+2];
1039
1040 Label L_startBlock = new Label();
1041 Label L_endBlock = new Label();
1042 Label L_handler = new Label();
1043 Label L_done = new Label();
1044
1045 Class<?> returnType = result.function.resolvedHandle.type().returnType();
1046 MethodType type = args.function.resolvedHandle.type()
1047 .dropParameterTypes(0,1)
1048 .changeReturnType(returnType);
1049
1050 mv.visitTryCatchBlock(L_startBlock, L_endBlock, L_handler, "java/lang/Throwable");
1051
1052 // Normal case
1053 mv.visitLabel(L_startBlock);
1054 // load target
1055 emitPushArgument(invoker, 0);
1056 emitPushArguments(args, 1); // skip 1st argument: method handle
1057 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString(), false);
1058 mv.visitLabel(L_endBlock);
1059 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1060
1061 // Exceptional case
1062 mv.visitLabel(L_handler);
1063
1064 // Check exception's type
1065 mv.visitInsn(Opcodes.DUP);
1066 // load exception class
1067 emitPushArgument(invoker, 1);
1068 mv.visitInsn(Opcodes.SWAP);
1069 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Class", "isInstance", "(Ljava/lang/Object;)Z", false);
1070 Label L_rethrow = new Label();
1071 mv.visitJumpInsn(Opcodes.IFEQ, L_rethrow);
1072
1073 // Invoke catcher
1074 // load catcher
1075 emitPushArgument(invoker, 2);
1076 mv.visitInsn(Opcodes.SWAP);
1077 emitPushArguments(args, 1); // skip 1st argument: method handle
1078 MethodType catcherType = type.insertParameterTypes(0, Throwable.class);
1079 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", catcherType.basicType().toMethodDescriptorString(), false);
1080 mv.visitJumpInsn(Opcodes.GOTO, L_done);
1081
1082 mv.visitLabel(L_rethrow);
1083 mv.visitInsn(Opcodes.ATHROW);
1084
1085 mv.visitLabel(L_done);
1086 }
1087
1088 private void emitPushArguments(Name args, int start) {
1089 for (int i = start; i < args.arguments.length; i++) {
1090 emitPushArgument(args, i);
1091 }
1092 }
1093
1094 private void emitPushArgument(Name name, int paramIndex) {
1095 Object arg = name.arguments[paramIndex];
1096 Class<?> ptype = name.function.methodType().parameterType(paramIndex);
1097 emitPushArgument(ptype, arg);
1098 }
1099
1100 private void emitPushArgument(Class<?> ptype, Object arg) {
1101 BasicType bptype = basicType(ptype);
1102 if (arg instanceof Name) {
1103 Name n = (Name) arg;
1104 emitLoadInsn(n.type, n.index());
1105 emitImplicitConversion(n.type, ptype, n);
1106 } else if ((arg == null || arg instanceof String) && bptype == L_TYPE) {
1107 emitConst(arg);
1108 } else {
1109 if (Wrapper.isWrapperType(arg.getClass()) && bptype != L_TYPE) {
1110 emitConst(arg);
1111 } else {
1112 mv.visitLdcInsn(constantPlaceholder(arg));
1113 emitImplicitConversion(L_TYPE, ptype, arg);
1114 }
1115 }
1116 }
1117
1118 /**
1119 * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1120 */
1121 private void emitReturn() {
1122 // return statement
1123 Class<?> rclass = invokerType.returnType();
1124 BasicType rtype = lambdaForm.returnType();
1125 assert(rtype == basicType(rclass)); // must agree
1126 if (rtype == V_TYPE) {
1127 // void
1128 mv.visitInsn(Opcodes.RETURN);
1129 // it doesn't matter what rclass is; the JVM will discard any value
1130 } else {
1131 LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1132
1133 // put return value on the stack if it is not already there
1134 if (lambdaForm.result != lambdaForm.names.length - 1 ||
1135 lambdaForm.result < lambdaForm.arity) {
1136 emitLoadInsn(rtype, lambdaForm.result);
1137 }
1138
1139 emitImplicitConversion(rtype, rclass, rn);
1140
1141 // generate actual return statement
1142 emitReturnInsn(rtype);
1143 }
1144 }
1145
1146 /**
1147 * Emit a type conversion bytecode casting from "from" to "to".
1148 */
1149 private void emitPrimCast(Wrapper from, Wrapper to) {
1150 // Here's how.
1151 // - indicates forbidden
1152 // <-> indicates implicit
1153 // to ----> boolean byte short char int long float double
1154 // from boolean <-> - - - - - - -
1155 // byte - <-> i2s i2c <-> i2l i2f i2d
1156 // short - i2b <-> i2c <-> i2l i2f i2d
1157 // char - i2b i2s <-> <-> i2l i2f i2d
1158 // int - i2b i2s i2c <-> i2l i2f i2d
1159 // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1160 // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1161 // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1162 if (from == to) {
1163 // no cast required, should be dead code anyway
1164 return;
1165 }
1166 if (from.isSubwordOrInt()) {
1167 // cast from {byte,short,char,int} to anything
1168 emitI2X(to);
1169 } else {
1170 // cast from {long,float,double} to anything
1171 if (to.isSubwordOrInt()) {
1172 // cast to {byte,short,char,int}
1173 emitX2I(from);
1174 if (to.bitWidth() < 32) {
1175 // targets other than int require another conversion
1176 emitI2X(to);
1177 }
1178 } else {
1179 // cast to {long,float,double} - this is verbose
1180 boolean error = false;
1181 switch (from) {
1182 case LONG:
1183 switch (to) {
1184 case FLOAT: mv.visitInsn(Opcodes.L2F); break;
1185 case DOUBLE: mv.visitInsn(Opcodes.L2D); break;
1186 default: error = true; break;
1187 }
1188 break;
1189 case FLOAT:
1190 switch (to) {
1191 case LONG : mv.visitInsn(Opcodes.F2L); break;
1192 case DOUBLE: mv.visitInsn(Opcodes.F2D); break;
1193 default: error = true; break;
1194 }
1195 break;
1196 case DOUBLE:
1197 switch (to) {
1198 case LONG : mv.visitInsn(Opcodes.D2L); break;
1199 case FLOAT: mv.visitInsn(Opcodes.D2F); break;
1200 default: error = true; break;
1201 }
1202 break;
1203 default:
1204 error = true;
1205 break;
1206 }
1207 if (error) {
1208 throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1209 }
1210 }
1211 }
1212 }
1213
1214 private void emitI2X(Wrapper type) {
1215 switch (type) {
1216 case BYTE: mv.visitInsn(Opcodes.I2B); break;
1217 case SHORT: mv.visitInsn(Opcodes.I2S); break;
1218 case CHAR: mv.visitInsn(Opcodes.I2C); break;
1219 case INT: /* naught */ break;
1220 case LONG: mv.visitInsn(Opcodes.I2L); break;
1221 case FLOAT: mv.visitInsn(Opcodes.I2F); break;
1222 case DOUBLE: mv.visitInsn(Opcodes.I2D); break;
1223 case BOOLEAN:
1224 // For compatibility with ValueConversions and explicitCastArguments:
1225 mv.visitInsn(Opcodes.ICONST_1);
1226 mv.visitInsn(Opcodes.IAND);
1227 break;
1228 default: throw new InternalError("unknown type: " + type);
1229 }
1230 }
1231
1232 private void emitX2I(Wrapper type) {
1233 switch (type) {
1234 case LONG: mv.visitInsn(Opcodes.L2I); break;
1235 case FLOAT: mv.visitInsn(Opcodes.F2I); break;
1236 case DOUBLE: mv.visitInsn(Opcodes.D2I); break;
1237 default: throw new InternalError("unknown type: " + type);
1238 }
1239 }
1240
1241 /**
1242 * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1243 */
1244 static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1245 assert(isValidSignature(sig));
1246 String name = "interpret_"+signatureReturn(sig).basicTypeChar();
1247 MethodType type = signatureType(sig); // sig includes leading argument
1248 type = type.changeParameterType(0, MethodHandle.class);
1249 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", name, type);
1250 return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1251 }
1252
1253 private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1254 classFilePrologue();
1255
1256 // Suppress this method in backtraces displayed to the user.
1257 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1258
1259 // Don't inline the interpreter entry.
1260 mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1261
1262 // create parameter array
1263 emitIconstInsn(invokerType.parameterCount());
1264 mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1265
1266 // fill parameter array
1267 for (int i = 0; i < invokerType.parameterCount(); i++) {
1268 Class<?> ptype = invokerType.parameterType(i);
1269 mv.visitInsn(Opcodes.DUP);
1270 emitIconstInsn(i);
1271 emitLoadInsn(basicType(ptype), i);
1272 // box if primitive type
1273 if (ptype.isPrimitive()) {
1274 emitBoxing(Wrapper.forPrimitiveType(ptype));
1275 }
1276 mv.visitInsn(Opcodes.AASTORE);
1277 }
1278 // invoke
1279 emitAloadInsn(0);
1280 mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1281 mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1282 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;", false);
1283
1284 // maybe unbox
1285 Class<?> rtype = invokerType.returnType();
1286 if (rtype.isPrimitive() && rtype != void.class) {
1287 emitUnboxing(Wrapper.forPrimitiveType(rtype));
1288 }
1289
1290 // return statement
1291 emitReturnInsn(basicType(rtype));
1292
1293 classFileEpilogue();
1294 bogusMethod(invokerType);
1295
1296 final byte[] classFile = cw.toByteArray();
1297 maybeDump(className, classFile);
1298 return classFile;
1299 }
1300
1301 /**
1302 * Generate bytecode for a NamedFunction invoker.
1303 */
1304 static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1305 MethodType invokerType = NamedFunction.INVOKER_METHOD_TYPE;
1306 String invokerName = "invoke_" + shortenSignature(basicTypeSignature(typeForm.erasedType()));
1307 InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1308 return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1309 }
1310
1311 static int nfi = 0;
1312
1313 private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1314 MethodType dstType = typeForm.erasedType();
1315 classFilePrologue();
1316
1317 // Suppress this method in backtraces displayed to the user.
1318 mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1319
1320 // Force inlining of this invoker method.
1321 mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1322
1323 // Load receiver
1324 emitAloadInsn(0);
1325
1326 // Load arguments from array
1327 for (int i = 0; i < dstType.parameterCount(); i++) {
1328 emitAloadInsn(1);
1329 emitIconstInsn(i);
1330 mv.visitInsn(Opcodes.AALOAD);
1331
1332 // Maybe unbox
1333 Class<?> dptype = dstType.parameterType(i);
1334 if (dptype.isPrimitive()) {
1335 Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1336 Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1337 Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1338 emitUnboxing(srcWrapper);
1339 emitPrimCast(srcWrapper, dstWrapper);
1340 }
1341 }
1342
1343 // Invoke
1344 String targetDesc = dstType.basicType().toMethodDescriptorString();
1345 mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc, false);
1346
1347 // Box primitive types
1348 Class<?> rtype = dstType.returnType();
1349 if (rtype != void.class && rtype.isPrimitive()) {
1350 Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1351 Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1352 // boolean casts not allowed
1353 emitPrimCast(srcWrapper, dstWrapper);
1354 emitBoxing(dstWrapper);
1355 }
1356
1357 // If the return type is void we return a null reference.
1358 if (rtype == void.class) {
1359 mv.visitInsn(Opcodes.ACONST_NULL);
1360 }
1361 emitReturnInsn(L_TYPE); // NOTE: NamedFunction invokers always return a reference value.
1362
1363 classFileEpilogue();
1364 bogusMethod(dstType);
1365
1366 final byte[] classFile = cw.toByteArray();
1367 maybeDump(className, classFile);
1368 return classFile;
1369 }
1370
1371 /**
1372 * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1373 * for debugging purposes.
1374 */
1375 private void bogusMethod(Object... os) {
1376 if (DUMP_CLASS_FILES) {
1377 mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1378 for (Object o : os) {
1379 mv.visitLdcInsn(o.toString());
1380 mv.visitInsn(Opcodes.POP);
1381 }
1382 mv.visitInsn(Opcodes.RETURN);
1383 mv.visitMaxs(0, 0);
1384 mv.visitEnd();
1385 }
1386 }
1387 }