1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/rt/emul/compact/src/main/java/java/lang/invoke/InvokerBytecodeGenerator.java Sat Aug 09 11:11:13 2014 +0200
1.3 @@ -0,0 +1,1052 @@
1.4 +/*
1.5 + * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package java.lang.invoke;
1.30 +
1.31 +import sun.invoke.util.VerifyAccess;
1.32 +import java.lang.invoke.LambdaForm.Name;
1.33 +import java.lang.invoke.MethodHandles.Lookup;
1.34 +
1.35 +import sun.invoke.util.Wrapper;
1.36 +
1.37 +import java.io.*;
1.38 +import java.util.*;
1.39 +
1.40 +import jdk.internal.org.objectweb.asm.*;
1.41 +
1.42 +import java.lang.reflect.*;
1.43 +import static java.lang.invoke.MethodHandleStatics.*;
1.44 +import static java.lang.invoke.MethodHandleNatives.Constants.*;
1.45 +import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
1.46 +import sun.invoke.util.ValueConversions;
1.47 +import sun.invoke.util.VerifyType;
1.48 +
1.49 +/**
1.50 + * Code generation backend for LambdaForm.
1.51 + * <p>
1.52 + * @author John Rose, JSR 292 EG
1.53 + */
1.54 +class InvokerBytecodeGenerator {
1.55 + /** Define class names for convenience. */
1.56 + private static final String MH = "java/lang/invoke/MethodHandle";
1.57 + private static final String BMH = "java/lang/invoke/BoundMethodHandle";
1.58 + private static final String LF = "java/lang/invoke/LambdaForm";
1.59 + private static final String LFN = "java/lang/invoke/LambdaForm$Name";
1.60 + private static final String CLS = "java/lang/Class";
1.61 + private static final String OBJ = "java/lang/Object";
1.62 + private static final String OBJARY = "[Ljava/lang/Object;";
1.63 +
1.64 + private static final String LF_SIG = "L" + LF + ";";
1.65 + private static final String LFN_SIG = "L" + LFN + ";";
1.66 + private static final String LL_SIG = "(L" + OBJ + ";)L" + OBJ + ";";
1.67 +
1.68 + /** Name of its super class*/
1.69 + private static final String superName = LF;
1.70 +
1.71 + /** Name of new class */
1.72 + private final String className;
1.73 +
1.74 + /** Name of the source file (for stack trace printing). */
1.75 + private final String sourceFile;
1.76 +
1.77 + private final LambdaForm lambdaForm;
1.78 + private final String invokerName;
1.79 + private final MethodType invokerType;
1.80 + private final int[] localsMap;
1.81 +
1.82 + /** ASM bytecode generation. */
1.83 + private ClassWriter cw;
1.84 + private MethodVisitor mv;
1.85 +
1.86 + private static final MemberName.Factory MEMBERNAME_FACTORY = MemberName.getFactory();
1.87 + private static final Class<?> HOST_CLASS = LambdaForm.class;
1.88 +
1.89 + private InvokerBytecodeGenerator(LambdaForm lambdaForm, int localsMapSize,
1.90 + String className, String invokerName, MethodType invokerType) {
1.91 + if (invokerName.contains(".")) {
1.92 + int p = invokerName.indexOf(".");
1.93 + className = invokerName.substring(0, p);
1.94 + invokerName = invokerName.substring(p+1);
1.95 + }
1.96 + if (DUMP_CLASS_FILES) {
1.97 + className = makeDumpableClassName(className);
1.98 + }
1.99 + this.className = superName + "$" + className;
1.100 + this.sourceFile = "LambdaForm$" + className;
1.101 + this.lambdaForm = lambdaForm;
1.102 + this.invokerName = invokerName;
1.103 + this.invokerType = invokerType;
1.104 + this.localsMap = new int[localsMapSize];
1.105 + }
1.106 +
1.107 + private InvokerBytecodeGenerator(String className, String invokerName, MethodType invokerType) {
1.108 + this(null, invokerType.parameterCount(),
1.109 + className, invokerName, invokerType);
1.110 + // Create an array to map name indexes to locals indexes.
1.111 + for (int i = 0; i < localsMap.length; i++) {
1.112 + localsMap[i] = invokerType.parameterSlotCount() - invokerType.parameterSlotDepth(i);
1.113 + }
1.114 + }
1.115 +
1.116 + private InvokerBytecodeGenerator(String className, LambdaForm form, MethodType invokerType) {
1.117 + this(form, form.names.length,
1.118 + className, form.debugName, invokerType);
1.119 + // Create an array to map name indexes to locals indexes.
1.120 + Name[] names = form.names;
1.121 + for (int i = 0, index = 0; i < localsMap.length; i++) {
1.122 + localsMap[i] = index;
1.123 + index += Wrapper.forBasicType(names[i].type).stackSlots();
1.124 + }
1.125 + }
1.126 +
1.127 +
1.128 + /** instance counters for dumped classes */
1.129 + private final static HashMap<String,Integer> DUMP_CLASS_FILES_COUNTERS;
1.130 + /** debugging flag for saving generated class files */
1.131 + private final static File DUMP_CLASS_FILES_DIR;
1.132 +
1.133 + static {
1.134 + if (DUMP_CLASS_FILES) {
1.135 + DUMP_CLASS_FILES_COUNTERS = new HashMap<>();
1.136 + try {
1.137 + File dumpDir = new File("DUMP_CLASS_FILES");
1.138 + if (!dumpDir.exists()) {
1.139 + dumpDir.mkdirs();
1.140 + }
1.141 + DUMP_CLASS_FILES_DIR = dumpDir;
1.142 + System.out.println("Dumping class files to "+DUMP_CLASS_FILES_DIR+"/...");
1.143 + } catch (Exception e) {
1.144 + throw newInternalError(e);
1.145 + }
1.146 + } else {
1.147 + DUMP_CLASS_FILES_COUNTERS = null;
1.148 + DUMP_CLASS_FILES_DIR = null;
1.149 + }
1.150 + }
1.151 +
1.152 + static void maybeDump(final String className, final byte[] classFile) {
1.153 + if (DUMP_CLASS_FILES) {
1.154 + System.out.println("dump: " + className);
1.155 + java.security.AccessController.doPrivileged(
1.156 + new java.security.PrivilegedAction<Void>() {
1.157 + public Void run() {
1.158 + try {
1.159 + String dumpName = className;
1.160 + //dumpName = dumpName.replace('/', '-');
1.161 + File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
1.162 + dumpFile.getParentFile().mkdirs();
1.163 + FileOutputStream file = new FileOutputStream(dumpFile);
1.164 + file.write(classFile);
1.165 + file.close();
1.166 + return null;
1.167 + } catch (IOException ex) {
1.168 + throw newInternalError(ex);
1.169 + }
1.170 + }
1.171 + });
1.172 + }
1.173 +
1.174 + }
1.175 +
1.176 + private static String makeDumpableClassName(String className) {
1.177 + Integer ctr;
1.178 + synchronized (DUMP_CLASS_FILES_COUNTERS) {
1.179 + ctr = DUMP_CLASS_FILES_COUNTERS.get(className);
1.180 + if (ctr == null) ctr = 0;
1.181 + DUMP_CLASS_FILES_COUNTERS.put(className, ctr+1);
1.182 + }
1.183 + String sfx = ctr.toString();
1.184 + while (sfx.length() < 3)
1.185 + sfx = "0"+sfx;
1.186 + className += sfx;
1.187 + return className;
1.188 + }
1.189 +
1.190 + class CpPatch {
1.191 + final int index;
1.192 + final String placeholder;
1.193 + final Object value;
1.194 + CpPatch(int index, String placeholder, Object value) {
1.195 + this.index = index;
1.196 + this.placeholder = placeholder;
1.197 + this.value = value;
1.198 + }
1.199 + public String toString() {
1.200 + return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
1.201 + }
1.202 + }
1.203 +
1.204 + Map<Object, CpPatch> cpPatches = new HashMap<>();
1.205 +
1.206 + int cph = 0; // for counting constant placeholders
1.207 +
1.208 + String constantPlaceholder(Object arg) {
1.209 + String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + cph++;
1.210 + if (DUMP_CLASS_FILES) cpPlaceholder += " <<" + arg.toString() + ">>"; // debugging aid
1.211 + if (cpPatches.containsKey(cpPlaceholder)) {
1.212 + throw new InternalError("observed CP placeholder twice: " + cpPlaceholder);
1.213 + }
1.214 + // insert placeholder in CP and remember the patch
1.215 + int index = cw.newConst((Object) cpPlaceholder); // TODO check if aready in the constant pool
1.216 + cpPatches.put(cpPlaceholder, new CpPatch(index, cpPlaceholder, arg));
1.217 + return cpPlaceholder;
1.218 + }
1.219 +
1.220 + Object[] cpPatches(byte[] classFile) {
1.221 + int size = getConstantPoolSize(classFile);
1.222 + Object[] res = new Object[size];
1.223 + for (CpPatch p : cpPatches.values()) {
1.224 + if (p.index >= size)
1.225 + throw new InternalError("in cpool["+size+"]: "+p+"\n"+Arrays.toString(Arrays.copyOf(classFile, 20)));
1.226 + res[p.index] = p.value;
1.227 + }
1.228 + return res;
1.229 + }
1.230 +
1.231 + /**
1.232 + * Extract the number of constant pool entries from a given class file.
1.233 + *
1.234 + * @param classFile the bytes of the class file in question.
1.235 + * @return the number of entries in the constant pool.
1.236 + */
1.237 + private static int getConstantPoolSize(byte[] classFile) {
1.238 + // The first few bytes:
1.239 + // u4 magic;
1.240 + // u2 minor_version;
1.241 + // u2 major_version;
1.242 + // u2 constant_pool_count;
1.243 + return ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
1.244 + }
1.245 +
1.246 + /**
1.247 + * Extract the MemberName of a newly-defined method.
1.248 + */
1.249 + private MemberName loadMethod(byte[] classFile) {
1.250 + Class<?> invokerClass = loadAndInitializeInvokerClass(classFile, cpPatches(classFile));
1.251 + return resolveInvokerMember(invokerClass, invokerName, invokerType);
1.252 + }
1.253 +
1.254 + /**
1.255 + * Define a given class as anonymous class in the runtime system.
1.256 + */
1.257 + private static Class<?> loadAndInitializeInvokerClass(byte[] classBytes, Object[] patches) {
1.258 + Class<?> invokerClass = UNSAFE.defineAnonymousClass(HOST_CLASS, classBytes, patches);
1.259 + UNSAFE.ensureClassInitialized(invokerClass); // Make sure the class is initialized; VM might complain.
1.260 + return invokerClass;
1.261 + }
1.262 +
1.263 + private static MemberName resolveInvokerMember(Class<?> invokerClass, String name, MethodType type) {
1.264 + MemberName member = new MemberName(invokerClass, name, type, REF_invokeStatic);
1.265 + //System.out.println("resolveInvokerMember => "+member);
1.266 + //for (Method m : invokerClass.getDeclaredMethods()) System.out.println(" "+m);
1.267 + try {
1.268 + member = MEMBERNAME_FACTORY.resolveOrFail(REF_invokeStatic, member, HOST_CLASS, ReflectiveOperationException.class);
1.269 + } catch (ReflectiveOperationException e) {
1.270 + throw newInternalError(e);
1.271 + }
1.272 + //System.out.println("resolveInvokerMember => "+member);
1.273 + return member;
1.274 + }
1.275 +
1.276 + /**
1.277 + * Set up class file generation.
1.278 + */
1.279 + private void classFilePrologue() {
1.280 + cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES);
1.281 + cw.visit(Opcodes.V1_8, Opcodes.ACC_PUBLIC + Opcodes.ACC_FINAL + Opcodes.ACC_SUPER, className, null, superName, null);
1.282 + cw.visitSource(sourceFile, null);
1.283 +
1.284 + String invokerDesc = invokerType.toMethodDescriptorString();
1.285 + mv = cw.visitMethod(Opcodes.ACC_STATIC, invokerName, invokerDesc, null, null);
1.286 + }
1.287 +
1.288 + /**
1.289 + * Tear down class file generation.
1.290 + */
1.291 + private void classFileEpilogue() {
1.292 + mv.visitMaxs(0, 0);
1.293 + mv.visitEnd();
1.294 + }
1.295 +
1.296 + /*
1.297 + * Low-level emit helpers.
1.298 + */
1.299 + private void emitConst(Object con) {
1.300 + if (con == null) {
1.301 + mv.visitInsn(Opcodes.ACONST_NULL);
1.302 + return;
1.303 + }
1.304 + if (con instanceof Integer) {
1.305 + emitIconstInsn((int) con);
1.306 + return;
1.307 + }
1.308 + if (con instanceof Long) {
1.309 + long x = (long) con;
1.310 + if (x == (short) x) {
1.311 + emitIconstInsn((int) x);
1.312 + mv.visitInsn(Opcodes.I2L);
1.313 + return;
1.314 + }
1.315 + }
1.316 + if (con instanceof Float) {
1.317 + float x = (float) con;
1.318 + if (x == (short) x) {
1.319 + emitIconstInsn((int) x);
1.320 + mv.visitInsn(Opcodes.I2F);
1.321 + return;
1.322 + }
1.323 + }
1.324 + if (con instanceof Double) {
1.325 + double x = (double) con;
1.326 + if (x == (short) x) {
1.327 + emitIconstInsn((int) x);
1.328 + mv.visitInsn(Opcodes.I2D);
1.329 + return;
1.330 + }
1.331 + }
1.332 + if (con instanceof Boolean) {
1.333 + emitIconstInsn((boolean) con ? 1 : 0);
1.334 + return;
1.335 + }
1.336 + // fall through:
1.337 + mv.visitLdcInsn(con);
1.338 + }
1.339 +
1.340 + private void emitIconstInsn(int i) {
1.341 + int opcode;
1.342 + switch (i) {
1.343 + case 0: opcode = Opcodes.ICONST_0; break;
1.344 + case 1: opcode = Opcodes.ICONST_1; break;
1.345 + case 2: opcode = Opcodes.ICONST_2; break;
1.346 + case 3: opcode = Opcodes.ICONST_3; break;
1.347 + case 4: opcode = Opcodes.ICONST_4; break;
1.348 + case 5: opcode = Opcodes.ICONST_5; break;
1.349 + default:
1.350 + if (i == (byte) i) {
1.351 + mv.visitIntInsn(Opcodes.BIPUSH, i & 0xFF);
1.352 + } else if (i == (short) i) {
1.353 + mv.visitIntInsn(Opcodes.SIPUSH, (char) i);
1.354 + } else {
1.355 + mv.visitLdcInsn(i);
1.356 + }
1.357 + return;
1.358 + }
1.359 + mv.visitInsn(opcode);
1.360 + }
1.361 +
1.362 + /*
1.363 + * NOTE: These load/store methods use the localsMap to find the correct index!
1.364 + */
1.365 + private void emitLoadInsn(char type, int index) {
1.366 + int opcode;
1.367 + switch (type) {
1.368 + case 'I': opcode = Opcodes.ILOAD; break;
1.369 + case 'J': opcode = Opcodes.LLOAD; break;
1.370 + case 'F': opcode = Opcodes.FLOAD; break;
1.371 + case 'D': opcode = Opcodes.DLOAD; break;
1.372 + case 'L': opcode = Opcodes.ALOAD; break;
1.373 + default:
1.374 + throw new InternalError("unknown type: " + type);
1.375 + }
1.376 + mv.visitVarInsn(opcode, localsMap[index]);
1.377 + }
1.378 + private void emitAloadInsn(int index) {
1.379 + emitLoadInsn('L', index);
1.380 + }
1.381 +
1.382 + private void emitStoreInsn(char type, int index) {
1.383 + int opcode;
1.384 + switch (type) {
1.385 + case 'I': opcode = Opcodes.ISTORE; break;
1.386 + case 'J': opcode = Opcodes.LSTORE; break;
1.387 + case 'F': opcode = Opcodes.FSTORE; break;
1.388 + case 'D': opcode = Opcodes.DSTORE; break;
1.389 + case 'L': opcode = Opcodes.ASTORE; break;
1.390 + default:
1.391 + throw new InternalError("unknown type: " + type);
1.392 + }
1.393 + mv.visitVarInsn(opcode, localsMap[index]);
1.394 + }
1.395 + private void emitAstoreInsn(int index) {
1.396 + emitStoreInsn('L', index);
1.397 + }
1.398 +
1.399 + /**
1.400 + * Emit a boxing call.
1.401 + *
1.402 + * @param type primitive type class to box.
1.403 + */
1.404 + private void emitBoxing(Class<?> type) {
1.405 + Wrapper wrapper = Wrapper.forPrimitiveType(type);
1.406 + String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
1.407 + String name = "valueOf";
1.408 + String desc = "(" + wrapper.basicTypeChar() + ")L" + owner + ";";
1.409 + mv.visitMethodInsn(Opcodes.INVOKESTATIC, owner, name, desc);
1.410 + }
1.411 +
1.412 + /**
1.413 + * Emit an unboxing call (plus preceding checkcast).
1.414 + *
1.415 + * @param type wrapper type class to unbox.
1.416 + */
1.417 + private void emitUnboxing(Class<?> type) {
1.418 + Wrapper wrapper = Wrapper.forWrapperType(type);
1.419 + String owner = "java/lang/" + wrapper.wrapperType().getSimpleName();
1.420 + String name = wrapper.primitiveSimpleName() + "Value";
1.421 + String desc = "()" + wrapper.basicTypeChar();
1.422 + mv.visitTypeInsn(Opcodes.CHECKCAST, owner);
1.423 + mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc);
1.424 + }
1.425 +
1.426 + /**
1.427 + * Emit an implicit conversion.
1.428 + *
1.429 + * @param ptype type of value present on stack
1.430 + * @param pclass type of value required on stack
1.431 + */
1.432 + private void emitImplicitConversion(char ptype, Class<?> pclass) {
1.433 + switch (ptype) {
1.434 + case 'L':
1.435 + if (VerifyType.isNullConversion(Object.class, pclass))
1.436 + return;
1.437 + if (isStaticallyNameable(pclass)) {
1.438 + mv.visitTypeInsn(Opcodes.CHECKCAST, getInternalName(pclass));
1.439 + } else {
1.440 + mv.visitLdcInsn(constantPlaceholder(pclass));
1.441 + mv.visitTypeInsn(Opcodes.CHECKCAST, CLS);
1.442 + mv.visitInsn(Opcodes.SWAP);
1.443 + mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, CLS, "cast", LL_SIG);
1.444 + if (pclass.isArray())
1.445 + mv.visitTypeInsn(Opcodes.CHECKCAST, OBJARY);
1.446 + }
1.447 + return;
1.448 + case 'I':
1.449 + if (!VerifyType.isNullConversion(int.class, pclass))
1.450 + emitPrimCast(ptype, Wrapper.basicTypeChar(pclass));
1.451 + return;
1.452 + case 'J':
1.453 + assert(pclass == long.class);
1.454 + return;
1.455 + case 'F':
1.456 + assert(pclass == float.class);
1.457 + return;
1.458 + case 'D':
1.459 + assert(pclass == double.class);
1.460 + return;
1.461 + }
1.462 + throw new InternalError("bad implicit conversion: tc="+ptype+": "+pclass);
1.463 + }
1.464 +
1.465 + /**
1.466 + * Emits an actual return instruction conforming to the given return type.
1.467 + */
1.468 + private void emitReturnInsn(Class<?> type) {
1.469 + int opcode;
1.470 + switch (Wrapper.basicTypeChar(type)) {
1.471 + case 'I': opcode = Opcodes.IRETURN; break;
1.472 + case 'J': opcode = Opcodes.LRETURN; break;
1.473 + case 'F': opcode = Opcodes.FRETURN; break;
1.474 + case 'D': opcode = Opcodes.DRETURN; break;
1.475 + case 'L': opcode = Opcodes.ARETURN; break;
1.476 + case 'V': opcode = Opcodes.RETURN; break;
1.477 + default:
1.478 + throw new InternalError("unknown return type: " + type);
1.479 + }
1.480 + mv.visitInsn(opcode);
1.481 + }
1.482 +
1.483 + private static String getInternalName(Class<?> c) {
1.484 + assert(VerifyAccess.isTypeVisible(c, Object.class));
1.485 + return c.getName().replace('.', '/');
1.486 + }
1.487 +
1.488 + /**
1.489 + * Generate customized bytecode for a given LambdaForm.
1.490 + */
1.491 + static MemberName generateCustomizedCode(LambdaForm form, MethodType invokerType) {
1.492 + InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("MH", form, invokerType);
1.493 + return g.loadMethod(g.generateCustomizedCodeBytes());
1.494 + }
1.495 +
1.496 + /**
1.497 + * Generate an invoker method for the passed {@link LambdaForm}.
1.498 + */
1.499 + private byte[] generateCustomizedCodeBytes() {
1.500 + classFilePrologue();
1.501 +
1.502 + // Suppress this method in backtraces displayed to the user.
1.503 + mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1.504 +
1.505 + // Mark this method as a compiled LambdaForm
1.506 + mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Compiled;", true);
1.507 +
1.508 + // Force inlining of this invoker method.
1.509 + mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1.510 +
1.511 + // iterate over the form's names, generating bytecode instructions for each
1.512 + // start iterating at the first name following the arguments
1.513 + for (int i = lambdaForm.arity; i < lambdaForm.names.length; i++) {
1.514 + Name name = lambdaForm.names[i];
1.515 + MemberName member = name.function.member();
1.516 +
1.517 + if (isSelectAlternative(member)) {
1.518 + // selectAlternative idiom
1.519 + // FIXME: make sure this idiom is really present!
1.520 + emitSelectAlternative(name, lambdaForm.names[i + 1]);
1.521 + i++; // skip MH.invokeBasic of the selectAlternative result
1.522 + } else if (isStaticallyInvocable(member)) {
1.523 + emitStaticInvoke(member, name);
1.524 + } else {
1.525 + emitInvoke(name);
1.526 + }
1.527 +
1.528 + // store the result from evaluating to the target name in a local if required
1.529 + // (if this is the last value, i.e., the one that is going to be returned,
1.530 + // avoid store/load/return and just return)
1.531 + if (i == lambdaForm.names.length - 1 && i == lambdaForm.result) {
1.532 + // return value - do nothing
1.533 + } else if (name.type != 'V') {
1.534 + // non-void: actually assign
1.535 + emitStoreInsn(name.type, name.index());
1.536 + }
1.537 + }
1.538 +
1.539 + // return statement
1.540 + emitReturn();
1.541 +
1.542 + classFileEpilogue();
1.543 + bogusMethod(lambdaForm);
1.544 +
1.545 + final byte[] classFile = cw.toByteArray();
1.546 + maybeDump(className, classFile);
1.547 + return classFile;
1.548 + }
1.549 +
1.550 + /**
1.551 + * Emit an invoke for the given name.
1.552 + */
1.553 + void emitInvoke(Name name) {
1.554 + if (true) {
1.555 + // push receiver
1.556 + MethodHandle target = name.function.resolvedHandle;
1.557 + assert(target != null) : name.exprString();
1.558 + mv.visitLdcInsn(constantPlaceholder(target));
1.559 + mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
1.560 + } else {
1.561 + // load receiver
1.562 + emitAloadInsn(0);
1.563 + mv.visitTypeInsn(Opcodes.CHECKCAST, MH);
1.564 + mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", LF_SIG);
1.565 + mv.visitFieldInsn(Opcodes.GETFIELD, LF, "names", LFN_SIG);
1.566 + // TODO more to come
1.567 + }
1.568 +
1.569 + // push arguments
1.570 + for (int i = 0; i < name.arguments.length; i++) {
1.571 + emitPushArgument(name, i);
1.572 + }
1.573 +
1.574 + // invocation
1.575 + MethodType type = name.function.methodType();
1.576 + mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", type.basicType().toMethodDescriptorString());
1.577 + }
1.578 +
1.579 + static private Class<?>[] STATICALLY_INVOCABLE_PACKAGES = {
1.580 + // Sample classes from each package we are willing to bind to statically:
1.581 + java.lang.Object.class,
1.582 + java.util.Arrays.class,
1.583 + sun.misc.Unsafe.class
1.584 + //MethodHandle.class already covered
1.585 + };
1.586 +
1.587 + static boolean isStaticallyInvocable(MemberName member) {
1.588 + if (member == null) return false;
1.589 + if (member.isConstructor()) return false;
1.590 + Class<?> cls = member.getDeclaringClass();
1.591 + if (cls.isArray() || cls.isPrimitive())
1.592 + return false; // FIXME
1.593 + if (cls.isAnonymousClass() || cls.isLocalClass())
1.594 + return false; // inner class of some sort
1.595 + if (cls.getClassLoader() != MethodHandle.class.getClassLoader())
1.596 + return false; // not on BCP
1.597 + MethodType mtype = member.getMethodOrFieldType();
1.598 + if (!isStaticallyNameable(mtype.returnType()))
1.599 + return false;
1.600 + for (Class<?> ptype : mtype.parameterArray())
1.601 + if (!isStaticallyNameable(ptype))
1.602 + return false;
1.603 + if (!member.isPrivate() && VerifyAccess.isSamePackage(MethodHandle.class, cls))
1.604 + return true; // in java.lang.invoke package
1.605 + if (member.isPublic() && isStaticallyNameable(cls))
1.606 + return true;
1.607 + return false;
1.608 + }
1.609 +
1.610 + static boolean isStaticallyNameable(Class<?> cls) {
1.611 + while (cls.isArray())
1.612 + cls = cls.getComponentType();
1.613 + if (cls.isPrimitive())
1.614 + return true; // int[].class, for example
1.615 + // could use VerifyAccess.isClassAccessible but the following is a safe approximation
1.616 + if (cls.getClassLoader() != Object.class.getClassLoader())
1.617 + return false;
1.618 + if (VerifyAccess.isSamePackage(MethodHandle.class, cls))
1.619 + return true;
1.620 + if (!Modifier.isPublic(cls.getModifiers()))
1.621 + return false;
1.622 + for (Class<?> pkgcls : STATICALLY_INVOCABLE_PACKAGES) {
1.623 + if (VerifyAccess.isSamePackage(pkgcls, cls))
1.624 + return true;
1.625 + }
1.626 + return false;
1.627 + }
1.628 +
1.629 + /**
1.630 + * Emit an invoke for the given name, using the MemberName directly.
1.631 + */
1.632 + void emitStaticInvoke(MemberName member, Name name) {
1.633 + assert(member.equals(name.function.member()));
1.634 + String cname = getInternalName(member.getDeclaringClass());
1.635 + String mname = member.getName();
1.636 + String mtype;
1.637 + byte refKind = member.getReferenceKind();
1.638 + if (refKind == REF_invokeSpecial) {
1.639 + // in order to pass the verifier, we need to convert this to invokevirtual in all cases
1.640 + assert(member.canBeStaticallyBound()) : member;
1.641 + refKind = REF_invokeVirtual;
1.642 + }
1.643 +
1.644 + if (member.getDeclaringClass().isInterface() && refKind == REF_invokeVirtual) {
1.645 + // Methods from Object declared in an interface can be resolved by JVM to invokevirtual kind.
1.646 + // Need to convert it back to invokeinterface to pass verification and make the invocation works as expected.
1.647 + refKind = REF_invokeInterface;
1.648 + }
1.649 +
1.650 + // push arguments
1.651 + for (int i = 0; i < name.arguments.length; i++) {
1.652 + emitPushArgument(name, i);
1.653 + }
1.654 +
1.655 + // invocation
1.656 + if (member.isMethod()) {
1.657 + mtype = member.getMethodType().toMethodDescriptorString();
1.658 + mv.visitMethodInsn(refKindOpcode(refKind), cname, mname, mtype,
1.659 + member.getDeclaringClass().isInterface());
1.660 + } else {
1.661 + mtype = MethodType.toFieldDescriptorString(member.getFieldType());
1.662 + mv.visitFieldInsn(refKindOpcode(refKind), cname, mname, mtype);
1.663 + }
1.664 + }
1.665 + int refKindOpcode(byte refKind) {
1.666 + switch (refKind) {
1.667 + case REF_invokeVirtual: return Opcodes.INVOKEVIRTUAL;
1.668 + case REF_invokeStatic: return Opcodes.INVOKESTATIC;
1.669 + case REF_invokeSpecial: return Opcodes.INVOKESPECIAL;
1.670 + case REF_invokeInterface: return Opcodes.INVOKEINTERFACE;
1.671 + case REF_getField: return Opcodes.GETFIELD;
1.672 + case REF_putField: return Opcodes.PUTFIELD;
1.673 + case REF_getStatic: return Opcodes.GETSTATIC;
1.674 + case REF_putStatic: return Opcodes.PUTSTATIC;
1.675 + }
1.676 + throw new InternalError("refKind="+refKind);
1.677 + }
1.678 +
1.679 + /**
1.680 + * Check if MemberName is a call to MethodHandleImpl.selectAlternative.
1.681 + */
1.682 + private boolean isSelectAlternative(MemberName member) {
1.683 + return member != null &&
1.684 + member.getDeclaringClass() == MethodHandleImpl.class &&
1.685 + member.getName().equals("selectAlternative");
1.686 + }
1.687 +
1.688 + /**
1.689 + * Emit bytecode for the selectAlternative idiom.
1.690 + *
1.691 + * The pattern looks like (Cf. MethodHandleImpl.makeGuardWithTest):
1.692 + * <blockquote><pre>{@code
1.693 + * Lambda(a0:L,a1:I)=>{
1.694 + * t2:I=foo.test(a1:I);
1.695 + * t3:L=MethodHandleImpl.selectAlternative(t2:I,(MethodHandle(int)int),(MethodHandle(int)int));
1.696 + * t4:I=MethodHandle.invokeBasic(t3:L,a1:I);t4:I}
1.697 + * }</pre></blockquote>
1.698 + */
1.699 + private void emitSelectAlternative(Name selectAlternativeName, Name invokeBasicName) {
1.700 + MethodType type = selectAlternativeName.function.methodType();
1.701 +
1.702 + Name receiver = (Name) invokeBasicName.arguments[0];
1.703 +
1.704 + Label L_fallback = new Label();
1.705 + Label L_done = new Label();
1.706 +
1.707 + // load test result
1.708 + emitPushArgument(selectAlternativeName, 0);
1.709 + mv.visitInsn(Opcodes.ICONST_1);
1.710 +
1.711 + // if_icmpne L_fallback
1.712 + mv.visitJumpInsn(Opcodes.IF_ICMPNE, L_fallback);
1.713 +
1.714 + // invoke selectAlternativeName.arguments[1]
1.715 + MethodHandle target = (MethodHandle) selectAlternativeName.arguments[1];
1.716 + emitPushArgument(selectAlternativeName, 1); // get 2nd argument of selectAlternative
1.717 + emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1.718 + emitInvoke(invokeBasicName);
1.719 +
1.720 + // goto L_done
1.721 + mv.visitJumpInsn(Opcodes.GOTO, L_done);
1.722 +
1.723 + // L_fallback:
1.724 + mv.visitLabel(L_fallback);
1.725 +
1.726 + // invoke selectAlternativeName.arguments[2]
1.727 + MethodHandle fallback = (MethodHandle) selectAlternativeName.arguments[2];
1.728 + emitPushArgument(selectAlternativeName, 2); // get 3rd argument of selectAlternative
1.729 + emitAstoreInsn(receiver.index()); // store the MH in the receiver slot
1.730 + emitInvoke(invokeBasicName);
1.731 +
1.732 + // L_done:
1.733 + mv.visitLabel(L_done);
1.734 + }
1.735 +
1.736 + private void emitPushArgument(Name name, int paramIndex) {
1.737 + Object arg = name.arguments[paramIndex];
1.738 + char ptype = name.function.parameterType(paramIndex);
1.739 + MethodType mtype = name.function.methodType();
1.740 + if (arg instanceof Name) {
1.741 + Name n = (Name) arg;
1.742 + emitLoadInsn(n.type, n.index());
1.743 + emitImplicitConversion(n.type, mtype.parameterType(paramIndex));
1.744 + } else if ((arg == null || arg instanceof String) && ptype == 'L') {
1.745 + emitConst(arg);
1.746 + } else {
1.747 + if (Wrapper.isWrapperType(arg.getClass()) && ptype != 'L') {
1.748 + emitConst(arg);
1.749 + } else {
1.750 + mv.visitLdcInsn(constantPlaceholder(arg));
1.751 + emitImplicitConversion('L', mtype.parameterType(paramIndex));
1.752 + }
1.753 + }
1.754 + }
1.755 +
1.756 + /**
1.757 + * Emits a return statement from a LF invoker. If required, the result type is cast to the correct return type.
1.758 + */
1.759 + private void emitReturn() {
1.760 + // return statement
1.761 + if (lambdaForm.result == -1) {
1.762 + // void
1.763 + mv.visitInsn(Opcodes.RETURN);
1.764 + } else {
1.765 + LambdaForm.Name rn = lambdaForm.names[lambdaForm.result];
1.766 + char rtype = Wrapper.basicTypeChar(invokerType.returnType());
1.767 +
1.768 + // put return value on the stack if it is not already there
1.769 + if (lambdaForm.result != lambdaForm.names.length - 1) {
1.770 + emitLoadInsn(rn.type, lambdaForm.result);
1.771 + }
1.772 +
1.773 + // potentially generate cast
1.774 + // rtype is the return type of the invoker - generated code must conform to this
1.775 + // rn.type is the type of the result Name in the LF
1.776 + if (rtype != rn.type) {
1.777 + // need cast
1.778 + if (rtype == 'L') {
1.779 + // possibly cast the primitive to the correct type for boxing
1.780 + char boxedType = Wrapper.forWrapperType(invokerType.returnType()).basicTypeChar();
1.781 + if (boxedType != rn.type) {
1.782 + emitPrimCast(rn.type, boxedType);
1.783 + }
1.784 + // cast primitive to reference ("boxing")
1.785 + emitBoxing(invokerType.returnType());
1.786 + } else {
1.787 + // to-primitive cast
1.788 + if (rn.type != 'L') {
1.789 + // prim-to-prim cast
1.790 + emitPrimCast(rn.type, rtype);
1.791 + } else {
1.792 + // ref-to-prim cast ("unboxing")
1.793 + throw new InternalError("no ref-to-prim (unboxing) casts supported right now");
1.794 + }
1.795 + }
1.796 + }
1.797 +
1.798 + // generate actual return statement
1.799 + emitReturnInsn(invokerType.returnType());
1.800 + }
1.801 + }
1.802 +
1.803 + /**
1.804 + * Emit a type conversion bytecode casting from "from" to "to".
1.805 + */
1.806 + private void emitPrimCast(char from, char to) {
1.807 + // Here's how.
1.808 + // - indicates forbidden
1.809 + // <-> indicates implicit
1.810 + // to ----> boolean byte short char int long float double
1.811 + // from boolean <-> - - - - - - -
1.812 + // byte - <-> i2s i2c <-> i2l i2f i2d
1.813 + // short - i2b <-> i2c <-> i2l i2f i2d
1.814 + // char - i2b i2s <-> <-> i2l i2f i2d
1.815 + // int - i2b i2s i2c <-> i2l i2f i2d
1.816 + // long - l2i,i2b l2i,i2s l2i,i2c l2i <-> l2f l2d
1.817 + // float - f2i,i2b f2i,i2s f2i,i2c f2i f2l <-> f2d
1.818 + // double - d2i,i2b d2i,i2s d2i,i2c d2i d2l d2f <->
1.819 + if (from == to) {
1.820 + // no cast required, should be dead code anyway
1.821 + return;
1.822 + }
1.823 + Wrapper wfrom = Wrapper.forBasicType(from);
1.824 + Wrapper wto = Wrapper.forBasicType(to);
1.825 + if (wfrom.isSubwordOrInt()) {
1.826 + // cast from {byte,short,char,int} to anything
1.827 + emitI2X(to);
1.828 + } else {
1.829 + // cast from {long,float,double} to anything
1.830 + if (wto.isSubwordOrInt()) {
1.831 + // cast to {byte,short,char,int}
1.832 + emitX2I(from);
1.833 + if (wto.bitWidth() < 32) {
1.834 + // targets other than int require another conversion
1.835 + emitI2X(to);
1.836 + }
1.837 + } else {
1.838 + // cast to {long,float,double} - this is verbose
1.839 + boolean error = false;
1.840 + switch (from) {
1.841 + case 'J':
1.842 + if (to == 'F') { mv.visitInsn(Opcodes.L2F); }
1.843 + else if (to == 'D') { mv.visitInsn(Opcodes.L2D); }
1.844 + else error = true;
1.845 + break;
1.846 + case 'F':
1.847 + if (to == 'J') { mv.visitInsn(Opcodes.F2L); }
1.848 + else if (to == 'D') { mv.visitInsn(Opcodes.F2D); }
1.849 + else error = true;
1.850 + break;
1.851 + case 'D':
1.852 + if (to == 'J') { mv.visitInsn(Opcodes.D2L); }
1.853 + else if (to == 'F') { mv.visitInsn(Opcodes.D2F); }
1.854 + else error = true;
1.855 + break;
1.856 + default:
1.857 + error = true;
1.858 + break;
1.859 + }
1.860 + if (error) {
1.861 + throw new IllegalStateException("unhandled prim cast: " + from + "2" + to);
1.862 + }
1.863 + }
1.864 + }
1.865 + }
1.866 +
1.867 + private void emitI2X(char type) {
1.868 + switch (type) {
1.869 + case 'B': mv.visitInsn(Opcodes.I2B); break;
1.870 + case 'S': mv.visitInsn(Opcodes.I2S); break;
1.871 + case 'C': mv.visitInsn(Opcodes.I2C); break;
1.872 + case 'I': /* naught */ break;
1.873 + case 'J': mv.visitInsn(Opcodes.I2L); break;
1.874 + case 'F': mv.visitInsn(Opcodes.I2F); break;
1.875 + case 'D': mv.visitInsn(Opcodes.I2D); break;
1.876 + case 'Z':
1.877 + // For compatibility with ValueConversions and explicitCastArguments:
1.878 + mv.visitInsn(Opcodes.ICONST_1);
1.879 + mv.visitInsn(Opcodes.IAND);
1.880 + break;
1.881 + default: throw new InternalError("unknown type: " + type);
1.882 + }
1.883 + }
1.884 +
1.885 + private void emitX2I(char type) {
1.886 + switch (type) {
1.887 + case 'J': mv.visitInsn(Opcodes.L2I); break;
1.888 + case 'F': mv.visitInsn(Opcodes.F2I); break;
1.889 + case 'D': mv.visitInsn(Opcodes.D2I); break;
1.890 + default: throw new InternalError("unknown type: " + type);
1.891 + }
1.892 + }
1.893 +
1.894 + private static String basicTypeCharSignature(String prefix, MethodType type) {
1.895 + StringBuilder buf = new StringBuilder(prefix);
1.896 + for (Class<?> ptype : type.parameterList())
1.897 + buf.append(Wrapper.forBasicType(ptype).basicTypeChar());
1.898 + buf.append('_').append(Wrapper.forBasicType(type.returnType()).basicTypeChar());
1.899 + return buf.toString();
1.900 + }
1.901 +
1.902 + /**
1.903 + * Generate bytecode for a LambdaForm.vmentry which calls interpretWithArguments.
1.904 + */
1.905 + static MemberName generateLambdaFormInterpreterEntryPoint(String sig) {
1.906 + assert(LambdaForm.isValidSignature(sig));
1.907 + //System.out.println("generateExactInvoker "+sig);
1.908 + // compute method type
1.909 + // first parameter and return type
1.910 + char tret = LambdaForm.signatureReturn(sig);
1.911 + MethodType type = MethodType.methodType(LambdaForm.typeClass(tret), MethodHandle.class);
1.912 + // other parameter types
1.913 + int arity = LambdaForm.signatureArity(sig);
1.914 + for (int i = 1; i < arity; i++) {
1.915 + type = type.appendParameterTypes(LambdaForm.typeClass(sig.charAt(i)));
1.916 + }
1.917 + InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("LFI", "interpret_"+tret, type);
1.918 + return g.loadMethod(g.generateLambdaFormInterpreterEntryPointBytes());
1.919 + }
1.920 +
1.921 + private byte[] generateLambdaFormInterpreterEntryPointBytes() {
1.922 + classFilePrologue();
1.923 +
1.924 + // Suppress this method in backtraces displayed to the user.
1.925 + mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1.926 +
1.927 + // Don't inline the interpreter entry.
1.928 + mv.visitAnnotation("Ljava/lang/invoke/DontInline;", true);
1.929 +
1.930 + // create parameter array
1.931 + emitIconstInsn(invokerType.parameterCount());
1.932 + mv.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
1.933 +
1.934 + // fill parameter array
1.935 + for (int i = 0; i < invokerType.parameterCount(); i++) {
1.936 + Class<?> ptype = invokerType.parameterType(i);
1.937 + mv.visitInsn(Opcodes.DUP);
1.938 + emitIconstInsn(i);
1.939 + emitLoadInsn(Wrapper.basicTypeChar(ptype), i);
1.940 + // box if primitive type
1.941 + if (ptype.isPrimitive()) {
1.942 + emitBoxing(ptype);
1.943 + }
1.944 + mv.visitInsn(Opcodes.AASTORE);
1.945 + }
1.946 + // invoke
1.947 + emitAloadInsn(0);
1.948 + mv.visitFieldInsn(Opcodes.GETFIELD, MH, "form", "Ljava/lang/invoke/LambdaForm;");
1.949 + mv.visitInsn(Opcodes.SWAP); // swap form and array; avoid local variable
1.950 + mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, LF, "interpretWithArguments", "([Ljava/lang/Object;)Ljava/lang/Object;");
1.951 +
1.952 + // maybe unbox
1.953 + Class<?> rtype = invokerType.returnType();
1.954 + if (rtype.isPrimitive() && rtype != void.class) {
1.955 + emitUnboxing(Wrapper.asWrapperType(rtype));
1.956 + }
1.957 +
1.958 + // return statement
1.959 + emitReturnInsn(rtype);
1.960 +
1.961 + classFileEpilogue();
1.962 + bogusMethod(invokerType);
1.963 +
1.964 + final byte[] classFile = cw.toByteArray();
1.965 + maybeDump(className, classFile);
1.966 + return classFile;
1.967 + }
1.968 +
1.969 + /**
1.970 + * Generate bytecode for a NamedFunction invoker.
1.971 + */
1.972 + static MemberName generateNamedFunctionInvoker(MethodTypeForm typeForm) {
1.973 + MethodType invokerType = LambdaForm.NamedFunction.INVOKER_METHOD_TYPE;
1.974 + String invokerName = basicTypeCharSignature("invoke_", typeForm.erasedType());
1.975 + InvokerBytecodeGenerator g = new InvokerBytecodeGenerator("NFI", invokerName, invokerType);
1.976 + return g.loadMethod(g.generateNamedFunctionInvokerImpl(typeForm));
1.977 + }
1.978 +
1.979 + static int nfi = 0;
1.980 +
1.981 + private byte[] generateNamedFunctionInvokerImpl(MethodTypeForm typeForm) {
1.982 + MethodType dstType = typeForm.erasedType();
1.983 + classFilePrologue();
1.984 +
1.985 + // Suppress this method in backtraces displayed to the user.
1.986 + mv.visitAnnotation("Ljava/lang/invoke/LambdaForm$Hidden;", true);
1.987 +
1.988 + // Force inlining of this invoker method.
1.989 + mv.visitAnnotation("Ljava/lang/invoke/ForceInline;", true);
1.990 +
1.991 + // Load receiver
1.992 + emitAloadInsn(0);
1.993 +
1.994 + // Load arguments from array
1.995 + for (int i = 0; i < dstType.parameterCount(); i++) {
1.996 + emitAloadInsn(1);
1.997 + emitIconstInsn(i);
1.998 + mv.visitInsn(Opcodes.AALOAD);
1.999 +
1.1000 + // Maybe unbox
1.1001 + Class<?> dptype = dstType.parameterType(i);
1.1002 + if (dptype.isPrimitive()) {
1.1003 + Class<?> sptype = dstType.basicType().wrap().parameterType(i);
1.1004 + Wrapper dstWrapper = Wrapper.forBasicType(dptype);
1.1005 + Wrapper srcWrapper = dstWrapper.isSubwordOrInt() ? Wrapper.INT : dstWrapper; // narrow subword from int
1.1006 + emitUnboxing(srcWrapper.wrapperType());
1.1007 + emitPrimCast(srcWrapper.basicTypeChar(), dstWrapper.basicTypeChar());
1.1008 + }
1.1009 + }
1.1010 +
1.1011 + // Invoke
1.1012 + String targetDesc = dstType.basicType().toMethodDescriptorString();
1.1013 + mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, MH, "invokeBasic", targetDesc);
1.1014 +
1.1015 + // Box primitive types
1.1016 + Class<?> rtype = dstType.returnType();
1.1017 + if (rtype != void.class && rtype.isPrimitive()) {
1.1018 + Wrapper srcWrapper = Wrapper.forBasicType(rtype);
1.1019 + Wrapper dstWrapper = srcWrapper.isSubwordOrInt() ? Wrapper.INT : srcWrapper; // widen subword to int
1.1020 + // boolean casts not allowed
1.1021 + emitPrimCast(srcWrapper.basicTypeChar(), dstWrapper.basicTypeChar());
1.1022 + emitBoxing(dstWrapper.primitiveType());
1.1023 + }
1.1024 +
1.1025 + // If the return type is void we return a null reference.
1.1026 + if (rtype == void.class) {
1.1027 + mv.visitInsn(Opcodes.ACONST_NULL);
1.1028 + }
1.1029 + emitReturnInsn(Object.class); // NOTE: NamedFunction invokers always return a reference value.
1.1030 +
1.1031 + classFileEpilogue();
1.1032 + bogusMethod(dstType);
1.1033 +
1.1034 + final byte[] classFile = cw.toByteArray();
1.1035 + maybeDump(className, classFile);
1.1036 + return classFile;
1.1037 + }
1.1038 +
1.1039 + /**
1.1040 + * Emit a bogus method that just loads some string constants. This is to get the constants into the constant pool
1.1041 + * for debugging purposes.
1.1042 + */
1.1043 + private void bogusMethod(Object... os) {
1.1044 + if (DUMP_CLASS_FILES) {
1.1045 + mv = cw.visitMethod(Opcodes.ACC_STATIC, "dummy", "()V", null, null);
1.1046 + for (Object o : os) {
1.1047 + mv.visitLdcInsn(o.toString());
1.1048 + mv.visitInsn(Opcodes.POP);
1.1049 + }
1.1050 + mv.visitInsn(Opcodes.RETURN);
1.1051 + mv.visitMaxs(0, 0);
1.1052 + mv.visitEnd();
1.1053 + }
1.1054 + }
1.1055 +}