/* * Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package java.lang.invoke; import static com.sun.xml.internal.ws.org.objectweb.asm.Opcodes.*; import static java.lang.invoke.LambdaForm.basicTypes; import static java.lang.invoke.MethodHandleNatives.Constants.REF_invokeStatic; import static java.lang.invoke.MethodHandleStatics.*; import java.lang.invoke.LambdaForm.Name; import java.lang.invoke.LambdaForm.NamedFunction; import java.lang.invoke.MethodHandles.Lookup; import java.lang.reflect.Field; import java.util.Arrays; import java.util.HashMap; import sun.invoke.util.ValueConversions; import sun.invoke.util.Wrapper; import com.sun.xml.internal.ws.org.objectweb.asm.ClassWriter; import com.sun.xml.internal.ws.org.objectweb.asm.MethodVisitor; import com.sun.xml.internal.ws.org.objectweb.asm.Type; /** * The flavor of method handle which emulates an invoke instruction * on a predetermined argument. The JVM dispatches to the correct method * when the handle is created, not when it is invoked. * * All bound arguments are encapsulated in dedicated species. */ /* non-public */ abstract class BoundMethodHandle extends MethodHandle { /* non-public */ BoundMethodHandle(MethodType type, LambdaForm form) { super(type, form); } // // BMH API and internals // static MethodHandle bindSingle(MethodType type, LambdaForm form, char xtype, Object x) { // for some type signatures, there exist pre-defined concrete BMH classes try { switch (xtype) { case 'L': if (true) return bindSingle(type, form, x); // Use known fast path. return (BoundMethodHandle) SpeciesData.EMPTY.extendWithType('L').constructor[0].invokeBasic(type, form, x); case 'I': return (BoundMethodHandle) SpeciesData.EMPTY.extendWithType('I').constructor[0].invokeBasic(type, form, ValueConversions.widenSubword(x)); case 'J': return (BoundMethodHandle) SpeciesData.EMPTY.extendWithType('J').constructor[0].invokeBasic(type, form, (long) x); case 'F': return (BoundMethodHandle) SpeciesData.EMPTY.extendWithType('F').constructor[0].invokeBasic(type, form, (float) x); case 'D': return (BoundMethodHandle) SpeciesData.EMPTY.extendWithType('D').constructor[0].invokeBasic(type, form, (double) x); default : throw new InternalError("unexpected xtype: " + xtype); } } catch (Throwable t) { throw newInternalError(t); } } static MethodHandle bindSingle(MethodType type, LambdaForm form, Object x) { return new Species_L(type, form, x); } MethodHandle cloneExtend(MethodType type, LambdaForm form, char xtype, Object x) { try { switch (xtype) { case 'L': return cloneExtendL(type, form, x); case 'I': return cloneExtendI(type, form, ValueConversions.widenSubword(x)); case 'J': return cloneExtendJ(type, form, (long) x); case 'F': return cloneExtendF(type, form, (float) x); case 'D': return cloneExtendD(type, form, (double) x); } } catch (Throwable t) { throw newInternalError(t); } throw new InternalError("unexpected type: " + xtype); } @Override MethodHandle bindArgument(int pos, char basicType, Object value) { MethodType type = type().dropParameterTypes(pos, pos+1); LambdaForm form = internalForm().bind(1+pos, speciesData()); return cloneExtend(type, form, basicType, value); } @Override MethodHandle dropArguments(MethodType srcType, int pos, int drops) { LambdaForm form = internalForm().addArguments(pos, srcType.parameterList().subList(pos, pos+drops)); try { return clone(srcType, form); } catch (Throwable t) { throw newInternalError(t); } } @Override MethodHandle permuteArguments(MethodType newType, int[] reorder) { try { return clone(newType, form.permuteArguments(1, reorder, basicTypes(newType.parameterList()))); } catch (Throwable t) { throw newInternalError(t); } } static final String EXTENSION_TYPES = "LIJFD"; static final byte INDEX_L = 0, INDEX_I = 1, INDEX_J = 2, INDEX_F = 3, INDEX_D = 4; static byte extensionIndex(char type) { int i = EXTENSION_TYPES.indexOf(type); if (i < 0) throw new InternalError(); return (byte) i; } /** * Return the {@link SpeciesData} instance representing this BMH species. All subclasses must provide a * static field containing this value, and they must accordingly implement this method. */ protected abstract SpeciesData speciesData(); @Override final Object internalProperties() { return "/BMH="+internalValues(); } @Override final Object internalValues() { Object[] boundValues = new Object[speciesData().fieldCount()]; for (int i = 0; i < boundValues.length; ++i) { boundValues[i] = arg(i); } return Arrays.asList(boundValues); } public final Object arg(int i) { try { switch (speciesData().fieldType(i)) { case 'L': return argL(i); case 'I': return argI(i); case 'F': return argF(i); case 'D': return argD(i); case 'J': return argJ(i); } } catch (Throwable ex) { throw newInternalError(ex); } throw new InternalError("unexpected type: " + speciesData().types+"."+i); } public final Object argL(int i) throws Throwable { return speciesData().getters[i].invokeBasic(this); } public final int argI(int i) throws Throwable { return (int) speciesData().getters[i].invokeBasic(this); } public final float argF(int i) throws Throwable { return (float) speciesData().getters[i].invokeBasic(this); } public final double argD(int i) throws Throwable { return (double) speciesData().getters[i].invokeBasic(this); } public final long argJ(int i) throws Throwable { return (long) speciesData().getters[i].invokeBasic(this); } // // cloning API // public abstract BoundMethodHandle clone(MethodType mt, LambdaForm lf) throws Throwable; public abstract BoundMethodHandle cloneExtendL(MethodType mt, LambdaForm lf, Object narg) throws Throwable; public abstract BoundMethodHandle cloneExtendI(MethodType mt, LambdaForm lf, int narg) throws Throwable; public abstract BoundMethodHandle cloneExtendJ(MethodType mt, LambdaForm lf, long narg) throws Throwable; public abstract BoundMethodHandle cloneExtendF(MethodType mt, LambdaForm lf, float narg) throws Throwable; public abstract BoundMethodHandle cloneExtendD(MethodType mt, LambdaForm lf, double narg) throws Throwable; // The following is a grossly irregular hack: @Override MethodHandle reinvokerTarget() { try { return (MethodHandle) argL(0); } catch (Throwable ex) { throw newInternalError(ex); } } // // concrete BMH classes required to close bootstrap loops // private // make it private to force users to access the enclosing class first static final class Species_L extends BoundMethodHandle { final Object argL0; public Species_L(MethodType mt, LambdaForm lf, Object argL0) { super(mt, lf); this.argL0 = argL0; } // The following is a grossly irregular hack: @Override MethodHandle reinvokerTarget() { return (MethodHandle) argL0; } @Override public SpeciesData speciesData() { return SPECIES_DATA; } public static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("L", Species_L.class); @Override public final BoundMethodHandle clone(MethodType mt, LambdaForm lf) throws Throwable { return new Species_L(mt, lf, argL0); } @Override public final BoundMethodHandle cloneExtendL(MethodType mt, LambdaForm lf, Object narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_L).constructor[0].invokeBasic(mt, lf, argL0, narg); } @Override public final BoundMethodHandle cloneExtendI(MethodType mt, LambdaForm lf, int narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_I).constructor[0].invokeBasic(mt, lf, argL0, narg); } @Override public final BoundMethodHandle cloneExtendJ(MethodType mt, LambdaForm lf, long narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_J).constructor[0].invokeBasic(mt, lf, argL0, narg); } @Override public final BoundMethodHandle cloneExtendF(MethodType mt, LambdaForm lf, float narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_F).constructor[0].invokeBasic(mt, lf, argL0, narg); } @Override public final BoundMethodHandle cloneExtendD(MethodType mt, LambdaForm lf, double narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_D).constructor[0].invokeBasic(mt, lf, argL0, narg); } } /* static final class Species_LL extends BoundMethodHandle { final Object argL0; final Object argL1; public Species_LL(MethodType mt, LambdaForm lf, Object argL0, Object argL1) { super(mt, lf); this.argL0 = argL0; this.argL1 = argL1; } @Override public SpeciesData speciesData() { return SPECIES_DATA; } public static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LL", Species_LL.class); @Override public final BoundMethodHandle clone(MethodType mt, LambdaForm lf) throws Throwable { return new Species_LL(mt, lf, argL0, argL1); } @Override public final BoundMethodHandle cloneExtendL(MethodType mt, LambdaForm lf, Object narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_L).constructor[0].invokeBasic(mt, lf, argL0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendI(MethodType mt, LambdaForm lf, int narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_I).constructor[0].invokeBasic(mt, lf, argL0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendJ(MethodType mt, LambdaForm lf, long narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_J).constructor[0].invokeBasic(mt, lf, argL0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendF(MethodType mt, LambdaForm lf, float narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_F).constructor[0].invokeBasic(mt, lf, argL0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendD(MethodType mt, LambdaForm lf, double narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_D).constructor[0].invokeBasic(mt, lf, argL0, argL1, narg); } } static final class Species_JL extends BoundMethodHandle { final long argJ0; final Object argL1; public Species_JL(MethodType mt, LambdaForm lf, long argJ0, Object argL1) { super(mt, lf); this.argJ0 = argJ0; this.argL1 = argL1; } @Override public SpeciesData speciesData() { return SPECIES_DATA; } public static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("JL", Species_JL.class); @Override public final long argJ0() { return argJ0; } @Override public final Object argL1() { return argL1; } @Override public final BoundMethodHandle clone(MethodType mt, LambdaForm lf) throws Throwable { return new Species_JL(mt, lf, argJ0, argL1); } @Override public final BoundMethodHandle cloneExtendL(MethodType mt, LambdaForm lf, Object narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_L).constructor[0].invokeBasic(mt, lf, argJ0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendI(MethodType mt, LambdaForm lf, int narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_I).constructor[0].invokeBasic(mt, lf, argJ0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendJ(MethodType mt, LambdaForm lf, long narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_J).constructor[0].invokeBasic(mt, lf, argJ0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendF(MethodType mt, LambdaForm lf, float narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_F).constructor[0].invokeBasic(mt, lf, argJ0, argL1, narg); } @Override public final BoundMethodHandle cloneExtendD(MethodType mt, LambdaForm lf, double narg) throws Throwable { return (BoundMethodHandle) SPECIES_DATA.extendWithIndex(INDEX_D).constructor[0].invokeBasic(mt, lf, argJ0, argL1, narg); } } */ // // BMH species meta-data // /** * Meta-data wrapper for concrete BMH classes. */ static class SpeciesData { final String types; final Class clazz; // Bootstrapping requires circular relations MH -> BMH -> SpeciesData -> MH // Therefore, we need a non-final link in the chain. Use array elements. final MethodHandle[] constructor; final MethodHandle[] getters; final SpeciesData[] extensions; public int fieldCount() { return types.length(); } public char fieldType(int i) { return types.charAt(i); } public String toString() { return "SpeciesData["+(isPlaceholder() ? "" : clazz.getSimpleName())+":"+types+"]"; } /** * Return a {@link LambdaForm.Name} containing a {@link LambdaForm.NamedFunction} that * represents a MH bound to a generic invoker, which in turn forwards to the corresponding * getter. */ Name getterName(Name mhName, int i) { MethodHandle mh = getters[i]; assert(mh != null) : this+"."+i; return new Name(mh, mhName); } static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class); private SpeciesData(String types, Class clazz) { this.types = types; this.clazz = clazz; if (!INIT_DONE) { this.constructor = new MethodHandle[1]; this.getters = new MethodHandle[types.length()]; } else { this.constructor = Factory.makeCtors(clazz, types, null); this.getters = Factory.makeGetters(clazz, types, null); } this.extensions = new SpeciesData[EXTENSION_TYPES.length()]; } private void initForBootstrap() { assert(!INIT_DONE); if (constructor[0] == null) { Factory.makeCtors(clazz, types, this.constructor); Factory.makeGetters(clazz, types, this.getters); } } private SpeciesData(String types) { // Placeholder only. this.types = types; this.clazz = null; this.constructor = null; this.getters = null; this.extensions = null; } private boolean isPlaceholder() { return clazz == null; } private static final HashMap CACHE = new HashMap<>(); private static final boolean INIT_DONE; // set after finishes... SpeciesData extendWithType(char type) { int i = extensionIndex(type); SpeciesData d = extensions[i]; if (d != null) return d; extensions[i] = d = get(types+type); return d; } SpeciesData extendWithIndex(byte index) { SpeciesData d = extensions[index]; if (d != null) return d; extensions[index] = d = get(types+EXTENSION_TYPES.charAt(index)); return d; } private static SpeciesData get(String types) { // Acquire cache lock for query. SpeciesData d = lookupCache(types); if (!d.isPlaceholder()) return d; synchronized (d) { // Use synch. on the placeholder to prevent multiple instantiation of one species. // Creating this class forces a recursive call to getForClass. if (lookupCache(types).isPlaceholder()) Factory.generateConcreteBMHClass(types); } // Reacquire cache lock. d = lookupCache(types); // Class loading must have upgraded the cache. assert(d != null && !d.isPlaceholder()); return d; } static SpeciesData getForClass(String types, Class clazz) { // clazz is a new class which is initializing its SPECIES_DATA field return updateCache(types, new SpeciesData(types, clazz)); } private static synchronized SpeciesData lookupCache(String types) { SpeciesData d = CACHE.get(types); if (d != null) return d; d = new SpeciesData(types); assert(d.isPlaceholder()); CACHE.put(types, d); return d; } private static synchronized SpeciesData updateCache(String types, SpeciesData d) { SpeciesData d2; assert((d2 = CACHE.get(types)) == null || d2.isPlaceholder()); assert(!d.isPlaceholder()); CACHE.put(types, d); return d; } static { // pre-fill the BMH speciesdata cache with BMH's inner classes final Class rootCls = BoundMethodHandle.class; SpeciesData d0 = BoundMethodHandle.SPECIES_DATA; // trigger class init assert(d0 == null || d0 == lookupCache("")) : d0; try { for (Class c : rootCls.getDeclaredClasses()) { if (rootCls.isAssignableFrom(c)) { final Class cbmh = c.asSubclass(BoundMethodHandle.class); SpeciesData d = Factory.speciesDataFromConcreteBMHClass(cbmh); assert(d != null) : cbmh.getName(); assert(d.clazz == cbmh); assert(d == lookupCache(d.types)); } } } catch (Throwable e) { throw newInternalError(e); } for (SpeciesData d : CACHE.values()) { d.initForBootstrap(); } // Note: Do not simplify this, because INIT_DONE must not be // a compile-time constant during bootstrapping. INIT_DONE = Boolean.TRUE; } } static SpeciesData getSpeciesData(String types) { return SpeciesData.get(types); } /** * Generation of concrete BMH classes. * * A concrete BMH species is fit for binding a number of values adhering to a * given type pattern. Reference types are erased. * * BMH species are cached by type pattern. * * A BMH species has a number of fields with the concrete (possibly erased) types of * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs, * which can be included as names in lambda forms. */ static class Factory { static final String JLO_SIG = "Ljava/lang/Object;"; static final String JLS_SIG = "Ljava/lang/String;"; static final String JLC_SIG = "Ljava/lang/Class;"; static final String MH = "java/lang/invoke/MethodHandle"; static final String MH_SIG = "L"+MH+";"; static final String BMH = "java/lang/invoke/BoundMethodHandle"; static final String BMH_SIG = "L"+BMH+";"; static final String SPECIES_DATA = "java/lang/invoke/BoundMethodHandle$SpeciesData"; static final String SPECIES_DATA_SIG = "L"+SPECIES_DATA+";"; static final String SPECIES_PREFIX_NAME = "Species_"; static final String SPECIES_PREFIX_PATH = BMH + "$" + SPECIES_PREFIX_NAME; static final String BMHSPECIES_DATA_EWI_SIG = "(B)" + SPECIES_DATA_SIG; static final String BMHSPECIES_DATA_GFC_SIG = "(" + JLS_SIG + JLC_SIG + ")" + SPECIES_DATA_SIG; static final String MYSPECIES_DATA_SIG = "()" + SPECIES_DATA_SIG; static final String VOID_SIG = "()V"; static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;"; static final Class[] TYPES = new Class[] { Object.class, int.class, long.class, float.class, double.class }; static final String[] E_THROWABLE = new String[] { "java/lang/Throwable" }; /** * Generate a concrete subclass of BMH for a given combination of bound types. * * A concrete BMH species adheres to the following schema: * *
         * class Species_<> extends BoundMethodHandle {
         *     <>
         *     final SpeciesData speciesData() { return SpeciesData.get("<>"); }
         * }
         * 
* * The {@code <>} signature is precisely the string that is passed to this * method. * * The {@code <>} section consists of one field definition per character in * the type signature, adhering to the naming schema described in the definition of * {@link #makeFieldName()}. * * For example, a concrete BMH species for two reference and one integral bound values * would have the following shape: * *
         * class BoundMethodHandle { ... private static
         * final class Species_LLI extends BoundMethodHandle {
         *     final Object argL0;
         *     final Object argL1;
         *     final int argI2;
         *     public Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
         *         super(mt, lf);
         *         this.argL0 = argL0;
         *         this.argL1 = argL1;
         *         this.argI2 = argI2;
         *     }
         *     public final SpeciesData speciesData() { return SPECIES_DATA; }
         *     public static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LLI", Species_LLI.class);
         *     public final BoundMethodHandle clone(MethodType mt, LambdaForm lf) {
         *         return SPECIES_DATA.constructor[0].invokeBasic(mt, lf, argL0, argL1, argI2);
         *     }
         *     public final BoundMethodHandle cloneExtendL(MethodType mt, LambdaForm lf, Object narg) {
         *         return SPECIES_DATA.extendWithIndex(INDEX_L).constructor[0].invokeBasic(mt, lf, argL0, argL1, argI2, narg);
         *     }
         *     public final BoundMethodHandle cloneExtendI(MethodType mt, LambdaForm lf, int narg) {
         *         return SPECIES_DATA.extendWithIndex(INDEX_I).constructor[0].invokeBasic(mt, lf, argL0, argL1, argI2, narg);
         *     }
         *     public final BoundMethodHandle cloneExtendJ(MethodType mt, LambdaForm lf, long narg) {
         *         return SPECIES_DATA.extendWithIndex(INDEX_J).constructor[0].invokeBasic(mt, lf, argL0, argL1, argI2, narg);
         *     }
         *     public final BoundMethodHandle cloneExtendF(MethodType mt, LambdaForm lf, float narg) {
         *         return SPECIES_DATA.extendWithIndex(INDEX_F).constructor[0].invokeBasic(mt, lf, argL0, argL1, argI2, narg);
         *     }
         *     public final BoundMethodHandle cloneExtendD(MethodType mt, LambdaForm lf, double narg) {
         *         return SPECIES_DATA.extendWithIndex(INDEX_D).constructor[0].invokeBasic(mt, lf, argL0, argL1, argI2, narg);
         *     }
         * }
         * 
* * @param types the type signature, wherein reference types are erased to 'L' * @return the generated concrete BMH class */ static Class generateConcreteBMHClass(String types) { final ClassWriter cw = new ClassWriter(ClassWriter.COMPUTE_MAXS + ClassWriter.COMPUTE_FRAMES); final String className = SPECIES_PREFIX_PATH + types; final String sourceFile = SPECIES_PREFIX_NAME + types; cw.visit(V1_6, ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null); cw.visitSource(sourceFile, null); // emit static types and SPECIES_DATA fields cw.visitField(ACC_PUBLIC + ACC_STATIC, "SPECIES_DATA", SPECIES_DATA_SIG, null, null).visitEnd(); // emit bound argument fields for (int i = 0; i < types.length(); ++i) { final char t = types.charAt(i); final String fieldName = makeFieldName(types, i); final String fieldDesc = t == 'L' ? JLO_SIG : String.valueOf(t); cw.visitField(ACC_FINAL, fieldName, fieldDesc, null, null).visitEnd(); } MethodVisitor mv; // emit constructor mv = cw.visitMethod(ACC_PUBLIC, "", makeSignature(types, true), null, null); mv.visitCode(); mv.visitVarInsn(ALOAD, 0); mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 2); mv.visitMethodInsn(INVOKESPECIAL, BMH, "", makeSignature("", true)); for (int i = 0, j = 0; i < types.length(); ++i, ++j) { // i counts the arguments, j counts corresponding argument slots char t = types.charAt(i); mv.visitVarInsn(ALOAD, 0); mv.visitVarInsn(typeLoadOp(t), j + 3); // parameters start at 3 mv.visitFieldInsn(PUTFIELD, className, makeFieldName(types, i), typeSig(t)); if (t == 'J' || t == 'D') { ++j; // adjust argument register access } } mv.visitInsn(RETURN); mv.visitMaxs(0, 0); mv.visitEnd(); // emit implementation of reinvokerTarget() mv = cw.visitMethod(ACC_PUBLIC + ACC_FINAL, "reinvokerTarget", "()" + MH_SIG, null, null); mv.visitCode(); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, className, "argL0", JLO_SIG); mv.visitTypeInsn(CHECKCAST, MH); mv.visitInsn(ARETURN); mv.visitMaxs(0, 0); mv.visitEnd(); // emit implementation of speciesData() mv = cw.visitMethod(ACC_PUBLIC + ACC_FINAL, "speciesData", MYSPECIES_DATA_SIG, null, null); mv.visitCode(); mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); mv.visitInsn(ARETURN); mv.visitMaxs(0, 0); mv.visitEnd(); // emit clone() mv = cw.visitMethod(ACC_PUBLIC + ACC_FINAL, "clone", makeSignature("", false), null, E_THROWABLE); mv.visitCode(); // return speciesData().constructor[0].invokeBasic(mt, lf, argL0, ...) // obtain constructor mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); mv.visitFieldInsn(GETFIELD, SPECIES_DATA, "constructor", "[" + MH_SIG); mv.visitInsn(ICONST_0); mv.visitInsn(AALOAD); // load mt, lf mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 2); // put fields on the stack emitPushFields(types, className, mv); // finally, invoke the constructor and return mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types, false)); mv.visitInsn(ARETURN); mv.visitMaxs(0, 0); mv.visitEnd(); // for each type, emit cloneExtendT() for (Class c : TYPES) { char t = Wrapper.basicTypeChar(c); mv = cw.visitMethod(ACC_PUBLIC + ACC_FINAL, "cloneExtend" + t, makeSignature(String.valueOf(t), false), null, E_THROWABLE); mv.visitCode(); // return SPECIES_DATA.extendWithIndex(extensionIndex(t)).constructor[0].invokeBasic(mt, lf, argL0, ..., narg) // obtain constructor mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); int iconstInsn = ICONST_0 + extensionIndex(t); assert(iconstInsn <= ICONST_5); mv.visitInsn(iconstInsn); mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWithIndex", BMHSPECIES_DATA_EWI_SIG); mv.visitFieldInsn(GETFIELD, SPECIES_DATA, "constructor", "[" + MH_SIG); mv.visitInsn(ICONST_0); mv.visitInsn(AALOAD); // load mt, lf mv.visitVarInsn(ALOAD, 1); mv.visitVarInsn(ALOAD, 2); // put fields on the stack emitPushFields(types, className, mv); // put narg on stack mv.visitVarInsn(typeLoadOp(t), 3); // finally, invoke the constructor and return mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + t, false)); mv.visitInsn(ARETURN); mv.visitMaxs(0, 0); mv.visitEnd(); } // emit class initializer mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "", VOID_SIG, null, null); mv.visitCode(); mv.visitLdcInsn(types); mv.visitLdcInsn(Type.getObjectType(className)); mv.visitMethodInsn(INVOKESTATIC, SPECIES_DATA, "getForClass", BMHSPECIES_DATA_GFC_SIG); mv.visitFieldInsn(PUTSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG); mv.visitInsn(RETURN); mv.visitMaxs(0, 0); mv.visitEnd(); cw.visitEnd(); // load class final byte[] classFile = cw.toByteArray(); InvokerBytecodeGenerator.maybeDump(className, classFile); Class bmhClass = //UNSAFE.defineAnonymousClass(BoundMethodHandle.class, classFile, null).asSubclass(BoundMethodHandle.class); UNSAFE.defineClass(className, classFile, 0, classFile.length).asSubclass(BoundMethodHandle.class); UNSAFE.ensureClassInitialized(bmhClass); return bmhClass; } private static int typeLoadOp(char t) { switch (t) { case 'L': return ALOAD; case 'I': return ILOAD; case 'J': return LLOAD; case 'F': return FLOAD; case 'D': return DLOAD; default : throw new InternalError("unrecognized type " + t); } } private static void emitPushFields(String types, String className, MethodVisitor mv) { for (int i = 0; i < types.length(); ++i) { char tc = types.charAt(i); mv.visitVarInsn(ALOAD, 0); mv.visitFieldInsn(GETFIELD, className, makeFieldName(types, i), typeSig(tc)); } } static String typeSig(char t) { return t == 'L' ? JLO_SIG : String.valueOf(t); } // // Getter MH generation. // private static MethodHandle makeGetter(Class cbmhClass, String types, int index) { String fieldName = makeFieldName(types, index); Class fieldType = Wrapper.forBasicType(types.charAt(index)).primitiveType(); try { return LOOKUP.findGetter(cbmhClass, fieldName, fieldType); } catch (NoSuchFieldException | IllegalAccessException e) { throw newInternalError(e); } } static MethodHandle[] makeGetters(Class cbmhClass, String types, MethodHandle[] mhs) { if (mhs == null) mhs = new MethodHandle[types.length()]; for (int i = 0; i < mhs.length; ++i) { mhs[i] = makeGetter(cbmhClass, types, i); assert(mhs[i].internalMemberName().getDeclaringClass() == cbmhClass); } return mhs; } static MethodHandle[] makeCtors(Class cbmh, String types, MethodHandle mhs[]) { if (mhs == null) mhs = new MethodHandle[1]; mhs[0] = makeCbmhCtor(cbmh, types); return mhs; } // // Auxiliary methods. // static SpeciesData speciesDataFromConcreteBMHClass(Class cbmh) { try { Field F_SPECIES_DATA = cbmh.getDeclaredField("SPECIES_DATA"); return (SpeciesData) F_SPECIES_DATA.get(null); } catch (ReflectiveOperationException ex) { throw newInternalError(ex); } } /** * Field names in concrete BMHs adhere to this pattern: * arg + type + index * where type is a single character (L, I, J, F, D). */ private static String makeFieldName(String types, int index) { assert index >= 0 && index < types.length(); return "arg" + types.charAt(index) + index; } private static String makeSignature(String types, boolean ctor) { StringBuilder buf = new StringBuilder(SIG_INCIPIT); for (char c : types.toCharArray()) { buf.append(typeSig(c)); } return buf.append(')').append(ctor ? "V" : BMH_SIG).toString(); } static MethodHandle makeCbmhCtor(Class cbmh, String types) { try { return linkConstructor(LOOKUP.findConstructor(cbmh, MethodType.fromMethodDescriptorString(makeSignature(types, true), null))); } catch (NoSuchMethodException | IllegalAccessException | IllegalArgumentException | TypeNotPresentException e) { throw newInternalError(e); } } /** * Wrap a constructor call in a {@link LambdaForm}. * * If constructors ({@code } methods) are called in LFs, problems might arise if the LFs * are turned into bytecode, because the call to the allocator is routed through an MH, and the * verifier cannot find a {@code NEW} instruction preceding the {@code INVOKESPECIAL} to * {@code }. To avoid this, we add an indirection by invoking {@code } through * {@link MethodHandle#linkToSpecial}. * * The last {@link LambdaForm#Name Name} in the argument's form is expected to be the {@code void} * result of the {@code } invocation. This entry is replaced. */ private static MethodHandle linkConstructor(MethodHandle cmh) { final LambdaForm lf = cmh.form; final int initNameIndex = lf.names.length - 1; final Name initName = lf.names[initNameIndex]; final MemberName ctorMN = initName.function.member; final MethodType ctorMT = ctorMN.getInvocationType(); // obtain function member (call target) // linker method type replaces initial parameter (BMH species) with BMH to avoid naming a species (anonymous class!) final MethodType linkerMT = ctorMT.changeParameterType(0, BoundMethodHandle.class).appendParameterTypes(MemberName.class); MemberName linkerMN = new MemberName(MethodHandle.class, "linkToSpecial", linkerMT, REF_invokeStatic); try { linkerMN = MemberName.getFactory().resolveOrFail(REF_invokeStatic, linkerMN, null, NoSuchMethodException.class); assert(linkerMN.isStatic()); } catch (ReflectiveOperationException ex) { throw newInternalError(ex); } // extend arguments array Object[] newArgs = Arrays.copyOf(initName.arguments, initName.arguments.length + 1); newArgs[newArgs.length - 1] = ctorMN; // replace function final NamedFunction nf = new NamedFunction(linkerMN); final Name linkedCtor = new Name(nf, newArgs); linkedCtor.initIndex(initNameIndex); lf.names[initNameIndex] = linkedCtor; return cmh; } } private static final Lookup LOOKUP = Lookup.IMPL_LOOKUP; /** * All subclasses must provide such a value describing their type signature. */ static final SpeciesData SPECIES_DATA = SpeciesData.EMPTY; }