Java example source code file (BoundMethodHandle.java)
The BoundMethodHandle.java Java example source code/*
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* 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.
*
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package java.lang.invoke;
import static jdk.internal.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 jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.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<? extends BoundMethodHandle> 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() ? "<placeholder>" : 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);
}
NamedFunction getterFunction(int i) {
return new NamedFunction(getters[i]);
}
static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class);
private SpeciesData(String types, Class<? extends BoundMethodHandle> 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<String, SpeciesData> CACHE = new HashMap<>();
static { CACHE.put("", EMPTY); } // make bootstrap predictable
private static final boolean INIT_DONE; // set after <clinit> 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<? extends BoundMethodHandle> 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<BoundMethodHandle> 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<? extends BoundMethodHandle> 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:
*
* <pre>
* class Species_[[types]] extends BoundMethodHandle {
* [[fields]]
* final SpeciesData speciesData() { return SpeciesData.get("[[types]]"); }
* }
* </pre>
*
* The {@code [[types]]} signature is precisely the string that is passed to this
* method.
*
* The {@code [[fields]]} 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:
*
* <pre>
* 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);
* }
* }
* </pre>
*
* @param types the type signature, wherein reference types are erased to 'L'
* @return the generated concrete BMH class
*/
static Class<? extends BoundMethodHandle> 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, "<init>", makeSignature(types, true), null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ALOAD, 2);
mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", 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, "<clinit>", 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<? extends BoundMethodHandle> bmhClass =
//UNSAFE.defineAnonymousClass(BoundMethodHandle.class, classFile, null).asSubclass(BoundMethodHandle.class);
UNSAFE.defineClass(className, classFile, 0, classFile.length,
BoundMethodHandle.class.getClassLoader(), null)
.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<? extends BoundMethodHandle> 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<? extends BoundMethodHandle> 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<? extends BoundMethodHandle> 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 <init>} 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 <init>}. To avoid this, we add an indirection by invoking {@code
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