JDK8/Java8源码在线阅读
/*
* Copyright (c) 2008, 2013, 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
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package java.lang.invoke;
import static jdk.internal.org.objectweb.asm.Opcodes.*;
import static java.lang.invoke.LambdaForm.*;
import static java.lang.invoke.LambdaForm.BasicType.*;
import static java.lang.invoke.MethodHandleStatics.*;
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);
assert(speciesData() == speciesData(form));
}
//
// BMH API and internals
//
static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) {
// for some type signatures, there exist pre-defined concrete BMH classes
try {
switch (xtype) {
case L_TYPE:
return bindSingle(type, form, x); // Use known fast path.
case I_TYPE:
return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(I_TYPE).constructor().invokeBasic(type, form, ValueConversions.widenSubword(x));
case J_TYPE:
return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(J_TYPE).constructor().invokeBasic(type, form, (long) x);
case F_TYPE:
return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(F_TYPE).constructor().invokeBasic(type, form, (float) x);
case D_TYPE:
return (BoundMethodHandle) SpeciesData.EMPTY.extendWith(D_TYPE).constructor().invokeBasic(type, form, (double) x);
default : throw newInternalError("unexpected xtype: " + xtype);
}
} catch (Throwable t) {
throw newInternalError(t);
}
}
/*non-public*/
LambdaFormEditor editor() {
return form.editor();
}
static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) {
return Species_L.make(type, form, x);
}
@Override // there is a default binder in the super class, for 'L' types only
/*non-public*/
BoundMethodHandle bindArgumentL(int pos, Object value) {
return editor().bindArgumentL(this, pos, value);
}
/*non-public*/
BoundMethodHandle bindArgumentI(int pos, int value) {
return editor().bindArgumentI(this, pos, value);
}
/*non-public*/
BoundMethodHandle bindArgumentJ(int pos, long value) {
return editor().bindArgumentJ(this, pos, value);
}
/*non-public*/
BoundMethodHandle bindArgumentF(int pos, float value) {
return editor().bindArgumentF(this, pos, value);
}
/*non-public*/
BoundMethodHandle bindArgumentD(int pos, double value) {
return editor().bindArgumentD(this, pos, value);
}
@Override
BoundMethodHandle rebind() {
if (!tooComplex()) {
return this;
}
return makeReinvoker(this);
}
private boolean tooComplex() {
return (fieldCount() > FIELD_COUNT_THRESHOLD ||
form.expressionCount() > FORM_EXPRESSION_THRESHOLD);
}
private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count
private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count
/**
* A reinvoker MH has this form:
* {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }}
*/
static BoundMethodHandle makeReinvoker(MethodHandle target) {
LambdaForm form = DelegatingMethodHandle.makeReinvokerForm(
target, MethodTypeForm.LF_REBIND,
Species_L.SPECIES_DATA, Species_L.SPECIES_DATA.getterFunction(0));
return Species_L.make(target.type(), form, target);
}
/**
* 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.
*/
/*non-public*/ abstract SpeciesData speciesData();
/*non-public*/ static SpeciesData speciesData(LambdaForm form) {
Object c = form.names[0].constraint;
if (c instanceof SpeciesData)
return (SpeciesData) c;
// if there is no BMH constraint, then use the null constraint
return SpeciesData.EMPTY;
}
/**
* Return the number of fields in this BMH. Equivalent to speciesData().fieldCount().
*/
/*non-public*/ abstract int fieldCount();
@Override
Object internalProperties() {
return "\n& 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);
}
/*non-public*/ final Object arg(int i) {
try {
switch (speciesData().fieldType(i)) {
case L_TYPE: return speciesData().getters[i].invokeBasic(this);
case I_TYPE: return (int) speciesData().getters[i].invokeBasic(this);
case J_TYPE: return (long) speciesData().getters[i].invokeBasic(this);
case F_TYPE: return (float) speciesData().getters[i].invokeBasic(this);
case D_TYPE: return (double) speciesData().getters[i].invokeBasic(this);
}
} catch (Throwable ex) {
throw newInternalError(ex);
}
throw new InternalError("unexpected type: " + speciesData().typeChars+"."+i);
}
//
// cloning API
//
/*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf);
/*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg);
/*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg);
/*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg);
/*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg);
/*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
//
// 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;
private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
super(mt, lf);
this.argL0 = argL0;
}
@Override
/*non-public*/ SpeciesData speciesData() {
return SPECIES_DATA;
}
@Override
/*non-public*/ int fieldCount() {
return 1;
}
/*non-public*/ static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("L", Species_L.class);
/*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) {
return new Species_L(mt, lf, argL0);
}
@Override
/*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
return new Species_L(mt, lf, argL0);
}
@Override
/*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
try {
return (BoundMethodHandle) SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
}
@Override
/*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
try {
return (BoundMethodHandle) SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
}
@Override
/*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
try {
return (BoundMethodHandle) SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
}
@Override
/*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
try {
return (BoundMethodHandle) SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
}
@Override
/*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
try {
return (BoundMethodHandle) SPECIES_DATA.extendWith(D_TYPE).constructor().invokeBasic(mt, lf, argL0, narg);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
}
}
//
// BMH species meta-data
//
/**
* Meta-data wrapper for concrete BMH types.
* Each BMH type corresponds to a given sequence of basic field types (LIJFD).
* The fields are immutable; their values are fully specified at object construction.
* Each BMH type supplies an array of getter functions which may be used in lambda forms.
* A BMH is constructed by cloning a shorter BMH and adding one or more new field values.
* The shortest possible BMH has zero fields; its class is SimpleMethodHandle.
* BMH species are not interrelated by subtyping, even though it would appear that
* a shorter BMH could serve as a supertype of a longer one which extends it.
*/
static class SpeciesData {
private final String typeChars;
private final BasicType[] typeCodes;
private 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.
@Stable private final MethodHandle[] constructor;
@Stable private final MethodHandle[] getters;
@Stable private final NamedFunction[] nominalGetters;
@Stable private final SpeciesData[] extensions;
/*non-public*/ int fieldCount() {
return typeCodes.length;
}
/*non-public*/ BasicType fieldType(int i) {
return typeCodes[i];
}
/*non-public*/ char fieldTypeChar(int i) {
return typeChars.charAt(i);
}
Object fieldSignature() {
return typeChars;
}
public Class<? extends BoundMethodHandle> fieldHolder() {
return clazz;
}
public String toString() {
return "SpeciesData<"+fieldSignature()+">";
}
/**
* 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.
*/
NamedFunction getterFunction(int i) {
NamedFunction nf = nominalGetters[i];
assert(nf.memberDeclaringClassOrNull() == fieldHolder());
assert(nf.returnType() == fieldType(i));
return nf;
}
NamedFunction[] getterFunctions() {
return nominalGetters;
}
MethodHandle[] getterHandles() { return getters; }
MethodHandle constructor() {
return constructor[0];
}
static final SpeciesData EMPTY = new SpeciesData("", BoundMethodHandle.class);
private SpeciesData(String types, Class<? extends BoundMethodHandle> clazz) {
this.typeChars = types;
this.typeCodes = basicTypes(types);
this.clazz = clazz;
if (!INIT_DONE) {
this.constructor = new MethodHandle[1]; // only one ctor
this.getters = new MethodHandle[types.length()];
this.nominalGetters = new NamedFunction[types.length()];
} else {
this.constructor = Factory.makeCtors(clazz, types, null);
this.getters = Factory.makeGetters(clazz, types, null);
this.nominalGetters = Factory.makeNominalGetters(types, null, this.getters);
}
this.extensions = new SpeciesData[ARG_TYPE_LIMIT];
}
private void initForBootstrap() {
assert(!INIT_DONE);
if (constructor() == null) {
String types = typeChars;
Factory.makeCtors(clazz, types, this.constructor);
Factory.makeGetters(clazz, types, this.getters);
Factory.makeNominalGetters(types, this.nominalGetters, this.getters);
}
}
private SpeciesData(String typeChars) {
// Placeholder only.
this.typeChars = typeChars;
this.typeCodes = basicTypes(typeChars);
this.clazz = null;
this.constructor = null;
this.getters = null;
this.nominalGetters = 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 extendWith(byte type) {
return extendWith(BasicType.basicType(type));
}
SpeciesData extendWith(BasicType type) {
int ord = type.ordinal();
SpeciesData d = extensions[ord];
if (d != null) return d;
extensions[ord] = d = get(typeChars+type.basicTypeChar());
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;
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.typeChars));
}
}
} 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 INT_SIG = "()I";
static final String SIG_INCIPIT = "(Ljava/lang/invoke/MethodType;Ljava/lang/invoke/LambdaForm;";
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;
* private Species_LLI(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
* super(mt, lf);
* this.argL0 = argL0;
* this.argL1 = argL1;
* this.argI2 = argI2;
* }
* final SpeciesData speciesData() { return SPECIES_DATA; }
* final int fieldCount() { return 3; }
* static final SpeciesData SPECIES_DATA = SpeciesData.getForClass("LLI", Species_LLI.class);
* static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0, Object argL1, int argI2) {
* return new Species_LLI(mt, lf, argL0, argL1, argI2);
* }
* final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
* return new Species_LLI(mt, lf, argL0, argL1, argI2);
* }
* final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
* return SPECIES_DATA.extendWith(L_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
* }
* final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
* return SPECIES_DATA.extendWith(I_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
* }
* final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
* return SPECIES_DATA.extendWith(J_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
* }
* final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
* return SPECIES_DATA.extendWith(F_TYPE).constructor().invokeBasic(mt, lf, argL0, argL1, argI2, narg);
* }
* public final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
* return SPECIES_DATA.extendWith(D_TYPE).constructor().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);
String shortTypes = LambdaForm.shortenSignature(types);
final String className = SPECIES_PREFIX_PATH + shortTypes;
final String sourceFile = SPECIES_PREFIX_NAME + shortTypes;
final int NOT_ACC_PUBLIC = 0; // not ACC_PUBLIC
cw.visit(V1_6, NOT_ACC_PUBLIC + ACC_FINAL + ACC_SUPER, className, null, BMH, null);
cw.visitSource(sourceFile, null);
// emit static types and SPECIES_DATA fields
cw.visitField(NOT_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_PRIVATE, "<init>", makeSignature(types, true), null, null);
mv.visitCode();
mv.visitVarInsn(ALOAD, 0); // this
mv.visitVarInsn(ALOAD, 1); // type
mv.visitVarInsn(ALOAD, 2); // form
mv.visitMethodInsn(INVOKESPECIAL, BMH, "<init>", makeSignature("", true), false);
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 speciesData()
mv = cw.visitMethod(NOT_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 implementation of fieldCount()
mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "fieldCount", INT_SIG, null, null);
mv.visitCode();
int fc = types.length();
if (fc <= (ICONST_5 - ICONST_0)) {
mv.visitInsn(ICONST_0 + fc);
} else {
mv.visitIntInsn(SIPUSH, fc);
}
mv.visitInsn(IRETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
// emit make() ...factory method wrapping constructor
mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_STATIC, "make", makeSignature(types, false), null, null);
mv.visitCode();
// make instance
mv.visitTypeInsn(NEW, className);
mv.visitInsn(DUP);
// load mt, lf
mv.visitVarInsn(ALOAD, 0); // type
mv.visitVarInsn(ALOAD, 1); // form
// load factory method arguments
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(typeLoadOp(t), j + 2); // parameters start at 3
if (t == 'J' || t == 'D') {
++j; // adjust argument register access
}
}
// finally, invoke the constructor and return
mv.visitMethodInsn(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
mv.visitInsn(ARETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
// emit copyWith()
mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWith", makeSignature("", false), null, null);
mv.visitCode();
// make instance
mv.visitTypeInsn(NEW, className);
mv.visitInsn(DUP);
// 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(INVOKESPECIAL, className, "<init>", makeSignature(types, true), false);
mv.visitInsn(ARETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
// for each type, emit copyWithExtendT()
for (BasicType type : BasicType.ARG_TYPES) {
int ord = type.ordinal();
char btChar = type.basicTypeChar();
mv = cw.visitMethod(NOT_ACC_PUBLIC + ACC_FINAL, "copyWithExtend" + btChar, makeSignature(String.valueOf(btChar), false), null, E_THROWABLE);
mv.visitCode();
// return SPECIES_DATA.extendWith(t).constructor().invokeBasic(mt, lf, argL0, ..., narg)
// obtain constructor
mv.visitFieldInsn(GETSTATIC, className, "SPECIES_DATA", SPECIES_DATA_SIG);
int iconstInsn = ICONST_0 + ord;
assert(iconstInsn <= ICONST_5);
mv.visitInsn(iconstInsn);
mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "extendWith", BMHSPECIES_DATA_EWI_SIG, false);
mv.visitMethodInsn(INVOKEVIRTUAL, SPECIES_DATA, "constructor", "()" + MH_SIG, false);
// 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(btChar), 3);
// finally, invoke the constructor and return
mv.visitMethodInsn(INVOKEVIRTUAL, MH, "invokeBasic", makeSignature(types + btChar, false), false);
mv.visitInsn(ARETURN);
mv.visitMaxs(0, 0);
mv.visitEnd();
}
// emit class initializer
mv = cw.visitMethod(NOT_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, false);
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 newInternalError("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) {
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