7109063: JSR 292: fix for 7085860 is incomplete
Reviewed-by: iveresov, alanb, jrose
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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 sun.invoke.util.VerifyType;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import sun.invoke.empty.Empty;
import sun.invoke.util.ValueConversions;
import sun.invoke.util.Wrapper;
import sun.misc.Unsafe;
import static java.lang.invoke.MethodHandleStatics.*;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
/**
* Trusted implementation code for MethodHandle.
* @author jrose
*/
/*non-public*/ abstract class MethodHandleImpl {
/// Factory methods to create method handles:
private static final MemberName.Factory LOOKUP = MemberName.Factory.INSTANCE;
static void initStatics() {
// Trigger preceding sequence.
}
/** Look up a given method.
* Callable only from sun.invoke and related packages.
* <p>
* The resulting method handle type will be of the given type,
* with a receiver type {@code rcvc} prepended if the member is not static.
* <p>
* Access checks are made as of the given lookup class.
* In particular, if the method is protected and {@code defc} is in a
* different package from the lookup class, then {@code rcvc} must be
* the lookup class or a subclass.
* @param token Proof that the lookup class has access to this package.
* @param member Resolved method or constructor to call.
* @param name Name of the desired method.
* @param rcvc Receiver type of desired non-static method (else null)
* @param doDispatch whether the method handle will test the receiver type
* @param lookupClass access-check relative to this class
* @return a direct handle to the matching method
* @throws IllegalAccessException if the given method cannot be accessed by the lookup class
*/
static
MethodHandle findMethod(MemberName method,
boolean doDispatch, Class<?> lookupClass) throws IllegalAccessException {
MethodType mtype = method.getMethodType();
if (!method.isStatic()) {
// adjust the advertised receiver type to be exactly the one requested
// (in the case of invokespecial, this will be the calling class)
Class<?> recvType = method.getDeclaringClass();
mtype = mtype.insertParameterTypes(0, recvType);
}
DirectMethodHandle mh = new DirectMethodHandle(mtype, method, doDispatch, lookupClass);
if (!mh.isValid())
throw method.makeAccessException("no direct method handle", lookupClass);
assert(mh.type() == mtype);
if (!method.isVarargs())
return mh;
int argc = mtype.parameterCount();
if (argc != 0) {
Class<?> arrayType = mtype.parameterType(argc-1);
if (arrayType.isArray())
return AdapterMethodHandle.makeVarargsCollector(mh, arrayType);
}
throw method.makeAccessException("cannot make variable arity", null);
}
static
MethodHandle makeAllocator(MethodHandle rawConstructor) {
MethodType rawConType = rawConstructor.type();
Class<?> allocateClass = rawConType.parameterType(0);
// Wrap the raw (unsafe) constructor with the allocation of a suitable object.
assert(AdapterMethodHandle.canCollectArguments(rawConType, MethodType.methodType(allocateClass), 0, true));
// allocator(arg...)
// [fold]=> cookedConstructor(obj=allocate(C), arg...)
// [dup,collect]=> identity(obj, void=rawConstructor(obj, arg...))
MethodHandle returner = MethodHandles.identity(allocateClass);
MethodType ctype = rawConType.insertParameterTypes(0, allocateClass).changeReturnType(allocateClass);
MethodHandle cookedConstructor = AdapterMethodHandle.makeCollectArguments(returner, rawConstructor, 1, false);
assert(cookedConstructor.type().equals(ctype));
ctype = ctype.dropParameterTypes(0, 1);
cookedConstructor = AdapterMethodHandle.makeCollectArguments(cookedConstructor, returner, 0, true);
MethodHandle allocator = new AllocateObject(allocateClass);
// allocate() => new C(void)
assert(allocator.type().equals(MethodType.methodType(allocateClass)));
ctype = ctype.dropParameterTypes(0, 1);
MethodHandle fold = foldArguments(cookedConstructor, ctype, 0, allocator);
return fold;
}
static final class AllocateObject<C> extends BoundMethodHandle {
private static final Unsafe unsafe = Unsafe.getUnsafe();
private final Class<C> allocateClass;
// for allocation only:
private AllocateObject(Class<C> allocateClass) {
super(ALLOCATE.asType(MethodType.methodType(allocateClass, AllocateObject.class)));
this.allocateClass = allocateClass;
}
@SuppressWarnings("unchecked")
private C allocate() throws InstantiationException {
return (C) unsafe.allocateInstance(allocateClass);
}
static final MethodHandle ALLOCATE;
static {
try {
ALLOCATE = IMPL_LOOKUP.findVirtual(AllocateObject.class, "allocate", MethodType.genericMethodType(0));
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
}
}
static
MethodHandle accessField(MemberName member, boolean isSetter,
Class<?> lookupClass) {
// Use sun. misc.Unsafe to dig up the dirt on the field.
MethodHandle mh = new FieldAccessor(member, isSetter);
return mh;
}
static
MethodHandle accessArrayElement(Class<?> arrayClass, boolean isSetter) {
if (!arrayClass.isArray())
throw newIllegalArgumentException("not an array: "+arrayClass);
Class<?> elemClass = arrayClass.getComponentType();
MethodHandle[] mhs = FieldAccessor.ARRAY_CACHE.get(elemClass);
if (mhs == null) {
if (!FieldAccessor.doCache(elemClass))
return FieldAccessor.ahandle(arrayClass, isSetter);
mhs = new MethodHandle[] {
FieldAccessor.ahandle(arrayClass, false),
FieldAccessor.ahandle(arrayClass, true)
};
if (mhs[0].type().parameterType(0) == Class.class) {
mhs[0] = mhs[0].bindTo(elemClass);
mhs[1] = mhs[1].bindTo(elemClass);
}
synchronized (FieldAccessor.ARRAY_CACHE) {} // memory barrier
FieldAccessor.ARRAY_CACHE.put(elemClass, mhs);
}
return mhs[isSetter ? 1 : 0];
}
static final class FieldAccessor<C,V> extends BoundMethodHandle {
private static final Unsafe unsafe = Unsafe.getUnsafe();
final Object base; // for static refs only
final long offset;
final String name;
FieldAccessor(MemberName field, boolean isSetter) {
super(fhandle(field.getDeclaringClass(), field.getFieldType(), isSetter, field.isStatic()));
this.offset = (long) field.getVMIndex();
this.name = field.getName();
this.base = staticBase(field);
}
@Override
String debugString() { return addTypeString(name, this); }
int getFieldI(C obj) { return unsafe.getInt(obj, offset); }
void setFieldI(C obj, int x) { unsafe.putInt(obj, offset, x); }
long getFieldJ(C obj) { return unsafe.getLong(obj, offset); }
void setFieldJ(C obj, long x) { unsafe.putLong(obj, offset, x); }
float getFieldF(C obj) { return unsafe.getFloat(obj, offset); }
void setFieldF(C obj, float x) { unsafe.putFloat(obj, offset, x); }
double getFieldD(C obj) { return unsafe.getDouble(obj, offset); }
void setFieldD(C obj, double x) { unsafe.putDouble(obj, offset, x); }
boolean getFieldZ(C obj) { return unsafe.getBoolean(obj, offset); }
void setFieldZ(C obj, boolean x) { unsafe.putBoolean(obj, offset, x); }
byte getFieldB(C obj) { return unsafe.getByte(obj, offset); }
void setFieldB(C obj, byte x) { unsafe.putByte(obj, offset, x); }
short getFieldS(C obj) { return unsafe.getShort(obj, offset); }
void setFieldS(C obj, short x) { unsafe.putShort(obj, offset, x); }
char getFieldC(C obj) { return unsafe.getChar(obj, offset); }
void setFieldC(C obj, char x) { unsafe.putChar(obj, offset, x); }
@SuppressWarnings("unchecked")
V getFieldL(C obj) { return (V) unsafe.getObject(obj, offset); }
@SuppressWarnings("unchecked")
void setFieldL(C obj, V x) { unsafe.putObject(obj, offset, x); }
// cast (V) is OK here, since we wrap convertArguments around the MH.
static Object staticBase(final MemberName field) {
if (!field.isStatic()) return null;
return AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
try {
Class c = field.getDeclaringClass();
// FIXME: Should not have to create 'f' to get this value.
java.lang.reflect.Field f = c.getDeclaredField(field.getName());
return unsafe.staticFieldBase(f);
} catch (NoSuchFieldException ee) {
throw uncaughtException(ee);
}
}
});
}
int getStaticI() { return unsafe.getInt(base, offset); }
void setStaticI(int x) { unsafe.putInt(base, offset, x); }
long getStaticJ() { return unsafe.getLong(base, offset); }
void setStaticJ(long x) { unsafe.putLong(base, offset, x); }
float getStaticF() { return unsafe.getFloat(base, offset); }
void setStaticF(float x) { unsafe.putFloat(base, offset, x); }
double getStaticD() { return unsafe.getDouble(base, offset); }
void setStaticD(double x) { unsafe.putDouble(base, offset, x); }
boolean getStaticZ() { return unsafe.getBoolean(base, offset); }
void setStaticZ(boolean x) { unsafe.putBoolean(base, offset, x); }
byte getStaticB() { return unsafe.getByte(base, offset); }
void setStaticB(byte x) { unsafe.putByte(base, offset, x); }
short getStaticS() { return unsafe.getShort(base, offset); }
void setStaticS(short x) { unsafe.putShort(base, offset, x); }
char getStaticC() { return unsafe.getChar(base, offset); }
void setStaticC(char x) { unsafe.putChar(base, offset, x); }
V getStaticL() { return (V) unsafe.getObject(base, offset); }
void setStaticL(V x) { unsafe.putObject(base, offset, x); }
static String fname(Class<?> vclass, boolean isSetter, boolean isStatic) {
String stem;
if (!isStatic)
stem = (!isSetter ? "getField" : "setField");
else
stem = (!isSetter ? "getStatic" : "setStatic");
return stem + Wrapper.basicTypeChar(vclass);
}
static MethodType ftype(Class<?> cclass, Class<?> vclass, boolean isSetter, boolean isStatic) {
MethodType type;
if (!isStatic) {
if (!isSetter)
return MethodType.methodType(vclass, cclass);
else
return MethodType.methodType(void.class, cclass, vclass);
} else {
if (!isSetter)
return MethodType.methodType(vclass);
else
return MethodType.methodType(void.class, vclass);
}
}
static MethodHandle fhandle(Class<?> cclass, Class<?> vclass, boolean isSetter, boolean isStatic) {
String name = FieldAccessor.fname(vclass, isSetter, isStatic);
if (cclass.isPrimitive()) throw newIllegalArgumentException("primitive "+cclass);
Class<?> ecclass = Object.class; //erase this type
Class<?> evclass = vclass;
if (!evclass.isPrimitive()) evclass = Object.class;
MethodType type = FieldAccessor.ftype(ecclass, evclass, isSetter, isStatic);
MethodHandle mh;
try {
mh = IMPL_LOOKUP.findVirtual(FieldAccessor.class, name, type);
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
if (evclass != vclass || (!isStatic && ecclass != cclass)) {
MethodType strongType = FieldAccessor.ftype(cclass, vclass, isSetter, isStatic);
strongType = strongType.insertParameterTypes(0, FieldAccessor.class);
mh = convertArguments(mh, strongType, 0);
}
return mh;
}
/// Support for array element access
static final HashMap<Class<?>, MethodHandle[]> ARRAY_CACHE =
new HashMap<Class<?>, MethodHandle[]>();
// FIXME: Cache on the classes themselves, not here.
static boolean doCache(Class<?> elemClass) {
if (elemClass.isPrimitive()) return true;
ClassLoader cl = elemClass.getClassLoader();
return cl == null || cl == ClassLoader.getSystemClassLoader();
}
static int getElementI(int[] a, int i) { return a[i]; }
static void setElementI(int[] a, int i, int x) { a[i] = x; }
static long getElementJ(long[] a, int i) { return a[i]; }
static void setElementJ(long[] a, int i, long x) { a[i] = x; }
static float getElementF(float[] a, int i) { return a[i]; }
static void setElementF(float[] a, int i, float x) { a[i] = x; }
static double getElementD(double[] a, int i) { return a[i]; }
static void setElementD(double[] a, int i, double x) { a[i] = x; }
static boolean getElementZ(boolean[] a, int i) { return a[i]; }
static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
static byte getElementB(byte[] a, int i) { return a[i]; }
static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
static short getElementS(short[] a, int i) { return a[i]; }
static void setElementS(short[] a, int i, short x) { a[i] = x; }
static char getElementC(char[] a, int i) { return a[i]; }
static void setElementC(char[] a, int i, char x) { a[i] = x; }
static Object getElementL(Object[] a, int i) { return a[i]; }
static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
static <V> V getElementL(Class<V[]> aclass, V[] a, int i) { return aclass.cast(a)[i]; }
static <V> void setElementL(Class<V[]> aclass, V[] a, int i, V x) { aclass.cast(a)[i] = x; }
static String aname(Class<?> aclass, boolean isSetter) {
Class<?> vclass = aclass.getComponentType();
if (vclass == null) throw new IllegalArgumentException();
return (!isSetter ? "getElement" : "setElement") + Wrapper.basicTypeChar(vclass);
}
static MethodType atype(Class<?> aclass, boolean isSetter) {
Class<?> vclass = aclass.getComponentType();
if (!isSetter)
return MethodType.methodType(vclass, aclass, int.class);
else
return MethodType.methodType(void.class, aclass, int.class, vclass);
}
static MethodHandle ahandle(Class<?> aclass, boolean isSetter) {
Class<?> vclass = aclass.getComponentType();
String name = FieldAccessor.aname(aclass, isSetter);
Class<?> caclass = null;
if (!vclass.isPrimitive() && vclass != Object.class) {
caclass = aclass;
aclass = Object[].class;
vclass = Object.class;
}
MethodType type = FieldAccessor.atype(aclass, isSetter);
if (caclass != null)
type = type.insertParameterTypes(0, Class.class);
MethodHandle mh;
try {
mh = IMPL_LOOKUP.findStatic(FieldAccessor.class, name, type);
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
if (caclass != null) {
MethodType strongType = FieldAccessor.atype(caclass, isSetter);
mh = mh.bindTo(caclass);
mh = convertArguments(mh, strongType, 0);
}
return mh;
}
}
/** Bind a predetermined first argument to the given direct method handle.
* Callable only from MethodHandles.
* @param token Proof that the caller has access to this package.
* @param target Any direct method handle.
* @param receiver Receiver (or first static method argument) to pre-bind.
* @return a BoundMethodHandle for the given DirectMethodHandle, or null if it does not exist
*/
static
MethodHandle bindReceiver(MethodHandle target, Object receiver) {
if (receiver == null) return null;
if (target instanceof AdapterMethodHandle &&
((AdapterMethodHandle)target).conversionOp() == MethodHandleNatives.Constants.OP_RETYPE_ONLY
) {
Object info = MethodHandleNatives.getTargetInfo(target);
if (info instanceof DirectMethodHandle) {
DirectMethodHandle dmh = (DirectMethodHandle) info;
if (dmh.type().parameterType(0).isAssignableFrom(receiver.getClass())) {
MethodHandle bmh = new BoundMethodHandle(dmh, receiver, 0);
MethodType newType = target.type().dropParameterTypes(0, 1);
return convertArguments(bmh, newType, bmh.type(), 0);
}
}
}
if (target instanceof DirectMethodHandle)
return new BoundMethodHandle((DirectMethodHandle)target, receiver, 0);
return null; // let caller try something else
}
/** Bind a predetermined argument to the given arbitrary method handle.
* Callable only from MethodHandles.
* @param token Proof that the caller has access to this package.
* @param target Any method handle.
* @param receiver Argument (which can be a boxed primitive) to pre-bind.
* @return a suitable BoundMethodHandle
*/
static
MethodHandle bindArgument(MethodHandle target, int argnum, Object receiver) {
return new BoundMethodHandle(target, receiver, argnum);
}
static MethodHandle permuteArguments(MethodHandle target,
MethodType newType,
MethodType oldType,
int[] permutationOrNull) {
assert(oldType.parameterCount() == target.type().parameterCount());
int outargs = oldType.parameterCount(), inargs = newType.parameterCount();
if (permutationOrNull.length != outargs)
throw newIllegalArgumentException("wrong number of arguments in permutation");
// Make the individual outgoing argument types match up first.
Class<?>[] callTypeArgs = new Class<?>[outargs];
for (int i = 0; i < outargs; i++)
callTypeArgs[i] = newType.parameterType(permutationOrNull[i]);
MethodType callType = MethodType.methodType(oldType.returnType(), callTypeArgs);
target = convertArguments(target, callType, oldType, 0);
assert(target != null);
oldType = target.type();
List<Integer> goal = new ArrayList<Integer>(); // i*TOKEN
List<Integer> state = new ArrayList<Integer>(); // i*TOKEN
List<Integer> drops = new ArrayList<Integer>(); // not tokens
List<Integer> dups = new ArrayList<Integer>(); // not tokens
final int TOKEN = 10; // to mark items which are symbolic only
// state represents the argument values coming into target
for (int i = 0; i < outargs; i++) {
state.add(permutationOrNull[i] * TOKEN);
}
// goal represents the desired state
for (int i = 0; i < inargs; i++) {
if (state.contains(i * TOKEN)) {
goal.add(i * TOKEN);
} else {
// adapter must initially drop all unused arguments
drops.add(i);
}
}
// detect duplications
while (state.size() > goal.size()) {
for (int i2 = 0; i2 < state.size(); i2++) {
int arg1 = state.get(i2);
int i1 = state.indexOf(arg1);
if (i1 != i2) {
// found duplicate occurrence at i2
int arg2 = (inargs++) * TOKEN;
state.set(i2, arg2);
dups.add(goal.indexOf(arg1));
goal.add(arg2);
}
}
}
assert(state.size() == goal.size());
int size = goal.size();
while (!state.equals(goal)) {
// Look for a maximal sequence of adjacent misplaced arguments,
// and try to rotate them into place.
int bestRotArg = -10 * TOKEN, bestRotLen = 0;
int thisRotArg = -10 * TOKEN, thisRotLen = 0;
for (int i = 0; i < size; i++) {
int arg = state.get(i);
// Does this argument match the current run?
if (arg == thisRotArg + TOKEN) {
thisRotArg = arg;
thisRotLen += 1;
if (bestRotLen < thisRotLen) {
bestRotLen = thisRotLen;
bestRotArg = thisRotArg;
}
} else {
// The old sequence (if any) stops here.
thisRotLen = 0;
thisRotArg = -10 * TOKEN;
// But maybe a new one starts here also.
int wantArg = goal.get(i);
final int MAX_ARG_ROTATION = AdapterMethodHandle.MAX_ARG_ROTATION;
if (arg != wantArg &&
arg >= wantArg - TOKEN * MAX_ARG_ROTATION &&
arg <= wantArg + TOKEN * MAX_ARG_ROTATION) {
thisRotArg = arg;
thisRotLen = 1;
}
}
}
if (bestRotLen >= 2) {
// Do a rotation if it can improve argument positioning
// by at least 2 arguments. This is not always optimal,
// but it seems to catch common cases.
int dstEnd = state.indexOf(bestRotArg);
int srcEnd = goal.indexOf(bestRotArg);
int rotBy = dstEnd - srcEnd;
int dstBeg = dstEnd - (bestRotLen - 1);
int srcBeg = srcEnd - (bestRotLen - 1);
assert((dstEnd | dstBeg | srcEnd | srcBeg) >= 0); // no negs
// Make a span which covers both source and destination.
int rotBeg = Math.min(dstBeg, srcBeg);
int rotEnd = Math.max(dstEnd, srcEnd);
int score = 0;
for (int i = rotBeg; i <= rotEnd; i++) {
if ((int)state.get(i) != (int)goal.get(i))
score += 1;
}
List<Integer> rotSpan = state.subList(rotBeg, rotEnd+1);
Collections.rotate(rotSpan, -rotBy); // reverse direction
for (int i = rotBeg; i <= rotEnd; i++) {
if ((int)state.get(i) != (int)goal.get(i))
score -= 1;
}
if (score >= 2) {
// Improved at least two argument positions. Do it.
List<Class<?>> ptypes = Arrays.asList(oldType.parameterArray());
Collections.rotate(ptypes.subList(rotBeg, rotEnd+1), -rotBy);
MethodType rotType = MethodType.methodType(oldType.returnType(), ptypes);
MethodHandle nextTarget
= AdapterMethodHandle.makeRotateArguments(rotType, target,
rotBeg, rotSpan.size(), rotBy);
if (nextTarget != null) {
//System.out.println("Rot: "+rotSpan+" by "+rotBy);
target = nextTarget;
oldType = rotType;
continue;
}
}
// Else de-rotate, and drop through to the swap-fest.
Collections.rotate(rotSpan, rotBy);
}
// Now swap like the wind!
List<Class<?>> ptypes = Arrays.asList(oldType.parameterArray());
for (int i = 0; i < size; i++) {
// What argument do I want here?
int arg = goal.get(i);
if (arg != state.get(i)) {
// Where is it now?
int j = state.indexOf(arg);
Collections.swap(ptypes, i, j);
MethodType swapType = MethodType.methodType(oldType.returnType(), ptypes);
target = AdapterMethodHandle.makeSwapArguments(swapType, target, i, j);
if (target == null) throw newIllegalArgumentException("cannot swap");
assert(target.type() == swapType);
oldType = swapType;
Collections.swap(state, i, j);
}
}
// One pass of swapping must finish the job.
assert(state.equals(goal));
}
while (!dups.isEmpty()) {
// Grab a contiguous trailing sequence of dups.
int grab = dups.size() - 1;
int dupArgPos = dups.get(grab), dupArgCount = 1;
while (grab - 1 >= 0) {
int dup0 = dups.get(grab - 1);
if (dup0 != dupArgPos - 1) break;
dupArgPos -= 1;
dupArgCount += 1;
grab -= 1;
}
//if (dupArgCount > 1) System.out.println("Dup: "+dups.subList(grab, dups.size()));
dups.subList(grab, dups.size()).clear();
// In the new target type drop that many args from the tail:
List<Class<?>> ptypes = oldType.parameterList();
ptypes = ptypes.subList(0, ptypes.size() - dupArgCount);
MethodType dupType = MethodType.methodType(oldType.returnType(), ptypes);
target = AdapterMethodHandle.makeDupArguments(dupType, target, dupArgPos, dupArgCount);
if (target == null)
throw newIllegalArgumentException("cannot dup");
oldType = target.type();
}
while (!drops.isEmpty()) {
// Grab a contiguous initial sequence of drops.
int dropArgPos = drops.get(0), dropArgCount = 1;
while (dropArgCount < drops.size()) {
int drop1 = drops.get(dropArgCount);
if (drop1 != dropArgPos + dropArgCount) break;
dropArgCount += 1;
}
//if (dropArgCount > 1) System.out.println("Drop: "+drops.subList(0, dropArgCount));
drops.subList(0, dropArgCount).clear();
List<Class<?>> dropTypes = newType.parameterList()
.subList(dropArgPos, dropArgPos + dropArgCount);
MethodType dropType = oldType.insertParameterTypes(dropArgPos, dropTypes);
target = AdapterMethodHandle.makeDropArguments(dropType, target, dropArgPos, dropArgCount);
if (target == null) throw newIllegalArgumentException("cannot drop");
oldType = target.type();
}
target = convertArguments(target, newType, oldType, 0);
assert(target != null);
return target;
}
/*non-public*/ static
MethodHandle convertArguments(MethodHandle target, MethodType newType, int level) {
MethodType oldType = target.type();
if (oldType.equals(newType))
return target;
assert(level > 1 || oldType.isConvertibleTo(newType));
MethodHandle retFilter = null;
Class<?> oldRT = oldType.returnType();
Class<?> newRT = newType.returnType();
if (!VerifyType.isNullConversion(oldRT, newRT)) {
if (oldRT == void.class) {
Wrapper wrap = newRT.isPrimitive() ? Wrapper.forPrimitiveType(newRT) : Wrapper.OBJECT;
retFilter = ValueConversions.zeroConstantFunction(wrap);
} else {
retFilter = MethodHandles.identity(newRT);
retFilter = convertArguments(retFilter, retFilter.type().changeParameterType(0, oldRT), level);
}
newType = newType.changeReturnType(oldRT);
}
MethodHandle res = null;
Exception ex = null;
try {
res = convertArguments(target, newType, oldType, level);
} catch (IllegalArgumentException ex1) {
ex = ex1;
}
if (res == null) {
WrongMethodTypeException wmt = new WrongMethodTypeException("cannot convert to "+newType+": "+target);
wmt.initCause(ex);
throw wmt;
}
if (retFilter != null)
res = MethodHandles.filterReturnValue(res, retFilter);
return res;
}
static MethodHandle convertArguments(MethodHandle target,
MethodType newType,
MethodType oldType,
int level) {
assert(oldType.parameterCount() == target.type().parameterCount());
if (newType == oldType)
return target;
if (oldType.parameterCount() != newType.parameterCount())
throw newIllegalArgumentException("mismatched parameter count", oldType, newType);
return AdapterMethodHandle.makePairwiseConvert(newType, target, level);
}
static MethodHandle spreadArguments(MethodHandle target, Class<?> arrayType, int arrayLength) {
MethodType oldType = target.type();
int nargs = oldType.parameterCount();
int keepPosArgs = nargs - arrayLength;
MethodType newType = oldType
.dropParameterTypes(keepPosArgs, nargs)
.insertParameterTypes(keepPosArgs, arrayType);
return spreadArguments(target, newType, keepPosArgs, arrayType, arrayLength);
}
// called internally only
static MethodHandle spreadArgumentsFromPos(MethodHandle target, MethodType newType, int spreadArgPos) {
int arrayLength = target.type().parameterCount() - spreadArgPos;
return spreadArguments(target, newType, spreadArgPos, Object[].class, arrayLength);
}
static MethodHandle spreadArguments(MethodHandle target,
MethodType newType,
int spreadArgPos,
Class<?> arrayType,
int arrayLength) {
// TO DO: maybe allow the restarg to be Object and implicitly cast to Object[]
MethodType oldType = target.type();
// spread the last argument of newType to oldType
assert(arrayLength == oldType.parameterCount() - spreadArgPos);
assert(newType.parameterType(spreadArgPos) == arrayType);
return AdapterMethodHandle.makeSpreadArguments(newType, target, arrayType, spreadArgPos, arrayLength);
}
static MethodHandle collectArguments(MethodHandle target,
int collectArg,
MethodHandle collector) {
MethodType type = target.type();
Class<?> collectType = collector.type().returnType();
assert(collectType != void.class); // else use foldArguments
if (collectType != type.parameterType(collectArg))
target = target.asType(type.changeParameterType(collectArg, collectType));
MethodType newType = type
.dropParameterTypes(collectArg, collectArg+1)
.insertParameterTypes(collectArg, collector.type().parameterArray());
return collectArguments(target, newType, collectArg, collector);
}
static MethodHandle collectArguments(MethodHandle target,
MethodType newType,
int collectArg,
MethodHandle collector) {
MethodType oldType = target.type(); // (a...,c)=>r
// newType // (a..., b...)=>r
MethodType colType = collector.type(); // (b...)=>c
// oldType // (a..., b...)=>r
assert(newType.parameterCount() == collectArg + colType.parameterCount());
assert(oldType.parameterCount() == collectArg + 1);
assert(AdapterMethodHandle.canCollectArguments(oldType, colType, collectArg, false));
return AdapterMethodHandle.makeCollectArguments(target, collector, collectArg, false);
}
static MethodHandle filterArgument(MethodHandle target,
int pos,
MethodHandle filter) {
MethodType ttype = target.type();
MethodType ftype = filter.type();
assert(ftype.parameterCount() == 1);
return AdapterMethodHandle.makeCollectArguments(target, filter, pos, false);
}
static MethodHandle foldArguments(MethodHandle target,
MethodType newType,
int foldPos,
MethodHandle combiner) {
MethodType oldType = target.type();
MethodType ctype = combiner.type();
assert(AdapterMethodHandle.canCollectArguments(oldType, ctype, foldPos, true));
return AdapterMethodHandle.makeCollectArguments(target, combiner, foldPos, true);
}
static
MethodHandle dropArguments(MethodHandle target,
MethodType newType, int argnum) {
int drops = newType.parameterCount() - target.type().parameterCount();
return AdapterMethodHandle.makeDropArguments(newType, target, argnum, drops);
}
static
MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
return testResult ? target : fallback;
}
static MethodHandle SELECT_ALTERNATIVE;
static MethodHandle selectAlternative() {
if (SELECT_ALTERNATIVE != null) return SELECT_ALTERNATIVE;
try {
SELECT_ALTERNATIVE
= IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "selectAlternative",
MethodType.methodType(MethodHandle.class, boolean.class, MethodHandle.class, MethodHandle.class));
} catch (ReflectiveOperationException ex) {
throw new RuntimeException(ex);
}
return SELECT_ALTERNATIVE;
}
static
MethodHandle makeGuardWithTest(MethodHandle test,
MethodHandle target,
MethodHandle fallback) {
// gwt(arg...)
// [fold]=> continueAfterTest(z=test(arg...), arg...)
// [filter]=> (tf=select(z))(arg...)
// where select(z) = select(z, t, f).bindTo(t, f) => z ? t f
// [tailcall]=> tf(arg...)
assert(test.type().returnType() == boolean.class);
MethodType targetType = target.type();
MethodType foldTargetType = targetType.insertParameterTypes(0, boolean.class);
assert(AdapterMethodHandle.canCollectArguments(foldTargetType, test.type(), 0, true));
// working backwards, as usual:
assert(target.type().equals(fallback.type()));
MethodHandle tailcall = MethodHandles.exactInvoker(target.type());
MethodHandle select = selectAlternative();
select = bindArgument(select, 2, CountingMethodHandle.wrap(fallback));
select = bindArgument(select, 1, CountingMethodHandle.wrap(target));
// select(z: boolean) => (z ? target : fallback)
MethodHandle filter = filterArgument(tailcall, 0, select);
assert(filter.type().parameterType(0) == boolean.class);
MethodHandle fold = foldArguments(filter, filter.type().dropParameterTypes(0, 1), 0, test);
return fold;
}
private static class GuardWithCatch extends BoundMethodHandle {
private final MethodHandle target;
private final Class<? extends Throwable> exType;
private final MethodHandle catcher;
GuardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher) {
this(INVOKES[target.type().parameterCount()], target, exType, catcher);
}
// FIXME: Build the control flow out of foldArguments.
GuardWithCatch(MethodHandle invoker,
MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher) {
super(invoker);
this.target = target;
this.exType = exType;
this.catcher = catcher;
}
@Override
String debugString() {
return addTypeString(target, this);
}
private Object invoke_V(Object... av) throws Throwable {
try {
return target.invokeExact(av);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, av);
}
}
private Object invoke_L0() throws Throwable {
try {
return target.invokeExact();
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t);
}
}
private Object invoke_L1(Object a0) throws Throwable {
try {
return target.invokeExact(a0);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0);
}
}
private Object invoke_L2(Object a0, Object a1) throws Throwable {
try {
return target.invokeExact(a0, a1);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1);
}
}
private Object invoke_L3(Object a0, Object a1, Object a2) throws Throwable {
try {
return target.invokeExact(a0, a1, a2);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1, a2);
}
}
private Object invoke_L4(Object a0, Object a1, Object a2, Object a3) throws Throwable {
try {
return target.invokeExact(a0, a1, a2, a3);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1, a2, a3);
}
}
private Object invoke_L5(Object a0, Object a1, Object a2, Object a3, Object a4) throws Throwable {
try {
return target.invokeExact(a0, a1, a2, a3, a4);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1, a2, a3, a4);
}
}
private Object invoke_L6(Object a0, Object a1, Object a2, Object a3, Object a4, Object a5) throws Throwable {
try {
return target.invokeExact(a0, a1, a2, a3, a4, a5);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1, a2, a3, a4, a5);
}
}
private Object invoke_L7(Object a0, Object a1, Object a2, Object a3, Object a4, Object a5, Object a6) throws Throwable {
try {
return target.invokeExact(a0, a1, a2, a3, a4, a5, a6);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1, a2, a3, a4, a5, a6);
}
}
private Object invoke_L8(Object a0, Object a1, Object a2, Object a3, Object a4, Object a5, Object a6, Object a7) throws Throwable {
try {
return target.invokeExact(a0, a1, a2, a3, a4, a5, a6, a7);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.invokeExact(t, a0, a1, a2, a3, a4, a5, a6, a7);
}
}
static MethodHandle[] makeInvokes() {
ArrayList<MethodHandle> invokes = new ArrayList<MethodHandle>();
MethodHandles.Lookup lookup = IMPL_LOOKUP;
for (;;) {
int nargs = invokes.size();
String name = "invoke_L"+nargs;
MethodHandle invoke = null;
try {
invoke = lookup.findVirtual(GuardWithCatch.class, name, MethodType.genericMethodType(nargs));
} catch (ReflectiveOperationException ex) {
}
if (invoke == null) break;
invokes.add(invoke);
}
assert(invokes.size() == 9); // current number of methods
return invokes.toArray(new MethodHandle[0]);
};
static final MethodHandle[] INVOKES = makeInvokes();
// For testing use this:
//static final MethodHandle[] INVOKES = Arrays.copyOf(makeInvokes(), 2);
static final MethodHandle VARARGS_INVOKE;
static {
try {
VARARGS_INVOKE = IMPL_LOOKUP.findVirtual(GuardWithCatch.class, "invoke_V", MethodType.genericMethodType(0, true));
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
}
}
static
MethodHandle makeGuardWithCatch(MethodHandle target,
Class<? extends Throwable> exType,
MethodHandle catcher) {
MethodType type = target.type();
MethodType ctype = catcher.type();
int nargs = type.parameterCount();
if (nargs < GuardWithCatch.INVOKES.length) {
MethodType gtype = type.generic();
MethodType gcatchType = gtype.insertParameterTypes(0, Throwable.class);
// Note: convertArguments(...2) avoids interface casts present in convertArguments(...0)
MethodHandle gtarget = convertArguments(target, gtype, type, 2);
MethodHandle gcatcher = convertArguments(catcher, gcatchType, ctype, 2);
MethodHandle gguard = new GuardWithCatch(gtarget, exType, gcatcher);
if (gtarget == null || gcatcher == null || gguard == null) return null;
return convertArguments(gguard, type, gtype, 2);
} else {
MethodType gtype = MethodType.genericMethodType(0, true);
MethodType gcatchType = gtype.insertParameterTypes(0, Throwable.class);
MethodHandle gtarget = spreadArgumentsFromPos(target, gtype, 0);
catcher = catcher.asType(ctype.changeParameterType(0, Throwable.class));
MethodHandle gcatcher = spreadArgumentsFromPos(catcher, gcatchType, 1);
MethodHandle gguard = new GuardWithCatch(GuardWithCatch.VARARGS_INVOKE, gtarget, exType, gcatcher);
if (gtarget == null || gcatcher == null || gguard == null) return null;
return collectArguments(gguard, type, 0, ValueConversions.varargsArray(nargs)).asType(type);
}
}
static
MethodHandle throwException(MethodType type) {
return AdapterMethodHandle.makeRetypeRaw(type, throwException());
}
static MethodHandle THROW_EXCEPTION;
static MethodHandle throwException() {
if (THROW_EXCEPTION != null) return THROW_EXCEPTION;
try {
THROW_EXCEPTION
= IMPL_LOOKUP.findStatic(MethodHandleImpl.class, "throwException",
MethodType.methodType(Empty.class, Throwable.class));
} catch (ReflectiveOperationException ex) {
throw new RuntimeException(ex);
}
return THROW_EXCEPTION;
}
static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
}