/
MethodHandleImpl.java
2341 lines (2107 loc) · 106 KB
/
MethodHandleImpl.java
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/*
* Copyright (c) 2008, 2022, 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 jdk.internal.access.JavaLangInvokeAccess;
import jdk.internal.access.SharedSecrets;
import jdk.internal.foreign.abi.NativeEntryPoint;
import jdk.internal.org.objectweb.asm.ClassWriter;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
import jdk.internal.vm.annotation.ForceInline;
import jdk.internal.vm.annotation.Hidden;
import jdk.internal.vm.annotation.Stable;
import sun.invoke.empty.Empty;
import sun.invoke.util.ValueConversions;
import sun.invoke.util.VerifyType;
import sun.invoke.util.Wrapper;
import java.lang.invoke.MethodHandles.Lookup;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.nio.ByteOrder;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
import java.util.stream.Stream;
import static java.lang.invoke.LambdaForm.*;
import static java.lang.invoke.MethodHandleStatics.*;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
import static java.lang.invoke.MethodHandles.Lookup.ClassOption.NESTMATE;
import static jdk.internal.org.objectweb.asm.Opcodes.*;
/**
* Trusted implementation code for MethodHandle.
* @author jrose
*/
/*non-public*/
abstract class MethodHandleImpl {
/// Factory methods to create method handles:
static MethodHandle makeArrayElementAccessor(Class<?> arrayClass, ArrayAccess access) {
if (arrayClass == Object[].class) {
return ArrayAccess.objectAccessor(access);
}
if (!arrayClass.isArray())
throw newIllegalArgumentException("not an array: "+arrayClass);
MethodHandle[] cache = ArrayAccessor.TYPED_ACCESSORS.get(arrayClass);
int cacheIndex = ArrayAccess.cacheIndex(access);
MethodHandle mh = cache[cacheIndex];
if (mh != null) return mh;
mh = ArrayAccessor.getAccessor(arrayClass, access);
MethodType correctType = ArrayAccessor.correctType(arrayClass, access);
if (mh.type() != correctType) {
assert(mh.type().parameterType(0) == Object[].class);
/* if access == SET */ assert(access != ArrayAccess.SET || mh.type().parameterType(2) == Object.class);
/* if access == GET */ assert(access != ArrayAccess.GET ||
(mh.type().returnType() == Object.class &&
correctType.parameterType(0).getComponentType() == correctType.returnType()));
// safe to view non-strictly, because element type follows from array type
mh = mh.viewAsType(correctType, false);
}
mh = makeIntrinsic(mh, ArrayAccess.intrinsic(access));
// Atomically update accessor cache.
synchronized(cache) {
if (cache[cacheIndex] == null) {
cache[cacheIndex] = mh;
} else {
// Throw away newly constructed accessor and use cached version.
mh = cache[cacheIndex];
}
}
return mh;
}
enum ArrayAccess {
GET, SET, LENGTH;
// As ArrayAccess and ArrayAccessor have a circular dependency, the ArrayAccess properties cannot be stored in
// final fields.
static String opName(ArrayAccess a) {
return switch (a) {
case GET -> "getElement";
case SET -> "setElement";
case LENGTH -> "length";
default -> throw unmatchedArrayAccess(a);
};
}
static MethodHandle objectAccessor(ArrayAccess a) {
return switch (a) {
case GET -> ArrayAccessor.OBJECT_ARRAY_GETTER;
case SET -> ArrayAccessor.OBJECT_ARRAY_SETTER;
case LENGTH -> ArrayAccessor.OBJECT_ARRAY_LENGTH;
default -> throw unmatchedArrayAccess(a);
};
}
static int cacheIndex(ArrayAccess a) {
return switch (a) {
case GET -> ArrayAccessor.GETTER_INDEX;
case SET -> ArrayAccessor.SETTER_INDEX;
case LENGTH -> ArrayAccessor.LENGTH_INDEX;
default -> throw unmatchedArrayAccess(a);
};
}
static Intrinsic intrinsic(ArrayAccess a) {
return switch (a) {
case GET -> Intrinsic.ARRAY_LOAD;
case SET -> Intrinsic.ARRAY_STORE;
case LENGTH -> Intrinsic.ARRAY_LENGTH;
default -> throw unmatchedArrayAccess(a);
};
}
}
static InternalError unmatchedArrayAccess(ArrayAccess a) {
return newInternalError("should not reach here (unmatched ArrayAccess: " + a + ")");
}
static final class ArrayAccessor {
/// Support for array element and length access
static final int GETTER_INDEX = 0, SETTER_INDEX = 1, LENGTH_INDEX = 2, INDEX_LIMIT = 3;
static final ClassValue<MethodHandle[]> TYPED_ACCESSORS
= new ClassValue<MethodHandle[]>() {
@Override
protected MethodHandle[] computeValue(Class<?> type) {
return new MethodHandle[INDEX_LIMIT];
}
};
static final MethodHandle OBJECT_ARRAY_GETTER, OBJECT_ARRAY_SETTER, OBJECT_ARRAY_LENGTH;
static {
MethodHandle[] cache = TYPED_ACCESSORS.get(Object[].class);
cache[GETTER_INDEX] = OBJECT_ARRAY_GETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.GET), Intrinsic.ARRAY_LOAD);
cache[SETTER_INDEX] = OBJECT_ARRAY_SETTER = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.SET), Intrinsic.ARRAY_STORE);
cache[LENGTH_INDEX] = OBJECT_ARRAY_LENGTH = makeIntrinsic(getAccessor(Object[].class, ArrayAccess.LENGTH), Intrinsic.ARRAY_LENGTH);
assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_GETTER.internalMemberName()));
assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_SETTER.internalMemberName()));
assert(InvokerBytecodeGenerator.isStaticallyInvocable(ArrayAccessor.OBJECT_ARRAY_LENGTH.internalMemberName()));
}
static int getElementI(int[] a, int i) { return a[i]; }
static long getElementJ(long[] a, int i) { return a[i]; }
static float getElementF(float[] a, int i) { return a[i]; }
static double getElementD(double[] a, int i) { return a[i]; }
static boolean getElementZ(boolean[] a, int i) { return a[i]; }
static byte getElementB(byte[] a, int i) { return a[i]; }
static short getElementS(short[] a, int i) { return a[i]; }
static char getElementC(char[] a, int i) { return a[i]; }
static Object getElementL(Object[] a, int i) { return a[i]; }
static void setElementI(int[] a, int i, int x) { a[i] = x; }
static void setElementJ(long[] a, int i, long x) { a[i] = x; }
static void setElementF(float[] a, int i, float x) { a[i] = x; }
static void setElementD(double[] a, int i, double x) { a[i] = x; }
static void setElementZ(boolean[] a, int i, boolean x) { a[i] = x; }
static void setElementB(byte[] a, int i, byte x) { a[i] = x; }
static void setElementS(short[] a, int i, short x) { a[i] = x; }
static void setElementC(char[] a, int i, char x) { a[i] = x; }
static void setElementL(Object[] a, int i, Object x) { a[i] = x; }
static int lengthI(int[] a) { return a.length; }
static int lengthJ(long[] a) { return a.length; }
static int lengthF(float[] a) { return a.length; }
static int lengthD(double[] a) { return a.length; }
static int lengthZ(boolean[] a) { return a.length; }
static int lengthB(byte[] a) { return a.length; }
static int lengthS(short[] a) { return a.length; }
static int lengthC(char[] a) { return a.length; }
static int lengthL(Object[] a) { return a.length; }
static String name(Class<?> arrayClass, ArrayAccess access) {
Class<?> elemClass = arrayClass.getComponentType();
if (elemClass == null) throw newIllegalArgumentException("not an array", arrayClass);
return ArrayAccess.opName(access) + Wrapper.basicTypeChar(elemClass);
}
static MethodType type(Class<?> arrayClass, ArrayAccess access) {
Class<?> elemClass = arrayClass.getComponentType();
Class<?> arrayArgClass = arrayClass;
if (!elemClass.isPrimitive()) {
arrayArgClass = Object[].class;
elemClass = Object.class;
}
return switch (access) {
case GET -> MethodType.methodType(elemClass, arrayArgClass, int.class);
case SET -> MethodType.methodType(void.class, arrayArgClass, int.class, elemClass);
case LENGTH -> MethodType.methodType(int.class, arrayArgClass);
default -> throw unmatchedArrayAccess(access);
};
}
static MethodType correctType(Class<?> arrayClass, ArrayAccess access) {
Class<?> elemClass = arrayClass.getComponentType();
return switch (access) {
case GET -> MethodType.methodType(elemClass, arrayClass, int.class);
case SET -> MethodType.methodType(void.class, arrayClass, int.class, elemClass);
case LENGTH -> MethodType.methodType(int.class, arrayClass);
default -> throw unmatchedArrayAccess(access);
};
}
static MethodHandle getAccessor(Class<?> arrayClass, ArrayAccess access) {
String name = name(arrayClass, access);
MethodType type = type(arrayClass, access);
try {
return IMPL_LOOKUP.findStatic(ArrayAccessor.class, name, type);
} catch (ReflectiveOperationException ex) {
throw uncaughtException(ex);
}
}
}
/**
* Create a JVM-level adapter method handle to conform the given method
* handle to the similar newType, using only pairwise argument conversions.
* For each argument, convert incoming argument to the exact type needed.
* The argument conversions allowed are casting, boxing and unboxing,
* integral widening or narrowing, and floating point widening or narrowing.
* @param srcType required call type
* @param target original method handle
* @param strict if true, only asType conversions are allowed; if false, explicitCastArguments conversions allowed
* @param monobox if true, unboxing conversions are assumed to be exactly typed (Integer to int only, not long or double)
* @return an adapter to the original handle with the desired new type,
* or the original target if the types are already identical
* or null if the adaptation cannot be made
*/
static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
boolean strict, boolean monobox) {
MethodType dstType = target.type();
if (srcType == dstType)
return target;
return makePairwiseConvertByEditor(target, srcType, strict, monobox);
}
private static int countNonNull(Object[] array) {
int count = 0;
if (array != null) {
for (Object x : array) {
if (x != null) ++count;
}
}
return count;
}
static MethodHandle makePairwiseConvertByEditor(MethodHandle target, MethodType srcType,
boolean strict, boolean monobox) {
// In method types arguments start at index 0, while the LF
// editor have the MH receiver at position 0 - adjust appropriately.
final int MH_RECEIVER_OFFSET = 1;
Object[] convSpecs = computeValueConversions(srcType, target.type(), strict, monobox);
int convCount = countNonNull(convSpecs);
if (convCount == 0)
return target.viewAsType(srcType, strict);
MethodType basicSrcType = srcType.basicType();
MethodType midType = target.type().basicType();
BoundMethodHandle mh = target.rebind();
// Match each unique conversion to the positions at which it is to be applied
HashMap<Object, int[]> convSpecMap = HashMap.newHashMap(convCount);
for (int i = 0; i < convSpecs.length - MH_RECEIVER_OFFSET; i++) {
Object convSpec = convSpecs[i];
if (convSpec == null) continue;
int[] positions = convSpecMap.get(convSpec);
if (positions == null) {
positions = new int[] { i + MH_RECEIVER_OFFSET };
} else {
positions = Arrays.copyOf(positions, positions.length + 1);
positions[positions.length - 1] = i + MH_RECEIVER_OFFSET;
}
convSpecMap.put(convSpec, positions);
}
for (var entry : convSpecMap.entrySet()) {
Object convSpec = entry.getKey();
MethodHandle fn;
if (convSpec instanceof Class) {
fn = getConstantHandle(MH_cast).bindTo(convSpec);
} else {
fn = (MethodHandle) convSpec;
}
int[] positions = entry.getValue();
Class<?> newType = basicSrcType.parameterType(positions[0] - MH_RECEIVER_OFFSET);
BasicType newBasicType = BasicType.basicType(newType);
convCount -= positions.length;
if (convCount == 0) {
midType = srcType;
} else {
Class<?>[] ptypes = midType.ptypes().clone();
for (int pos : positions) {
ptypes[pos - 1] = newType;
}
midType = MethodType.methodType(midType.rtype(), ptypes, true);
}
LambdaForm form2;
if (positions.length > 1) {
form2 = mh.editor().filterRepeatedArgumentForm(newBasicType, positions);
} else {
form2 = mh.editor().filterArgumentForm(positions[0], newBasicType);
}
mh = mh.copyWithExtendL(midType, form2, fn);
}
Object convSpec = convSpecs[convSpecs.length - 1];
if (convSpec != null) {
MethodHandle fn;
if (convSpec instanceof Class) {
if (convSpec == void.class)
fn = null;
else
fn = getConstantHandle(MH_cast).bindTo(convSpec);
} else {
fn = (MethodHandle) convSpec;
}
Class<?> newType = basicSrcType.returnType();
assert(--convCount == 0);
midType = srcType;
if (fn != null) {
mh = mh.rebind(); // rebind if too complex
LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), false);
mh = mh.copyWithExtendL(midType, form2, fn);
} else {
LambdaForm form2 = mh.editor().filterReturnForm(BasicType.basicType(newType), true);
mh = mh.copyWith(midType, form2);
}
}
assert(convCount == 0);
assert(mh.type().equals(srcType));
return mh;
}
static Object[] computeValueConversions(MethodType srcType, MethodType dstType,
boolean strict, boolean monobox) {
final int INARG_COUNT = srcType.parameterCount();
Object[] convSpecs = null;
for (int i = 0; i <= INARG_COUNT; i++) {
boolean isRet = (i == INARG_COUNT);
Class<?> src = isRet ? dstType.returnType() : srcType.parameterType(i);
Class<?> dst = isRet ? srcType.returnType() : dstType.parameterType(i);
if (!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)) {
if (convSpecs == null) {
convSpecs = new Object[INARG_COUNT + 1];
}
convSpecs[i] = valueConversion(src, dst, strict, monobox);
}
}
return convSpecs;
}
static MethodHandle makePairwiseConvert(MethodHandle target, MethodType srcType,
boolean strict) {
return makePairwiseConvert(target, srcType, strict, /*monobox=*/ false);
}
/**
* Find a conversion function from the given source to the given destination.
* This conversion function will be used as a LF NamedFunction.
* Return a Class object if a simple cast is needed.
* Return void.class if void is involved.
*/
static Object valueConversion(Class<?> src, Class<?> dst, boolean strict, boolean monobox) {
assert(!VerifyType.isNullConversion(src, dst, /*keepInterfaces=*/ strict)); // caller responsibility
if (dst == void.class)
return dst;
MethodHandle fn;
if (src.isPrimitive()) {
if (src == void.class) {
return void.class; // caller must recognize this specially
} else if (dst.isPrimitive()) {
// Examples: int->byte, byte->int, boolean->int (!strict)
fn = ValueConversions.convertPrimitive(src, dst);
} else {
// Examples: int->Integer, boolean->Object, float->Number
Wrapper wsrc = Wrapper.forPrimitiveType(src);
fn = ValueConversions.boxExact(wsrc);
assert(fn.type().parameterType(0) == wsrc.primitiveType());
assert(fn.type().returnType() == wsrc.wrapperType());
if (!VerifyType.isNullConversion(wsrc.wrapperType(), dst, strict)) {
// Corner case, such as int->Long, which will probably fail.
MethodType mt = MethodType.methodType(dst, src);
if (strict)
fn = fn.asType(mt);
else
fn = MethodHandleImpl.makePairwiseConvert(fn, mt, /*strict=*/ false);
}
}
} else if (dst.isPrimitive()) {
Wrapper wdst = Wrapper.forPrimitiveType(dst);
if (monobox || src == wdst.wrapperType()) {
// Use a strongly-typed unboxer, if possible.
fn = ValueConversions.unboxExact(wdst, strict);
} else {
// Examples: Object->int, Number->int, Comparable->int, Byte->int
// must include additional conversions
// src must be examined at runtime, to detect Byte, Character, etc.
fn = (strict
? ValueConversions.unboxWiden(wdst)
: ValueConversions.unboxCast(wdst));
}
} else {
// Simple reference conversion.
// Note: Do not check for a class hierarchy relation
// between src and dst. In all cases a 'null' argument
// will pass the cast conversion.
return dst;
}
assert(fn.type().parameterCount() <= 1) : "pc"+Arrays.asList(src.getSimpleName(), dst.getSimpleName(), fn);
return fn;
}
static MethodHandle makeVarargsCollector(MethodHandle target, Class<?> arrayType) {
MethodType type = target.type();
int last = type.parameterCount() - 1;
if (type.parameterType(last) != arrayType)
target = target.asType(type.changeParameterType(last, arrayType));
target = target.asFixedArity(); // make sure this attribute is turned off
return new AsVarargsCollector(target, arrayType);
}
static final class AsVarargsCollector extends DelegatingMethodHandle {
private final MethodHandle target;
private final Class<?> arrayType;
private MethodHandle asCollectorCache;
AsVarargsCollector(MethodHandle target, Class<?> arrayType) {
this(target.type(), target, arrayType);
}
AsVarargsCollector(MethodType type, MethodHandle target, Class<?> arrayType) {
super(type, target);
this.target = target;
this.arrayType = arrayType;
}
@Override
public boolean isVarargsCollector() {
return true;
}
@Override
protected MethodHandle getTarget() {
return target;
}
@Override
public MethodHandle asFixedArity() {
return target;
}
@Override
MethodHandle setVarargs(MemberName member) {
if (member.isVarargs()) return this;
return asFixedArity();
}
@Override
public MethodHandle withVarargs(boolean makeVarargs) {
if (makeVarargs) return this;
return asFixedArity();
}
@Override
public MethodHandle asTypeUncached(MethodType newType) {
MethodType type = this.type();
int collectArg = type.parameterCount() - 1;
int newArity = newType.parameterCount();
if (newArity == collectArg+1 &&
type.parameterType(collectArg).isAssignableFrom(newType.parameterType(collectArg))) {
// if arity and trailing parameter are compatible, do normal thing
return asFixedArity().asType(newType);
}
// check cache
MethodHandle acc = asCollectorCache;
if (acc != null && acc.type().parameterCount() == newArity)
return acc.asType(newType);
// build and cache a collector
int arrayLength = newArity - collectArg;
MethodHandle collector;
try {
collector = asFixedArity().asCollector(arrayType, arrayLength);
assert(collector.type().parameterCount() == newArity) : "newArity="+newArity+" but collector="+collector;
} catch (IllegalArgumentException ex) {
throw new WrongMethodTypeException("cannot build collector", ex);
}
asCollectorCache = collector;
return collector.asType(newType);
}
@Override
boolean viewAsTypeChecks(MethodType newType, boolean strict) {
super.viewAsTypeChecks(newType, true);
if (strict) return true;
// extra assertion for non-strict checks:
assert (type().lastParameterType().getComponentType()
.isAssignableFrom(
newType.lastParameterType().getComponentType()))
: Arrays.asList(this, newType);
return true;
}
@Override
public Object invokeWithArguments(Object... arguments) throws Throwable {
MethodType type = this.type();
int argc;
final int MAX_SAFE = 127; // 127 longs require 254 slots, which is safe to spread
if (arguments == null
|| (argc = arguments.length) <= MAX_SAFE
|| argc < type.parameterCount()) {
return super.invokeWithArguments(arguments);
}
// a jumbo invocation requires more explicit reboxing of the trailing arguments
int uncollected = type.parameterCount() - 1;
Class<?> elemType = arrayType.getComponentType();
int collected = argc - uncollected;
Object collArgs = (elemType == Object.class)
? new Object[collected] : Array.newInstance(elemType, collected);
if (!elemType.isPrimitive()) {
// simple cast: just do some casting
try {
System.arraycopy(arguments, uncollected, collArgs, 0, collected);
} catch (ArrayStoreException ex) {
return super.invokeWithArguments(arguments);
}
} else {
// corner case of flat array requires reflection (or specialized copy loop)
MethodHandle arraySetter = MethodHandles.arrayElementSetter(arrayType);
try {
for (int i = 0; i < collected; i++) {
arraySetter.invoke(collArgs, i, arguments[uncollected + i]);
}
} catch (WrongMethodTypeException|ClassCastException ex) {
return super.invokeWithArguments(arguments);
}
}
// chop the jumbo list down to size and call in non-varargs mode
Object[] newArgs = new Object[uncollected + 1];
System.arraycopy(arguments, 0, newArgs, 0, uncollected);
newArgs[uncollected] = collArgs;
return asFixedArity().invokeWithArguments(newArgs);
}
}
static void checkSpreadArgument(Object av, int n) {
if (av == null && n == 0) {
return;
} else if (av == null) {
throw new NullPointerException("null array reference");
} else if (av instanceof Object[]) {
int len = ((Object[])av).length;
if (len == n) return;
} else {
int len = java.lang.reflect.Array.getLength(av);
if (len == n) return;
}
// fall through to error:
throw newIllegalArgumentException("array is not of length "+n);
}
@Hidden
static MethodHandle selectAlternative(boolean testResult, MethodHandle target, MethodHandle fallback) {
if (testResult) {
return target;
} else {
return fallback;
}
}
// Intrinsified by C2. Counters are used during parsing to calculate branch frequencies.
@Hidden
@jdk.internal.vm.annotation.IntrinsicCandidate
static boolean profileBoolean(boolean result, int[] counters) {
// Profile is int[2] where [0] and [1] correspond to false and true occurrences respectively.
int idx = result ? 1 : 0;
try {
counters[idx] = Math.addExact(counters[idx], 1);
} catch (ArithmeticException e) {
// Avoid continuous overflow by halving the problematic count.
counters[idx] = counters[idx] / 2;
}
return result;
}
// Intrinsified by C2. Returns true if obj is a compile-time constant.
@Hidden
@jdk.internal.vm.annotation.IntrinsicCandidate
static boolean isCompileConstant(Object obj) {
return false;
}
static MethodHandle makeGuardWithTest(MethodHandle test,
MethodHandle target,
MethodHandle fallback) {
MethodType type = target.type();
assert(test.type().equals(type.changeReturnType(boolean.class)) && fallback.type().equals(type));
MethodType basicType = type.basicType();
LambdaForm form = makeGuardWithTestForm(basicType);
BoundMethodHandle mh;
try {
if (PROFILE_GWT) {
int[] counts = new int[2];
mh = (BoundMethodHandle)
BoundMethodHandle.speciesData_LLLL().factory().invokeBasic(type, form,
(Object) test, (Object) profile(target), (Object) profile(fallback), counts);
} else {
mh = (BoundMethodHandle)
BoundMethodHandle.speciesData_LLL().factory().invokeBasic(type, form,
(Object) test, (Object) profile(target), (Object) profile(fallback));
}
} catch (Throwable ex) {
throw uncaughtException(ex);
}
assert(mh.type() == type);
return mh;
}
static MethodHandle profile(MethodHandle target) {
if (DONT_INLINE_THRESHOLD >= 0) {
return makeBlockInliningWrapper(target);
} else {
return target;
}
}
/**
* Block inlining during JIT-compilation of a target method handle if it hasn't been invoked enough times.
* Corresponding LambdaForm has @DontInline when compiled into bytecode.
*/
static MethodHandle makeBlockInliningWrapper(MethodHandle target) {
LambdaForm lform;
if (DONT_INLINE_THRESHOLD > 0) {
lform = Makers.PRODUCE_BLOCK_INLINING_FORM.apply(target);
} else {
lform = Makers.PRODUCE_REINVOKER_FORM.apply(target);
}
return new CountingWrapper(target, lform,
Makers.PRODUCE_BLOCK_INLINING_FORM, Makers.PRODUCE_REINVOKER_FORM,
DONT_INLINE_THRESHOLD);
}
private static final class Makers {
/** Constructs reinvoker lambda form which block inlining during JIT-compilation for a particular method handle */
static final Function<MethodHandle, LambdaForm> PRODUCE_BLOCK_INLINING_FORM = new Function<MethodHandle, LambdaForm>() {
@Override
public LambdaForm apply(MethodHandle target) {
return DelegatingMethodHandle.makeReinvokerForm(target,
MethodTypeForm.LF_DELEGATE_BLOCK_INLINING, CountingWrapper.class, false,
DelegatingMethodHandle.NF_getTarget, CountingWrapper.NF_maybeStopCounting);
}
};
/** Constructs simple reinvoker lambda form for a particular method handle */
static final Function<MethodHandle, LambdaForm> PRODUCE_REINVOKER_FORM = new Function<MethodHandle, LambdaForm>() {
@Override
public LambdaForm apply(MethodHandle target) {
return DelegatingMethodHandle.makeReinvokerForm(target,
MethodTypeForm.LF_DELEGATE, DelegatingMethodHandle.class, DelegatingMethodHandle.NF_getTarget);
}
};
/** Maker of type-polymorphic varargs */
static final ClassValue<MethodHandle[]> TYPED_COLLECTORS = new ClassValue<MethodHandle[]>() {
@Override
protected MethodHandle[] computeValue(Class<?> type) {
return new MethodHandle[MAX_JVM_ARITY + 1];
}
};
}
/**
* Counting method handle. It has 2 states: counting and non-counting.
* It is in counting state for the first n invocations and then transitions to non-counting state.
* Behavior in counting and non-counting states is determined by lambda forms produced by
* countingFormProducer & nonCountingFormProducer respectively.
*/
static final class CountingWrapper extends DelegatingMethodHandle {
private final MethodHandle target;
private int count;
private Function<MethodHandle, LambdaForm> countingFormProducer;
private Function<MethodHandle, LambdaForm> nonCountingFormProducer;
private volatile boolean isCounting;
private CountingWrapper(MethodHandle target, LambdaForm lform,
Function<MethodHandle, LambdaForm> countingFromProducer,
Function<MethodHandle, LambdaForm> nonCountingFormProducer,
int count) {
super(target.type(), lform);
this.target = target;
this.count = count;
this.countingFormProducer = countingFromProducer;
this.nonCountingFormProducer = nonCountingFormProducer;
this.isCounting = (count > 0);
}
@Hidden
@Override
protected MethodHandle getTarget() {
return target;
}
@Override
public MethodHandle asTypeUncached(MethodType newType) {
MethodHandle newTarget = target.asType(newType);
MethodHandle wrapper;
if (isCounting) {
LambdaForm lform;
lform = countingFormProducer.apply(newTarget);
wrapper = new CountingWrapper(newTarget, lform, countingFormProducer, nonCountingFormProducer, DONT_INLINE_THRESHOLD);
} else {
wrapper = newTarget; // no need for a counting wrapper anymore
}
return wrapper;
}
boolean countDown() {
int c = count;
target.maybeCustomize(); // customize if counting happens for too long
if (c <= 1) {
// Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
if (isCounting) {
isCounting = false;
return true;
} else {
return false;
}
} else {
count = c - 1;
return false;
}
}
@Hidden
static void maybeStopCounting(Object o1) {
final CountingWrapper wrapper = (CountingWrapper) o1;
if (wrapper.countDown()) {
// Reached invocation threshold. Replace counting behavior with a non-counting one.
wrapper.updateForm(new Function<>() {
public LambdaForm apply(LambdaForm oldForm) {
LambdaForm lform = wrapper.nonCountingFormProducer.apply(wrapper.target);
lform.compileToBytecode(); // speed up warmup by avoiding LF interpretation again after transition
return lform;
}});
}
}
static final NamedFunction NF_maybeStopCounting;
static {
Class<?> THIS_CLASS = CountingWrapper.class;
try {
NF_maybeStopCounting = new NamedFunction(THIS_CLASS.getDeclaredMethod("maybeStopCounting", Object.class));
} catch (ReflectiveOperationException ex) {
throw newInternalError(ex);
}
}
}
static LambdaForm makeGuardWithTestForm(MethodType basicType) {
LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWT);
if (lform != null) return lform;
final int THIS_MH = 0; // the BMH_LLL
final int ARG_BASE = 1; // start of incoming arguments
final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
int nameCursor = ARG_LIMIT;
final int GET_TEST = nameCursor++;
final int GET_TARGET = nameCursor++;
final int GET_FALLBACK = nameCursor++;
final int GET_COUNTERS = PROFILE_GWT ? nameCursor++ : -1;
final int CALL_TEST = nameCursor++;
final int PROFILE = (GET_COUNTERS != -1) ? nameCursor++ : -1;
final int TEST = nameCursor-1; // previous statement: either PROFILE or CALL_TEST
final int SELECT_ALT = nameCursor++;
final int CALL_TARGET = nameCursor++;
assert(CALL_TARGET == SELECT_ALT+1); // must be true to trigger IBG.emitSelectAlternative
MethodType lambdaType = basicType.invokerType();
Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
BoundMethodHandle.SpeciesData data =
(GET_COUNTERS != -1) ? BoundMethodHandle.speciesData_LLLL()
: BoundMethodHandle.speciesData_LLL();
names[THIS_MH] = names[THIS_MH].withConstraint(data);
names[GET_TEST] = new Name(data.getterFunction(0), names[THIS_MH]);
names[GET_TARGET] = new Name(data.getterFunction(1), names[THIS_MH]);
names[GET_FALLBACK] = new Name(data.getterFunction(2), names[THIS_MH]);
if (GET_COUNTERS != -1) {
names[GET_COUNTERS] = new Name(data.getterFunction(3), names[THIS_MH]);
}
Object[] invokeArgs = Arrays.copyOfRange(names, 0, ARG_LIMIT, Object[].class);
// call test
MethodType testType = basicType.changeReturnType(boolean.class).basicType();
invokeArgs[0] = names[GET_TEST];
names[CALL_TEST] = new Name(testType, invokeArgs);
// profile branch
if (PROFILE != -1) {
names[PROFILE] = new Name(getFunction(NF_profileBoolean), names[CALL_TEST], names[GET_COUNTERS]);
}
// call selectAlternative
names[SELECT_ALT] = new Name(new NamedFunction(
makeIntrinsic(getConstantHandle(MH_selectAlternative), Intrinsic.SELECT_ALTERNATIVE)),
names[TEST], names[GET_TARGET], names[GET_FALLBACK]);
// call target or fallback
invokeArgs[0] = names[SELECT_ALT];
names[CALL_TARGET] = new Name(basicType, invokeArgs);
lform = new LambdaForm(lambdaType.parameterCount(), names, /*forceInline=*/true, Kind.GUARD);
return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWT, lform);
}
/**
* The LambdaForm shape for catchException combinator is the following:
* <blockquote><pre>{@code
* guardWithCatch=Lambda(a0:L,a1:L,a2:L)=>{
* t3:L=BoundMethodHandle$Species_LLLLL.argL0(a0:L);
* t4:L=BoundMethodHandle$Species_LLLLL.argL1(a0:L);
* t5:L=BoundMethodHandle$Species_LLLLL.argL2(a0:L);
* t6:L=BoundMethodHandle$Species_LLLLL.argL3(a0:L);
* t7:L=BoundMethodHandle$Species_LLLLL.argL4(a0:L);
* t8:L=MethodHandle.invokeBasic(t6:L,a1:L,a2:L);
* t9:L=MethodHandleImpl.guardWithCatch(t3:L,t4:L,t5:L,t8:L);
* t10:I=MethodHandle.invokeBasic(t7:L,t9:L);t10:I}
* }</pre></blockquote>
*
* argL0 and argL2 are target and catcher method handles. argL1 is exception class.
* argL3 and argL4 are auxiliary method handles: argL3 boxes arguments and wraps them into Object[]
* (ValueConversions.array()) and argL4 unboxes result if necessary (ValueConversions.unbox()).
*
* Having t8 and t10 passed outside and not hardcoded into a lambda form allows to share lambda forms
* among catchException combinators with the same basic type.
*/
private static LambdaForm makeGuardWithCatchForm(MethodType basicType) {
MethodType lambdaType = basicType.invokerType();
LambdaForm lform = basicType.form().cachedLambdaForm(MethodTypeForm.LF_GWC);
if (lform != null) {
return lform;
}
final int THIS_MH = 0; // the BMH_LLLLL
final int ARG_BASE = 1; // start of incoming arguments
final int ARG_LIMIT = ARG_BASE + basicType.parameterCount();
int nameCursor = ARG_LIMIT;
final int GET_TARGET = nameCursor++;
final int GET_CLASS = nameCursor++;
final int GET_CATCHER = nameCursor++;
final int GET_COLLECT_ARGS = nameCursor++;
final int GET_UNBOX_RESULT = nameCursor++;
final int BOXED_ARGS = nameCursor++;
final int TRY_CATCH = nameCursor++;
final int UNBOX_RESULT = nameCursor++;
Name[] names = arguments(nameCursor - ARG_LIMIT, lambdaType);
BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
names[THIS_MH] = names[THIS_MH].withConstraint(data);
names[GET_TARGET] = new Name(data.getterFunction(0), names[THIS_MH]);
names[GET_CLASS] = new Name(data.getterFunction(1), names[THIS_MH]);
names[GET_CATCHER] = new Name(data.getterFunction(2), names[THIS_MH]);
names[GET_COLLECT_ARGS] = new Name(data.getterFunction(3), names[THIS_MH]);
names[GET_UNBOX_RESULT] = new Name(data.getterFunction(4), names[THIS_MH]);
// FIXME: rework argument boxing/result unboxing logic for LF interpretation
// t_{i}:L=MethodHandle.invokeBasic(collectArgs:L,a1:L,...);
MethodType collectArgsType = basicType.changeReturnType(Object.class);
MethodHandle invokeBasic = MethodHandles.basicInvoker(collectArgsType);
Object[] args = new Object[invokeBasic.type().parameterCount()];
args[0] = names[GET_COLLECT_ARGS];
System.arraycopy(names, ARG_BASE, args, 1, ARG_LIMIT-ARG_BASE);
names[BOXED_ARGS] = new Name(new NamedFunction(makeIntrinsic(invokeBasic, Intrinsic.GUARD_WITH_CATCH)), args);
// t_{i+1}:L=MethodHandleImpl.guardWithCatch(target:L,exType:L,catcher:L,t_{i}:L);
Object[] gwcArgs = new Object[] {names[GET_TARGET], names[GET_CLASS], names[GET_CATCHER], names[BOXED_ARGS]};
names[TRY_CATCH] = new Name(getFunction(NF_guardWithCatch), gwcArgs);
// t_{i+2}:I=MethodHandle.invokeBasic(unbox:L,t_{i+1}:L);
MethodHandle invokeBasicUnbox = MethodHandles.basicInvoker(MethodType.methodType(basicType.rtype(), Object.class));
Object[] unboxArgs = new Object[] {names[GET_UNBOX_RESULT], names[TRY_CATCH]};
names[UNBOX_RESULT] = new Name(invokeBasicUnbox, unboxArgs);
lform = new LambdaForm(lambdaType.parameterCount(), names, Kind.GUARD_WITH_CATCH);
return basicType.form().setCachedLambdaForm(MethodTypeForm.LF_GWC, lform);
}
static MethodHandle makeGuardWithCatch(MethodHandle target,
Class<? extends Throwable> exType,
MethodHandle catcher) {
MethodType type = target.type();
LambdaForm form = makeGuardWithCatchForm(type.basicType());
// Prepare auxiliary method handles used during LambdaForm interpretation.
// Box arguments and wrap them into Object[]: ValueConversions.array().
MethodType varargsType = type.changeReturnType(Object[].class);
MethodHandle collectArgs = varargsArray(type.parameterCount()).asType(varargsType);
MethodHandle unboxResult = unboxResultHandle(type.returnType());
BoundMethodHandle.SpeciesData data = BoundMethodHandle.speciesData_LLLLL();
BoundMethodHandle mh;
try {
mh = (BoundMethodHandle) data.factory().invokeBasic(type, form, (Object) target, (Object) exType,
(Object) catcher, (Object) collectArgs, (Object) unboxResult);
} catch (Throwable ex) {
throw uncaughtException(ex);
}
assert(mh.type() == type);
return mh;
}
/**
* Intrinsified during LambdaForm compilation
* (see {@link InvokerBytecodeGenerator#emitGuardWithCatch emitGuardWithCatch}).
*/
@Hidden
static Object guardWithCatch(MethodHandle target, Class<? extends Throwable> exType, MethodHandle catcher,
Object... av) throws Throwable {
// Use asFixedArity() to avoid unnecessary boxing of last argument for VarargsCollector case.
try {
return target.asFixedArity().invokeWithArguments(av);
} catch (Throwable t) {
if (!exType.isInstance(t)) throw t;
return catcher.asFixedArity().invokeWithArguments(prepend(av, t));
}
}
/** Prepend elements to an array. */
@Hidden
private static Object[] prepend(Object[] array, Object... elems) {
int nArray = array.length;
int nElems = elems.length;
Object[] newArray = new Object[nArray + nElems];
System.arraycopy(elems, 0, newArray, 0, nElems);
System.arraycopy(array, 0, newArray, nElems, nArray);
return newArray;
}
static MethodHandle throwException(MethodType type) {
assert(Throwable.class.isAssignableFrom(type.parameterType(0)));
int arity = type.parameterCount();
if (arity > 1) {
MethodHandle mh = throwException(type.dropParameterTypes(1, arity));
mh = MethodHandles.dropArgumentsTrusted(mh, 1, Arrays.copyOfRange(type.ptypes(), 1, arity));
return mh;
}
return makePairwiseConvert(getFunction(NF_throwException).resolvedHandle(), type, false, true);
}
static <T extends Throwable> Empty throwException(T t) throws T { throw t; }
static MethodHandle[] FAKE_METHOD_HANDLE_INVOKE = new MethodHandle[2];
static MethodHandle fakeMethodHandleInvoke(MemberName method) {
assert(method.isMethodHandleInvoke());
int idx = switch (method.getName()) {
case "invoke" -> 0;
case "invokeExact" -> 1;
default -> throw new InternalError(method.getName());
};
MethodHandle mh = FAKE_METHOD_HANDLE_INVOKE[idx];
if (mh != null) return mh;
MethodType type = MethodType.methodType(Object.class, UnsupportedOperationException.class,
MethodHandle.class, Object[].class);
mh = throwException(type);
mh = mh.bindTo(new UnsupportedOperationException("cannot reflectively invoke MethodHandle"));
if (!method.getInvocationType().equals(mh.type()))
throw new InternalError(method.toString());
mh = mh.withInternalMemberName(method, false);