/*
* Copyright (c) 2008, 2011, 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 java.lang.invoke.MethodHandles.Lookup;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import static java.lang.invoke.MethodHandleNatives.Constants.*;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
/**
* The JVM interface for the method handles package is all here.
* This is an interface internal and private to an implemetantion of JSR 292.
* <em>This class is not part of the JSR 292 standard.</em>
* @author jrose
*/
class MethodHandleNatives {
private MethodHandleNatives() { } // static only
/// MethodName support
static native void init(MemberName self, Object ref);
static native void expand(MemberName self);
static native void resolve(MemberName self, Class<?> caller);
static native int getMembers(Class<?> defc, String matchName, String matchSig,
int matchFlags, Class<?> caller, int skip, MemberName[] results);
/// MethodHandle support
/** Initialize the method handle to adapt the call. */
static native void init(AdapterMethodHandle self, MethodHandle target, int argnum);
/** Initialize the method handle to call the correct method, directly. */
static native void init(BoundMethodHandle self, Object target, int argnum);
/** Initialize the method handle to call as if by an invoke* instruction. */
static native void init(DirectMethodHandle self, Object ref, boolean doDispatch, Class<?> caller);
/** Initialize a method type, once per form. */
static native void init(MethodType self);
/** Fetch the vmtarget field.
* It will be sanitized as necessary to avoid exposing non-Java references.
* This routine is for debugging and reflection.
*/
static native Object getTarget(MethodHandle self, int format);
/** Fetch the name of the handled method, if available.
* This routine is for debugging and reflection.
*/
static MemberName getMethodName(MethodHandle self) {
return (MemberName) getTarget(self, ETF_METHOD_NAME);
}
/** Fetch the reflective version of the handled method, if available.
*/
static AccessibleObject getTargetMethod(MethodHandle self) {
return (AccessibleObject) getTarget(self, ETF_REFLECT_METHOD);
}
/** Fetch the target of this method handle.
* If it directly targets a method, return a MemberName for the method.
* If it is chained to another method handle, return that handle.
*/
static Object getTargetInfo(MethodHandle self) {
return getTarget(self, ETF_HANDLE_OR_METHOD_NAME);
}
static Object[] makeTarget(Class<?> defc, String name, String sig, int mods, Class<?> refc) {
return new Object[] { defc, name, sig, mods, refc };
}
/** Fetch MH-related JVM parameter.
* which=0 retrieves MethodHandlePushLimit
* which=1 retrieves stack slot push size (in address units)
*/
static native int getConstant(int which);
/** Java copy of MethodHandlePushLimit in range 2..255. */
static final int JVM_PUSH_LIMIT;
/** JVM stack motion (in words) after one slot is pushed, usually -1.
*/
static final int JVM_STACK_MOVE_UNIT;
/** Which conv-ops are implemented by the JVM? */
static final int CONV_OP_IMPLEMENTED_MASK;
/** Derived mode flag. Only false on some old JVM implementations. */
static final boolean HAVE_RICOCHET_FRAMES;
static final int OP_ROT_ARGS_DOWN_LIMIT_BIAS;
static final boolean COUNT_GWT;
/// CallSite support
/** Tell the JVM that we need to change the target of a CallSite. */
static native void setCallSiteTargetNormal(CallSite site, MethodHandle target);
static native void setCallSiteTargetVolatile(CallSite site, MethodHandle target);
private static native void registerNatives();
static {
registerNatives();
int k;
JVM_PUSH_LIMIT = getConstant(Constants.GC_JVM_PUSH_LIMIT);
JVM_STACK_MOVE_UNIT = getConstant(Constants.GC_JVM_STACK_MOVE_UNIT);
k = getConstant(Constants.GC_CONV_OP_IMPLEMENTED_MASK);
CONV_OP_IMPLEMENTED_MASK = (k != 0) ? k : DEFAULT_CONV_OP_IMPLEMENTED_MASK;
k = getConstant(Constants.GC_OP_ROT_ARGS_DOWN_LIMIT_BIAS);
OP_ROT_ARGS_DOWN_LIMIT_BIAS = (k != 0) ? (byte)k : -1;
HAVE_RICOCHET_FRAMES = (CONV_OP_IMPLEMENTED_MASK & (1<<OP_COLLECT_ARGS)) != 0;
COUNT_GWT = getConstant(Constants.GC_COUNT_GWT) != 0;
//sun.reflect.Reflection.registerMethodsToFilter(MethodHandleImpl.class, "init");
}
// All compile-time constants go here.
// There is an opportunity to check them against the JVM's idea of them.
static class Constants {
Constants() { } // static only
// MethodHandleImpl
static final int // for getConstant
GC_JVM_PUSH_LIMIT = 0,
GC_JVM_STACK_MOVE_UNIT = 1,
GC_CONV_OP_IMPLEMENTED_MASK = 2,
GC_OP_ROT_ARGS_DOWN_LIMIT_BIAS = 3,
GC_COUNT_GWT = 4;
static final int
ETF_HANDLE_OR_METHOD_NAME = 0, // all available data (immediate MH or method)
ETF_DIRECT_HANDLE = 1, // ultimate method handle (will be a DMH, may be self)
ETF_METHOD_NAME = 2, // ultimate method as MemberName
ETF_REFLECT_METHOD = 3; // ultimate method as java.lang.reflect object (sans refClass)
// MemberName
// The JVM uses values of -2 and above for vtable indexes.
// Field values are simple positive offsets.
// Ref: src/share/vm/oops/methodOop.hpp
// This value is negative enough to avoid such numbers,
// but not too negative.
static final int
MN_IS_METHOD = 0x00010000, // method (not constructor)
MN_IS_CONSTRUCTOR = 0x00020000, // constructor
MN_IS_FIELD = 0x00040000, // field
MN_IS_TYPE = 0x00080000, // nested type
MN_SEARCH_SUPERCLASSES = 0x00100000, // for MHN.getMembers
MN_SEARCH_INTERFACES = 0x00200000, // for MHN.getMembers
VM_INDEX_UNINITIALIZED = -99;
// BoundMethodHandle
/** Constants for decoding the vmargslot field, which contains 2 values. */
static final int
ARG_SLOT_PUSH_SHIFT = 16,
ARG_SLOT_MASK = (1<<ARG_SLOT_PUSH_SHIFT)-1;
// AdapterMethodHandle
/** Conversions recognized by the JVM.
* They must align with the constants in java.lang.invoke.AdapterMethodHandle,
* in the JVM file hotspot/src/share/vm/classfile/javaClasses.hpp.
*/
static final int
OP_RETYPE_ONLY = 0x0, // no argument changes; straight retype
OP_RETYPE_RAW = 0x1, // straight retype, trusted (void->int, Object->T)
OP_CHECK_CAST = 0x2, // ref-to-ref conversion; requires a Class argument
OP_PRIM_TO_PRIM = 0x3, // converts from one primitive to another
OP_REF_TO_PRIM = 0x4, // unboxes a wrapper to produce a primitive
OP_PRIM_TO_REF = 0x5, // boxes a primitive into a wrapper
OP_SWAP_ARGS = 0x6, // swap arguments (vminfo is 2nd arg)
OP_ROT_ARGS = 0x7, // rotate arguments (vminfo is displaced arg)
OP_DUP_ARGS = 0x8, // duplicates one or more arguments (at TOS)
OP_DROP_ARGS = 0x9, // remove one or more argument slots
OP_COLLECT_ARGS = 0xA, // combine arguments using an auxiliary function
OP_SPREAD_ARGS = 0xB, // expand in place a varargs array (of known size)
OP_FOLD_ARGS = 0xC, // combine but do not remove arguments; prepend result
//OP_UNUSED_13 = 0xD, // unused code, perhaps for reified argument lists
CONV_OP_LIMIT = 0xE; // limit of CONV_OP enumeration
/** Shift and mask values for decoding the AMH.conversion field.
* These numbers are shared with the JVM for creating AMHs.
*/
static final int
CONV_OP_MASK = 0xF00, // this nybble contains the conversion op field
CONV_TYPE_MASK = 0x0F, // fits T_ADDRESS and below
CONV_VMINFO_MASK = 0x0FF, // LSB is reserved for JVM use
CONV_VMINFO_SHIFT = 0, // position of bits in CONV_VMINFO_MASK
CONV_OP_SHIFT = 8, // position of bits in CONV_OP_MASK
CONV_DEST_TYPE_SHIFT = 12, // byte 2 has the adapter BasicType (if needed)
CONV_SRC_TYPE_SHIFT = 16, // byte 2 has the source BasicType (if needed)
CONV_STACK_MOVE_SHIFT = 20, // high 12 bits give signed SP change
CONV_STACK_MOVE_MASK = (1 << (32 - CONV_STACK_MOVE_SHIFT)) - 1;
/** Which conv-ops are implemented by the JVM? */
static final int DEFAULT_CONV_OP_IMPLEMENTED_MASK =
// Value to use if the corresponding JVM query fails.
((1<<OP_RETYPE_ONLY)
|(1<<OP_RETYPE_RAW)
|(1<<OP_CHECK_CAST)
|(1<<OP_PRIM_TO_PRIM)
|(1<<OP_REF_TO_PRIM)
|(1<<OP_SWAP_ARGS)
|(1<<OP_ROT_ARGS)
|(1<<OP_DUP_ARGS)
|(1<<OP_DROP_ARGS)
//|(1<<OP_SPREAD_ARGS)
);
/**
* Basic types as encoded in the JVM. These code values are not
* intended for use outside this class. They are used as part of
* a private interface between the JVM and this class.
*/
static final int
T_BOOLEAN = 4,
T_CHAR = 5,
T_FLOAT = 6,
T_DOUBLE = 7,
T_BYTE = 8,
T_SHORT = 9,
T_INT = 10,
T_LONG = 11,
T_OBJECT = 12,
//T_ARRAY = 13
T_VOID = 14,
//T_ADDRESS = 15
T_ILLEGAL = 99;
/**
* Constant pool reference-kind codes, as used by CONSTANT_MethodHandle CP entries.
*/
static final int
REF_getField = 1,
REF_getStatic = 2,
REF_putField = 3,
REF_putStatic = 4,
REF_invokeVirtual = 5,
REF_invokeStatic = 6,
REF_invokeSpecial = 7,
REF_newInvokeSpecial = 8,
REF_invokeInterface = 9;
}
private static native int getNamedCon(int which, Object[] name);
static boolean verifyConstants() {
Object[] box = { null };
for (int i = 0; ; i++) {
box[0] = null;
int vmval = getNamedCon(i, box);
if (box[0] == null) break;
String name = (String) box[0];
try {
Field con = Constants.class.getDeclaredField(name);
int jval = con.getInt(null);
if (jval == vmval) continue;
String err = (name+": JVM has "+vmval+" while Java has "+jval);
if (name.equals("CONV_OP_LIMIT")) {
System.err.println("warning: "+err);
continue;
}
throw new InternalError(err);
} catch (Exception ex) {
if (ex instanceof NoSuchFieldException) {
String err = (name+": JVM has "+vmval+" which Java does not define");
// ignore exotic ops the JVM cares about; we just wont issue them
if (name.startsWith("OP_") || name.startsWith("GC_")) {
System.err.println("warning: "+err);
continue;
}
}
throw new InternalError(name+": access failed, got "+ex);
}
}
return true;
}
static {
assert(verifyConstants());
}
// Up-calls from the JVM.
// These must NOT be public.
/**
* The JVM is linking an invokedynamic instruction. Create a reified call site for it.
*/
static CallSite makeDynamicCallSite(MethodHandle bootstrapMethod,
String name, MethodType type,
Object info,
MemberName callerMethod, int callerBCI) {
return CallSite.makeSite(bootstrapMethod, name, type, info, callerMethod, callerBCI);
}
/**
* Called by the JVM to check the length of a spread array.
*/
static void checkSpreadArgument(Object av, int n) {
MethodHandleStatics.checkSpreadArgument(av, n);
}
/**
* The JVM wants a pointer to a MethodType. Oblige it by finding or creating one.
*/
static MethodType findMethodHandleType(Class<?> rtype, Class<?>[] ptypes) {
return MethodType.makeImpl(rtype, ptypes, true);
}
/**
* The JVM wants to use a MethodType with inexact invoke. Give the runtime fair warning.
*/
static void notifyGenericMethodType(MethodType type) {
type.form().notifyGenericMethodType();
}
/**
* The JVM wants to raise an exception. Here's the path.
*/
static void raiseException(int code, Object actual, Object required) {
String message = null;
switch (code) {
case 190: // arraylength
try {
String reqLength = "";
if (required instanceof AdapterMethodHandle) {
int conv = ((AdapterMethodHandle)required).getConversion();
int spChange = AdapterMethodHandle.extractStackMove(conv);
reqLength = " of length "+(spChange+1);
}
int actualLength = actual == null ? 0 : java.lang.reflect.Array.getLength(actual);
message = "required array"+reqLength+", but encountered wrong length "+actualLength;
break;
} catch (IllegalArgumentException ex) {
}
required = Object[].class; // should have been an array
code = 192; // checkcast
break;
case 191: // athrow
// JVM is asking us to wrap an exception which happened during resolving
if (required == BootstrapMethodError.class) {
throw new BootstrapMethodError((Throwable) actual);
}
break;
}
// disregard the identity of the actual object, if it is not a class:
if (message == null) {
if (!(actual instanceof Class) && !(actual instanceof MethodType))
actual = actual.getClass();
if (actual != null)
message = "required "+required+" but encountered "+actual;
else
message = "required "+required;
}
switch (code) {
case 190: // arraylength
throw new ArrayIndexOutOfBoundsException(message);
case 50: //_aaload
throw new ClassCastException(message);
case 192: // checkcast
throw new ClassCastException(message);
default:
throw new InternalError("unexpected code "+code+": "+message);
}
}
/**
* The JVM is resolving a CONSTANT_MethodHandle CP entry. And it wants our help.
* It will make an up-call to this method. (Do not change the name or signature.)
*/
static MethodHandle linkMethodHandleConstant(Class<?> callerClass, int refKind,
Class<?> defc, String name, Object type) {
try {
Lookup lookup = IMPL_LOOKUP.in(callerClass);
return lookup.linkMethodHandleConstant(refKind, defc, name, type);
} catch (ReflectiveOperationException ex) {
Error err = new IncompatibleClassChangeError();
err.initCause(ex);
throw err;
}
}
/**
* This assertion marks code which was written before ricochet frames were implemented.
* Such code will go away when the ports catch up.
*/
static boolean workaroundWithoutRicochetFrames() {
assert(!HAVE_RICOCHET_FRAMES) : "this code should not be executed if `-XX:+UseRicochetFrames is enabled";
return true;
}
}