Java example source code file (MemberName.java)
The MemberName.java Java example source code/*
* 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.lang.invoke;
import sun.invoke.util.BytecodeDescriptor;
import sun.invoke.util.VerifyAccess;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Member;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import static java.lang.invoke.MethodHandleNatives.Constants.*;
import static java.lang.invoke.MethodHandleStatics.*;
import java.util.Objects;
/**
* A {@code MemberName} is a compact symbolic datum which fully characterizes
* a method or field reference.
* A member name refers to a field, method, constructor, or member type.
* Every member name has a simple name (a string) and a type (either a Class or MethodType).
* A member name may also have a non-null declaring class, or it may be simply
* a naked name/type pair.
* A member name may also have non-zero modifier flags.
* Finally, a member name may be either resolved or unresolved.
* If it is resolved, the existence of the named
* <p>
* Whether resolved or not, a member name provides no access rights or
* invocation capability to its possessor. It is merely a compact
* representation of all symbolic information necessary to link to
* and properly use the named member.
* <p>
* When resolved, a member name's internal implementation may include references to JVM metadata.
* This representation is stateless and only decriptive.
* It provides no private information and no capability to use the member.
* <p>
* By contrast, a {@linkplain java.lang.reflect.Method} contains fuller information
* about the internals of a method (except its bytecodes) and also
* allows invocation. A MemberName is much lighter than a Method,
* since it contains about 7 fields to the 16 of Method (plus its sub-arrays),
* and those seven fields omit much of the information in Method.
* @author jrose
*/
/*non-public*/ final class MemberName implements Member, Cloneable {
private Class<?> clazz; // class in which the method is defined
private String name; // may be null if not yet materialized
private Object type; // may be null if not yet materialized
private int flags; // modifier bits; see reflect.Modifier
//@Injected JVM_Method* vmtarget;
//@Injected int vmindex;
private Object resolution; // if null, this guy is resolved
/** Return the declaring class of this member.
* In the case of a bare name and type, the declaring class will be null.
*/
public Class<?> getDeclaringClass() {
return clazz;
}
/** Utility method producing the class loader of the declaring class. */
public ClassLoader getClassLoader() {
return clazz.getClassLoader();
}
/** Return the simple name of this member.
* For a type, it is the same as {@link Class#getSimpleName}.
* For a method or field, it is the simple name of the member.
* For a constructor, it is always {@code "<init>"}.
*/
public String getName() {
if (name == null) {
expandFromVM();
if (name == null) {
return null;
}
}
return name;
}
public MethodType getMethodOrFieldType() {
if (isInvocable())
return getMethodType();
if (isGetter())
return MethodType.methodType(getFieldType());
if (isSetter())
return MethodType.methodType(void.class, getFieldType());
throw new InternalError("not a method or field: "+this);
}
/** Return the declared type of this member, which
* must be a method or constructor.
*/
public MethodType getMethodType() {
if (type == null) {
expandFromVM();
if (type == null) {
return null;
}
}
if (!isInvocable()) {
throw newIllegalArgumentException("not invocable, no method type");
}
{
// Get a snapshot of type which doesn't get changed by racing threads.
final Object type = this.type;
if (type instanceof MethodType) {
return (MethodType) type;
}
}
// type is not a MethodType yet. Convert it thread-safely.
synchronized (this) {
if (type instanceof String) {
String sig = (String) type;
MethodType res = MethodType.fromMethodDescriptorString(sig, getClassLoader());
type = res;
} else if (type instanceof Object[]) {
Object[] typeInfo = (Object[]) type;
Class<?>[] ptypes = (Class[]) typeInfo[1];
Class<?> rtype = (Class) typeInfo[0];
MethodType res = MethodType.methodType(rtype, ptypes);
type = res;
}
// Make sure type is a MethodType for racing threads.
assert type instanceof MethodType : "bad method type " + type;
}
return (MethodType) type;
}
/** Return the actual type under which this method or constructor must be invoked.
* For non-static methods or constructors, this is the type with a leading parameter,
* a reference to declaring class. For static methods, it is the same as the declared type.
*/
public MethodType getInvocationType() {
MethodType itype = getMethodOrFieldType();
if (isConstructor() && getReferenceKind() == REF_newInvokeSpecial)
return itype.changeReturnType(clazz);
if (!isStatic())
return itype.insertParameterTypes(0, clazz);
return itype;
}
/** Utility method producing the parameter types of the method type. */
public Class<?>[] getParameterTypes() {
return getMethodType().parameterArray();
}
/** Utility method producing the return type of the method type. */
public Class<?> getReturnType() {
return getMethodType().returnType();
}
/** Return the declared type of this member, which
* must be a field or type.
* If it is a type member, that type itself is returned.
*/
public Class<?> getFieldType() {
if (type == null) {
expandFromVM();
if (type == null) {
return null;
}
}
if (isInvocable()) {
throw newIllegalArgumentException("not a field or nested class, no simple type");
}
{
// Get a snapshot of type which doesn't get changed by racing threads.
final Object type = this.type;
if (type instanceof Class<?>) {
return (Class<?>) type;
}
}
// type is not a Class yet. Convert it thread-safely.
synchronized (this) {
if (type instanceof String) {
String sig = (String) type;
MethodType mtype = MethodType.fromMethodDescriptorString("()"+sig, getClassLoader());
Class<?> res = mtype.returnType();
type = res;
}
// Make sure type is a Class for racing threads.
assert type instanceof Class<?> : "bad field type " + type;
}
return (Class<?>) type;
}
/** Utility method to produce either the method type or field type of this member. */
public Object getType() {
return (isInvocable() ? getMethodType() : getFieldType());
}
/** Utility method to produce the signature of this member,
* used within the class file format to describe its type.
*/
public String getSignature() {
if (type == null) {
expandFromVM();
if (type == null) {
return null;
}
}
if (isInvocable())
return BytecodeDescriptor.unparse(getMethodType());
else
return BytecodeDescriptor.unparse(getFieldType());
}
/** Return the modifier flags of this member.
* @see java.lang.reflect.Modifier
*/
public int getModifiers() {
return (flags & RECOGNIZED_MODIFIERS);
}
/** Return the reference kind of this member, or zero if none.
*/
public byte getReferenceKind() {
return (byte) ((flags >>> MN_REFERENCE_KIND_SHIFT) & MN_REFERENCE_KIND_MASK);
}
private boolean referenceKindIsConsistent() {
byte refKind = getReferenceKind();
if (refKind == REF_NONE) return isType();
if (isField()) {
assert(staticIsConsistent());
assert(MethodHandleNatives.refKindIsField(refKind));
} else if (isConstructor()) {
assert(refKind == REF_newInvokeSpecial || refKind == REF_invokeSpecial);
} else if (isMethod()) {
assert(staticIsConsistent());
assert(MethodHandleNatives.refKindIsMethod(refKind));
if (clazz.isInterface())
assert(refKind == REF_invokeInterface ||
refKind == REF_invokeStatic ||
refKind == REF_invokeSpecial ||
refKind == REF_invokeVirtual && isObjectPublicMethod());
} else {
assert(false);
}
return true;
}
private boolean isObjectPublicMethod() {
if (clazz == Object.class) return true;
MethodType mtype = getMethodType();
if (name.equals("toString") && mtype.returnType() == String.class && mtype.parameterCount() == 0)
return true;
if (name.equals("hashCode") && mtype.returnType() == int.class && mtype.parameterCount() == 0)
return true;
if (name.equals("equals") && mtype.returnType() == boolean.class && mtype.parameterCount() == 1 && mtype.parameterType(0) == Object.class)
return true;
return false;
}
/*non-public*/ boolean referenceKindIsConsistentWith(int originalRefKind) {
int refKind = getReferenceKind();
if (refKind == originalRefKind) return true;
switch (originalRefKind) {
case REF_invokeInterface:
// Looking up an interface method, can get (e.g.) Object.hashCode
assert(refKind == REF_invokeVirtual ||
refKind == REF_invokeSpecial) : this;
return true;
case REF_invokeVirtual:
case REF_newInvokeSpecial:
// Looked up a virtual, can get (e.g.) final String.hashCode.
assert(refKind == REF_invokeSpecial) : this;
return true;
}
assert(false) : this+" != "+MethodHandleNatives.refKindName((byte)originalRefKind);
return true;
}
private boolean staticIsConsistent() {
byte refKind = getReferenceKind();
return MethodHandleNatives.refKindIsStatic(refKind) == isStatic() || getModifiers() == 0;
}
private boolean vminfoIsConsistent() {
byte refKind = getReferenceKind();
assert(isResolved()); // else don't call
Object vminfo = MethodHandleNatives.getMemberVMInfo(this);
assert(vminfo instanceof Object[]);
long vmindex = (Long) ((Object[])vminfo)[0];
Object vmtarget = ((Object[])vminfo)[1];
if (MethodHandleNatives.refKindIsField(refKind)) {
assert(vmindex >= 0) : vmindex + ":" + this;
assert(vmtarget instanceof Class);
} else {
if (MethodHandleNatives.refKindDoesDispatch(refKind))
assert(vmindex >= 0) : vmindex + ":" + this;
else
assert(vmindex < 0) : vmindex;
assert(vmtarget instanceof MemberName) : vmtarget + " in " + this;
}
return true;
}
private MemberName changeReferenceKind(byte refKind, byte oldKind) {
assert(getReferenceKind() == oldKind);
assert(MethodHandleNatives.refKindIsValid(refKind));
flags += (((int)refKind - oldKind) << MN_REFERENCE_KIND_SHIFT);
// if (isConstructor() && refKind != REF_newInvokeSpecial)
// flags += (IS_METHOD - IS_CONSTRUCTOR);
// else if (refKind == REF_newInvokeSpecial && isMethod())
// flags += (IS_CONSTRUCTOR - IS_METHOD);
return this;
}
private boolean testFlags(int mask, int value) {
return (flags & mask) == value;
}
private boolean testAllFlags(int mask) {
return testFlags(mask, mask);
}
private boolean testAnyFlags(int mask) {
return !testFlags(mask, 0);
}
/** Utility method to query if this member is a method handle invocation (invoke or invokeExact). */
public boolean isMethodHandleInvoke() {
final int bits = MH_INVOKE_MODS;
final int negs = Modifier.STATIC;
if (testFlags(bits | negs, bits) &&
clazz == MethodHandle.class) {
return isMethodHandleInvokeName(name);
}
return false;
}
public static boolean isMethodHandleInvokeName(String name) {
return name.equals("invoke") || name.equals("invokeExact");
}
private static final int MH_INVOKE_MODS = Modifier.NATIVE | Modifier.FINAL | Modifier.PUBLIC;
/** Utility method to query the modifier flags of this member. */
public boolean isStatic() {
return Modifier.isStatic(flags);
}
/** Utility method to query the modifier flags of this member. */
public boolean isPublic() {
return Modifier.isPublic(flags);
}
/** Utility method to query the modifier flags of this member. */
public boolean isPrivate() {
return Modifier.isPrivate(flags);
}
/** Utility method to query the modifier flags of this member. */
public boolean isProtected() {
return Modifier.isProtected(flags);
}
/** Utility method to query the modifier flags of this member. */
public boolean isFinal() {
return Modifier.isFinal(flags);
}
/** Utility method to query whether this member or its defining class is final. */
public boolean canBeStaticallyBound() {
return Modifier.isFinal(flags | clazz.getModifiers());
}
/** Utility method to query the modifier flags of this member. */
public boolean isVolatile() {
return Modifier.isVolatile(flags);
}
/** Utility method to query the modifier flags of this member. */
public boolean isAbstract() {
return Modifier.isAbstract(flags);
}
/** Utility method to query the modifier flags of this member. */
public boolean isNative() {
return Modifier.isNative(flags);
}
// let the rest (native, volatile, transient, etc.) be tested via Modifier.isFoo
// unofficial modifier flags, used by HotSpot:
static final int BRIDGE = 0x00000040;
static final int VARARGS = 0x00000080;
static final int SYNTHETIC = 0x00001000;
static final int ANNOTATION= 0x00002000;
static final int ENUM = 0x00004000;
/** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
public boolean isBridge() {
return testAllFlags(IS_METHOD | BRIDGE);
}
/** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
public boolean isVarargs() {
return testAllFlags(VARARGS) && isInvocable();
}
/** Utility method to query the modifier flags of this member; returns false if the member is not a method. */
public boolean isSynthetic() {
return testAllFlags(SYNTHETIC);
}
static final String CONSTRUCTOR_NAME = "<init>"; // the ever-popular
// modifiers exported by the JVM:
static final int RECOGNIZED_MODIFIERS = 0xFFFF;
// private flags, not part of RECOGNIZED_MODIFIERS:
static final int
IS_METHOD = MN_IS_METHOD, // method (not constructor)
IS_CONSTRUCTOR = MN_IS_CONSTRUCTOR, // constructor
IS_FIELD = MN_IS_FIELD, // field
IS_TYPE = MN_IS_TYPE, // nested type
CALLER_SENSITIVE = MN_CALLER_SENSITIVE; // @CallerSensitive annotation detected
static final int ALL_ACCESS = Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED;
static final int ALL_KINDS = IS_METHOD | IS_CONSTRUCTOR | IS_FIELD | IS_TYPE;
static final int IS_INVOCABLE = IS_METHOD | IS_CONSTRUCTOR;
static final int IS_FIELD_OR_METHOD = IS_METHOD | IS_FIELD;
static final int SEARCH_ALL_SUPERS = MN_SEARCH_SUPERCLASSES | MN_SEARCH_INTERFACES;
/** Utility method to query whether this member is a method or constructor. */
public boolean isInvocable() {
return testAnyFlags(IS_INVOCABLE);
}
/** Utility method to query whether this member is a method, constructor, or field. */
public boolean isFieldOrMethod() {
return testAnyFlags(IS_FIELD_OR_METHOD);
}
/** Query whether this member is a method. */
public boolean isMethod() {
return testAllFlags(IS_METHOD);
}
/** Query whether this member is a constructor. */
public boolean isConstructor() {
return testAllFlags(IS_CONSTRUCTOR);
}
/** Query whether this member is a field. */
public boolean isField() {
return testAllFlags(IS_FIELD);
}
/** Query whether this member is a type. */
public boolean isType() {
return testAllFlags(IS_TYPE);
}
/** Utility method to query whether this member is neither public, private, nor protected. */
public boolean isPackage() {
return !testAnyFlags(ALL_ACCESS);
}
/** Query whether this member has a CallerSensitive annotation. */
public boolean isCallerSensitive() {
return testAllFlags(CALLER_SENSITIVE);
}
/** Utility method to query whether this member is accessible from a given lookup class. */
public boolean isAccessibleFrom(Class<?> lookupClass) {
return VerifyAccess.isMemberAccessible(this.getDeclaringClass(), this.getDeclaringClass(), flags,
lookupClass, ALL_ACCESS|MethodHandles.Lookup.PACKAGE);
}
/** Initialize a query. It is not resolved. */
private void init(Class<?> defClass, String name, Object type, int flags) {
// defining class is allowed to be null (for a naked name/type pair)
//name.toString(); // null check
//type.equals(type); // null check
// fill in fields:
this.clazz = defClass;
this.name = name;
this.type = type;
this.flags = flags;
assert(testAnyFlags(ALL_KINDS));
assert(this.resolution == null); // nobody should have touched this yet
//assert(referenceKindIsConsistent()); // do this after resolution
}
/**
* Calls down to the VM to fill in the fields. This method is
* synchronized to avoid racing calls.
*/
private void expandFromVM() {
if (type != null) {
return;
}
if (!isResolved()) {
return;
}
MethodHandleNatives.expand(this);
}
// Capturing information from the Core Reflection API:
private static int flagsMods(int flags, int mods, byte refKind) {
assert((flags & RECOGNIZED_MODIFIERS) == 0);
assert((mods & ~RECOGNIZED_MODIFIERS) == 0);
assert((refKind & ~MN_REFERENCE_KIND_MASK) == 0);
return flags | mods | (refKind << MN_REFERENCE_KIND_SHIFT);
}
/** Create a name for the given reflected method. The resulting name will be in a resolved state. */
public MemberName(Method m) {
this(m, false);
}
@SuppressWarnings("LeakingThisInConstructor")
public MemberName(Method m, boolean wantSpecial) {
m.getClass(); // NPE check
// fill in vmtarget, vmindex while we have m in hand:
MethodHandleNatives.init(this, m);
if (clazz == null) { // MHN.init failed
if (m.getDeclaringClass() == MethodHandle.class &&
isMethodHandleInvokeName(m.getName())) {
// The JVM did not reify this signature-polymorphic instance.
// Need a special case here.
// See comments on MethodHandleNatives.linkMethod.
MethodType type = MethodType.methodType(m.getReturnType(), m.getParameterTypes());
int flags = flagsMods(IS_METHOD, m.getModifiers(), REF_invokeVirtual);
init(MethodHandle.class, m.getName(), type, flags);
if (isMethodHandleInvoke())
return;
}
throw new LinkageError(m.toString());
}
assert(isResolved() && this.clazz != null);
this.name = m.getName();
if (this.type == null)
this.type = new Object[] { m.getReturnType(), m.getParameterTypes() };
if (wantSpecial) {
if (isAbstract())
throw new AbstractMethodError(this.toString());
if (getReferenceKind() == REF_invokeVirtual)
changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
else if (getReferenceKind() == REF_invokeInterface)
// invokeSpecial on a default method
changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
}
}
public MemberName asSpecial() {
switch (getReferenceKind()) {
case REF_invokeSpecial: return this;
case REF_invokeVirtual: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeVirtual);
case REF_invokeInterface: return clone().changeReferenceKind(REF_invokeSpecial, REF_invokeInterface);
case REF_newInvokeSpecial: return clone().changeReferenceKind(REF_invokeSpecial, REF_newInvokeSpecial);
}
throw new IllegalArgumentException(this.toString());
}
/** If this MN is not REF_newInvokeSpecial, return a clone with that ref. kind.
* In that case it must already be REF_invokeSpecial.
*/
public MemberName asConstructor() {
switch (getReferenceKind()) {
case REF_invokeSpecial: return clone().changeReferenceKind(REF_newInvokeSpecial, REF_invokeSpecial);
case REF_newInvokeSpecial: return this;
}
throw new IllegalArgumentException(this.toString());
}
/** If this MN is a REF_invokeSpecial, return a clone with the "normal" kind
* REF_invokeVirtual; also switch either to REF_invokeInterface if clazz.isInterface.
* The end result is to get a fully virtualized version of the MN.
* (Note that resolving in the JVM will sometimes devirtualize, changing
* REF_invokeVirtual of a final to REF_invokeSpecial, and REF_invokeInterface
* in some corner cases to either of the previous two; this transform
* undoes that change under the assumption that it occurred.)
*/
public MemberName asNormalOriginal() {
byte normalVirtual = clazz.isInterface() ? REF_invokeInterface : REF_invokeVirtual;
byte refKind = getReferenceKind();
byte newRefKind = refKind;
MemberName result = this;
switch (refKind) {
case REF_invokeInterface:
case REF_invokeVirtual:
case REF_invokeSpecial:
newRefKind = normalVirtual;
break;
}
if (newRefKind == refKind)
return this;
result = clone().changeReferenceKind(newRefKind, refKind);
assert(this.referenceKindIsConsistentWith(result.getReferenceKind()));
return result;
}
/** Create a name for the given reflected constructor. The resulting name will be in a resolved state. */
@SuppressWarnings("LeakingThisInConstructor")
public MemberName(Constructor<?> ctor) {
ctor.getClass(); // NPE check
// fill in vmtarget, vmindex while we have ctor in hand:
MethodHandleNatives.init(this, ctor);
assert(isResolved() && this.clazz != null);
this.name = CONSTRUCTOR_NAME;
if (this.type == null)
this.type = new Object[] { void.class, ctor.getParameterTypes() };
}
/** Create a name for the given reflected field. The resulting name will be in a resolved state.
*/
public MemberName(Field fld) {
this(fld, false);
}
@SuppressWarnings("LeakingThisInConstructor")
public MemberName(Field fld, boolean makeSetter) {
fld.getClass(); // NPE check
// fill in vmtarget, vmindex while we have fld in hand:
MethodHandleNatives.init(this, fld);
assert(isResolved() && this.clazz != null);
this.name = fld.getName();
this.type = fld.getType();
assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
byte refKind = this.getReferenceKind();
assert(refKind == (isStatic() ? REF_getStatic : REF_getField));
if (makeSetter) {
changeReferenceKind((byte)(refKind + (REF_putStatic - REF_getStatic)), refKind);
}
}
public boolean isGetter() {
return MethodHandleNatives.refKindIsGetter(getReferenceKind());
}
public boolean isSetter() {
return MethodHandleNatives.refKindIsSetter(getReferenceKind());
}
public MemberName asSetter() {
byte refKind = getReferenceKind();
assert(MethodHandleNatives.refKindIsGetter(refKind));
assert((REF_putStatic - REF_getStatic) == (REF_putField - REF_getField));
byte setterRefKind = (byte)(refKind + (REF_putField - REF_getField));
return clone().changeReferenceKind(setterRefKind, refKind);
}
/** Create a name for the given class. The resulting name will be in a resolved state. */
public MemberName(Class<?> type) {
init(type.getDeclaringClass(), type.getSimpleName(), type,
flagsMods(IS_TYPE, type.getModifiers(), REF_NONE));
initResolved(true);
}
/**
* Create a name for a signature-polymorphic invoker.
* This is a placeholder for a signature-polymorphic instance
* (of MH.invokeExact, etc.) that the JVM does not reify.
* See comments on {@link MethodHandleNatives#linkMethod}.
*/
static MemberName makeMethodHandleInvoke(String name, MethodType type) {
return makeMethodHandleInvoke(name, type, MH_INVOKE_MODS | SYNTHETIC);
}
static MemberName makeMethodHandleInvoke(String name, MethodType type, int mods) {
MemberName mem = new MemberName(MethodHandle.class, name, type, REF_invokeVirtual);
mem.flags |= mods; // it's not resolved, but add these modifiers anyway
assert(mem.isMethodHandleInvoke()) : mem;
return mem;
}
// bare-bones constructor; the JVM will fill it in
MemberName() { }
// locally useful cloner
@Override protected MemberName clone() {
try {
return (MemberName) super.clone();
} catch (CloneNotSupportedException ex) {
throw newInternalError(ex);
}
}
/** Get the definition of this member name.
* This may be in a super-class of the declaring class of this member.
*/
public MemberName getDefinition() {
if (!isResolved()) throw new IllegalStateException("must be resolved: "+this);
if (isType()) return this;
MemberName res = this.clone();
res.clazz = null;
res.type = null;
res.name = null;
res.resolution = res;
res.expandFromVM();
assert(res.getName().equals(this.getName()));
return res;
}
@Override
public int hashCode() {
return Objects.hash(clazz, getReferenceKind(), name, getType());
}
@Override
public boolean equals(Object that) {
return (that instanceof MemberName && this.equals((MemberName)that));
}
/** Decide if two member names have exactly the same symbolic content.
* Does not take into account any actual class members, so even if
* two member names resolve to the same actual member, they may
* be distinct references.
*/
public boolean equals(MemberName that) {
if (this == that) return true;
if (that == null) return false;
return this.clazz == that.clazz
&& this.getReferenceKind() == that.getReferenceKind()
&& Objects.equals(this.name, that.name)
&& Objects.equals(this.getType(), that.getType());
}
// Construction from symbolic parts, for queries:
/** Create a field or type name from the given components:
* Declaring class, name, type, reference kind.
* The declaring class may be supplied as null if this is to be a bare name and type.
* The resulting name will in an unresolved state.
*/
public MemberName(Class<?> defClass, String name, Class type, byte refKind) {
init(defClass, name, type, flagsMods(IS_FIELD, 0, refKind));
initResolved(false);
}
/** Create a field or type name from the given components: Declaring class, name, type.
* The declaring class may be supplied as null if this is to be a bare name and type.
* The modifier flags default to zero.
* The resulting name will in an unresolved state.
*/
public MemberName(Class<?> defClass, String name, Class type, Void unused) {
this(defClass, name, type, REF_NONE);
initResolved(false);
}
/** Create a method or constructor name from the given components: Declaring class, name, type, modifiers.
* It will be a constructor if and only if the name is {@code "<init>"}.
* The declaring class may be supplied as null if this is to be a bare name and type.
* The last argument is optional, a boolean which requests REF_invokeSpecial.
* The resulting name will in an unresolved state.
*/
public MemberName(Class<?> defClass, String name, MethodType type, byte refKind) {
int initFlags = (name != null && name.equals(CONSTRUCTOR_NAME) ? IS_CONSTRUCTOR : IS_METHOD);
init(defClass, name, type, flagsMods(initFlags, 0, refKind));
initResolved(false);
}
/** Create a method, constructor, or field name from the given components:
* Reference kind, declaring class, name, type.
*/
public MemberName(byte refKind, Class<?> defClass, String name, Object type) {
int kindFlags;
if (MethodHandleNatives.refKindIsField(refKind)) {
kindFlags = IS_FIELD;
if (!(type instanceof Class))
throw newIllegalArgumentException("not a field type");
} else if (MethodHandleNatives.refKindIsMethod(refKind)) {
kindFlags = IS_METHOD;
if (!(type instanceof MethodType))
throw newIllegalArgumentException("not a method type");
} else if (refKind == REF_newInvokeSpecial) {
kindFlags = IS_CONSTRUCTOR;
if (!(type instanceof MethodType) ||
!CONSTRUCTOR_NAME.equals(name))
throw newIllegalArgumentException("not a constructor type or name");
} else {
throw newIllegalArgumentException("bad reference kind "+refKind);
}
init(defClass, name, type, flagsMods(kindFlags, 0, refKind));
initResolved(false);
}
/** Query whether this member name is resolved to a non-static, non-final method.
*/
public boolean hasReceiverTypeDispatch() {
return MethodHandleNatives.refKindDoesDispatch(getReferenceKind());
}
/** Query whether this member name is resolved.
* A resolved member name is one for which the JVM has found
* a method, constructor, field, or type binding corresponding exactly to the name.
* (Document?)
*/
public boolean isResolved() {
return resolution == null;
}
private void initResolved(boolean isResolved) {
assert(this.resolution == null); // not initialized yet!
if (!isResolved)
this.resolution = this;
assert(isResolved() == isResolved);
}
void checkForTypeAlias() {
if (isInvocable()) {
MethodType type;
if (this.type instanceof MethodType)
type = (MethodType) this.type;
else
this.type = type = getMethodType();
if (type.erase() == type) return;
if (VerifyAccess.isTypeVisible(type, clazz)) return;
throw new LinkageError("bad method type alias: "+type+" not visible from "+clazz);
} else {
Class<?> type;
if (this.type instanceof Class<?>)
type = (Class<?>) this.type;
else
this.type = type = getFieldType();
if (VerifyAccess.isTypeVisible(type, clazz)) return;
throw new LinkageError("bad field type alias: "+type+" not visible from "+clazz);
}
}
/** Produce a string form of this member name.
* For types, it is simply the type's own string (as reported by {@code toString}).
* For fields, it is {@code "DeclaringClass.name/type"}.
* For methods and constructors, it is {@code "DeclaringClass.name(ptype...)rtype"}.
* If the declaring class is null, the prefix {@code "DeclaringClass."} is omitted.
* If the member is unresolved, a prefix {@code "*."} is prepended.
*/
@SuppressWarnings("LocalVariableHidesMemberVariable")
@Override
public String toString() {
if (isType())
return type.toString(); // class java.lang.String
// else it is a field, method, or constructor
StringBuilder buf = new StringBuilder();
if (getDeclaringClass() != null) {
buf.append(getName(clazz));
buf.append('.');
}
String name = getName();
buf.append(name == null ? "*" : name);
Object type = getType();
if (!isInvocable()) {
buf.append('/');
buf.append(type == null ? "*" : getName(type));
} else {
buf.append(type == null ? "(*)*" : getName(type));
}
byte refKind = getReferenceKind();
if (refKind != REF_NONE) {
buf.append('/');
buf.append(MethodHandleNatives.refKindName(refKind));
}
//buf.append("#").append(System.identityHashCode(this));
return buf.toString();
}
private static String getName(Object obj) {
if (obj instanceof Class<?>)
return ((Class<?>)obj).getName();
return String.valueOf(obj);
}
public IllegalAccessException makeAccessException(String message, Object from) {
message = message + ": "+ toString();
if (from != null) message += ", from " + from;
return new IllegalAccessException(message);
}
private String message() {
if (isResolved())
return "no access";
else if (isConstructor())
return "no such constructor";
else if (isMethod())
return "no such method";
else
return "no such field";
}
public ReflectiveOperationException makeAccessException() {
String message = message() + ": "+ toString();
ReflectiveOperationException ex;
if (isResolved() || !(resolution instanceof NoSuchMethodError ||
resolution instanceof NoSuchFieldError))
ex = new IllegalAccessException(message);
else if (isConstructor())
ex = new NoSuchMethodException(message);
else if (isMethod())
ex = new NoSuchMethodException(message);
else
ex = new NoSuchFieldException(message);
if (resolution instanceof Throwable)
ex.initCause((Throwable) resolution);
return ex;
}
/** Actually making a query requires an access check. */
/*non-public*/ static Factory getFactory() {
return Factory.INSTANCE;
}
/** A factory type for resolving member names with the help of the VM.
* TBD: Define access-safe public constructors for this factory.
*/
/*non-public*/ static class Factory {
private Factory() { } // singleton pattern
static Factory INSTANCE = new Factory();
private static int ALLOWED_FLAGS = ALL_KINDS;
/// Queries
List<MemberName> getMembers(Class defc,
String matchName, Object matchType,
int matchFlags, Class<?> lookupClass) {
matchFlags &= ALLOWED_FLAGS;
String matchSig = null;
if (matchType != null) {
matchSig = BytecodeDescriptor.unparse(matchType);
if (matchSig.startsWith("("))
matchFlags &= ~(ALL_KINDS & ~IS_INVOCABLE);
else
matchFlags &= ~(ALL_KINDS & ~IS_FIELD);
}
final int BUF_MAX = 0x2000;
int len1 = matchName == null ? 10 : matchType == null ? 4 : 1;
MemberName[] buf = newMemberBuffer(len1);
int totalCount = 0;
ArrayList<MemberName[]> bufs = null;
int bufCount = 0;
for (;;) {
bufCount = MethodHandleNatives.getMembers(defc,
matchName, matchSig, matchFlags,
lookupClass,
totalCount, buf);
if (bufCount <= buf.length) {
if (bufCount < 0) bufCount = 0;
totalCount += bufCount;
break;
}
// JVM returned to us with an intentional overflow!
totalCount += buf.length;
int excess = bufCount - buf.length;
if (bufs == null) bufs = new ArrayList<>(1);
bufs.add(buf);
int len2 = buf.length;
len2 = Math.max(len2, excess);
len2 = Math.max(len2, totalCount / 4);
buf = newMemberBuffer(Math.min(BUF_MAX, len2));
}
ArrayList<MemberName> result = new ArrayList<>(totalCount);
if (bufs != null) {
for (MemberName[] buf0 : bufs) {
Collections.addAll(result, buf0);
}
}
result.addAll(Arrays.asList(buf).subList(0, bufCount));
// Signature matching is not the same as type matching, since
// one signature might correspond to several types.
// So if matchType is a Class or MethodType, refilter the results.
if (matchType != null && matchType != matchSig) {
for (Iterator<MemberName> it = result.iterator(); it.hasNext();) {
MemberName m = it.next();
if (!matchType.equals(m.getType()))
it.remove();
}
}
return result;
}
/** Produce a resolved version of the given member.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Access checking is performed on behalf of the given {@code lookupClass}.
* If lookup fails or access is not permitted, null is returned.
* Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
*/
private MemberName resolve(byte refKind, MemberName ref, Class<?> lookupClass) {
MemberName m = ref.clone(); // JVM will side-effect the ref
assert(refKind == m.getReferenceKind());
try {
m = MethodHandleNatives.resolve(m, lookupClass);
m.checkForTypeAlias();
m.resolution = null;
} catch (LinkageError ex) {
// JVM reports that the "bytecode behavior" would get an error
assert(!m.isResolved());
m.resolution = ex;
return m;
}
assert(m.referenceKindIsConsistent());
m.initResolved(true);
assert(m.vminfoIsConsistent());
return m;
}
/** Produce a resolved version of the given member.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Access checking is performed on behalf of the given {@code lookupClass}.
* If lookup fails or access is not permitted, a {@linkplain ReflectiveOperationException} is thrown.
* Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
*/
public
<NoSuchMemberException extends ReflectiveOperationException>
MemberName resolveOrFail(byte refKind, MemberName m, Class<?> lookupClass,
Class<NoSuchMemberException> nsmClass)
throws IllegalAccessException, NoSuchMemberException {
MemberName result = resolve(refKind, m, lookupClass);
if (result.isResolved())
return result;
ReflectiveOperationException ex = result.makeAccessException();
if (ex instanceof IllegalAccessException) throw (IllegalAccessException) ex;
throw nsmClass.cast(ex);
}
/** Produce a resolved version of the given member.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Access checking is performed on behalf of the given {@code lookupClass}.
* If lookup fails or access is not permitted, return null.
* Otherwise a fresh copy of the given member is returned, with modifier bits filled in.
*/
public
MemberName resolveOrNull(byte refKind, MemberName m, Class<?> lookupClass) {
MemberName result = resolve(refKind, m, lookupClass);
if (result.isResolved())
return result;
return null;
}
/** Return a list of all methods defined by the given class.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Access checking is performed on behalf of the given {@code lookupClass}.
* Inaccessible members are not added to the last.
*/
public List<MemberName> getMethods(Class defc, boolean searchSupers,
Class<?> lookupClass) {
return getMethods(defc, searchSupers, null, null, lookupClass);
}
/** Return a list of matching methods defined by the given class.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Returned methods will match the name (if not null) and the type (if not null).
* Access checking is performed on behalf of the given {@code lookupClass}.
* Inaccessible members are not added to the last.
*/
public List<MemberName> getMethods(Class defc, boolean searchSupers,
String name, MethodType type, Class<?> lookupClass) {
int matchFlags = IS_METHOD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
return getMembers(defc, name, type, matchFlags, lookupClass);
}
/** Return a list of all constructors defined by the given class.
* Access checking is performed on behalf of the given {@code lookupClass}.
* Inaccessible members are not added to the last.
*/
public List<MemberName> getConstructors(Class defc, Class lookupClass) {
return getMembers(defc, null, null, IS_CONSTRUCTOR, lookupClass);
}
/** Return a list of all fields defined by the given class.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Access checking is performed on behalf of the given {@code lookupClass}.
* Inaccessible members are not added to the last.
*/
public List<MemberName> getFields(Class defc, boolean searchSupers,
Class<?> lookupClass) {
return getFields(defc, searchSupers, null, null, lookupClass);
}
/** Return a list of all fields defined by the given class.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Returned fields will match the name (if not null) and the type (if not null).
* Access checking is performed on behalf of the given {@code lookupClass}.
* Inaccessible members are not added to the last.
*/
public List<MemberName> getFields(Class defc, boolean searchSupers,
String name, Class<?> type, Class lookupClass) {
int matchFlags = IS_FIELD | (searchSupers ? SEARCH_ALL_SUPERS : 0);
return getMembers(defc, name, type, matchFlags, lookupClass);
}
/** Return a list of all nested types defined by the given class.
* Super types are searched (for inherited members) if {@code searchSupers} is true.
* Access checking is performed on behalf of the given {@code lookupClass}.
* Inaccessible members are not added to the last.
*/
public List<MemberName> getNestedTypes(Class defc, boolean searchSupers,
Class<?> lookupClass) {
int matchFlags = IS_TYPE | (searchSupers ? SEARCH_ALL_SUPERS : 0);
return getMembers(defc, null, null, matchFlags, lookupClass);
}
private static MemberName[] newMemberBuffer(int length) {
MemberName[] buf = new MemberName[length];
// fill the buffer with dummy structs for the JVM to fill in
for (int i = 0; i < length; i++)
buf[i] = new MemberName();
return buf;
}
}
// static {
// System.out.println("Hello world! My methods are:");
// System.out.println(Factory.INSTANCE.getMethods(MemberName.class, true, null));
// }
}
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