/*
* Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package com.sun.tools.javac.jvm;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.code.TypeTag;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Types;
import com.sun.tools.javac.code.Types.UniqueType;
import com.sun.tools.javac.util.ArrayUtils;
import com.sun.tools.javac.util.Assert;
import com.sun.tools.javac.util.Filter;
import com.sun.tools.javac.util.Name;
import java.util.*;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;
import static com.sun.tools.javac.code.Kinds.*;
import static com.sun.tools.javac.code.Kinds.Kind.*;
/** An internal structure that corresponds to the constant pool of a classfile.
*
* <p><b>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
public class Pool {
public static final int MAX_ENTRIES = 0xFFFF;
public static final int MAX_STRING_LENGTH = 0xFFFF;
/** Index of next constant to be entered.
*/
int pp;
/** The initial pool buffer.
*/
Object[] pool;
/** A hashtable containing all constants in the pool.
*/
Map<Object,Integer> indices;
Types types;
/** Construct a pool with given number of elements and element array.
*/
public Pool(int pp, Object[] pool, Types types) {
this.pp = pp;
this.pool = pool;
this.types = types;
this.indices = new HashMap<>(pool.length);
for (int i = 1; i < pp; i++) {
if (pool[i] != null) indices.put(pool[i], i);
}
}
/** Construct an empty pool.
*/
public Pool(Types types) {
this(1, new Object[64], types);
}
/** Return the number of entries in the constant pool.
*/
public int numEntries() {
return pp;
}
/** Remove everything from this pool.
*/
public void reset() {
pp = 1;
indices.clear();
}
/** Place an object in the pool, unless it is already there.
* If object is a symbol also enter its owner unless the owner is a
* package. Return the object's index in the pool.
*/
public int put(Object value) {
value = makePoolValue(value);
Assert.check(!(value instanceof Type.TypeVar));
Assert.check(!(value instanceof Types.UniqueType &&
((UniqueType) value).type instanceof Type.TypeVar));
Integer index = indices.get(value);
if (index == null) {
index = pp;
indices.put(value, index);
pool = ArrayUtils.ensureCapacity(pool, pp);
pool[pp++] = value;
if (value instanceof Long || value instanceof Double) {
pool = ArrayUtils.ensureCapacity(pool, pp);
pool[pp++] = null;
}
}
return index.intValue();
}
Object makePoolValue(Object o) {
if (o instanceof DynamicMethodSymbol) {
return new DynamicMethod((DynamicMethodSymbol)o, types);
} else if (o instanceof MethodSymbol) {
return new Method((MethodSymbol)o, types);
} else if (o instanceof VarSymbol) {
return new Variable((VarSymbol)o, types);
} else if (o instanceof Type) {
Type t = (Type)o;
// ClassRefs can come from ClassSymbols or from Types.
// Return the symbol for these types to avoid duplicates
// in the constant pool
if (t.hasTag(TypeTag.CLASS))
return t.tsym;
else
return new UniqueType(t, types);
} else {
return o;
}
}
/** Return the given object's index in the pool,
* or -1 if object is not in there.
*/
public int get(Object o) {
Integer n = indices.get(o);
return n == null ? -1 : n.intValue();
}
static class Method extends DelegatedSymbol<MethodSymbol> {
UniqueType uniqueType;
Method(MethodSymbol m, Types types) {
super(m);
this.uniqueType = new UniqueType(m.type, types);
}
@DefinedBy(Api.LANGUAGE_MODEL)
public boolean equals(Object any) {
if (!(any instanceof Method)) return false;
MethodSymbol o = ((Method)any).other;
MethodSymbol m = this.other;
return
o.name == m.name &&
o.owner == m.owner &&
((Method)any).uniqueType.equals(uniqueType);
}
@DefinedBy(Api.LANGUAGE_MODEL)
public int hashCode() {
MethodSymbol m = this.other;
return
m.name.hashCode() * 33 +
m.owner.hashCode() * 9 +
uniqueType.hashCode();
}
}
static class DynamicMethod extends Method {
public Object[] uniqueStaticArgs;
DynamicMethod(DynamicMethodSymbol m, Types types) {
super(m, types);
uniqueStaticArgs = getUniqueTypeArray(m.staticArgs, types);
}
@Override @DefinedBy(Api.LANGUAGE_MODEL)
public boolean equals(Object any) {
return equalsImpl(any, true);
}
protected boolean equalsImpl(Object any, boolean includeDynamicArgs) {
if (includeDynamicArgs && !super.equals(any)) return false;
if (!(any instanceof DynamicMethod)) return false;
DynamicMethodSymbol dm1 = (DynamicMethodSymbol)other;
DynamicMethodSymbol dm2 = (DynamicMethodSymbol)((DynamicMethod)any).other;
return dm1.bsm == dm2.bsm &&
dm1.bsmKind == dm2.bsmKind &&
Arrays.equals(uniqueStaticArgs,
((DynamicMethod)any).uniqueStaticArgs);
}
@Override @DefinedBy(Api.LANGUAGE_MODEL)
public int hashCode() {
return hashCodeImpl(true);
}
protected int hashCodeImpl(boolean includeDynamicArgs) {
int hash = includeDynamicArgs ? super.hashCode() : 0;
DynamicMethodSymbol dm = (DynamicMethodSymbol)other;
hash += dm.bsmKind * 7 +
dm.bsm.hashCode() * 11;
for (int i = 0; i < dm.staticArgs.length; i++) {
hash += (uniqueStaticArgs[i].hashCode() * 23);
}
return hash;
}
private Object[] getUniqueTypeArray(Object[] objects, Types types) {
Object[] result = new Object[objects.length];
for (int i = 0; i < objects.length; i++) {
if (objects[i] instanceof Type) {
result[i] = new UniqueType((Type)objects[i], types);
} else {
result[i] = objects[i];
}
}
return result;
}
static class BootstrapMethodsKey extends DynamicMethod {
BootstrapMethodsKey(DynamicMethodSymbol m, Types types) {
super(m, types);
}
@Override @DefinedBy(Api.LANGUAGE_MODEL)
public boolean equals(Object any) {
return equalsImpl(any, false);
}
@Override @DefinedBy(Api.LANGUAGE_MODEL)
public int hashCode() {
return hashCodeImpl(false);
}
Object[] getUniqueArgs() {
return uniqueStaticArgs;
}
}
static class BootstrapMethodsValue {
final MethodHandle mh;
final int index;
public BootstrapMethodsValue(MethodHandle mh, int index) {
this.mh = mh;
this.index = index;
}
}
}
static class Variable extends DelegatedSymbol<VarSymbol> {
UniqueType uniqueType;
Variable(VarSymbol v, Types types) {
super(v);
this.uniqueType = new UniqueType(v.type, types);
}
@DefinedBy(Api.LANGUAGE_MODEL)
public boolean equals(Object any) {
if (!(any instanceof Variable)) return false;
VarSymbol o = ((Variable)any).other;
VarSymbol v = other;
return
o.name == v.name &&
o.owner == v.owner &&
((Variable)any).uniqueType.equals(uniqueType);
}
@DefinedBy(Api.LANGUAGE_MODEL)
public int hashCode() {
VarSymbol v = other;
return
v.name.hashCode() * 33 +
v.owner.hashCode() * 9 +
uniqueType.hashCode();
}
}
public static class MethodHandle {
/** Reference kind - see ClassFile */
int refKind;
/** Reference symbol */
Symbol refSym;
UniqueType uniqueType;
public MethodHandle(int refKind, Symbol refSym, Types types) {
this.refKind = refKind;
this.refSym = refSym;
this.uniqueType = new UniqueType(this.refSym.type, types);
checkConsistent();
}
public boolean equals(Object other) {
if (!(other instanceof MethodHandle)) return false;
MethodHandle mr = (MethodHandle) other;
if (mr.refKind != refKind) return false;
Symbol o = mr.refSym;
return
o.name == refSym.name &&
o.owner == refSym.owner &&
((MethodHandle)other).uniqueType.equals(uniqueType);
}
public int hashCode() {
return
refKind * 65 +
refSym.name.hashCode() * 33 +
refSym.owner.hashCode() * 9 +
uniqueType.hashCode();
}
/**
* Check consistency of reference kind and symbol (see JVMS 4.4.8)
*/
@SuppressWarnings("fallthrough")
private void checkConsistent() {
boolean staticOk = false;
Kind expectedKind = null;
Filter<Name> nameFilter = nonInitFilter;
boolean interfaceOwner = false;
switch (refKind) {
case ClassFile.REF_getStatic:
case ClassFile.REF_putStatic:
staticOk = true;
case ClassFile.REF_getField:
case ClassFile.REF_putField:
expectedKind = VAR;
break;
case ClassFile.REF_newInvokeSpecial:
nameFilter = initFilter;
expectedKind = MTH;
break;
case ClassFile.REF_invokeInterface:
interfaceOwner = true;
expectedKind = MTH;
break;
case ClassFile.REF_invokeStatic:
interfaceOwner = true;
staticOk = true;
case ClassFile.REF_invokeVirtual:
expectedKind = MTH;
break;
case ClassFile.REF_invokeSpecial:
interfaceOwner = true;
expectedKind = MTH;
break;
}
Assert.check(!refSym.isStatic() || staticOk);
Assert.check(refSym.kind == expectedKind);
Assert.check(nameFilter.accepts(refSym.name));
Assert.check(!refSym.owner.isInterface() || interfaceOwner);
}
//where
Filter<Name> nonInitFilter = new Filter<Name>() {
public boolean accepts(Name n) {
return n != n.table.names.init && n != n.table.names.clinit;
}
};
Filter<Name> initFilter = new Filter<Name>() {
public boolean accepts(Name n) {
return n == n.table.names.init;
}
};
}
}