duke@1: /*
ohair@554:  * Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.
duke@1:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1:  *
duke@1:  * This code is free software; you can redistribute it and/or modify it
duke@1:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
duke@1:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
duke@1:  *
duke@1:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@1:  * version 2 for more details (a copy is included in the LICENSE file that
duke@1:  * accompanied this code).
duke@1:  *
duke@1:  * You should have received a copy of the GNU General Public License version
duke@1:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@1:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
duke@1:  */
duke@1: 
duke@1: package com.sun.tools.javac.jvm;
duke@1: 
mcimadamore@1336: import com.sun.tools.javac.code.Flags;
mcimadamore@1336: import com.sun.tools.javac.code.Kinds;
duke@1: import java.util.*;
duke@1: 
mcimadamore@1336: import com.sun.tools.javac.code.Symbol;
duke@1: import com.sun.tools.javac.code.Symbol.*;
mcimadamore@1336: import com.sun.tools.javac.code.Type;
mcimadamore@1336: import com.sun.tools.javac.util.Assert;
mcimadamore@1336: import com.sun.tools.javac.util.Filter;
mcimadamore@1336: import com.sun.tools.javac.util.Name;
mcimadamore@1336: import com.sun.tools.javac.util.Names;
duke@1: 
duke@1: /** An internal structure that corresponds to the constant pool of a classfile.
duke@1:  *
jjg@581:  *  <p><b>This is NOT part of any supported API.
jjg@581:  *  If you write code that depends on this, you do so at your own risk.
duke@1:  *  This code and its internal interfaces are subject to change or
duke@1:  *  deletion without notice.</b>
duke@1:  */
duke@1: public class Pool {
duke@1: 
duke@1:     public static final int MAX_ENTRIES = 0xFFFF;
duke@1:     public static final int MAX_STRING_LENGTH = 0xFFFF;
duke@1: 
duke@1:     /** Index of next constant to be entered.
duke@1:      */
duke@1:     int pp;
duke@1: 
duke@1:     /** The initial pool buffer.
duke@1:      */
duke@1:     Object[] pool;
duke@1: 
duke@1:     /** A hashtable containing all constants in the pool.
duke@1:      */
duke@1:     Map<Object,Integer> indices;
duke@1: 
duke@1:     /** Construct a pool with given number of elements and element array.
duke@1:      */
duke@1:     public Pool(int pp, Object[] pool) {
duke@1:         this.pp = pp;
duke@1:         this.pool = pool;
duke@1:         this.indices = new HashMap<Object,Integer>(pool.length);
duke@1:         for (int i = 1; i < pp; i++) {
duke@1:             if (pool[i] != null) indices.put(pool[i], i);
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     /** Construct an empty pool.
duke@1:      */
duke@1:     public Pool() {
duke@1:         this(1, new Object[64]);
duke@1:     }
duke@1: 
duke@1:     /** Return the number of entries in the constant pool.
duke@1:      */
duke@1:     public int numEntries() {
duke@1:         return pp;
duke@1:     }
duke@1: 
duke@1:     /** Remove everything from this pool.
duke@1:      */
duke@1:     public void reset() {
duke@1:         pp = 1;
duke@1:         indices.clear();
duke@1:     }
duke@1: 
duke@1:     /** Double pool buffer in size.
duke@1:      */
duke@1:     private void doublePool() {
duke@1:         Object[] newpool = new Object[pool.length * 2];
duke@1:         System.arraycopy(pool, 0, newpool, 0, pool.length);
duke@1:         pool = newpool;
duke@1:     }
duke@1: 
duke@1:     /** Place an object in the pool, unless it is already there.
duke@1:      *  If object is a symbol also enter its owner unless the owner is a
duke@1:      *  package.  Return the object's index in the pool.
duke@1:      */
duke@1:     public int put(Object value) {
duke@1:         if (value instanceof MethodSymbol)
duke@1:             value = new Method((MethodSymbol)value);
duke@1:         else if (value instanceof VarSymbol)
duke@1:             value = new Variable((VarSymbol)value);
duke@1: //      assert !(value instanceof Type.TypeVar);
duke@1:         Integer index = indices.get(value);
duke@1:         if (index == null) {
duke@1: //          System.err.println("put " + value + " " + value.getClass());//DEBUG
duke@1:             index = pp;
duke@1:             indices.put(value, index);
duke@1:             if (pp == pool.length) doublePool();
duke@1:             pool[pp++] = value;
duke@1:             if (value instanceof Long || value instanceof Double) {
duke@1:                 if (pp == pool.length) doublePool();
duke@1:                 pool[pp++] = null;
duke@1:             }
duke@1:         }
duke@1:         return index.intValue();
duke@1:     }
duke@1: 
duke@1:     /** Return the given object's index in the pool,
duke@1:      *  or -1 if object is not in there.
duke@1:      */
duke@1:     public int get(Object o) {
duke@1:         Integer n = indices.get(o);
duke@1:         return n == null ? -1 : n.intValue();
duke@1:     }
duke@1: 
duke@1:     static class Method extends DelegatedSymbol {
duke@1:         MethodSymbol m;
duke@1:         Method(MethodSymbol m) {
duke@1:             super(m);
duke@1:             this.m = m;
duke@1:         }
duke@1:         public boolean equals(Object other) {
duke@1:             if (!(other instanceof Method)) return false;
duke@1:             MethodSymbol o = ((Method)other).m;
duke@1:             return
duke@1:                 o.name == m.name &&
duke@1:                 o.owner == m.owner &&
duke@1:                 o.type.equals(m.type);
duke@1:         }
duke@1:         public int hashCode() {
duke@1:             return
duke@1:                 m.name.hashCode() * 33 +
duke@1:                 m.owner.hashCode() * 9 +
duke@1:                 m.type.hashCode();
duke@1:         }
duke@1:     }
duke@1: 
duke@1:     static class Variable extends DelegatedSymbol {
duke@1:         VarSymbol v;
duke@1:         Variable(VarSymbol v) {
duke@1:             super(v);
duke@1:             this.v = v;
duke@1:         }
duke@1:         public boolean equals(Object other) {
duke@1:             if (!(other instanceof Variable)) return false;
duke@1:             VarSymbol o = ((Variable)other).v;
duke@1:             return
duke@1:                 o.name == v.name &&
duke@1:                 o.owner == v.owner &&
duke@1:                 o.type.equals(v.type);
duke@1:         }
duke@1:         public int hashCode() {
duke@1:             return
duke@1:                 v.name.hashCode() * 33 +
duke@1:                 v.owner.hashCode() * 9 +
duke@1:                 v.type.hashCode();
duke@1:         }
duke@1:     }
mcimadamore@1336: 
mcimadamore@1336:     public static class MethodHandle {
mcimadamore@1336: 
mcimadamore@1336:         /** Reference kind - see ClassFile */
mcimadamore@1336:         int refKind;
mcimadamore@1336: 
mcimadamore@1336:         /** Reference symbol */
mcimadamore@1336:         Symbol refSym;
mcimadamore@1336: 
mcimadamore@1336:         /** Reference to the name table */
mcimadamore@1336:         Names names;
mcimadamore@1336: 
mcimadamore@1336:         public MethodHandle(int refKind, Symbol refSym, Names names) {
mcimadamore@1336:             this.refKind = refKind;
mcimadamore@1336:             this.refSym = refSym;
mcimadamore@1336:             this.names = names;
mcimadamore@1336:             checkConsistent();
mcimadamore@1336:         }
mcimadamore@1336:         public boolean equals(Object other) {
mcimadamore@1336:             if (!(other instanceof MethodHandle)) return false;
mcimadamore@1336:             MethodHandle mr = (MethodHandle) other;
mcimadamore@1336:             if (mr.refKind != refKind)  return false;
mcimadamore@1336:             Symbol o = mr.refSym;
mcimadamore@1336:             return
mcimadamore@1336:                 o.name == refSym.name &&
mcimadamore@1336:                 o.owner == refSym.owner &&
mcimadamore@1336:                 o.type.equals(refSym.type);
mcimadamore@1336:         }
mcimadamore@1336:         public int hashCode() {
mcimadamore@1336:             return
mcimadamore@1336:                 refKind * 65 +
mcimadamore@1336:                 refSym.name.hashCode() * 33 +
mcimadamore@1336:                 refSym.owner.hashCode() * 9 +
mcimadamore@1336:                 refSym.type.hashCode();
mcimadamore@1336:         }
mcimadamore@1336: 
mcimadamore@1336:         /**
mcimadamore@1336:          * Check consistency of reference kind and symbol (see JVMS 4.4.8)
mcimadamore@1336:          */
mcimadamore@1336:         @SuppressWarnings("fallthrough")
mcimadamore@1336:         private void checkConsistent() {
mcimadamore@1336:             boolean staticOk = false;
mcimadamore@1336:             int expectedKind = -1;
mcimadamore@1336:             Filter<Name> nameFilter = nonInitFilter;
mcimadamore@1336:             boolean interfaceOwner = false;
mcimadamore@1336:             switch (refKind) {
mcimadamore@1336:                 case ClassFile.REF_getStatic:
mcimadamore@1336:                 case ClassFile.REF_putStatic:
mcimadamore@1336:                     staticOk = true;
mcimadamore@1336:                 case ClassFile.REF_getField:
mcimadamore@1336:                 case ClassFile.REF_putField:
mcimadamore@1336:                     expectedKind = Kinds.VAR;
mcimadamore@1336:                     break;
mcimadamore@1336:                 case ClassFile.REF_newInvokeSpecial:
mcimadamore@1336:                     nameFilter = initFilter;
mcimadamore@1336:                     expectedKind = Kinds.MTH;
mcimadamore@1336:                     break;
mcimadamore@1336:                 case ClassFile.REF_invokeInterface:
mcimadamore@1336:                     interfaceOwner = true;
mcimadamore@1336:                     expectedKind = Kinds.MTH;
mcimadamore@1336:                     break;
mcimadamore@1336:                 case ClassFile.REF_invokeStatic:
mcimadamore@1336:                     staticOk = true;
mcimadamore@1336:                 case ClassFile.REF_invokeVirtual:
mcimadamore@1336:                 case ClassFile.REF_invokeSpecial:
mcimadamore@1336:                     expectedKind = Kinds.MTH;
mcimadamore@1336:                     break;
mcimadamore@1336:             }
mcimadamore@1336:             Assert.check(!refSym.isStatic() || staticOk);
mcimadamore@1336:             Assert.check(refSym.kind == expectedKind);
mcimadamore@1336:             Assert.check(nameFilter.accepts(refSym.name));
mcimadamore@1336:             Assert.check(!refSym.owner.isInterface() || interfaceOwner);
mcimadamore@1336:         }
mcimadamore@1336:         //where
mcimadamore@1336:                 Filter<Name> nonInitFilter = new Filter<Name>() {
mcimadamore@1336:                     public boolean accepts(Name n) {
mcimadamore@1336:                         return n != names.init && n != names.clinit;
mcimadamore@1336:                     }
mcimadamore@1336:                 };
mcimadamore@1336: 
mcimadamore@1336:                 Filter<Name> initFilter = new Filter<Name>() {
mcimadamore@1336:                     public boolean accepts(Name n) {
mcimadamore@1336:                         return n == names.init;
mcimadamore@1336:                     }
mcimadamore@1336:                 };
mcimadamore@1336:     }
duke@1: }