/*
* Copyright 2000-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.bcel.generic;
import java.util.HashMap;
import java.util.Map;
import org.apache.bcel.Constants;
import org.apache.bcel.classfile.Constant;
import org.apache.bcel.classfile.ConstantCP;
import org.apache.bcel.classfile.ConstantClass;
import org.apache.bcel.classfile.ConstantDouble;
import org.apache.bcel.classfile.ConstantFieldref;
import org.apache.bcel.classfile.ConstantFloat;
import org.apache.bcel.classfile.ConstantInteger;
import org.apache.bcel.classfile.ConstantInterfaceMethodref;
import org.apache.bcel.classfile.ConstantLong;
import org.apache.bcel.classfile.ConstantMethodref;
import org.apache.bcel.classfile.ConstantNameAndType;
import org.apache.bcel.classfile.ConstantPool;
import org.apache.bcel.classfile.ConstantString;
import org.apache.bcel.classfile.ConstantUtf8;
/**
* This class is used to build up a constant pool. The user adds
* constants via `addXXX' methods, `addString', `addClass',
* etc.. These methods return an index into the constant
* pool. Finally, `getFinalConstantPool()' returns the constant pool
* built up. Intermediate versions of the constant pool can be
* obtained with `getConstantPool()'. A constant pool has capacity for
* Constants.MAX_SHORT entries. Note that the first (0) is used by the
* JVM and that Double and Long constants need two slots.
*
* @version $Id: ConstantPoolGen.java 386056 2006-03-15 11:31:56Z tcurdt $
* @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
* @see Constant
*/
public class ConstantPoolGen implements java.io.Serializable {
protected int size = 1024; // Inital size, sufficient in most cases
protected Constant[] constants = new Constant[size];
protected int index = 1; // First entry (0) used by JVM
private static final String METHODREF_DELIM = ":";
private static final String IMETHODREF_DELIM = "#";
private static final String FIELDREF_DELIM = "&";
private static final String NAT_DELIM = "%";
private static class Index implements java.io.Serializable {
int index;
Index(int i) {
index = i;
}
}
/**
* Initialize with given array of constants.
*
* @param cs array of given constants, new ones will be appended
*/
public ConstantPoolGen(Constant[] cs) {
if (cs.length > size) {
size = cs.length;
constants = new Constant[size];
}
System.arraycopy(cs, 0, constants, 0, cs.length);
if (cs.length > 0) {
index = cs.length;
}
for (int i = 1; i < index; i++) {
Constant c = constants[i];
if (c instanceof ConstantString) {
ConstantString s = (ConstantString) c;
ConstantUtf8 u8 = (ConstantUtf8) constants[s.getStringIndex()];
String key = u8.getBytes();
if (!string_table.containsKey(key)) {
string_table.put(key, new Index(i));
}
} else if (c instanceof ConstantClass) {
ConstantClass s = (ConstantClass) c;
ConstantUtf8 u8 = (ConstantUtf8) constants[s.getNameIndex()];
String key = u8.getBytes();
if (!class_table.containsKey(key)) {
class_table.put(key, new Index(i));
}
} else if (c instanceof ConstantNameAndType) {
ConstantNameAndType n = (ConstantNameAndType) c;
ConstantUtf8 u8 = (ConstantUtf8) constants[n.getNameIndex()];
ConstantUtf8 u8_2 = (ConstantUtf8) constants[n.getSignatureIndex()];
String key = u8.getBytes() + NAT_DELIM + u8_2.getBytes();
if (!n_a_t_table.containsKey(key)) {
n_a_t_table.put(key, new Index(i));
}
} else if (c instanceof ConstantUtf8) {
ConstantUtf8 u = (ConstantUtf8) c;
String key = u.getBytes();
if (!utf8_table.containsKey(key)) {
utf8_table.put(key, new Index(i));
}
} else if (c instanceof ConstantCP) {
ConstantCP m = (ConstantCP) c;
ConstantClass clazz = (ConstantClass) constants[m.getClassIndex()];
ConstantNameAndType n = (ConstantNameAndType) constants[m.getNameAndTypeIndex()];
ConstantUtf8 u8 = (ConstantUtf8) constants[clazz.getNameIndex()];
String class_name = u8.getBytes().replace('/', '.');
u8 = (ConstantUtf8) constants[n.getNameIndex()];
String method_name = u8.getBytes();
u8 = (ConstantUtf8) constants[n.getSignatureIndex()];
String signature = u8.getBytes();
String delim = METHODREF_DELIM;
if (c instanceof ConstantInterfaceMethodref) {
delim = IMETHODREF_DELIM;
} else if (c instanceof ConstantFieldref) {
delim = FIELDREF_DELIM;
}
String key = class_name + delim + method_name + delim + signature;
if (!cp_table.containsKey(key)) {
cp_table.put(key, new Index(i));
}
}
}
}
/**
* Initialize with given constant pool.
*/
public ConstantPoolGen(ConstantPool cp) {
this(cp.getConstantPool());
}
/**
* Create empty constant pool.
*/
public ConstantPoolGen() {
}
/** Resize internal array of constants.
*/
protected void adjustSize() {
if (index + 3 >= size) {
Constant[] cs = constants;
size *= 2;
constants = new Constant[size];
System.arraycopy(cs, 0, constants, 0, index);
}
}
private Map string_table = new HashMap();
/**
* Look for ConstantString in ConstantPool containing String `str'.
*
* @param str String to search for
* @return index on success, -1 otherwise
*/
public int lookupString( String str ) {
Index index = (Index) string_table.get(str);
return (index != null) ? index.index : -1;
}
/**
* Add a new String constant to the ConstantPool, if it is not already in there.
*
* @param str String to add
* @return index of entry
*/
public int addString( String str ) {
int ret;
if ((ret = lookupString(str)) != -1) {
return ret; // Already in CP
}
int utf8 = addUtf8(str);
adjustSize();
ConstantString s = new ConstantString(utf8);
ret = index;
constants[index++] = s;
if (!string_table.containsKey(str)) {
string_table.put(str, new Index(ret));
}
return ret;
}
private Map class_table = new HashMap();
/**
* Look for ConstantClass in ConstantPool named `str'.
*
* @param str String to search for
* @return index on success, -1 otherwise
*/
public int lookupClass( String str ) {
Index index = (Index) class_table.get(str.replace('.', '/'));
return (index != null) ? index.index : -1;
}
private int addClass_( String clazz ) {
int ret;
if ((ret = lookupClass(clazz)) != -1) {
return ret; // Already in CP
}
adjustSize();
ConstantClass c = new ConstantClass(addUtf8(clazz));
ret = index;
constants[index++] = c;
if (!class_table.containsKey(clazz)) {
class_table.put(clazz, new Index(ret));
}
return ret;
}
/**
* Add a new Class reference to the ConstantPool, if it is not already in there.
*
* @param str Class to add
* @return index of entry
*/
public int addClass( String str ) {
return addClass_(str.replace('.', '/'));
}
/**
* Add a new Class reference to the ConstantPool for a given type.
*
* @param type Class to add
* @return index of entry
*/
public int addClass( ObjectType type ) {
return addClass(type.getClassName());
}
/**
* Add a reference to an array class (e.g. String[][]) as needed by MULTIANEWARRAY
* instruction, e.g. to the ConstantPool.
*
* @param type type of array class
* @return index of entry
*/
public int addArrayClass( ArrayType type ) {
return addClass_(type.getSignature());
}
/**
* Look for ConstantInteger in ConstantPool.
*
* @param n integer number to look for
* @return index on success, -1 otherwise
*/
public int lookupInteger( int n ) {
for (int i = 1; i < index; i++) {
if (constants[i] instanceof ConstantInteger) {
ConstantInteger c = (ConstantInteger) constants[i];
if (c.getBytes() == n) {
return i;
}
}
}
return -1;
}
/**
* Add a new Integer constant to the ConstantPool, if it is not already in there.
*
* @param n integer number to add
* @return index of entry
*/
public int addInteger( int n ) {
int ret;
if ((ret = lookupInteger(n)) != -1) {
return ret; // Already in CP
}
adjustSize();
ret = index;
constants[index++] = new ConstantInteger(n);
return ret;
}
/**
* Look for ConstantFloat in ConstantPool.
*
* @param n Float number to look for
* @return index on success, -1 otherwise
*/
public int lookupFloat( float n ) {
int bits = Float.floatToIntBits(n);
for (int i = 1; i < index; i++) {
if (constants[i] instanceof ConstantFloat) {
ConstantFloat c = (ConstantFloat) constants[i];
if (Float.floatToIntBits(c.getBytes()) == bits) {
return i;
}
}
}
return -1;
}
/**
* Add a new Float constant to the ConstantPool, if it is not already in there.
*
* @param n Float number to add
* @return index of entry
*/
public int addFloat( float n ) {
int ret;
if ((ret = lookupFloat(n)) != -1) {
return ret; // Already in CP
}
adjustSize();
ret = index;
constants[index++] = new ConstantFloat(n);
return ret;
}
private Map utf8_table = new HashMap();
/**
* Look for ConstantUtf8 in ConstantPool.
*
* @param n Utf8 string to look for
* @return index on success, -1 otherwise
*/
public int lookupUtf8( String n ) {
Index index = (Index) utf8_table.get(n);
return (index != null) ? index.index : -1;
}
/**
* Add a new Utf8 constant to the ConstantPool, if it is not already in there.
*
* @param n Utf8 string to add
* @return index of entry
*/
public int addUtf8( String n ) {
int ret;
if ((ret = lookupUtf8(n)) != -1) {
return ret; // Already in CP
}
adjustSize();
ret = index;
constants[index++] = new ConstantUtf8(n);
if (!utf8_table.containsKey(n)) {
utf8_table.put(n, new Index(ret));
}
return ret;
}
/**
* Look for ConstantLong in ConstantPool.
*
* @param n Long number to look for
* @return index on success, -1 otherwise
*/
public int lookupLong( long n ) {
for (int i = 1; i < index; i++) {
if (constants[i] instanceof ConstantLong) {
ConstantLong c = (ConstantLong) constants[i];
if (c.getBytes() == n) {
return i;
}
}
}
return -1;
}
/**
* Add a new long constant to the ConstantPool, if it is not already in there.
*
* @param n Long number to add
* @return index of entry
*/
public int addLong( long n ) {
int ret;
if ((ret = lookupLong(n)) != -1) {
return ret; // Already in CP
}
adjustSize();
ret = index;
constants[index] = new ConstantLong(n);
index += 2; // Wastes one entry according to spec
return ret;
}
/**
* Look for ConstantDouble in ConstantPool.
*
* @param n Double number to look for
* @return index on success, -1 otherwise
*/
public int lookupDouble( double n ) {
long bits = Double.doubleToLongBits(n);
for (int i = 1; i < index; i++) {
if (constants[i] instanceof ConstantDouble) {
ConstantDouble c = (ConstantDouble) constants[i];
if (Double.doubleToLongBits(c.getBytes()) == bits) {
return i;
}
}
}
return -1;
}
/**
* Add a new double constant to the ConstantPool, if it is not already in there.
*
* @param n Double number to add
* @return index of entry
*/
public int addDouble( double n ) {
int ret;
if ((ret = lookupDouble(n)) != -1) {
return ret; // Already in CP
}
adjustSize();
ret = index;
constants[index] = new ConstantDouble(n);
index += 2; // Wastes one entry according to spec
return ret;
}
private Map n_a_t_table = new HashMap();
/**
* Look for ConstantNameAndType in ConstantPool.
*
* @param name of variable/method
* @param signature of variable/method
* @return index on success, -1 otherwise
*/
public int lookupNameAndType( String name, String signature ) {
Index _index = (Index) n_a_t_table.get(name + NAT_DELIM + signature);
return (_index != null) ? _index.index : -1;
}
/**
* Add a new NameAndType constant to the ConstantPool if it is not already
* in there.
*
* @param name Name string to add
* @param signature signature string to add
* @return index of entry
*/
public int addNameAndType( String name, String signature ) {
int ret;
int name_index, signature_index;
if ((ret = lookupNameAndType(name, signature)) != -1) {
return ret; // Already in CP
}
adjustSize();
name_index = addUtf8(name);
signature_index = addUtf8(signature);
ret = index;
constants[index++] = new ConstantNameAndType(name_index, signature_index);
String key = name + NAT_DELIM + signature;
if (!n_a_t_table.containsKey(key)) {
n_a_t_table.put(key, new Index(ret));
}
return ret;
}
private Map cp_table = new HashMap();
/**
* Look for ConstantMethodref in ConstantPool.
*
* @param class_name Where to find method
* @param method_name Guess what
* @param signature return and argument types
* @return index on success, -1 otherwise
*/
public int lookupMethodref( String class_name, String method_name, String signature ) {
Index index = (Index) cp_table.get(class_name + METHODREF_DELIM + method_name
+ METHODREF_DELIM + signature);
return (index != null) ? index.index : -1;
}
public int lookupMethodref( MethodGen method ) {
return lookupMethodref(method.getClassName(), method.getName(), method.getSignature());
}
/**
* Add a new Methodref constant to the ConstantPool, if it is not already
* in there.
*
* @param class_name class name string to add
* @param method_name method name string to add
* @param signature method signature string to add
* @return index of entry
*/
public int addMethodref( String class_name, String method_name, String signature ) {
int ret, class_index, name_and_type_index;
if ((ret = lookupMethodref(class_name, method_name, signature)) != -1) {
return ret; // Already in CP
}
adjustSize();
name_and_type_index = addNameAndType(method_name, signature);
class_index = addClass(class_name);
ret = index;
constants[index++] = new ConstantMethodref(class_index, name_and_type_index);
String key = class_name + METHODREF_DELIM + method_name + METHODREF_DELIM + signature;
if (!cp_table.containsKey(key)) {
cp_table.put(key, new Index(ret));
}
return ret;
}
public int addMethodref( MethodGen method ) {
return addMethodref(method.getClassName(), method.getName(), method.getSignature());
}
/**
* Look for ConstantInterfaceMethodref in ConstantPool.
*
* @param class_name Where to find method
* @param method_name Guess what
* @param signature return and argument types
* @return index on success, -1 otherwise
*/
public int lookupInterfaceMethodref( String class_name, String method_name, String signature ) {
Index index = (Index) cp_table.get(class_name + IMETHODREF_DELIM + method_name
+ IMETHODREF_DELIM + signature);
return (index != null) ? index.index : -1;
}
public int lookupInterfaceMethodref( MethodGen method ) {
return lookupInterfaceMethodref(method.getClassName(), method.getName(), method
.getSignature());
}
/**
* Add a new InterfaceMethodref constant to the ConstantPool, if it is not already
* in there.
*
* @param class_name class name string to add
* @param method_name method name string to add
* @param signature signature string to add
* @return index of entry
*/
public int addInterfaceMethodref( String class_name, String method_name, String signature ) {
int ret, class_index, name_and_type_index;
if ((ret = lookupInterfaceMethodref(class_name, method_name, signature)) != -1) {
return ret; // Already in CP
}
adjustSize();
class_index = addClass(class_name);
name_and_type_index = addNameAndType(method_name, signature);
ret = index;
constants[index++] = new ConstantInterfaceMethodref(class_index, name_and_type_index);
String key = class_name + IMETHODREF_DELIM + method_name + IMETHODREF_DELIM + signature;
if (!cp_table.containsKey(key)) {
cp_table.put(key, new Index(ret));
}
return ret;
}
public int addInterfaceMethodref( MethodGen method ) {
return addInterfaceMethodref(method.getClassName(), method.getName(), method.getSignature());
}
/**
* Look for ConstantFieldref in ConstantPool.
*
* @param class_name Where to find method
* @param field_name Guess what
* @param signature return and argument types
* @return index on success, -1 otherwise
*/
public int lookupFieldref( String class_name, String field_name, String signature ) {
Index index = (Index) cp_table.get(class_name + FIELDREF_DELIM + field_name
+ FIELDREF_DELIM + signature);
return (index != null) ? index.index : -1;
}
/**
* Add a new Fieldref constant to the ConstantPool, if it is not already
* in there.
*
* @param class_name class name string to add
* @param field_name field name string to add
* @param signature signature string to add
* @return index of entry
*/
public int addFieldref( String class_name, String field_name, String signature ) {
int ret;
int class_index, name_and_type_index;
if ((ret = lookupFieldref(class_name, field_name, signature)) != -1) {
return ret; // Already in CP
}
adjustSize();
class_index = addClass(class_name);
name_and_type_index = addNameAndType(field_name, signature);
ret = index;
constants[index++] = new ConstantFieldref(class_index, name_and_type_index);
String key = class_name + FIELDREF_DELIM + field_name + FIELDREF_DELIM + signature;
if (!cp_table.containsKey(key)) {
cp_table.put(key, new Index(ret));
}
return ret;
}
/**
* @param i index in constant pool
* @return constant pool entry at index i
*/
public Constant getConstant( int i ) {
return constants[i];
}
/**
* Use with care!
*
* @param i index in constant pool
* @param c new constant pool entry at index i
*/
public void setConstant( int i, Constant c ) {
constants[i] = c;
}
/**
* @return intermediate constant pool
*/
public ConstantPool getConstantPool() {
return new ConstantPool(constants);
}
/**
* @return current size of constant pool
*/
public int getSize() {
return index;
}
/**
* @return constant pool with proper length
*/
public ConstantPool getFinalConstantPool() {
Constant[] cs = new Constant[index];
System.arraycopy(constants, 0, cs, 0, index);
return new ConstantPool(cs);
}
/**
* @return String representation.
*/
public String toString() {
StringBuffer buf = new StringBuffer();
for (int i = 1; i < index; i++) {
buf.append(i).append(")").append(constants[i]).append("\n");
}
return buf.toString();
}
/** Import constant from another ConstantPool and return new index.
*/
public int addConstant( Constant c, ConstantPoolGen cp ) {
Constant[] constants = cp.getConstantPool().getConstantPool();
switch (c.getTag()) {
case Constants.CONSTANT_String: {
ConstantString s = (ConstantString) c;
ConstantUtf8 u8 = (ConstantUtf8) constants[s.getStringIndex()];
return addString(u8.getBytes());
}
case Constants.CONSTANT_Class: {
ConstantClass s = (ConstantClass) c;
ConstantUtf8 u8 = (ConstantUtf8) constants[s.getNameIndex()];
return addClass(u8.getBytes());
}
case Constants.CONSTANT_NameAndType: {
ConstantNameAndType n = (ConstantNameAndType) c;
ConstantUtf8 u8 = (ConstantUtf8) constants[n.getNameIndex()];
ConstantUtf8 u8_2 = (ConstantUtf8) constants[n.getSignatureIndex()];
return addNameAndType(u8.getBytes(), u8_2.getBytes());
}
case Constants.CONSTANT_Utf8:
return addUtf8(((ConstantUtf8) c).getBytes());
case Constants.CONSTANT_Double:
return addDouble(((ConstantDouble) c).getBytes());
case Constants.CONSTANT_Float:
return addFloat(((ConstantFloat) c).getBytes());
case Constants.CONSTANT_Long:
return addLong(((ConstantLong) c).getBytes());
case Constants.CONSTANT_Integer:
return addInteger(((ConstantInteger) c).getBytes());
case Constants.CONSTANT_InterfaceMethodref:
case Constants.CONSTANT_Methodref:
case Constants.CONSTANT_Fieldref: {
ConstantCP m = (ConstantCP) c;
ConstantClass clazz = (ConstantClass) constants[m.getClassIndex()];
ConstantNameAndType n = (ConstantNameAndType) constants[m.getNameAndTypeIndex()];
ConstantUtf8 u8 = (ConstantUtf8) constants[clazz.getNameIndex()];
String class_name = u8.getBytes().replace('/', '.');
u8 = (ConstantUtf8) constants[n.getNameIndex()];
String name = u8.getBytes();
u8 = (ConstantUtf8) constants[n.getSignatureIndex()];
String signature = u8.getBytes();
switch (c.getTag()) {
case Constants.CONSTANT_InterfaceMethodref:
return addInterfaceMethodref(class_name, name, signature);
case Constants.CONSTANT_Methodref:
return addMethodref(class_name, name, signature);
case Constants.CONSTANT_Fieldref:
return addFieldref(class_name, name, signature);
default: // Never reached
throw new RuntimeException("Unknown constant type " + c);
}
}
default: // Never reached
throw new RuntimeException("Unknown constant type " + c);
}
}
}