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A Java Optimization Framework
package soot.coffi;
/*-
* #%L
* Soot - a J*va Optimization Framework
* %%
* Copyright (C) 1997 Clark Verbrugge
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 2.1 of the
* License, or (at your option) any later version.
*
* This program 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 Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* .
* #L%
*/
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import soot.G;
import soot.Value;
import soot.jimple.StringConstant;
/**
* A constant pool entry of type CONSTANT_Utf8; note this is not multithread safe. It is, however, immutable.
*
* @see cp_info
* @author Clark Verbrugge
*/
public class CONSTANT_Utf8_info extends cp_info {
private static final Logger logger = LoggerFactory.getLogger(CONSTANT_Utf8_info.class);
// Some local private objects to help with efficient comparisons.
private int sHashCode;
// for caching the conversion.
private String s;
/** Byte array of actual utf8 string. */
private final byte bytes[];
/** Constructor from a DataInputSream */
public CONSTANT_Utf8_info(DataInputStream d) throws IOException {
int len;
len = d.readUnsignedShort();
bytes = new byte[len + 2];
bytes[0] = (byte) (len >> 8);
bytes[1] = (byte) (len & 0xff);
if (len > 0) {
int j;
for (j = 0; j < len; j++) {
bytes[j + 2] = (byte) d.readUnsignedByte();
}
}
}
/** For writing out the byte stream for this utf8 properly (incl size). */
public void writeBytes(DataOutputStream dd) throws IOException {
int len;
len = bytes.length;
dd.writeShort(len - 2);
dd.write(bytes, 2, len - 2);
}
/** Length in bytes of byte array. */
public int length() {
return (((((bytes[0])) & 0xff) << 8) + (((bytes[1])) & 0xff));
}
/**
* Returns the size of this cp_info object.
*
* @return number of bytes occupied by this object.
* @see cp_info#size
*/
public int size() {
return length() + 3;
}
/**
* Converts internal representation into an actual String.
*
* @return String version of this utf8 object.
*/
public String convert() {
if (s == null) {
try {
ByteArrayInputStream bs = new ByteArrayInputStream(bytes);
DataInputStream d = new DataInputStream(bs);
String buf = d.readUTF();
sHashCode = buf.hashCode();
return buf;
} catch (IOException e) {
return "!!IOException!!";
}
}
return s;
}
/**
* Fixes the actual String used to represent the internal representation. We must have rep == convert(); we verify
* hashCodes() to spot-check this. No user-visible effects.
*/
public void fixConversion(String rep) {
if (sHashCode != rep.hashCode()) {
throw new RuntimeException("bad use of fixConversion!");
}
if (s == null) {
s = rep;
}
}
/**
* Answers whether this utf8 string is the same as a given one.
*
* @param cu
* utf8 object with which to compare.
* @return true if they are equal, false if they are not.
*/
public boolean equals(CONSTANT_Utf8_info cu) {
int i, j;
j = bytes.length;
if (j != cu.bytes.length) {
return false;
}
for (i = 0; i < j; i++) {
if (bytes[i] != cu.bytes[i]) {
return false;
}
}
return true;
}
/**
* Compares this entry with another cp_info object (which may reside in a different constant pool).
*
* @param constant_pool
* constant pool of ClassFile for this.
* @param cp
* constant pool entry to compare against.
* @param cp_constant_pool
* constant pool of ClassFile for cp.
* @return a value <0, 0, or >0 indicating whether this is smaller, the same or larger than cp.
* @see cp_info#compareTo
* @see CONSTANT_Utf8_info#compareTo(cp_info)
*/
public int compareTo(cp_info constant_pool[], cp_info cp, cp_info cp_constant_pool[]) {
return compareTo(cp);
}
/**
* Compares this entry with another cp_info object; note that for Utf8 object it really doesn't matter whether they're in
* the same or a different constant pool, since they really do carry all their data.
*
* @param cp
* constant pool entry to compare against.
* @return a value <0, 0, or >0 indicating whether this is smaller, the same or larger than cp.
* @see cp_info#compareTo
* @see CONSTANT_Utf8_info#compareTo(cp_info[],cp_info,cp_info[])
*/
public int compareTo(cp_info cp) {
if (tag != cp.tag) {
return tag - cp.tag;
}
CONSTANT_Utf8_info cu = (CONSTANT_Utf8_info) cp;
G.v().coffi_CONSTANT_Utf8_info_e1.reset(bytes);
G.v().coffi_CONSTANT_Utf8_info_e2.reset(cu.bytes);
for (; G.v().coffi_CONSTANT_Utf8_info_e1.hasMoreElements() && G.v().coffi_CONSTANT_Utf8_info_e2.hasMoreElements();) {
G.v().coffi_CONSTANT_Utf8_info_e1.nextElement();
G.v().coffi_CONSTANT_Utf8_info_e2.nextElement();
if (G.v().coffi_CONSTANT_Utf8_info_e1.c < G.v().coffi_CONSTANT_Utf8_info_e2.c) {
return -1;
}
if (G.v().coffi_CONSTANT_Utf8_info_e2.c < G.v().coffi_CONSTANT_Utf8_info_e1.c) {
return 1;
}
}
if (G.v().coffi_CONSTANT_Utf8_info_e1.hasMoreElements()) {
return -1;
}
if (G.v().coffi_CONSTANT_Utf8_info_e2.hasMoreElements()) {
return 1;
}
return 0;
}
/**
* Utility method; converts the given String into a utf8 encoded array of bytes.
*
* @param s
* String to encode.
* @return array of bytes, utf8 encoded version of s.
*/
public static byte[] toUtf8(String s) {
try {
ByteArrayOutputStream bs = new ByteArrayOutputStream(s.length());
DataOutputStream d = new DataOutputStream(bs);
d.writeUTF(s);
return bs.toByteArray();
} catch (IOException e) {
logger.debug("Some sort of IO exception in toUtf8 with " + s);
}
return null;
}
/**
* Returns a String representation of this entry.
*
* @param constant_pool
* constant pool of ClassFile.
* @return String representation of this entry.
* @see cp_info#toString
*/
public String toString(cp_info constant_pool[]) {
return convert();
}
/**
* Returns a String description of what kind of entry this is.
*
* @return the String "utf8".
* @see cp_info#typeName
*/
public String typeName() {
return "utf8";
}
public Value createJimpleConstantValue(cp_info[] constant_pool) {
return StringConstant.v(convert());
}
}
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