javassist.bytecode.Descriptor Maven / Gradle / Ivy
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/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package javassist.bytecode;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtPrimitiveType;
import javassist.NotFoundException;
import java.util.Map;
/**
* A support class for dealing with descriptors.
*
* See chapter 4.3 in "The Java Virtual Machine Specification (2nd ed.)"
*/
public class Descriptor {
/**
* Converts a class name into the internal representation used in
* the JVM.
*
*
Note that toJvmName(toJvmName(s)) is equivalent
* to toJvmName(s).
*/
public static String toJvmName(String classname) {
return classname.replace('.', '/');
}
/**
* Converts a class name from the internal representation used in
* the JVM to the normal one used in Java.
* This method does not deal with an array type name such as
* "[Ljava/lang/Object;" and "[I;". For such names, use
* toClassName().
*
* @see #toClassName(String)
*/
public static String toJavaName(String classname) {
return classname.replace('/', '.');
}
/**
* Returns the internal representation of the class name in the
* JVM.
*/
public static String toJvmName(CtClass clazz) {
if (clazz.isArray())
return of(clazz);
else
return toJvmName(clazz.getName());
}
/**
* Converts to a Java class name from a descriptor.
*
* @param descriptor type descriptor.
*/
public static String toClassName(String descriptor) {
int arrayDim = 0;
int i = 0;
char c = descriptor.charAt(0);
while (c == '[') {
++arrayDim;
c = descriptor.charAt(++i);
}
String name;
if (c == 'L') {
int i2 = descriptor.indexOf(';', i++);
name = descriptor.substring(i, i2).replace('/', '.');
i = i2;
}
else if (c == 'V')
name = "void";
else if (c == 'I')
name = "int";
else if (c == 'B')
name = "byte";
else if (c == 'J')
name = "long";
else if (c == 'D')
name = "double";
else if (c == 'F')
name = "float";
else if (c == 'C')
name = "char";
else if (c == 'S')
name = "short";
else if (c == 'Z')
name = "boolean";
else
throw new RuntimeException("bad descriptor: " + descriptor);
if (i + 1 != descriptor.length())
throw new RuntimeException("multiple descriptors?: " + descriptor);
if (arrayDim == 0)
return name;
else {
StringBuffer sbuf = new StringBuffer(name);
do {
sbuf.append("[]");
} while (--arrayDim > 0);
return sbuf.toString();
}
}
/**
* Converts to a descriptor from a Java class name
*/
public static String of(String classname) {
if (classname.equals("void"))
return "V";
else if (classname.equals("int"))
return "I";
else if (classname.equals("byte"))
return "B";
else if (classname.equals("long"))
return "J";
else if (classname.equals("double"))
return "D";
else if (classname.equals("float"))
return "F";
else if (classname.equals("char"))
return "C";
else if (classname.equals("short"))
return "S";
else if (classname.equals("boolean"))
return "Z";
else
return "L" + toJvmName(classname) + ";";
}
/**
* Substitutes a class name
* in the given descriptor string.
*
* @param desc descriptor string
* @param oldname replaced JVM class name
* @param newname substituted JVM class name
*
* @see Descriptor#toJvmName(String)
*/
public static String rename(String desc, String oldname, String newname) {
if (desc.indexOf(oldname) < 0)
return desc;
StringBuffer newdesc = new StringBuffer();
int head = 0;
int i = 0;
for (;;) {
int j = desc.indexOf('L', i);
if (j < 0)
break;
else if (desc.startsWith(oldname, j + 1)
&& desc.charAt(j + oldname.length() + 1) == ';') {
newdesc.append(desc.substring(head, j));
newdesc.append('L');
newdesc.append(newname);
newdesc.append(';');
head = i = j + oldname.length() + 2;
}
else {
i = desc.indexOf(';', j) + 1;
if (i < 1)
break; // ';' was not found.
}
}
if (head == 0)
return desc;
else {
int len = desc.length();
if (head < len)
newdesc.append(desc.substring(head, len));
return newdesc.toString();
}
}
/**
* Substitutes class names in the given descriptor string
* according to the given map.
*
* @param map a map between replaced and substituted
* JVM class names.
* @see Descriptor#toJvmName(String)
*/
public static String rename(String desc, Map map) {
if (map == null)
return desc;
StringBuffer newdesc = new StringBuffer();
int head = 0;
int i = 0;
for (;;) {
int j = desc.indexOf('L', i);
if (j < 0)
break;
int k = desc.indexOf(';', j);
if (k < 0)
break;
i = k + 1;
String name = desc.substring(j + 1, k);
String name2 = (String)map.get(name);
if (name2 != null) {
newdesc.append(desc.substring(head, j));
newdesc.append('L');
newdesc.append(name2);
newdesc.append(';');
head = i;
}
}
if (head == 0)
return desc;
else {
int len = desc.length();
if (head < len)
newdesc.append(desc.substring(head, len));
return newdesc.toString();
}
}
/**
* Returns the descriptor representing the given type.
*/
public static String of(CtClass type) {
StringBuffer sbuf = new StringBuffer();
toDescriptor(sbuf, type);
return sbuf.toString();
}
private static void toDescriptor(StringBuffer desc, CtClass type) {
if (type.isArray()) {
desc.append('[');
try {
toDescriptor(desc, type.getComponentType());
}
catch (NotFoundException e) {
desc.append('L');
String name = type.getName();
desc.append(toJvmName(name.substring(0, name.length() - 2)));
desc.append(';');
}
}
else if (type.isPrimitive()) {
CtPrimitiveType pt = (CtPrimitiveType)type;
desc.append(pt.getDescriptor());
}
else { // class type
desc.append('L');
desc.append(type.getName().replace('.', '/'));
desc.append(';');
}
}
/**
* Returns the descriptor representing a constructor receiving
* the given parameter types.
*
* @param paramTypes parameter types
*/
public static String ofConstructor(CtClass[] paramTypes) {
return ofMethod(CtClass.voidType, paramTypes);
}
/**
* Returns the descriptor representing a method that receives
* the given parameter types and returns the given type.
*
* @param returnType return type
* @param paramTypes parameter types
*/
public static String ofMethod(CtClass returnType, CtClass[] paramTypes) {
StringBuffer desc = new StringBuffer();
desc.append('(');
if (paramTypes != null) {
int n = paramTypes.length;
for (int i = 0; i < n; ++i)
toDescriptor(desc, paramTypes[i]);
}
desc.append(')');
if (returnType != null)
toDescriptor(desc, returnType);
return desc.toString();
}
/**
* Returns the descriptor representing a list of parameter types.
* For example, if the given parameter types are two int,
* then this method returns "(II)".
*
* @param paramTypes parameter types
*/
public static String ofParameters(CtClass[] paramTypes) {
return ofMethod(null, paramTypes);
}
/**
* Appends a parameter type to the parameter list represented
* by the given descriptor.
*
*
classname must not be an array type.
*
* @param classname parameter type (not primitive type)
* @param desc descriptor
*/
public static String appendParameter(String classname, String desc) {
int i = desc.indexOf(')');
if (i < 0)
return desc;
else {
StringBuffer newdesc = new StringBuffer();
newdesc.append(desc.substring(0, i));
newdesc.append('L');
newdesc.append(classname.replace('.', '/'));
newdesc.append(';');
newdesc.append(desc.substring(i));
return newdesc.toString();
}
}
/**
* Inserts a parameter type at the beginning of the parameter
* list represented
* by the given descriptor.
*
*
classname must not be an array type.
*
* @param classname parameter type (not primitive type)
* @param desc descriptor
*/
public static String insertParameter(String classname, String desc) {
if (desc.charAt(0) != '(')
return desc;
else
return "(L" + classname.replace('.', '/') + ';'
+ desc.substring(1);
}
/**
* Appends a parameter type to the parameter list represented
* by the given descriptor. The appended parameter becomes
* the last parameter.
*
* @param type the type of the appended parameter.
* @param descriptor the original descriptor.
*/
public static String appendParameter(CtClass type, String descriptor) {
int i = descriptor.indexOf(')');
if (i < 0)
return descriptor;
else {
StringBuffer newdesc = new StringBuffer();
newdesc.append(descriptor.substring(0, i));
toDescriptor(newdesc, type);
newdesc.append(descriptor.substring(i));
return newdesc.toString();
}
}
/**
* Inserts a parameter type at the beginning of the parameter
* list represented
* by the given descriptor.
*
* @param type the type of the inserted parameter.
* @param descriptor the descriptor of the method.
*/
public static String insertParameter(CtClass type,
String descriptor) {
if (descriptor.charAt(0) != '(')
return descriptor;
else
return "(" + of(type) + descriptor.substring(1);
}
/**
* Changes the return type included in the given descriptor.
*
*
classname must not be an array type.
*
* @param classname return type
* @param desc descriptor
*/
public static String changeReturnType(String classname, String desc) {
int i = desc.indexOf(')');
if (i < 0)
return desc;
else {
StringBuffer newdesc = new StringBuffer();
newdesc.append(desc.substring(0, i + 1));
newdesc.append('L');
newdesc.append(classname.replace('.', '/'));
newdesc.append(';');
return newdesc.toString();
}
}
/**
* Returns the CtClass objects representing the parameter
* types specified by the given descriptor.
*
* @param desc descriptor
* @param cp the class pool used for obtaining
* a CtClass object.
*/
public static CtClass[] getParameterTypes(String desc, ClassPool cp)
throws NotFoundException
{
if (desc.charAt(0) != '(')
return null;
else {
int num = numOfParameters(desc);
CtClass[] args = new CtClass[num];
int n = 0;
int i = 1;
do {
i = toCtClass(cp, desc, i, args, n++);
} while (i > 0);
return args;
}
}
/**
* Returns true if the list of the parameter types of desc1 is equal to
* that of desc2.
* For example, "(II)V" and "(II)I" are equal.
*/
public static boolean eqParamTypes(String desc1, String desc2) {
if (desc1.charAt(0) != '(')
return false;
for (int i = 0; true; ++i) {
char c = desc1.charAt(i);
if (c != desc2.charAt(i))
return false;
if (c == ')')
return true;
}
}
/**
* Returns the signature of the given descriptor. The signature does
* not include the return type. For example, the signature of "(I)V"
* is "(I)".
*/
public static String getParamDescriptor(String decl) {
return decl.substring(0, decl.indexOf(')') + 1);
}
/**
* Returns the CtClass object representing the return
* type specified by the given descriptor.
*
* @param desc descriptor
* @param cp the class pool used for obtaining
* a CtClass object.
*/
public static CtClass getReturnType(String desc, ClassPool cp)
throws NotFoundException
{
int i = desc.indexOf(')');
if (i < 0)
return null;
else {
CtClass[] type = new CtClass[1];
toCtClass(cp, desc, i + 1, type, 0);
return type[0];
}
}
/**
* Returns the number of the prameters included in the given
* descriptor.
*
* @param desc descriptor
*/
public static int numOfParameters(String desc) {
int n = 0;
int i = 1;
for (;;) {
char c = desc.charAt(i);
if (c == ')')
break;
while (c == '[')
c = desc.charAt(++i);
if (c == 'L') {
i = desc.indexOf(';', i) + 1;
if (i <= 0)
throw new IndexOutOfBoundsException("bad descriptor");
}
else
++i;
++n;
}
return n;
}
/**
* Returns a CtClass object representing the type
* specified by the given descriptor.
*
*
This method works even if the package-class separator is
* not / but . (period). For example,
* it accepts Ljava.lang.Object;
* as well as Ljava/lang/Object;.
*
* @param desc descriptor.
* @param cp the class pool used for obtaining
* a CtClass object.
*/
public static CtClass toCtClass(String desc, ClassPool cp)
throws NotFoundException
{
CtClass[] clazz = new CtClass[1];
int res = toCtClass(cp, desc, 0, clazz, 0);
if (res >= 0)
return clazz[0];
else {
// maybe, you forgot to surround the class name with
// L and ;. It violates the protocol, but I'm tolerant...
return cp.get(desc.replace('/', '.'));
}
}
private static int toCtClass(ClassPool cp, String desc, int i,
CtClass[] args, int n)
throws NotFoundException
{
int i2;
String name;
int arrayDim = 0;
char c = desc.charAt(i);
while (c == '[') {
++arrayDim;
c = desc.charAt(++i);
}
if (c == 'L') {
i2 = desc.indexOf(';', ++i);
name = desc.substring(i, i2++).replace('/', '.');
}
else {
CtClass type = toPrimitiveClass(c);
if (type == null)
return -1; // error
i2 = i + 1;
if (arrayDim == 0) {
args[n] = type;
return i2; // neither an array type or a class type
}
else
name = type.getName();
}
if (arrayDim > 0) {
StringBuffer sbuf = new StringBuffer(name);
while (arrayDim-- > 0)
sbuf.append("[]");
name = sbuf.toString();
}
args[n] = cp.get(name);
return i2;
}
static CtClass toPrimitiveClass(char c) {
CtClass type = null;
switch (c) {
case 'Z' :
type = CtClass.booleanType;
break;
case 'C' :
type = CtClass.charType;
break;
case 'B' :
type = CtClass.byteType;
break;
case 'S' :
type = CtClass.shortType;
break;
case 'I' :
type = CtClass.intType;
break;
case 'J' :
type = CtClass.longType;
break;
case 'F' :
type = CtClass.floatType;
break;
case 'D' :
type = CtClass.doubleType;
break;
case 'V' :
type = CtClass.voidType;
break;
}
return type;
}
/**
* Computes the dimension of the array represented by the given
* descriptor. For example, if the descriptor is "[[I",
* then this method returns 2.
*
* @param desc the descriptor.
* @return 0 if the descriptor does not represent an array type.
*/
public static int arrayDimension(String desc) {
int dim = 0;
while (desc.charAt(dim) == '[')
++dim;
return dim;
}
/**
* Returns the descriptor of the type of the array component.
* For example, if the given descriptor is
* "[[Ljava/lang/String;" and the given dimension is 2,
* then this method returns "Ljava/lang/String;".
*
* @param desc the descriptor.
* @param dim the array dimension.
*/
public static String toArrayComponent(String desc, int dim) {
return desc.substring(dim);
}
/**
* Computes the data size specified by the given descriptor.
* For example, if the descriptor is "D", this method returns 2.
*
*
If the descriptor represents a method type, this method returns
* (the size of the returned value) - (the sum of the data sizes
* of all the parameters). For example, if the descriptor is
* "(I)D", then this method returns 1 (= 2 - 1).
*
* @param desc descriptor
*/
public static int dataSize(String desc) {
return dataSize(desc, true);
}
/**
* Computes the data size of parameters.
* If one of the parameters is double type, the size of that parameter
* is 2 words. For example, if the given descriptor is
* "(IJ)D", then this method returns 3. The size of the
* return type is not computed.
*
* @param desc a method descriptor.
*/
public static int paramSize(String desc) {
return -dataSize(desc, false);
}
private static int dataSize(String desc, boolean withRet) {
int n = 0;
char c = desc.charAt(0);
if (c == '(') {
int i = 1;
for (;;) {
c = desc.charAt(i);
if (c == ')') {
c = desc.charAt(i + 1);
break;
}
boolean array = false;
while (c == '[') {
array = true;
c = desc.charAt(++i);
}
if (c == 'L') {
i = desc.indexOf(';', i) + 1;
if (i <= 0)
throw new IndexOutOfBoundsException("bad descriptor");
}
else
++i;
if (!array && (c == 'J' || c == 'D'))
n -= 2;
else
--n;
}
}
if (withRet)
if (c == 'J' || c == 'D')
n += 2;
else if (c != 'V')
++n;
return n;
}
/**
* Returns a human-readable representation of the
* given descriptor. For example, Ljava/lang/Object;
* is converted into java.lang.Object.
* (I[I)V is converted into (int, int[])
* (the return type is ignored).
*/
public static String toString(String desc) {
return PrettyPrinter.toString(desc);
}
static class PrettyPrinter {
static String toString(String desc) {
StringBuffer sbuf = new StringBuffer();
if (desc.charAt(0) == '(') {
int pos = 1;
sbuf.append('(');
while (desc.charAt(pos) != ')') {
if (pos > 1)
sbuf.append(',');
pos = readType(sbuf, pos, desc);
}
sbuf.append(')');
}
else
readType(sbuf, 0, desc);
return sbuf.toString();
}
static int readType(StringBuffer sbuf, int pos, String desc) {
char c = desc.charAt(pos);
int arrayDim = 0;
while (c == '[') {
arrayDim++;
c = desc.charAt(++pos);
}
if (c == 'L')
while (true) {
c = desc.charAt(++pos);
if (c == ';')
break;
if (c == '/')
c = '.';
sbuf.append(c);
}
else {
CtClass t = toPrimitiveClass(c);
sbuf.append(t.getName());
}
while (arrayDim-- > 0)
sbuf.append("[]");
return pos + 1;
}
}
/**
* An Iterator over a descriptor.
*/
public static class Iterator {
private String desc;
private int index, curPos;
private boolean param;
/**
* Constructs an iterator.
*
* @param s descriptor.
*/
public Iterator(String s) {
desc = s;
index = curPos = 0;
param = false;
}
/**
* Returns true if the iteration has more elements.
*/
public boolean hasNext() {
return index < desc.length();
}
/**
* Returns true if the current element is a parameter type.
*/
public boolean isParameter() { return param; }
/**
* Returns the first character of the current element.
*/
public char currentChar() { return desc.charAt(curPos); }
/**
* Returns true if the current element is double or long type.
*/
public boolean is2byte() {
char c = currentChar();
return c == 'D' || c == 'J';
}
/**
* Returns the position of the next type character.
* That type character becomes a new current element.
*/
public int next() {
int nextPos = index;
char c = desc.charAt(nextPos);
if (c == '(') {
++index;
c = desc.charAt(++nextPos);
param = true;
}
if (c == ')') {
++index;
c = desc.charAt(++nextPos);
param = false;
}
while (c == '[')
c = desc.charAt(++nextPos);
if (c == 'L') {
nextPos = desc.indexOf(';', nextPos) + 1;
if (nextPos <= 0)
throw new IndexOutOfBoundsException("bad descriptor");
}
else
++nextPos;
curPos = index;
index = nextPos;
return curPos;
}
}
}