/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (C) 2000 INRIA, France Telecom
* Copyright (C) 2002 France Telecom
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Contact: Eric.Bruneton@rd.francetelecom.com
*
* Author: Eric Bruneton
*/
package org.gjt.sp.jedit.bsh.org.objectweb.asm;
/**
* A {@link org.gjt.sp.jedit.bsh.org.objectweb.asm.ClassVisitor ClassVisitor} that generates Java class files. More
* precisely this visitor generates a byte array conforming to the Java class
* file format. It can be used alone, to generate a Java class "from scratch",
* or with one or more adapter class
* visitors to generate a modified class from one or more existing Java classes.
*/
public class ClassWriter implements ClassVisitor {
/**
* The type of CONSTANT_Class constant pool items.
*/
final static int CLASS = 7;
/**
* The type of CONSTANT_Fieldref constant pool items.
*/
final static int FIELD = 9;
/**
* The type of CONSTANT_Methodref constant pool items.
*/
final static int METH = 10;
/**
* The type of CONSTANT_InterfaceMethodref constant pool items.
*/
final static int IMETH = 11;
/**
* The type of CONSTANT_String constant pool items.
*/
final static int STR = 8;
/**
* The type of CONSTANT_Integer constant pool items.
*/
final static int INT = 3;
/**
* The type of CONSTANT_Float constant pool items.
*/
final static int FLOAT = 4;
/**
* The type of CONSTANT_Long constant pool items.
*/
final static int LONG = 5;
/**
* The type of CONSTANT_Double constant pool items.
*/
final static int DOUBLE = 6;
/**
* The type of CONSTANT_NameAndType constant pool items.
*/
final static int NAME_TYPE = 12;
/**
* The type of CONSTANT_Utf8 constant pool items.
*/
final static int UTF8 = 1;
/**
* Index of the next item to be added in the constant pool.
*/
private short index;
/**
* The constant pool of this class.
*/
private ByteVector pool;
/**
* The constant pool's hash table data.
*/
private Item[] table;
/**
* The threshold of the constant pool's hash table.
*/
private int threshold;
/**
* The access flags of this class.
*/
private int access;
/**
* The constant pool item that contains the internal name of this class.
*/
private int name;
/**
* The constant pool item that contains the internal name of the super class
* of this class.
*/
private int superName;
/**
* Number of interfaces implemented or extended by this class or interface.
*/
private int interfaceCount;
/**
* The interfaces implemented or extended by this class or interface. More
* precisely, this array contains the indexes of the constant pool items
* that contain the internal names of these interfaces.
*/
private int[] interfaces;
/**
* The constant pool item that contains the name of the source file from
* which this class was compiled.
*/
private Item sourceFile;
/**
* Number of fields of this class.
*/
private int fieldCount;
/**
* The fields of this class.
*/
private ByteVector fields;
/**
* <tt>true</tt> if the maximum stack size and number of local variables must
* be automatically computed.
*/
private boolean computeMaxs;
/**
* The methods of this class. These methods are stored in a linked list of
* {@link CodeWriter CodeWriter} objects, linked to each other by their {@link
* CodeWriter#next} field. This field stores the first element of this list.
*/
CodeWriter firstMethod;
/**
* The methods of this class. These methods are stored in a linked list of
* {@link CodeWriter CodeWriter} objects, linked to each other by their {@link
* CodeWriter#next} field. This field stores the last element of this list.
*/
CodeWriter lastMethod;
/**
* The number of entries in the InnerClasses attribute.
*/
private int innerClassesCount;
/**
* The InnerClasses attribute.
*/
private ByteVector innerClasses;
/**
* A reusable key used to look for items in the hash {@link #table table}.
*/
Item key;
/**
* A reusable key used to look for items in the hash {@link #table table}.
*/
Item key2;
/**
* A reusable key used to look for items in the hash {@link #table table}.
*/
Item key3;
/**
* The type of instructions without any label.
*/
final static int NOARG_INSN = 0;
/**
* The type of instructions with an signed byte label.
*/
final static int SBYTE_INSN = 1;
/**
* The type of instructions with an signed short label.
*/
final static int SHORT_INSN = 2;
/**
* The type of instructions with a local variable index label.
*/
final static int VAR_INSN = 3;
/**
* The type of instructions with an implicit local variable index label.
*/
final static int IMPLVAR_INSN = 4;
/**
* The type of instructions with a type descriptor argument.
*/
final static int TYPE_INSN = 5;
/**
* The type of field and method invocations instructions.
*/
final static int FIELDORMETH_INSN = 6;
/**
* The type of the INVOKEINTERFACE instruction.
*/
final static int ITFMETH_INSN = 7;
/**
* The type of instructions with a 2 bytes bytecode offset label.
*/
final static int LABEL_INSN = 8;
/**
* The type of instructions with a 4 bytes bytecode offset label.
*/
final static int LABELW_INSN = 9;
/**
* The type of the LDC instruction.
*/
final static int LDC_INSN = 10;
/**
* The type of the LDC_W and LDC2_W instructions.
*/
final static int LDCW_INSN = 11;
/**
* The type of the IINC instruction.
*/
final static int IINC_INSN = 12;
/**
* The type of the TABLESWITCH instruction.
*/
final static int TABL_INSN = 13;
/**
* The type of the LOOKUPSWITCH instruction.
*/
final static int LOOK_INSN = 14;
/**
* The type of the MULTIANEWARRAY instruction.
*/
final static int MANA_INSN = 15;
/**
* The type of the WIDE instruction.
*/
final static int WIDE_INSN = 16;
/**
* The instruction types of all JVM opcodes.
*/
static byte[] TYPE;
// --------------------------------------------------------------------------
// Static initializer
// --------------------------------------------------------------------------
/**
* Computes the instruction types of JVM opcodes.
*/
static {
int i;
byte[] b = new byte[220];
String s =
"AAAAAAAAAAAAAAAABCKLLDDDDDEEEEEEEEEEEEEEEEEEEEAAAAAAAADDDDDEEEEEEEEE" +
"EEEEEEEEEEEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAMAAA" +
"AAAAAAAAAAAAAAAAAIIIIIIIIIIIIIIIIDNOAAAAAAGGGGGGGHAFBFAAFFAAQPIIJJII" +
"IIIIIIIIIIIIIIII";
for (i = 0; i < b.length; ++i) {
b[i] = (byte)(s.charAt(i) - 'A');
}
TYPE = b;
/* code to generate the above string
// SBYTE_INSN instructions
b[Constants.NEWARRAY] = SBYTE_INSN;
b[Constants.BIPUSH] = SBYTE_INSN;
// SHORT_INSN instructions
b[Constants.SIPUSH] = SHORT_INSN;
// (IMPL)VAR_INSN instructions
b[Constants.RET] = VAR_INSN;
for (i = Constants.ILOAD; i <= Constants.ALOAD; ++i) {
b[i] = VAR_INSN;
}
for (i = Constants.ISTORE; i <= Constants.ASTORE; ++i) {
b[i] = VAR_INSN;
}
for (i = 26; i <= 45; ++i) { // ILOAD_0 to ALOAD_3
b[i] = IMPLVAR_INSN;
}
for (i = 59; i <= 78; ++i) { // ISTORE_0 to ASTORE_3
b[i] = IMPLVAR_INSN;
}
// TYPE_INSN instructions
b[Constants.NEW] = TYPE_INSN;
b[Constants.ANEWARRAY] = TYPE_INSN;
b[Constants.CHECKCAST] = TYPE_INSN;
b[Constants.INSTANCEOF] = TYPE_INSN;
// (Set)FIELDORMETH_INSN instructions
for (i = Constants.GETSTATIC; i <= Constants.INVOKESTATIC; ++i) {
b[i] = FIELDORMETH_INSN;
}
b[Constants.INVOKEINTERFACE] = ITFMETH_INSN;
// LABEL(W)_INSN instructions
for (i = Constants.IFEQ; i <= Constants.JSR; ++i) {
b[i] = LABEL_INSN;
}
b[Constants.IFNULL] = LABEL_INSN;
b[Constants.IFNONNULL] = LABEL_INSN;
b[200] = LABELW_INSN; // GOTO_W
b[201] = LABELW_INSN; // JSR_W
// temporary opcodes used internally by ASM - see Label and CodeWriter
for (i = 202; i < 220; ++i) {
b[i] = LABEL_INSN;
}
// LDC(_W) instructions
b[Constants.LDC] = LDC_INSN;
b[19] = LDCW_INSN; // LDC_W
b[20] = LDCW_INSN; // LDC2_W
// special instructions
b[Constants.IINC] = IINC_INSN;
b[Constants.TABLESWITCH] = TABL_INSN;
b[Constants.LOOKUPSWITCH] = LOOK_INSN;
b[Constants.MULTIANEWARRAY] = MANA_INSN;
b[196] = WIDE_INSN; // WIDE
for (i = 0; i < b.length; ++i) {
System.err.print((char)('A' + b[i]));
}
System.err.println();
*/
}
// --------------------------------------------------------------------------
// Constructor
// --------------------------------------------------------------------------
/**
* Constructs a new {@link ClassWriter ClassWriter} object.
*
* @param computeMaxs <tt>true</tt> if the maximum stack size and the maximum
* number of local variables must be automatically computed. If this flag
* is <tt>true</tt>, then the arguments of the {@link
* CodeVisitor#visitMaxs visitMaxs} method of the {@link CodeVisitor
* CodeVisitor} returned by the {@link #visitMethod visitMethod} method
* will be ignored, and computed automatically from the signature and
* the bytecode of each method.
*/
public ClassWriter (final boolean computeMaxs) {
index = 1;
pool = new ByteVector();
table = new Item[64];
threshold = (int)(0.75d*table.length);
key = new Item();
key2 = new Item();
key3 = new Item();
this.computeMaxs = computeMaxs;
}
// --------------------------------------------------------------------------
// Implementation of the ClassVisitor interface
// --------------------------------------------------------------------------
public void visit (
final int access,
final String name,
final String superName,
final String[] interfaces,
final String sourceFile)
{
this.access = access;
this.name = newClass(name).index;
this.superName = superName == null ? 0 : newClass(superName).index;
if (interfaces != null && interfaces.length > 0) {
interfaceCount = interfaces.length;
this.interfaces = new int[interfaceCount];
for (int i = 0; i < interfaceCount; ++i) {
this.interfaces[i] = newClass(interfaces[i]).index;
}
}
if (sourceFile != null) {
newUTF8("SourceFile");
this.sourceFile = newUTF8(sourceFile);
}
if ((access & Constants.ACC_DEPRECATED) != 0) {
newUTF8("Deprecated");
}
}
public void visitInnerClass (
final String name,
final String outerName,
final String innerName,
final int access)
{
if (innerClasses == null) {
newUTF8("InnerClasses");
innerClasses = new ByteVector();
}
++innerClassesCount;
innerClasses.put2(name == null ? 0 : newClass(name).index);
innerClasses.put2(outerName == null ? 0 : newClass(outerName).index);
innerClasses.put2(innerName == null ? 0 : newUTF8(innerName).index);
innerClasses.put2(access);
}
public void visitField (
final int access,
final String name,
final String desc,
final Object value)
{
++fieldCount;
if (fields == null) {
fields = new ByteVector();
}
fields.put2(access).put2(newUTF8(name).index).put2(newUTF8(desc).index);
int attributeCount = 0;
if (value != null) {
++attributeCount;
}
if ((access & Constants.ACC_SYNTHETIC) != 0) {
++attributeCount;
}
if ((access & Constants.ACC_DEPRECATED) != 0) {
++attributeCount;
}
fields.put2(attributeCount);
if (value != null) {
fields.put2(newUTF8("ConstantValue").index);
fields.put4(2).put2(newCst(value).index);
}
if ((access & Constants.ACC_SYNTHETIC) != 0) {
fields.put2(newUTF8("Synthetic").index).put4(0);
}
if ((access & Constants.ACC_DEPRECATED) != 0) {
fields.put2(newUTF8("Deprecated").index).put4(0);
}
}
public CodeVisitor visitMethod (
final int access,
final String name,
final String desc,
final String[] exceptions)
{
CodeWriter cw = new CodeWriter(this, computeMaxs);
cw.init(access, name, desc, exceptions);
return cw;
}
public void visitEnd () {
}
// --------------------------------------------------------------------------
// Other public methods
// --------------------------------------------------------------------------
/**
* Returns the bytecode of the class that was build with this class writer.
*
* @return the bytecode of the class that was build with this class writer.
*/
public byte[] toByteArray () {
// computes the real size of the bytecode of this class
int size = 24 + 2*interfaceCount;
if (fields != null) {
size += fields.length;
}
int nbMethods = 0;
CodeWriter cb = firstMethod;
while (cb != null) {
++nbMethods;
size += cb.getSize();
cb = cb.next;
}
size += pool.length;
int attributeCount = 0;
if (sourceFile != null) {
++attributeCount;
size += 8;
}
if ((access & Constants.ACC_DEPRECATED) != 0) {
++attributeCount;
size += 6;
}
if (innerClasses != null) {
++attributeCount;
size += 8 + innerClasses.length;
}
// allocates a byte vector of this size, in order to avoid unnecessary
// arraycopy operations in the ByteVector.enlarge() method
ByteVector out = new ByteVector(size);
out.put4(0xCAFEBABE).put2(3).put2(45);
out.put2(index).putByteArray(pool.data, 0, pool.length);
out.put2(access).put2(name).put2(superName);
out.put2(interfaceCount);
for (int i = 0; i < interfaceCount; ++i) {
out.put2(interfaces[i]);
}
out.put2(fieldCount);
if (fields != null) {
out.putByteArray(fields.data, 0, fields.length);
}
out.put2(nbMethods);
cb = firstMethod;
while (cb != null) {
cb.put(out);
cb = cb.next;
}
out.put2(attributeCount);
if (sourceFile != null) {
out.put2(newUTF8("SourceFile").index).put4(2).put2(sourceFile.index);
}
if ((access & Constants.ACC_DEPRECATED) != 0) {
out.put2(newUTF8("Deprecated").index).put4(0);
}
if (innerClasses != null) {
out.put2(newUTF8("InnerClasses").index);
out.put4(innerClasses.length + 2).put2(innerClassesCount);
out.putByteArray(innerClasses.data, 0, innerClasses.length);
}
return out.data;
}
// --------------------------------------------------------------------------
// Utility methods: constant pool management
// --------------------------------------------------------------------------
/**
* Adds a number or string constant to the constant pool of the class being
* build. Does nothing if the constant pool already contains a similar item.
*
* @param cst the value of the constant to be added to the constant pool. This
* parameter must be an {@link java.lang.Integer Integer}, a {@link
* java.lang.Float Float}, a {@link java.lang.Long Long}, a {@link
java.lang.Double Double} or a {@link String String}.
* @return a new or already existing constant item with the given value.
*/
Item newCst (final Object cst) {
if (cst instanceof Integer) {
int val = ((Integer)cst).intValue();
return newInteger(val);
} else if (cst instanceof Float) {
float val = ((Float)cst).floatValue();
return newFloat(val);
} else if (cst instanceof Long) {
long val = ((Long)cst).longValue();
return newLong(val);
} else if (cst instanceof Double) {
double val = ((Double)cst).doubleValue();
return newDouble(val);
} else if (cst instanceof String) {
return newString((String)cst);
} else {
throw new IllegalArgumentException("value " + cst);
}
}
/**
* Adds an UTF string to the constant pool of the class being build. Does
* nothing if the constant pool already contains a similar item.
*
* @param value the String value.
* @return a new or already existing UTF8 item.
*/
Item newUTF8 (final String value) {
key.set(UTF8, value, null, null);
Item result = get(key);
if (result == null) {
pool.put1(UTF8).putUTF(value);
result = new Item(index++, key);
put(result);
}
return result;
}
/**
* Adds a class reference to the constant pool of the class being build. Does
* nothing if the constant pool already contains a similar item.
*
* @param value the internal name of the class.
* @return a new or already existing class reference item.
*/
Item newClass (final String value) {
key2.set(CLASS, value, null, null);
Item result = get(key2);
if (result == null) {
pool.put12(CLASS, newUTF8(value).index);
result = new Item(index++, key2);
put(result);
}
return result;
}
/**
* Adds a field reference to the constant pool of the class being build. Does
* nothing if the constant pool already contains a similar item.
*
* @param owner the internal name of the field's owner class.
* @param name the field's name.
* @param desc the field's descriptor.
* @return a new or already existing field reference item.
*/
Item newField (
final String owner,
final String name,
final String desc)
{
key3.set(FIELD, owner, name, desc);
Item result = get(key3);
if (result == null) {
put122(FIELD, newClass(owner).index, newNameType(name, desc).index);
result = new Item(index++, key3);
put(result);
}
return result;
}
/**
* Adds a method reference to the constant pool of the class being build. Does
* nothing if the constant pool already contains a similar item.
*
* @param owner the internal name of the method's owner class.
* @param name the method's name.
* @param desc the method's descriptor.
* @return a new or already existing method reference item.
*/
Item newMethod (
final String owner,
final String name,
final String desc)
{
key3.set(METH, owner, name, desc);
Item result = get(key3);
if (result == null) {
put122(METH, newClass(owner).index, newNameType(name, desc).index);
result = new Item(index++, key3);
put(result);
}
return result;
}
/**
* Adds an interface method reference to the constant pool of the class being
* build. Does nothing if the constant pool already contains a similar item.
*
* @param ownerItf the internal name of the method's owner interface.
* @param name the method's name.
* @param desc the method's descriptor.
* @return a new or already existing interface method reference item.
*/
Item newItfMethod (
final String ownerItf,
final String name,
final String desc)
{
key3.set(IMETH, ownerItf, name, desc);
Item result = get(key3);
if (result == null) {
put122(IMETH, newClass(ownerItf).index, newNameType(name, desc).index);
result = new Item(index++, key3);
put(result);
}
return result;
}
/**
* Adds an integer to the constant pool of the class being build. Does nothing
* if the constant pool already contains a similar item.
*
* @param value the int value.
* @return a new or already existing int item.
*/
private Item newInteger (final int value) {
key.set(value);
Item result = get(key);
if (result == null) {
pool.put1(INT).put4(value);
result = new Item(index++, key);
put(result);
}
return result;
}
/**
* Adds a float to the constant pool of the class being build. Does nothing if
* the constant pool already contains a similar item.
*
* @param value the float value.
* @return a new or already existing float item.
*/
private Item newFloat (final float value) {
key.set(value);
Item result = get(key);
if (result == null) {
pool.put1(FLOAT).put4(Float.floatToIntBits(value));
result = new Item(index++, key);
put(result);
}
return result;
}
/**
* Adds a long to the constant pool of the class being build. Does nothing if
* the constant pool already contains a similar item.
*
* @param value the long value.
* @return a new or already existing long item.
*/
private Item newLong (final long value) {
key.set(value);
Item result = get(key);
if (result == null) {
pool.put1(LONG).put8(value);
result = new Item(index, key);
put(result);
index += 2;
}
return result;
}
/**
* Adds a double to the constant pool of the class being build. Does nothing
* if the constant pool already contains a similar item.
*
* @param value the double value.
* @return a new or already existing double item.
*/
private Item newDouble (final double value) {
key.set(value);
Item result = get(key);
if (result == null) {
pool.put1(DOUBLE).put8(Double.doubleToLongBits(value));
result = new Item(index, key);
put(result);
index += 2;
}
return result;
}
/**
* Adds a string to the constant pool of the class being build. Does nothing
* if the constant pool already contains a similar item.
*
* @param value the String value.
* @return a new or already existing string item.
*/
private Item newString (final String value) {
key2.set(STR, value, null, null);
Item result = get(key2);
if (result == null) {
pool.put12(STR, newUTF8(value).index);
result = new Item(index++, key2);
put(result);
}
return result;
}
/**
* Adds a name and type to the constant pool of the class being build. Does
* nothing if the constant pool already contains a similar item.
*
* @param name a name.
* @param desc a type descriptor.
* @return a new or already existing name and type item.
*/
private Item newNameType (final String name, final String desc) {
key2.set(NAME_TYPE, name, desc, null);
Item result = get(key2);
if (result == null) {
put122(NAME_TYPE, newUTF8(name).index, newUTF8(desc).index);
result = new Item(index++, key2);
put(result);
}
return result;
}
/**
* Returns the constant pool's hash table item which is equal to the given
* item.
*
* @param key a constant pool item.
* @return the constant pool's hash table item which is equal to the given
* item, or <tt>null</tt> if there is no such item.
*/
private Item get (final Item key) {
Item tab[] = table;
int hashCode = key.hashCode;
int index = (hashCode & 0x7FFFFFFF) % tab.length;
for (Item i = tab[index]; i != null; i = i.next) {
if (i.hashCode == hashCode && key.isEqualTo(i)) {
return i;
}
}
return null;
}
/**
* Puts the given item in the constant pool's hash table. The hash table
* <i>must</i> not already contains this item.
*
* @param i the item to be added to the constant pool's hash table.
*/
private void put (final Item i) {
if (index > threshold) {
int oldCapacity = table.length;
Item oldMap[] = table;
int newCapacity = oldCapacity * 2 + 1;
Item newMap[] = new Item[newCapacity];
threshold = (int)(newCapacity * 0.75);
table = newMap;
for (int j = oldCapacity; j-- > 0; ) {
for (Item old = oldMap[j]; old != null; ) {
Item e = old;
old = old.next;
int index = (e.hashCode & 0x7FFFFFFF) % newCapacity;
e.next = newMap[index];
newMap[index] = e;
}
}
}
int index = (i.hashCode & 0x7FFFFFFF) % table.length;
i.next = table[index];
table[index] = i;
}
/**
* Puts one byte and two shorts into the constant pool.
*
* @param b a byte.
* @param s1 a short.
* @param s2 another short.
*/
private void put122 (final int b, final int s1, final int s2) {
pool.put12(b, s1).put2(s2);
}
}