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- /*
- * Javassist, a Java-bytecode translator toolkit.
- * Copyright (C) 1999-2006 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.
- *
- * 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 java.io.DataInputStream;
- import java.io.DataOutputStream;
- import java.io.IOException;
- import java.util.LinkedList;
- import java.util.List;
- import java.util.Map;
-
- /**
- * <code>method_info</code> structure.
- *
- * @see javassist.CtMethod#getMethodInfo()
- * @see javassist.CtConstructor#getMethodInfo()
- */
- public final class MethodInfo {
- ConstPool constPool;
- int accessFlags;
- int name;
- String cachedName;
- int descriptor;
- LinkedList attribute; // may be null
-
- /**
- * The name of constructors: <code><init></code>.
- */
- public static final String nameInit = "<init>";
-
- /**
- * The name of class initializer (static initializer):
- * <code><clinit></code>.
- */
- public static final String nameClinit = "<clinit>";
-
- private MethodInfo(ConstPool cp) {
- constPool = cp;
- attribute = null;
- }
-
- /**
- * Constructs a <code>method_info</code> structure. The initial value of
- * <code>access_flags</code> is zero.
- *
- * @param cp
- * a constant pool table
- * @param methodname
- * method name
- * @param desc
- * method descriptor
- * @see Descriptor
- */
- public MethodInfo(ConstPool cp, String methodname, String desc) {
- this(cp);
- accessFlags = 0;
- name = cp.addUtf8Info(methodname);
- cachedName = methodname;
- descriptor = constPool.addUtf8Info(desc);
- }
-
- MethodInfo(ConstPool cp, DataInputStream in) throws IOException {
- this(cp);
- read(in);
- }
-
- /**
- * Constructs a copy of <code>method_info</code> structure. Class names
- * appearing in the source <code>method_info</code> are renamed according
- * to <code>classnameMap</code>.
- *
- * <p>
- * Note: only <code>Code</code> and <code>Exceptions</code> attributes
- * are copied from the source. The other attributes are ignored.
- *
- * @param cp
- * a constant pool table
- * @param methodname
- * a method name
- * @param src
- * a source <code>method_info</code>
- * @param classnameMap
- * specifies pairs of replaced and substituted name.
- * @see Descriptor
- */
- public MethodInfo(ConstPool cp, String methodname, MethodInfo src,
- Map classnameMap) throws BadBytecode {
- this(cp);
- read(src, methodname, classnameMap);
- }
-
- /**
- * Returns a string representation of the object.
- */
- public String toString() {
- return getName() + " " + getDescriptor();
- }
-
- /**
- * Copies all constant pool items to a given new constant pool
- * and replaces the original items with the new ones.
- * This is used for garbage collecting the items of removed fields
- * and methods.
- *
- * @param cp the destination
- */
- void compact(ConstPool cp) {
- name = cp.addUtf8Info(getName());
- descriptor = cp.addUtf8Info(getDescriptor());
- attribute = AttributeInfo.copyAll(attribute, cp);
- constPool = cp;
- }
-
- void prune(ConstPool cp) {
- LinkedList newAttributes = new LinkedList();
- AttributeInfo invisibleAnnotations
- = getAttribute(AnnotationsAttribute.invisibleTag);
- if (invisibleAnnotations != null) {
- invisibleAnnotations = invisibleAnnotations.copy(cp, null);
- newAttributes.add(invisibleAnnotations);
- }
-
- AttributeInfo visibleAnnotations
- = getAttribute(AnnotationsAttribute.visibleTag);
- if (visibleAnnotations != null) {
- visibleAnnotations = visibleAnnotations.copy(cp, null);
- newAttributes.add(visibleAnnotations);
- }
-
- ExceptionsAttribute ea = getExceptionsAttribute();
- if (ea != null)
- newAttributes.add(ea);
-
- attribute = newAttributes;
- name = cp.addUtf8Info(getName());
- descriptor = cp.addUtf8Info(getDescriptor());
- constPool = cp;
- }
-
- /**
- * Returns a method name.
- */
- public String getName() {
- if (cachedName == null)
- cachedName = constPool.getUtf8Info(name);
-
- return cachedName;
- }
-
- /**
- * Sets a method name.
- */
- public void setName(String newName) {
- name = constPool.addUtf8Info(newName);
- cachedName = newName;
- }
-
- /**
- * Returns true if this is not a constructor or a class initializer (static
- * initializer).
- */
- public boolean isMethod() {
- String n = getName();
- return !n.equals(nameInit) && !n.equals(nameClinit);
- }
-
- /**
- * Returns a constant pool table used by this method.
- */
- public ConstPool getConstPool() {
- return constPool;
- }
-
- /**
- * Returns true if this is a constructor.
- */
- public boolean isConstructor() {
- return getName().equals(nameInit);
- }
-
- /**
- * Returns true if this is a class initializer (static initializer).
- */
- public boolean isStaticInitializer() {
- return getName().equals(nameClinit);
- }
-
- /**
- * Returns access flags.
- *
- * @see AccessFlag
- */
- public int getAccessFlags() {
- return accessFlags;
- }
-
- /**
- * Sets access flags.
- *
- * @see AccessFlag
- */
- public void setAccessFlags(int acc) {
- accessFlags = acc;
- }
-
- /**
- * Returns a method descriptor.
- *
- * @see Descriptor
- */
- public String getDescriptor() {
- return constPool.getUtf8Info(descriptor);
- }
-
- /**
- * Sets a method descriptor.
- *
- * @see Descriptor
- */
- public void setDescriptor(String desc) {
- if (!desc.equals(getDescriptor()))
- descriptor = constPool.addUtf8Info(desc);
- }
-
- /**
- * Returns all the attributes. The returned <code>List</code> object
- * is shared with this object. If you add a new attribute to the list,
- * the attribute is also added to the method represented by this
- * object. If you remove an attribute from the list, it is also removed
- * from the method.
- *
- * @return a list of <code>AttributeInfo</code> objects.
- * @see AttributeInfo
- */
- public List getAttributes() {
- if (attribute == null)
- attribute = new LinkedList();
-
- return attribute;
- }
-
- /**
- * Returns the attribute with the specified name. If it is not found, this
- * method returns null.
- *
- * @param name attribute name
- * @return an <code>AttributeInfo</code> object or null.
- * @see #getAttributes()
- */
- public AttributeInfo getAttribute(String name) {
- return AttributeInfo.lookup(attribute, name);
- }
-
- /**
- * Appends an attribute. If there is already an attribute with the same
- * name, the new one substitutes for it.
- *
- * @see #getAttributes()
- */
- public void addAttribute(AttributeInfo info) {
- if (attribute == null)
- attribute = new LinkedList();
-
- AttributeInfo.remove(attribute, info.getName());
- attribute.add(info);
- }
-
- /**
- * Returns an Exceptions attribute.
- *
- * @return an Exceptions attribute or null if it is not specified.
- */
- public ExceptionsAttribute getExceptionsAttribute() {
- AttributeInfo info = AttributeInfo.lookup(attribute,
- ExceptionsAttribute.tag);
- return (ExceptionsAttribute)info;
- }
-
- /**
- * Returns a Code attribute.
- *
- * @return a Code attribute or null if it is not specified.
- */
- public CodeAttribute getCodeAttribute() {
- AttributeInfo info = AttributeInfo.lookup(attribute, CodeAttribute.tag);
- return (CodeAttribute)info;
- }
-
- /**
- * Removes an Exception attribute.
- */
- public void removeExceptionsAttribute() {
- AttributeInfo.remove(attribute, ExceptionsAttribute.tag);
- }
-
- /**
- * Adds an Exception attribute.
- *
- * <p>
- * The added attribute must share the same constant pool table as this
- * <code>method_info</code> structure.
- */
- public void setExceptionsAttribute(ExceptionsAttribute cattr) {
- removeExceptionsAttribute();
- if (attribute == null)
- attribute = new LinkedList();
-
- attribute.add(cattr);
- }
-
- /**
- * Removes a Code attribute.
- */
- public void removeCodeAttribute() {
- AttributeInfo.remove(attribute, CodeAttribute.tag);
- }
-
- /**
- * Adds a Code attribute.
- *
- * <p>
- * The added attribute must share the same constant pool table as this
- * <code>method_info</code> structure.
- */
- public void setCodeAttribute(CodeAttribute cattr) {
- removeCodeAttribute();
- if (attribute == null)
- attribute = new LinkedList();
-
- attribute.add(cattr);
- }
-
- /**
- * Returns the line number of the source line corresponding to the specified
- * bytecode contained in this method.
- *
- * @param pos
- * the position of the bytecode (>= 0). an index into the code
- * array.
- * @return -1 if this information is not available.
- */
- public int getLineNumber(int pos) {
- CodeAttribute ca = getCodeAttribute();
- if (ca == null)
- return -1;
-
- LineNumberAttribute ainfo = (LineNumberAttribute)ca
- .getAttribute(LineNumberAttribute.tag);
- if (ainfo == null)
- return -1;
-
- return ainfo.toLineNumber(pos);
- }
-
- /**
- * Changes a super constructor called by this constructor.
- *
- * <p>
- * This method modifies a call to <code>super()</code>, which should be
- * at the head of a constructor body, so that a constructor in a different
- * super class is called. This method does not change actural parameters.
- * Hence the new super class must have a constructor with the same signature
- * as the original one.
- *
- * <p>
- * This method should be called when the super class of the class declaring
- * this method is changed.
- *
- * <p>
- * This method does not perform anything unless this <code>MethodInfo</code>
- * represents a constructor.
- *
- * @param superclass
- * the new super class
- */
- public void setSuperclass(String superclass) throws BadBytecode {
- if (!isConstructor())
- return;
-
- CodeAttribute ca = getCodeAttribute();
- byte[] code = ca.getCode();
- CodeIterator iterator = ca.iterator();
- int pos = iterator.skipSuperConstructor();
- if (pos >= 0) { // not this()
- ConstPool cp = constPool;
- int mref = ByteArray.readU16bit(code, pos + 1);
- int nt = cp.getMethodrefNameAndType(mref);
- int sc = cp.addClassInfo(superclass);
- int mref2 = cp.addMethodrefInfo(sc, nt);
- ByteArray.write16bit(mref2, code, pos + 1);
- }
- }
-
- private void read(MethodInfo src, String methodname, Map classnames)
- throws BadBytecode {
- ConstPool destCp = constPool;
- accessFlags = src.accessFlags;
- name = destCp.addUtf8Info(methodname);
- cachedName = methodname;
- ConstPool srcCp = src.constPool;
- String desc = srcCp.getUtf8Info(src.descriptor);
- String desc2 = Descriptor.rename(desc, classnames);
- descriptor = destCp.addUtf8Info(desc2);
-
- attribute = new LinkedList();
- ExceptionsAttribute eattr = src.getExceptionsAttribute();
- if (eattr != null)
- attribute.add(eattr.copy(destCp, classnames));
-
- CodeAttribute cattr = src.getCodeAttribute();
- if (cattr != null)
- attribute.add(cattr.copy(destCp, classnames));
- }
-
- private void read(DataInputStream in) throws IOException {
- accessFlags = in.readUnsignedShort();
- name = in.readUnsignedShort();
- descriptor = in.readUnsignedShort();
- int n = in.readUnsignedShort();
- attribute = new LinkedList();
- for (int i = 0; i < n; ++i)
- attribute.add(AttributeInfo.read(constPool, in));
- }
-
- void write(DataOutputStream out) throws IOException {
- out.writeShort(accessFlags);
- out.writeShort(name);
- out.writeShort(descriptor);
-
- if (attribute == null)
- out.writeShort(0);
- else {
- out.writeShort(attribute.size());
- AttributeInfo.writeAll(attribute, out);
- }
- }
- }
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