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- /*
- * Javassist, a Java-bytecode translator toolkit.
- * Copyright (C) 1999-2003 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.Map;
- import java.util.List;
- import java.util.LinkedList;
- import javassist.CannotCompileException;
-
- /**
- * <code>method_info</code> structure.
- *
- * @see javassist.CtMethod#getMethodInfo()
- * @see javassist.CtConstructor#getMethodInfo()
- */
- public final class MethodInfo {
- ConstPool constPool;
- int accessFlags;
- int name;
- 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.
- *
- * @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);
- 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 method name.
- */
- public String getName() {
- return constPool.getUtf8Info(name);
- }
-
- /**
- * Sets a method name.
- */
- public void setName(String newName) {
- name = constPool.addUtf8Info(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.
- *
- * @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.
- */
- 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.
- */
- 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.class);
- 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.class);
- return (CodeAttribute)info;
- }
-
- /**
- * Removes an Exception attribute.
- */
- public void removeExceptionsAttribute() {
- AttributeInfo.remove(attribute, ExceptionsAttribute.class);
- }
-
- /**
- * 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.class);
- }
-
- /**
- * 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);
-
- 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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