| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| package org.apache.bcel.generic; |
| |
| import org.apache.bcel.Const; |
| import org.apache.bcel.classfile.LocalVariable; |
| |
| /** |
| * Represents a local variable within a method. It contains its |
| * scope, name and type. The generated LocalVariable object can be obtained |
| * with getLocalVariable which needs the instruction list and the constant |
| * pool as parameters. |
| * |
| * @see LocalVariable |
| * @see MethodGen |
| */ |
| public class LocalVariableGen implements InstructionTargeter, NamedAndTyped, Cloneable { |
| |
| private int index; |
| private String name; |
| private Type type; |
| private InstructionHandle start; |
| private InstructionHandle end; |
| private int orig_index; // never changes; used to match up with LocalVariableTypeTable entries |
| private boolean live_to_end; |
| |
| |
| /** |
| * Generate a local variable that with index `index'. Note that double and long |
| * variables need two indexs. Index indices have to be provided by the user. |
| * |
| * @param index index of local variable |
| * @param name its name |
| * @param type its type |
| * @param start from where the instruction is valid (null means from the start) |
| * @param end until where the instruction is valid (null means to the end) |
| */ |
| public LocalVariableGen(final int index, final String name, final Type type, final InstructionHandle start, |
| final InstructionHandle end) { |
| if ((index < 0) || (index > Const.MAX_SHORT)) { |
| throw new ClassGenException("Invalid index index: " + index); |
| } |
| this.name = name; |
| this.type = type; |
| this.index = index; |
| setStart(start); |
| setEnd(end); |
| this.orig_index = index; |
| this.live_to_end = end == null; |
| } |
| |
| |
| /** |
| * Generates a local variable that with index `index'. Note that double and long |
| * variables need two indexs. Index indices have to be provided by the user. |
| * |
| * @param index index of local variable |
| * @param name its name |
| * @param type its type |
| * @param start from where the instruction is valid (null means from the start) |
| * @param end until where the instruction is valid (null means to the end) |
| * @param orig_index index of local variable prior to any changes to index |
| */ |
| public LocalVariableGen(final int index, final String name, final Type type, final InstructionHandle start, |
| final InstructionHandle end, final int orig_index) { |
| this(index, name, type, start, end); |
| this.orig_index = orig_index; |
| } |
| |
| |
| /** |
| * Gets LocalVariable object. |
| * |
| * This relies on that the instruction list has already been dumped to byte code or |
| * or that the `setPositions' methods has been called for the instruction list. |
| * |
| * Note that due to the conversion from byte code offset to InstructionHandle, |
| * it is impossible to tell the difference between a live range that ends BEFORE |
| * the last insturction of the method or a live range that ends AFTER the last |
| * instruction of the method. Hence the live_to_end flag to differentiate |
| * between these two cases. |
| * |
| * @param cp constant pool |
| */ |
| public LocalVariable getLocalVariable( final ConstantPoolGen cp ) { |
| int start_pc = 0; |
| int length = 0; |
| if ((start != null) && (end != null)) { |
| start_pc = start.getPosition(); |
| length = end.getPosition() - start_pc; |
| if ((end.getNext() == null) && live_to_end) { |
| length += end.getInstruction().getLength(); |
| } |
| } |
| final int name_index = cp.addUtf8(name); |
| final int signature_index = cp.addUtf8(type.getSignature()); |
| return new LocalVariable(start_pc, length, name_index, signature_index, index, cp |
| .getConstantPool(), orig_index); |
| } |
| |
| |
| public void setIndex( final int index ) { |
| this.index = index; |
| } |
| |
| |
| public int getIndex() { |
| return index; |
| } |
| |
| |
| public int getOrigIndex() { |
| return orig_index; |
| } |
| |
| |
| public void setLiveToEnd( final boolean live_to_end) { |
| this.live_to_end = live_to_end; |
| } |
| |
| |
| public boolean getLiveToEnd() { |
| return live_to_end; |
| } |
| |
| |
| @Override |
| public void setName( final String name ) { |
| this.name = name; |
| } |
| |
| |
| @Override |
| public String getName() { |
| return name; |
| } |
| |
| |
| @Override |
| public void setType( final Type type ) { |
| this.type = type; |
| } |
| |
| |
| @Override |
| public Type getType() { |
| return type; |
| } |
| |
| |
| public InstructionHandle getStart() { |
| return start; |
| } |
| |
| |
| public InstructionHandle getEnd() { |
| return end; |
| } |
| |
| |
| public void setStart( final InstructionHandle start ) { // TODO could be package-protected? |
| BranchInstruction.notifyTarget(this.start, start, this); |
| this.start = start; |
| } |
| |
| |
| public void setEnd( final InstructionHandle end ) { // TODO could be package-protected? |
| BranchInstruction.notifyTarget(this.end, end, this); |
| this.end = end; |
| } |
| |
| |
| /** |
| * @param old_ih old target, either start or end |
| * @param new_ih new target |
| */ |
| @Override |
| public void updateTarget( final InstructionHandle old_ih, final InstructionHandle new_ih ) { |
| boolean targeted = false; |
| if (start == old_ih) { |
| targeted = true; |
| setStart(new_ih); |
| } |
| if (end == old_ih) { |
| targeted = true; |
| setEnd(new_ih); |
| } |
| if (!targeted) { |
| throw new ClassGenException("Not targeting " + old_ih + ", but {" + start + ", " + end |
| + "}"); |
| } |
| } |
| |
| /** |
| * Clear the references from and to this variable when it's removed. |
| */ |
| void dispose() { |
| setStart(null); |
| setEnd(null); |
| } |
| |
| /** |
| * @return true, if ih is target of this variable |
| */ |
| @Override |
| public boolean containsTarget( final InstructionHandle ih ) { |
| return (start == ih) || (end == ih); |
| } |
| |
| |
| @Override |
| public int hashCode() { |
| // If the user changes the name or type, problems with the targeter hashmap will occur. |
| // Note: index cannot be part of hash as it may be changed by the user. |
| return name.hashCode() ^ type.hashCode(); |
| } |
| |
| |
| /** |
| * We consider to local variables to be equal, if the use the same index and |
| * are valid in the same range. |
| */ |
| @Override |
| public boolean equals( final Object o ) { |
| if (!(o instanceof LocalVariableGen)) { |
| return false; |
| } |
| final LocalVariableGen l = (LocalVariableGen) o; |
| return (l.index == index) && (l.start == start) && (l.end == end); |
| } |
| |
| |
| @Override |
| public String toString() { |
| return "LocalVariableGen(" + name + ", " + type + ", " + start + ", " + end + ")"; |
| } |
| |
| |
| @Override |
| public Object clone() { |
| try { |
| return super.clone(); |
| } catch (final CloneNotSupportedException e) { |
| throw new Error("Clone Not Supported"); // never happens |
| } |
| } |
| } |