com.sun.tools.javap.LocalVariableTableWriter Maven / Gradle / Ivy
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/*
* Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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 General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package com.sun.tools.javap;
import com.sun.tools.classfile.Attribute;
import com.sun.tools.classfile.Code_attribute;
import com.sun.tools.classfile.ConstantPool;
import com.sun.tools.classfile.ConstantPoolException;
import com.sun.tools.classfile.Descriptor;
import com.sun.tools.classfile.Descriptor.InvalidDescriptor;
import com.sun.tools.classfile.Instruction;
import com.sun.tools.classfile.LocalVariableTable_attribute;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
/**
* Annotate instructions with details about local variables.
*
* This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.
*/
public class LocalVariableTableWriter extends InstructionDetailWriter {
public enum NoteKind {
START("start") {
public boolean match(LocalVariableTable_attribute.Entry entry, int pc) {
return (pc == entry.start_pc);
}
},
END("end") {
public boolean match(LocalVariableTable_attribute.Entry entry, int pc) {
return (pc == entry.start_pc + entry.length);
}
};
NoteKind(String text) {
this.text = text;
}
public abstract boolean match(LocalVariableTable_attribute.Entry entry, int pc);
public final String text;
}
static LocalVariableTableWriter instance(Context context) {
LocalVariableTableWriter instance = context.get(LocalVariableTableWriter.class);
if (instance == null)
instance = new LocalVariableTableWriter(context);
return instance;
}
protected LocalVariableTableWriter(Context context) {
super(context);
context.put(LocalVariableTableWriter.class, this);
classWriter = ClassWriter.instance(context);
}
public void reset(Code_attribute attr) {
codeAttr = attr;
pcMap = new HashMap<>();
LocalVariableTable_attribute lvt =
(LocalVariableTable_attribute) (attr.attributes.get(Attribute.LocalVariableTable));
if (lvt == null)
return;
for (int i = 0; i < lvt.local_variable_table.length; i++) {
LocalVariableTable_attribute.Entry entry = lvt.local_variable_table[i];
put(entry.start_pc, entry);
put(entry.start_pc + entry.length, entry);
}
}
public void writeDetails(Instruction instr) {
int pc = instr.getPC();
writeLocalVariables(pc, NoteKind.END);
writeLocalVariables(pc, NoteKind.START);
}
@Override
public void flush() {
int pc = codeAttr.code_length;
writeLocalVariables(pc, NoteKind.END);
}
public void writeLocalVariables(int pc, NoteKind kind) {
ConstantPool constant_pool = classWriter.getClassFile().constant_pool;
String indent = space(2); // get from Options?
List entries = pcMap.get(pc);
if (entries != null) {
for (ListIterator iter =
entries.listIterator(kind == NoteKind.END ? entries.size() : 0);
kind == NoteKind.END ? iter.hasPrevious() : iter.hasNext() ; ) {
LocalVariableTable_attribute.Entry entry =
kind == NoteKind.END ? iter.previous() : iter.next();
if (kind.match(entry, pc)) {
print(indent);
print(kind.text);
print(" local ");
print(entry.index);
print(" // ");
Descriptor d = new Descriptor(entry.descriptor_index);
try {
print(d.getFieldType(constant_pool));
} catch (InvalidDescriptor e) {
print(report(e));
} catch (ConstantPoolException e) {
print(report(e));
}
print(" ");
try {
print(constant_pool.getUTF8Value(entry.name_index));
} catch (ConstantPoolException e) {
print(report(e));
}
println();
}
}
}
}
private void put(int pc, LocalVariableTable_attribute.Entry entry) {
List list = pcMap.get(pc);
if (list == null) {
list = new ArrayList<>();
pcMap.put(pc, list);
}
if (!list.contains(entry))
list.add(entry);
}
private ClassWriter classWriter;
private Code_attribute codeAttr;
private Map> pcMap;
}