1/*
2 * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.tools.javap;
27
28import com.sun.tools.classfile.Attribute;
29import com.sun.tools.classfile.Code_attribute;
30import com.sun.tools.classfile.ConstantPool;
31import com.sun.tools.classfile.ConstantPoolException;
32import com.sun.tools.classfile.Descriptor;
33import com.sun.tools.classfile.Descriptor.InvalidDescriptor;
34import com.sun.tools.classfile.Instruction;
35import com.sun.tools.classfile.LocalVariableTypeTable_attribute;
36import com.sun.tools.classfile.Signature;
37import java.util.ArrayList;
38import java.util.HashMap;
39import java.util.List;
40import java.util.ListIterator;
41import java.util.Map;
42
43/**
44 * Annotate instructions with details about local variables.
45 *
46 *  <p><b>This is NOT part of any supported API.
47 *  If you write code that depends on this, you do so at your own risk.
48 *  This code and its internal interfaces are subject to change or
49 *  deletion without notice.</b>
50 */
51public class LocalVariableTypeTableWriter extends  InstructionDetailWriter {
52    public enum NoteKind {
53        START("start") {
54            public boolean match(LocalVariableTypeTable_attribute.Entry entry, int pc) {
55                return (pc == entry.start_pc);
56            }
57        },
58        END("end") {
59            public boolean match(LocalVariableTypeTable_attribute.Entry entry, int pc) {
60                return (pc == entry.start_pc + entry.length);
61            }
62        };
63        NoteKind(String text) {
64            this.text = text;
65        }
66        public abstract boolean match(LocalVariableTypeTable_attribute.Entry entry, int pc);
67        public final String text;
68    }
69
70    static LocalVariableTypeTableWriter instance(Context context) {
71        LocalVariableTypeTableWriter instance = context.get(LocalVariableTypeTableWriter.class);
72        if (instance == null)
73            instance = new LocalVariableTypeTableWriter(context);
74        return instance;
75    }
76
77    protected LocalVariableTypeTableWriter(Context context) {
78        super(context);
79        context.put(LocalVariableTypeTableWriter.class, this);
80        classWriter = ClassWriter.instance(context);
81    }
82
83    public void reset(Code_attribute attr) {
84        codeAttr = attr;
85        pcMap = new HashMap<>();
86        LocalVariableTypeTable_attribute lvt =
87                (LocalVariableTypeTable_attribute) (attr.attributes.get(Attribute.LocalVariableTypeTable));
88        if (lvt == null)
89            return;
90
91        for (int i = 0; i < lvt.local_variable_table.length; i++) {
92            LocalVariableTypeTable_attribute.Entry entry = lvt.local_variable_table[i];
93            put(entry.start_pc, entry);
94            put(entry.start_pc + entry.length, entry);
95        }
96    }
97
98    public void writeDetails(Instruction instr) {
99        int pc = instr.getPC();
100        writeLocalVariables(pc, NoteKind.END);
101        writeLocalVariables(pc, NoteKind.START);
102    }
103
104    @Override
105    public void flush() {
106        int pc = codeAttr.code_length;
107        writeLocalVariables(pc, NoteKind.END);
108    }
109
110    public void writeLocalVariables(int pc, NoteKind kind) {
111        ConstantPool constant_pool = classWriter.getClassFile().constant_pool;
112        String indent = space(2); // get from Options?
113        List<LocalVariableTypeTable_attribute.Entry> entries = pcMap.get(pc);
114        if (entries != null) {
115            for (ListIterator<LocalVariableTypeTable_attribute.Entry> iter =
116                    entries.listIterator(kind == NoteKind.END ? entries.size() : 0);
117                    kind == NoteKind.END ? iter.hasPrevious() : iter.hasNext() ; ) {
118                LocalVariableTypeTable_attribute.Entry entry =
119                        kind == NoteKind.END ? iter.previous() : iter.next();
120                if (kind.match(entry, pc)) {
121                    print(indent);
122                    print(kind.text);
123                    print(" generic local ");
124                    print(entry.index);
125                    print(" // ");
126                    Descriptor d = new Signature(entry.signature_index);
127                    try {
128                        print(d.getFieldType(constant_pool).toString().replace("/", "."));
129                    } catch (InvalidDescriptor e) {
130                        print(report(e));
131                    } catch (ConstantPoolException e) {
132                        print(report(e));
133                    }
134                    print(" ");
135                    try {
136                        print(constant_pool.getUTF8Value(entry.name_index));
137                    } catch (ConstantPoolException e) {
138                        print(report(e));
139                    }
140                    println();
141                }
142            }
143        }
144    }
145
146    private void put(int pc, LocalVariableTypeTable_attribute.Entry entry) {
147        List<LocalVariableTypeTable_attribute.Entry> list = pcMap.get(pc);
148        if (list == null) {
149            list = new ArrayList<>();
150            pcMap.put(pc, list);
151        }
152        if (!list.contains(entry))
153            list.add(entry);
154    }
155
156    private ClassWriter classWriter;
157    private Code_attribute codeAttr;
158    private Map<Integer, List<LocalVariableTypeTable_attribute.Entry>> pcMap;
159}
160