1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167

mod encode;

use result::*;
use super::constpool::*;
use super::tree::*;
use self::encode::Encoder;

/// Writes a constant pool and class to a byte vector
pub fn write(constant_pool: &Pool, class: &Class) -> Result<Vec<u8>> {
    let mut encoder = Encoder::new();

    // write magic and version
    encoder.write_bytes(MAGIC);
    encoder.write_u16(class.minor_version);
    encoder.write_u16(class.major_version);

    write_constant_pool(&mut encoder, constant_pool);

    encoder.write_u16(class.access_flags.bits());
    encoder.write_u16(class.name);
    encoder.write_u16(class.super_name);

    encoder.write_u16(class.interfaces.len() as u16);
    for interface in &class.interfaces {
        encoder.write_u16(*interface);
    }

    write_fields(&mut encoder, &class.fields);
    write_methods(&mut encoder, &class.methods);

    write_attributes(&mut encoder, &class.attributes);

    Ok(encoder.bytes())
}

/// Writes the constant pool
fn write_constant_pool(encoder: &mut Encoder, pool: &Pool) {
    // write length and after that the items
    encoder.write_u16(pool.len());
    for (_index, item) in pool.iter() {
        match *item {
            Item::UTF8(ref s) => {
                encoder.write_u8(1);
                encoder.write_u16(s.len() as u16);
                encoder.write_str(s.as_ref());
            }
            Item::Integer(value) => {
                encoder.write_u8(3);
                encoder.write_i32(value);
            }
            Item::Float(value) => {
                encoder.write_u8(4);
                encoder.write_f32(value);
            }
            Item::Long(value) => {
                encoder.write_u8(5);
                encoder.write_i64(value);
            }
            Item::Double(value) => {
                encoder.write_u8(6);
                encoder.write_f64(value);
            }
            Item::Class(class) => {
                encoder.write_u8(7);
                encoder.write_u16(class);
            }
            Item::String(class) => {
                encoder.write_u8(8);
                encoder.write_u16(class);
            }
            Item::FieldRef {
                class,
                name_and_type,
            } => {
                encoder.write_u8(9);
                encoder.write_u16(class);
                encoder.write_u16(name_and_type);
            }
            Item::MethodRef {
                class,
                name_and_type,
            } => {
                encoder.write_u8(10);
                encoder.write_u16(class);
                encoder.write_u16(name_and_type);
            }
            Item::InterfaceMethodRef {
                class,
                name_and_type,
            } => {
                encoder.write_u8(11);
                encoder.write_u16(class);
                encoder.write_u16(name_and_type);
            }
            Item::NameAndType { name, desc } => {
                encoder.write_u8(12);
                encoder.write_u16(name);
                encoder.write_u16(desc);
            }
            Item::MethodHandle { ref kind, index } => {
                use self::ReferenceKind::*;

                encoder.write_u8(15);
                encoder.write_u8(match *kind {
                    GetField => 1,
                    GetStatic => 2,
                    PutField => 3,
                    PutStatic => 4,
                    InvokeVirtual => 5,
                    InvokeStatic => 6,
                    InvokeSpecial => 7,
                    NewInvokeSpecial => 8,
                    InvokeInterface => 9,
                });
                encoder.write_u16(index);
            }
            Item::MethodType(index) => {
                encoder.write_u8(16);
                encoder.write_u16(index);
            }
            Item::InvokeDynamic {
                bootstrap_method,
                name_and_type,
            } => {
                encoder.write_u8(18);
                encoder.write_u16(bootstrap_method);
                encoder.write_u16(name_and_type);
            }
            Item::Module(index) => {
                encoder.write_u8(19);
                encoder.write_u16(index);
            }
            Item::Package(index) => {
                encoder.write_u8(20);
                encoder.write_u16(index);
            }
        }
    }
}

/// Writes all fields to the encoder
fn write_fields(encoder: &mut Encoder, fields: &[Field]) {
    encoder.write_u16(fields.len() as u16);
    for field in fields {
        encoder.write_u16(field.access_flags.bits());
        encoder.write_u16(field.name);
        encoder.write_u16(field.desc);
        write_attributes(encoder, &field.attributes);
    }
}

/// Writes all methods to the encoder
fn write_methods(encoder: &mut Encoder, methods: &[Method]) {
    encoder.write_u16(methods.len() as u16);
    for method in methods {
        encoder.write_u16(method.access_flags.bits());
        encoder.write_u16(method.name);
        encoder.write_u16(method.desc);
        write_attributes(encoder, &method.attributes);
    }
}

/// Writes all attributes to the encoder
fn write_attributes(encoder: &mut Encoder, _attributes: &[Attribute]) {
    // implement later
    encoder.write_u16(0);
}