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
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193

use nom::{
  be_u8, be_u16, be_u32,
  IResult,
  ErrorKind,
};

use attribute_info::*;
use attribute_info::types::StackMapFrame::*;

pub fn attribute_parser(input: &[u8]) -> IResult<&[u8], AttributeInfo> {
    do_parse!(input,
        attribute_name_index: be_u16 >>
        attribute_length: be_u32 >>
        info: take!(attribute_length)>>
        (AttributeInfo {
            attribute_name_index: attribute_name_index,
            attribute_length: attribute_length,
            info: info.to_owned(),
        })
    )
}

pub fn exception_entry_parser(input: &[u8]) -> IResult<&[u8], ExceptionEntry> {
    do_parse!(input,
        start_pc: be_u16 >>
        end_pc: be_u16 >>
        handler_pc: be_u16 >>
        catch_type: be_u16>>
        (ExceptionEntry {
            start_pc: start_pc,
            end_pc: end_pc,
            handler_pc: handler_pc,
            catch_type: catch_type,
        })
    )
}

pub fn code_attribute_parser(input: &[u8]) -> IResult<&[u8], CodeAttribute> {
    do_parse!(input,
        max_stack: be_u16 >>
        max_locals: be_u16 >>
        code_length: be_u32 >>
        code: take!(code_length) >>
        exception_table_length: be_u16 >>
        exception_table: count!(exception_entry_parser, exception_table_length as usize) >>
        attributes_count: be_u16 >>
        attributes: count!(attribute_parser, attributes_count as usize) >>
        (CodeAttribute {
            max_stack: max_stack,
            max_locals: max_locals,
            code_length: code_length,
            code: code.to_owned(),
            exception_table_length: exception_table_length,
            exception_table: exception_table,
            attributes_count: attributes_count,
            attributes: attributes,
        })
    )
}

fn same_frame_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    value!(input, SameFrame { frame_type })
}

fn verification_type(v: &u8) -> Option<VerificationTypeInfo> {
    use self::VerificationTypeInfo::*;
    match *v {
        0 => Some(Top),
        1 => Some(Integer),
        2 => Some(Float),
        3 => Some(Double),
        4 => Some(Long),
        5 => Some(Null),
        6 => Some(UninitializedThis),
        7 => Some(Object),
        8 => Some(Uninitialized),
        _ => None,
    }
}

fn verification_type_parser(input: &[u8]) -> IResult<&[u8], VerificationTypeInfo> {
    match verification_type(&input[0]) {
        Some(x) => IResult::Done(&input[1..], x),
        _ => IResult::Error(error_position!(ErrorKind::Custom(1), input)),
    }
}

fn same_locals_1_stack_item_frame_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        stack: verification_type_parser >>
        (SameLocals1StackItemFrame { frame_type, stack })
    )
}

fn same_locals_1_stack_item_frame_extended_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        offset_delta: be_u16 >>
        stack: verification_type_parser >>
        (SameLocals1StackItemFrameExtended { frame_type, offset_delta, stack })
    )
}

fn chop_frame_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        offset_delta: be_u16 >>
        (ChopFrame { frame_type, offset_delta })
    )
}

fn same_frame_extended_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        offset_delta: be_u16 >>
        (SameFrameExtended { frame_type, offset_delta })
    )
}

fn append_frame_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        offset_delta: be_u16 >>
        locals: count!(verification_type_parser, (frame_type - 251) as usize) >>
        (AppendFrame { frame_type, offset_delta, locals })
    )
}

fn full_frame_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        offset_delta: be_u16 >>
        number_of_locals: be_u16 >>
        locals: count!(verification_type_parser, number_of_locals as usize) >>
        number_of_stack_items: be_u16 >>
        stack: count!(verification_type_parser, number_of_stack_items as usize) >>
        (FullFrame {
            frame_type,
            offset_delta,
            number_of_locals,
            locals,
            number_of_stack_items,
            stack,
        })
    )
}

fn stack_frame_parser(input: &[u8], frame_type: u8) -> IResult<&[u8], StackMapFrame> {
    match frame_type {
          0... 63 => same_frame_parser(input, frame_type),
         64...127 => same_locals_1_stack_item_frame_parser(input, frame_type),
        247       => same_locals_1_stack_item_frame_extended_parser(input, frame_type),
        248...250 => chop_frame_parser(input, frame_type),
        251       => same_frame_extended_parser(input, frame_type),
        252...254 => append_frame_parser(input, frame_type),
        255       => full_frame_parser(input, frame_type),
        _ => IResult::Error(error_position!(ErrorKind::Custom(2), input)),
    }
}

fn stack_map_frame_entry_parser(input: &[u8]) -> IResult<&[u8], StackMapFrame> {
    do_parse!(input,
        frame_type: be_u8 >>
        stack_frame: apply!(stack_frame_parser, frame_type) >>
        (stack_frame)
    )
}

pub fn stack_map_table_attribute_parser(input: &[u8]) -> IResult<&[u8], StackMapTableAttribute> {
    do_parse!(input,
        number_of_entries: be_u16 >>
        entries: count!(stack_map_frame_entry_parser, number_of_entries as usize) >>
        (StackMapTableAttribute {
            number_of_entries,
            entries,
        })
    )
}

pub fn exceptions_attribute_parser(input: &[u8]) -> IResult<&[u8], ExceptionsAttribute> {
    do_parse!(input,
        exception_table_length: be_u16 >>
        exception_table: count!(be_u16, exception_table_length as usize) >>
        (ExceptionsAttribute {
        exception_table_length: exception_table_length,
        exception_table: exception_table,
        })
    )
}

pub fn constant_value_attribute_parser(input: &[u8]) -> IResult<&[u8], ConstantValueAttribute> {
    do_parse!(input,
        constant_value_index: be_u16 >>
        (ConstantValueAttribute {
            constant_value_index: constant_value_index,
        })
    )
}