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

use core::str;

use crate::endian::LittleEndian as LE;
use crate::pe;
use crate::read::{
    self, ComdatKind, ObjectComdat, ReadError, ReadRef, Result, SectionIndex, SymbolIndex,
};

use super::CoffFile;

/// An iterator over the COMDAT section groups of a `CoffFile`.
#[derive(Debug)]
pub struct CoffComdatIterator<'data, 'file, R: ReadRef<'data> = &'data [u8]> {
    pub(super) file: &'file CoffFile<'data, R>,
    pub(super) index: usize,
}

impl<'data, 'file, R: ReadRef<'data>> Iterator for CoffComdatIterator<'data, 'file, R> {
    type Item = CoffComdat<'data, 'file, R>;

    fn next(&mut self) -> Option<Self::Item> {
        loop {
            let index = self.index;
            let symbol = self.file.common.symbols.symbol(index).ok()?;
            self.index += 1 + symbol.number_of_aux_symbols as usize;
            if let Some(comdat) = CoffComdat::parse(self.file, symbol, index) {
                return Some(comdat);
            }
        }
    }
}

/// A COMDAT section group of a `CoffFile`.
#[derive(Debug)]
pub struct CoffComdat<'data, 'file, R: ReadRef<'data> = &'data [u8]> {
    file: &'file CoffFile<'data, R>,
    symbol_index: SymbolIndex,
    symbol: &'data pe::ImageSymbol,
    selection: u8,
}

impl<'data, 'file, R: ReadRef<'data>> CoffComdat<'data, 'file, R> {
    fn parse(
        file: &'file CoffFile<'data, R>,
        section_symbol: &'data pe::ImageSymbol,
        index: usize,
    ) -> Option<CoffComdat<'data, 'file, R>> {
        // Must be a section symbol.
        if !section_symbol.has_aux_section() {
            return None;
        }

        // Auxiliary record must have a non-associative selection.
        let aux = file.common.symbols.aux_section(index).ok()?;
        let selection = aux.selection;
        if selection == 0 || selection == pe::IMAGE_COMDAT_SELECT_ASSOCIATIVE {
            return None;
        }

        // Find the COMDAT symbol.
        let mut symbol_index = index;
        let mut symbol = section_symbol;
        let section_number = section_symbol.section_number.get(LE);
        loop {
            symbol_index += 1 + symbol.number_of_aux_symbols as usize;
            symbol = file.common.symbols.symbol(symbol_index).ok()?;
            if section_number == symbol.section_number.get(LE) {
                break;
            }
        }

        Some(CoffComdat {
            file,
            symbol_index: SymbolIndex(symbol_index),
            symbol,
            selection,
        })
    }
}

impl<'data, 'file, R: ReadRef<'data>> read::private::Sealed for CoffComdat<'data, 'file, R> {}

impl<'data, 'file, R: ReadRef<'data>> ObjectComdat<'data> for CoffComdat<'data, 'file, R> {
    type SectionIterator = CoffComdatSectionIterator<'data, 'file, R>;

    #[inline]
    fn kind(&self) -> ComdatKind {
        match self.selection {
            pe::IMAGE_COMDAT_SELECT_NODUPLICATES => ComdatKind::NoDuplicates,
            pe::IMAGE_COMDAT_SELECT_ANY => ComdatKind::Any,
            pe::IMAGE_COMDAT_SELECT_SAME_SIZE => ComdatKind::SameSize,
            pe::IMAGE_COMDAT_SELECT_EXACT_MATCH => ComdatKind::ExactMatch,
            pe::IMAGE_COMDAT_SELECT_LARGEST => ComdatKind::Largest,
            pe::IMAGE_COMDAT_SELECT_NEWEST => ComdatKind::Newest,
            _ => ComdatKind::Unknown,
        }
    }

    #[inline]
    fn symbol(&self) -> SymbolIndex {
        self.symbol_index
    }

    #[inline]
    fn name_bytes(&self) -> Result<&[u8]> {
        // Find the name of first symbol referring to the section.
        self.symbol.name(self.file.common.symbols.strings())
    }

    #[inline]
    fn name(&self) -> Result<&str> {
        let bytes = self.name_bytes()?;
        str::from_utf8(bytes)
            .ok()
            .read_error("Non UTF-8 COFF COMDAT name")
    }

    #[inline]
    fn sections(&self) -> Self::SectionIterator {
        CoffComdatSectionIterator {
            file: self.file,
            section_number: self.symbol.section_number.get(LE),
            index: 0,
        }
    }
}

/// An iterator over the sections in a COMDAT section group of a `CoffFile`.
#[derive(Debug)]
pub struct CoffComdatSectionIterator<'data, 'file, R: ReadRef<'data> = &'data [u8]> {
    file: &'file CoffFile<'data, R>,
    section_number: u16,
    index: usize,
}

impl<'data, 'file, R: ReadRef<'data>> Iterator for CoffComdatSectionIterator<'data, 'file, R> {
    type Item = SectionIndex;

    fn next(&mut self) -> Option<Self::Item> {
        // Find associated COMDAT symbols.
        // TODO: it seems gcc doesn't use associated symbols for this
        loop {
            let index = self.index;
            let symbol = self.file.common.symbols.symbol(index).ok()?;
            self.index += 1 + symbol.number_of_aux_symbols as usize;

            // Must be a section symbol.
            if !symbol.has_aux_section() {
                continue;
            }

            let section_number = symbol.section_number.get(LE);

            let aux = self.file.common.symbols.aux_section(index).ok()?;
            if aux.selection == pe::IMAGE_COMDAT_SELECT_ASSOCIATIVE {
                // TODO: use high_number for bigobj
                if aux.number.get(LE) == self.section_number {
                    return Some(SectionIndex(section_number as usize));
                }
            } else if aux.selection != 0 {
                if section_number == self.section_number {
                    return Some(SectionIndex(section_number as usize));
                }
            }
        }
    }
}