diff options
Diffstat (limited to 'third_party/rust/object/src/read/coff/comdat.rs')
-rw-r--r-- | third_party/rust/object/src/read/coff/comdat.rs | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/third_party/rust/object/src/read/coff/comdat.rs b/third_party/rust/object/src/read/coff/comdat.rs new file mode 100644 index 0000000000..22e061a236 --- /dev/null +++ b/third_party/rust/object/src/read/coff/comdat.rs @@ -0,0 +1,207 @@ +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, CoffHeader, ImageSymbol}; + +/// An iterator over the COMDAT section groups of a `CoffBigFile`. +pub type CoffBigComdatIterator<'data, 'file, R = &'data [u8]> = + CoffComdatIterator<'data, 'file, R, pe::AnonObjectHeaderBigobj>; + +/// An iterator over the COMDAT section groups of a `CoffFile`. +#[derive(Debug)] +pub struct CoffComdatIterator< + 'data, + 'file, + R: ReadRef<'data> = &'data [u8], + Coff: CoffHeader = pe::ImageFileHeader, +> { + pub(super) file: &'file CoffFile<'data, R, Coff>, + pub(super) index: usize, +} + +impl<'data, 'file, R: ReadRef<'data>, Coff: CoffHeader> Iterator + for CoffComdatIterator<'data, 'file, R, Coff> +{ + type Item = CoffComdat<'data, 'file, R, Coff>; + + 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 `CoffBigFile`. +pub type CoffBigComdat<'data, 'file, R = &'data [u8]> = + CoffComdat<'data, 'file, R, pe::AnonObjectHeaderBigobj>; + +/// A COMDAT section group of a `CoffFile`. +#[derive(Debug)] +pub struct CoffComdat< + 'data, + 'file, + R: ReadRef<'data> = &'data [u8], + Coff: CoffHeader = pe::ImageFileHeader, +> { + file: &'file CoffFile<'data, R, Coff>, + symbol_index: SymbolIndex, + symbol: &'data Coff::ImageSymbol, + selection: u8, +} + +impl<'data, 'file, R: ReadRef<'data>, Coff: CoffHeader> CoffComdat<'data, 'file, R, Coff> { + fn parse( + file: &'file CoffFile<'data, R, Coff>, + section_symbol: &'data Coff::ImageSymbol, + index: usize, + ) -> Option<CoffComdat<'data, 'file, R, Coff>> { + // 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(); + 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() { + break; + } + } + + Some(CoffComdat { + file, + symbol_index: SymbolIndex(symbol_index), + symbol, + selection, + }) + } +} + +impl<'data, 'file, R: ReadRef<'data>, Coff: CoffHeader> read::private::Sealed + for CoffComdat<'data, 'file, R, Coff> +{ +} + +impl<'data, 'file, R: ReadRef<'data>, Coff: CoffHeader> ObjectComdat<'data> + for CoffComdat<'data, 'file, R, Coff> +{ + type SectionIterator = CoffComdatSectionIterator<'data, 'file, R, Coff>; + + #[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(), + index: 0, + } + } +} + +/// An iterator over the sections in a COMDAT section group of a `CoffBigFile`. +pub type CoffBigComdatSectionIterator<'data, 'file, R = &'data [u8]> = + CoffComdatSectionIterator<'data, 'file, R, pe::AnonObjectHeaderBigobj>; + +/// 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], + Coff: CoffHeader = pe::ImageFileHeader, +> { + file: &'file CoffFile<'data, R, Coff>, + section_number: i32, + index: usize, +} + +impl<'data, 'file, R: ReadRef<'data>, Coff: CoffHeader> Iterator + for CoffComdatSectionIterator<'data, 'file, R, Coff> +{ + 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(); + + let aux = self.file.common.symbols.aux_section(index).ok()?; + if aux.selection == pe::IMAGE_COMDAT_SELECT_ASSOCIATIVE { + let number = if Coff::is_type_bigobj() { + u32::from(aux.number.get(LE)) | (u32::from(aux.high_number.get(LE)) << 16) + } else { + u32::from(aux.number.get(LE)) + }; + if number as i32 == 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)); + } + } + } + } +} |