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use core::fmt::Debug;
use core::{iter, result, slice, str};
use crate::endian::BigEndian as BE;
use crate::pod::Pod;
use crate::read::{
self, CompressedData, CompressedFileRange, Error, ObjectSection, ReadError, ReadRef,
RelocationMap, Result, SectionFlags, SectionIndex, SectionKind,
};
use crate::xcoff;
use super::{AuxHeader, FileHeader, Rel, XcoffFile, XcoffRelocationIterator};
/// An iterator for the sections in an [`XcoffFile32`](super::XcoffFile32).
pub type XcoffSectionIterator32<'data, 'file, R = &'data [u8]> =
XcoffSectionIterator<'data, 'file, xcoff::FileHeader32, R>;
/// An iterator for the sections in an [`XcoffFile64`](super::XcoffFile64).
pub type XcoffSectionIterator64<'data, 'file, R = &'data [u8]> =
XcoffSectionIterator<'data, 'file, xcoff::FileHeader64, R>;
/// An iterator for the sections in an [`XcoffFile`].
#[derive(Debug)]
pub struct XcoffSectionIterator<'data, 'file, Xcoff, R = &'data [u8]>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
pub(super) file: &'file XcoffFile<'data, Xcoff, R>,
pub(super) iter: iter::Enumerate<slice::Iter<'data, Xcoff::SectionHeader>>,
}
impl<'data, 'file, Xcoff, R> Iterator for XcoffSectionIterator<'data, 'file, Xcoff, R>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
type Item = XcoffSection<'data, 'file, Xcoff, R>;
fn next(&mut self) -> Option<Self::Item> {
self.iter.next().map(|(index, section)| XcoffSection {
index: SectionIndex(index + 1),
file: self.file,
section,
})
}
}
/// A section in an [`XcoffFile32`](super::XcoffFile32).
pub type XcoffSection32<'data, 'file, R = &'data [u8]> =
XcoffSection<'data, 'file, xcoff::FileHeader32, R>;
/// A section in an [`XcoffFile64`](super::XcoffFile64).
pub type XcoffSection64<'data, 'file, R = &'data [u8]> =
XcoffSection<'data, 'file, xcoff::FileHeader64, R>;
/// A section in an [`XcoffFile`].
///
/// Most functionality is provided by the [`ObjectSection`] trait implementation.
#[derive(Debug)]
pub struct XcoffSection<'data, 'file, Xcoff, R = &'data [u8]>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
pub(super) file: &'file XcoffFile<'data, Xcoff, R>,
pub(super) section: &'data Xcoff::SectionHeader,
pub(super) index: SectionIndex,
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> XcoffSection<'data, 'file, Xcoff, R> {
/// Get the XCOFF file containing this section.
pub fn xcoff_file(&self) -> &'file XcoffFile<'data, Xcoff, R> {
self.file
}
/// Get the raw XCOFF section header.
pub fn xcoff_section(&self) -> &'data Xcoff::SectionHeader {
self.section
}
/// Get the raw XCOFF relocation entries for this section.
pub fn xcoff_relocations(&self) -> Result<&'data [Xcoff::Rel]> {
self.section.relocations(self.file.data)
}
fn bytes(&self) -> Result<&'data [u8]> {
self.section
.data(self.file.data)
.read_error("Invalid XCOFF section offset or size")
}
}
impl<'data, 'file, Xcoff, R> read::private::Sealed for XcoffSection<'data, 'file, Xcoff, R>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
}
impl<'data, 'file, Xcoff, R> ObjectSection<'data> for XcoffSection<'data, 'file, Xcoff, R>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
type RelocationIterator = XcoffRelocationIterator<'data, 'file, Xcoff, R>;
fn index(&self) -> SectionIndex {
self.index
}
fn address(&self) -> u64 {
self.section.s_paddr().into()
}
fn size(&self) -> u64 {
self.section.s_size().into()
}
fn align(&self) -> u64 {
// The default section alignment is 4.
if let Some(aux_header) = self.file.aux_header {
match self.kind() {
SectionKind::Text => aux_header.o_algntext().into(),
SectionKind::Data => aux_header.o_algndata().into(),
_ => 4,
}
} else {
4
}
}
fn file_range(&self) -> Option<(u64, u64)> {
self.section.file_range()
}
fn data(&self) -> Result<&'data [u8]> {
self.bytes()
}
fn data_range(&self, address: u64, size: u64) -> Result<Option<&'data [u8]>> {
Ok(read::util::data_range(
self.bytes()?,
self.address(),
address,
size,
))
}
fn compressed_file_range(&self) -> Result<CompressedFileRange> {
Ok(CompressedFileRange::none(self.file_range()))
}
fn compressed_data(&self) -> Result<CompressedData<'data>> {
self.data().map(CompressedData::none)
}
fn name_bytes(&self) -> read::Result<&'data [u8]> {
Ok(self.section.name())
}
fn name(&self) -> read::Result<&'data str> {
let name = self.name_bytes()?;
str::from_utf8(name)
.ok()
.read_error("Non UTF-8 XCOFF section name")
}
fn segment_name_bytes(&self) -> Result<Option<&[u8]>> {
Ok(None)
}
fn segment_name(&self) -> Result<Option<&str>> {
Ok(None)
}
fn kind(&self) -> SectionKind {
let section_type = self.section.s_flags() as u16;
if section_type & xcoff::STYP_TEXT != 0 {
SectionKind::Text
} else if section_type & xcoff::STYP_DATA != 0 {
SectionKind::Data
} else if section_type & xcoff::STYP_TDATA != 0 {
SectionKind::Tls
} else if section_type & xcoff::STYP_BSS != 0 {
SectionKind::UninitializedData
} else if section_type & xcoff::STYP_TBSS != 0 {
SectionKind::UninitializedTls
} else if section_type & (xcoff::STYP_DEBUG | xcoff::STYP_DWARF) != 0 {
SectionKind::Debug
} else if section_type & (xcoff::STYP_LOADER | xcoff::STYP_OVRFLO) != 0 {
SectionKind::Metadata
} else if section_type
& (xcoff::STYP_INFO | xcoff::STYP_EXCEPT | xcoff::STYP_PAD | xcoff::STYP_TYPCHK)
!= 0
{
SectionKind::Other
} else {
SectionKind::Unknown
}
}
fn relocations(&self) -> Self::RelocationIterator {
let rel = self.xcoff_relocations().unwrap_or(&[]);
XcoffRelocationIterator {
file: self.file,
relocations: rel.iter(),
}
}
fn relocation_map(&self) -> read::Result<RelocationMap> {
RelocationMap::new(self.file, self)
}
fn flags(&self) -> SectionFlags {
SectionFlags::Xcoff {
s_flags: self.section.s_flags(),
}
}
fn uncompressed_data(&self) -> Result<alloc::borrow::Cow<'data, [u8]>> {
self.compressed_data()?.decompress()
}
}
/// The table of section headers in an XCOFF file.
///
/// Returned by [`FileHeader::sections`].
#[derive(Debug, Clone, Copy)]
pub struct SectionTable<'data, Xcoff: FileHeader> {
sections: &'data [Xcoff::SectionHeader],
}
impl<'data, Xcoff> Default for SectionTable<'data, Xcoff>
where
Xcoff: FileHeader,
{
fn default() -> Self {
Self { sections: &[] }
}
}
impl<'data, Xcoff> SectionTable<'data, Xcoff>
where
Xcoff: FileHeader,
{
/// Parse the section table.
///
/// `data` must be the entire file data.
/// `offset` must be after the optional file header.
pub fn parse<R: ReadRef<'data>>(header: &Xcoff, data: R, offset: &mut u64) -> Result<Self> {
let section_num = header.f_nscns();
if section_num == 0 {
return Ok(SectionTable::default());
}
let sections = data
.read_slice(offset, section_num as usize)
.read_error("Invalid XCOFF section headers")?;
Ok(SectionTable { sections })
}
/// Iterate over the section headers.
#[inline]
pub fn iter(&self) -> slice::Iter<'data, Xcoff::SectionHeader> {
self.sections.iter()
}
/// Return true if the section table is empty.
#[inline]
pub fn is_empty(&self) -> bool {
self.sections.is_empty()
}
/// The number of section headers.
#[inline]
pub fn len(&self) -> usize {
self.sections.len()
}
/// Return the section header at the given index.
///
/// The index is 1-based.
pub fn section(&self, index: SectionIndex) -> read::Result<&'data Xcoff::SectionHeader> {
self.sections
.get(index.0.wrapping_sub(1))
.read_error("Invalid XCOFF section index")
}
}
/// A trait for generic access to [`xcoff::SectionHeader32`] and [`xcoff::SectionHeader64`].
#[allow(missing_docs)]
pub trait SectionHeader: Debug + Pod {
type Word: Into<u64>;
type HalfWord: Into<u32>;
type Xcoff: FileHeader<SectionHeader = Self, Word = Self::Word>;
type Rel: Rel<Word = Self::Word>;
fn s_name(&self) -> &[u8; 8];
fn s_paddr(&self) -> Self::Word;
fn s_vaddr(&self) -> Self::Word;
fn s_size(&self) -> Self::Word;
fn s_scnptr(&self) -> Self::Word;
fn s_relptr(&self) -> Self::Word;
fn s_lnnoptr(&self) -> Self::Word;
fn s_nreloc(&self) -> Self::HalfWord;
fn s_nlnno(&self) -> Self::HalfWord;
fn s_flags(&self) -> u32;
/// Return the section name.
fn name(&self) -> &[u8] {
let sectname = &self.s_name()[..];
match memchr::memchr(b'\0', sectname) {
Some(end) => §name[..end],
None => sectname,
}
}
/// Return the offset and size of the section in the file.
fn file_range(&self) -> Option<(u64, u64)> {
Some((self.s_scnptr().into(), self.s_size().into()))
}
/// Return the section data.
///
/// Returns `Ok(&[])` if the section has no data.
/// Returns `Err` for invalid values.
fn data<'data, R: ReadRef<'data>>(&self, data: R) -> result::Result<&'data [u8], ()> {
if let Some((offset, size)) = self.file_range() {
data.read_bytes_at(offset, size)
} else {
Ok(&[])
}
}
/// Read the relocations.
fn relocations<'data, R: ReadRef<'data>>(&self, data: R) -> read::Result<&'data [Self::Rel]>;
}
impl SectionHeader for xcoff::SectionHeader32 {
type Word = u32;
type HalfWord = u16;
type Xcoff = xcoff::FileHeader32;
type Rel = xcoff::Rel32;
fn s_name(&self) -> &[u8; 8] {
&self.s_name
}
fn s_paddr(&self) -> Self::Word {
self.s_paddr.get(BE)
}
fn s_vaddr(&self) -> Self::Word {
self.s_vaddr.get(BE)
}
fn s_size(&self) -> Self::Word {
self.s_size.get(BE)
}
fn s_scnptr(&self) -> Self::Word {
self.s_scnptr.get(BE)
}
fn s_relptr(&self) -> Self::Word {
self.s_relptr.get(BE)
}
fn s_lnnoptr(&self) -> Self::Word {
self.s_lnnoptr.get(BE)
}
fn s_nreloc(&self) -> Self::HalfWord {
self.s_nreloc.get(BE)
}
fn s_nlnno(&self) -> Self::HalfWord {
self.s_nlnno.get(BE)
}
fn s_flags(&self) -> u32 {
self.s_flags.get(BE)
}
/// Read the relocations in a XCOFF32 file.
///
/// `data` must be the entire file data.
fn relocations<'data, R: ReadRef<'data>>(&self, data: R) -> read::Result<&'data [Self::Rel]> {
let reloc_num = self.s_nreloc() as usize;
// TODO: If more than 65,534 relocation entries are required, the field value will be 65535,
// and an STYP_OVRFLO section header will contain the actual count of relocation entries in
// the s_paddr field.
if reloc_num == 65535 {
return Err(Error("Overflow section is not supported yet."));
}
data.read_slice_at(self.s_relptr().into(), reloc_num)
.read_error("Invalid XCOFF relocation offset or number")
}
}
impl SectionHeader for xcoff::SectionHeader64 {
type Word = u64;
type HalfWord = u32;
type Xcoff = xcoff::FileHeader64;
type Rel = xcoff::Rel64;
fn s_name(&self) -> &[u8; 8] {
&self.s_name
}
fn s_paddr(&self) -> Self::Word {
self.s_paddr.get(BE)
}
fn s_vaddr(&self) -> Self::Word {
self.s_vaddr.get(BE)
}
fn s_size(&self) -> Self::Word {
self.s_size.get(BE)
}
fn s_scnptr(&self) -> Self::Word {
self.s_scnptr.get(BE)
}
fn s_relptr(&self) -> Self::Word {
self.s_relptr.get(BE)
}
fn s_lnnoptr(&self) -> Self::Word {
self.s_lnnoptr.get(BE)
}
fn s_nreloc(&self) -> Self::HalfWord {
self.s_nreloc.get(BE)
}
fn s_nlnno(&self) -> Self::HalfWord {
self.s_nlnno.get(BE)
}
fn s_flags(&self) -> u32 {
self.s_flags.get(BE)
}
/// Read the relocations in a XCOFF64 file.
///
/// `data` must be the entire file data.
fn relocations<'data, R: ReadRef<'data>>(&self, data: R) -> read::Result<&'data [Self::Rel]> {
data.read_slice_at(self.s_relptr(), self.s_nreloc() as usize)
.read_error("Invalid XCOFF relocation offset or number")
}
}