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use alloc::fmt;
use core::convert::TryInto;
use core::fmt::Debug;
use core::marker::PhantomData;
use core::str;
use crate::endian::{BigEndian as BE, U32Bytes};
use crate::pod::{bytes_of, Pod};
use crate::read::util::StringTable;
use crate::xcoff;
use crate::read::{
self, Bytes, Error, ObjectSymbol, ObjectSymbolTable, ReadError, ReadRef, Result, SectionIndex,
SymbolFlags, SymbolIndex, SymbolKind, SymbolScope, SymbolSection,
};
use super::{FileHeader, XcoffFile};
/// A table of symbol entries in an XCOFF file.
///
/// Also includes the string table used for the symbol names.
#[derive(Debug)]
pub struct SymbolTable<'data, Xcoff, R = &'data [u8]>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
symbols: &'data [xcoff::SymbolBytes],
strings: StringTable<'data, R>,
header: PhantomData<Xcoff>,
}
impl<'data, Xcoff, R> Default for SymbolTable<'data, Xcoff, R>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
fn default() -> Self {
Self {
symbols: &[],
strings: StringTable::default(),
header: PhantomData,
}
}
}
impl<'data, Xcoff, R> SymbolTable<'data, Xcoff, R>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
/// Parse the symbol table.
pub fn parse(header: Xcoff, data: R) -> Result<Self> {
let mut offset = header.f_symptr().into();
let (symbols, strings) = if offset != 0 {
let symbols = data
.read_slice(&mut offset, header.f_nsyms() as usize)
.read_error("Invalid XCOFF symbol table offset or size")?;
// Parse the string table.
// Note: don't update data when reading length; the length includes itself.
let length = data
.read_at::<U32Bytes<_>>(offset)
.read_error("Missing XCOFF string table")?
.get(BE);
let str_end = offset
.checked_add(length as u64)
.read_error("Invalid XCOFF string table length")?;
let strings = StringTable::new(data, offset, str_end);
(symbols, strings)
} else {
(&[][..], StringTable::default())
};
Ok(SymbolTable {
symbols,
strings,
header: PhantomData,
})
}
/// Return the symbol entry at the given index and offset.
pub fn get<T: Pod>(&self, index: usize, offset: usize) -> Result<&'data T> {
let entry = index
.checked_add(offset)
.and_then(|x| self.symbols.get(x))
.read_error("Invalid XCOFF symbol index")?;
let bytes = bytes_of(entry);
Bytes(bytes).read().read_error("Invalid XCOFF symbol data")
}
/// Return the symbol at the given index.
pub fn symbol(&self, index: usize) -> Result<&'data Xcoff::Symbol> {
self.get::<Xcoff::Symbol>(index, 0)
}
/// Return a file auxiliary symbol.
pub fn aux_file(&self, index: usize, offset: usize) -> Result<&'data Xcoff::FileAux> {
debug_assert!(self.symbol(index)?.has_aux_file());
let aux_file = self.get::<Xcoff::FileAux>(index, offset)?;
if let Some(aux_type) = aux_file.x_auxtype() {
if aux_type != xcoff::AUX_FILE {
return Err(Error("Invalid index for file auxiliary symbol."));
}
}
Ok(aux_file)
}
/// Return the csect auxiliary symbol.
pub fn aux_csect(&self, index: usize, offset: usize) -> Result<&'data Xcoff::CsectAux> {
debug_assert!(self.symbol(index)?.has_aux_csect());
let aux_csect = self.get::<Xcoff::CsectAux>(index, offset)?;
if let Some(aux_type) = aux_csect.x_auxtype() {
if aux_type != xcoff::AUX_CSECT {
return Err(Error("Invalid index/offset for csect auxiliary symbol."));
}
}
Ok(aux_csect)
}
/// Return true if the symbol table is empty.
#[inline]
pub fn is_empty(&self) -> bool {
self.symbols.is_empty()
}
/// The number of symbol table entries.
///
/// This includes auxiliary symbol table entries.
#[inline]
pub fn len(&self) -> usize {
self.symbols.len()
}
}
/// A symbol table of an `XcoffFile32`.
pub type XcoffSymbolTable32<'data, 'file, R = &'data [u8]> =
XcoffSymbolTable<'data, 'file, xcoff::FileHeader32, R>;
/// A symbol table of an `XcoffFile64`.
pub type XcoffSymbolTable64<'data, 'file, R = &'data [u8]> =
XcoffSymbolTable<'data, 'file, xcoff::FileHeader64, R>;
/// A symbol table of an `XcoffFile`.
#[derive(Debug, Clone, Copy)]
pub struct XcoffSymbolTable<'data, 'file, Xcoff, R = &'data [u8]>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
pub(crate) file: &'file XcoffFile<'data, Xcoff, R>,
pub(super) symbols: &'file SymbolTable<'data, Xcoff, R>,
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> read::private::Sealed
for XcoffSymbolTable<'data, 'file, Xcoff, R>
{
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> ObjectSymbolTable<'data>
for XcoffSymbolTable<'data, 'file, Xcoff, R>
{
type Symbol = XcoffSymbol<'data, 'file, Xcoff, R>;
type SymbolIterator = XcoffSymbolIterator<'data, 'file, Xcoff, R>;
fn symbols(&self) -> Self::SymbolIterator {
XcoffSymbolIterator {
file: self.file,
symbols: self.symbols,
index: 0,
}
}
fn symbol_by_index(&self, index: SymbolIndex) -> read::Result<Self::Symbol> {
let symbol = self.symbols.symbol(index.0)?;
Ok(XcoffSymbol {
file: self.file,
symbols: self.symbols,
index,
symbol,
})
}
}
/// An iterator over the symbols of an `XcoffFile32`.
pub type XcoffSymbolIterator32<'data, 'file, R = &'data [u8]> =
XcoffSymbolIterator<'data, 'file, xcoff::FileHeader32, R>;
/// An iterator over the symbols of an `XcoffFile64`.
pub type XcoffSymbolIterator64<'data, 'file, R = &'data [u8]> =
XcoffSymbolIterator<'data, 'file, xcoff::FileHeader64, R>;
/// An iterator over the symbols of an `XcoffFile`.
pub struct XcoffSymbolIterator<'data, 'file, Xcoff, R = &'data [u8]>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
pub(crate) file: &'file XcoffFile<'data, Xcoff, R>,
pub(super) symbols: &'file SymbolTable<'data, Xcoff, R>,
pub(super) index: usize,
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> fmt::Debug
for XcoffSymbolIterator<'data, 'file, Xcoff, R>
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("XcoffSymbolIterator").finish()
}
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> Iterator
for XcoffSymbolIterator<'data, 'file, Xcoff, R>
{
type Item = XcoffSymbol<'data, 'file, Xcoff, R>;
fn next(&mut self) -> Option<Self::Item> {
let index = self.index;
let symbol = self.symbols.symbol(index).ok()?;
// TODO: skip over the auxiliary symbols for now.
self.index += 1 + symbol.n_numaux() as usize;
Some(XcoffSymbol {
file: self.file,
symbols: self.symbols,
index: SymbolIndex(index),
symbol,
})
}
}
/// A symbol of an `XcoffFile32`.
pub type XcoffSymbol32<'data, 'file, R = &'data [u8]> =
XcoffSymbol<'data, 'file, xcoff::FileHeader32, R>;
/// A symbol of an `XcoffFile64`.
pub type XcoffSymbol64<'data, 'file, R = &'data [u8]> =
XcoffSymbol<'data, 'file, xcoff::FileHeader64, R>;
/// A symbol of an `XcoffFile`.
#[derive(Debug, Clone, Copy)]
pub struct XcoffSymbol<'data, 'file, Xcoff, R = &'data [u8]>
where
Xcoff: FileHeader,
R: ReadRef<'data>,
{
pub(crate) file: &'file XcoffFile<'data, Xcoff, R>,
pub(super) symbols: &'file SymbolTable<'data, Xcoff, R>,
pub(super) index: SymbolIndex,
pub(super) symbol: &'data Xcoff::Symbol,
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> read::private::Sealed
for XcoffSymbol<'data, 'file, Xcoff, R>
{
}
impl<'data, 'file, Xcoff: FileHeader, R: ReadRef<'data>> ObjectSymbol<'data>
for XcoffSymbol<'data, 'file, Xcoff, R>
{
#[inline]
fn index(&self) -> SymbolIndex {
self.index
}
fn name_bytes(&self) -> Result<&'data [u8]> {
if self.symbol.has_aux_file() {
// By convention the file name is in the first auxiliary entry.
self.symbols
.aux_file(self.index.0, 1)?
.fname(self.symbols.strings)
} else {
self.symbol.name(self.symbols.strings)
}
}
fn name(&self) -> Result<&'data str> {
let name = self.name_bytes()?;
str::from_utf8(name)
.ok()
.read_error("Non UTF-8 XCOFF symbol name")
}
#[inline]
fn address(&self) -> u64 {
match self.symbol.n_sclass() {
// Relocatable address.
xcoff::C_EXT
| xcoff::C_WEAKEXT
| xcoff::C_HIDEXT
| xcoff::C_FCN
| xcoff::C_BLOCK
| xcoff::C_STAT
| xcoff::C_INFO => self.symbol.n_value().into(),
_ => 0,
}
}
#[inline]
fn size(&self) -> u64 {
if self.symbol.has_aux_csect() {
// XCOFF32 must have the csect auxiliary entry as the last auxiliary entry.
// XCOFF64 doesn't require this, but conventionally does.
if let Ok(aux_csect) = self
.file
.symbols
.aux_csect(self.index.0, self.symbol.n_numaux() as usize)
{
let sym_type = aux_csect.sym_type() & 0x07;
if sym_type == xcoff::XTY_SD || sym_type == xcoff::XTY_CM {
return aux_csect.x_scnlen();
}
}
}
0
}
fn kind(&self) -> SymbolKind {
if self.symbol.has_aux_csect() {
if let Ok(aux_csect) = self
.file
.symbols
.aux_csect(self.index.0, self.symbol.n_numaux() as usize)
{
let sym_type = aux_csect.sym_type() & 0x07;
if sym_type == xcoff::XTY_SD || sym_type == xcoff::XTY_CM {
return match aux_csect.x_smclas() {
xcoff::XMC_PR | xcoff::XMC_GL => SymbolKind::Text,
xcoff::XMC_RO | xcoff::XMC_RW | xcoff::XMC_TD | xcoff::XMC_BS => {
SymbolKind::Data
}
xcoff::XMC_TL | xcoff::XMC_UL => SymbolKind::Tls,
xcoff::XMC_DS | xcoff::XMC_TC0 | xcoff::XMC_TC => {
// `Metadata` might be a better kind for these if we had it.
SymbolKind::Data
}
_ => SymbolKind::Unknown,
};
} else if sym_type == xcoff::XTY_LD {
// A function entry point. Neither `Text` nor `Label` are a good fit for this.
return SymbolKind::Text;
} else if sym_type == xcoff::XTY_ER {
return SymbolKind::Unknown;
}
}
}
match self.symbol.n_sclass() {
xcoff::C_NULL => SymbolKind::Null,
xcoff::C_FILE => SymbolKind::File,
_ => SymbolKind::Unknown,
}
}
fn section(&self) -> SymbolSection {
match self.symbol.n_scnum() {
xcoff::N_ABS => SymbolSection::Absolute,
xcoff::N_UNDEF => SymbolSection::Undefined,
xcoff::N_DEBUG => SymbolSection::None,
index if index > 0 => SymbolSection::Section(SectionIndex(index as usize)),
_ => SymbolSection::Unknown,
}
}
#[inline]
fn is_undefined(&self) -> bool {
self.symbol.is_undefined()
}
/// Return true if the symbol is a definition of a function or data object.
#[inline]
fn is_definition(&self) -> bool {
if self.symbol.has_aux_csect() {
if let Ok(aux_csect) = self
.symbols
.aux_csect(self.index.0, self.symbol.n_numaux() as usize)
{
let smclas = aux_csect.x_smclas();
self.symbol.n_scnum() != xcoff::N_UNDEF
&& (smclas == xcoff::XMC_PR
|| smclas == xcoff::XMC_RW
|| smclas == xcoff::XMC_RO)
} else {
false
}
} else {
false
}
}
#[inline]
fn is_common(&self) -> bool {
self.symbol.n_sclass() == xcoff::C_EXT && self.symbol.n_scnum() == xcoff::N_UNDEF
}
#[inline]
fn is_weak(&self) -> bool {
self.symbol.n_sclass() == xcoff::C_WEAKEXT
}
fn scope(&self) -> SymbolScope {
if self.symbol.n_scnum() == xcoff::N_UNDEF {
SymbolScope::Unknown
} else {
match self.symbol.n_sclass() {
xcoff::C_EXT | xcoff::C_WEAKEXT | xcoff::C_HIDEXT => {
let visibility = self.symbol.n_type() & xcoff::SYM_V_MASK;
if visibility == xcoff::SYM_V_HIDDEN {
SymbolScope::Linkage
} else {
SymbolScope::Dynamic
}
}
_ => SymbolScope::Compilation,
}
}
}
#[inline]
fn is_global(&self) -> bool {
match self.symbol.n_sclass() {
xcoff::C_EXT | xcoff::C_WEAKEXT => true,
_ => false,
}
}
#[inline]
fn is_local(&self) -> bool {
!self.is_global()
}
#[inline]
fn flags(&self) -> SymbolFlags<SectionIndex, SymbolIndex> {
let mut x_smtyp = 0;
let mut x_smclas = 0;
let mut containing_csect = None;
if self.symbol.has_aux_csect() {
if let Ok(aux_csect) = self
.file
.symbols
.aux_csect(self.index.0, self.symbol.n_numaux() as usize)
{
x_smtyp = aux_csect.x_smtyp();
x_smclas = aux_csect.x_smclas();
if x_smtyp == xcoff::XTY_LD {
containing_csect = Some(SymbolIndex(aux_csect.x_scnlen() as usize))
}
}
}
SymbolFlags::Xcoff {
n_sclass: self.symbol.n_sclass(),
x_smtyp,
x_smclas,
containing_csect,
}
}
}
/// A trait for generic access to `Symbol32` and `Symbol64`.
#[allow(missing_docs)]
pub trait Symbol: Debug + Pod {
type Word: Into<u64>;
fn n_value(&self) -> Self::Word;
fn n_scnum(&self) -> i16;
fn n_type(&self) -> u16;
fn n_sclass(&self) -> u8;
fn n_numaux(&self) -> u8;
fn name<'data, R: ReadRef<'data>>(
&'data self,
strings: StringTable<'data, R>,
) -> Result<&'data [u8]>;
/// Return true if the symbol is undefined.
#[inline]
fn is_undefined(&self) -> bool {
let n_sclass = self.n_sclass();
(n_sclass == xcoff::C_EXT || n_sclass == xcoff::C_WEAKEXT)
&& self.n_scnum() == xcoff::N_UNDEF
}
/// Return true if the symbol has file auxiliary entry.
fn has_aux_file(&self) -> bool {
self.n_numaux() > 0 && self.n_sclass() == xcoff::C_FILE
}
/// Return true if the symbol has csect auxiliary entry.
///
/// A csect auxiliary entry is required for each symbol table entry that has
/// a storage class value of C_EXT, C_WEAKEXT, or C_HIDEXT.
fn has_aux_csect(&self) -> bool {
let sclass = self.n_sclass();
self.n_numaux() > 0
&& (sclass == xcoff::C_EXT || sclass == xcoff::C_WEAKEXT || sclass == xcoff::C_HIDEXT)
}
}
impl Symbol for xcoff::Symbol64 {
type Word = u64;
fn n_value(&self) -> Self::Word {
self.n_value.get(BE)
}
fn n_scnum(&self) -> i16 {
self.n_scnum.get(BE)
}
fn n_type(&self) -> u16 {
self.n_type.get(BE)
}
fn n_sclass(&self) -> u8 {
self.n_sclass
}
fn n_numaux(&self) -> u8 {
self.n_numaux
}
/// Parse the symbol name for XCOFF64.
fn name<'data, R: ReadRef<'data>>(
&'data self,
strings: StringTable<'data, R>,
) -> Result<&'data [u8]> {
strings
.get(self.n_offset.get(BE))
.read_error("Invalid XCOFF symbol name offset")
}
}
impl Symbol for xcoff::Symbol32 {
type Word = u32;
fn n_value(&self) -> Self::Word {
self.n_value.get(BE)
}
fn n_scnum(&self) -> i16 {
self.n_scnum.get(BE)
}
fn n_type(&self) -> u16 {
self.n_type.get(BE)
}
fn n_sclass(&self) -> u8 {
self.n_sclass
}
fn n_numaux(&self) -> u8 {
self.n_numaux
}
/// Parse the symbol name for XCOFF32.
fn name<'data, R: ReadRef<'data>>(
&'data self,
strings: StringTable<'data, R>,
) -> Result<&'data [u8]> {
if self.n_name[0] == 0 {
// If the name starts with 0 then the last 4 bytes are a string table offset.
let offset = u32::from_be_bytes(self.n_name[4..8].try_into().unwrap());
strings
.get(offset)
.read_error("Invalid XCOFF symbol name offset")
} else {
// The name is inline and padded with nulls.
Ok(match memchr::memchr(b'\0', &self.n_name) {
Some(end) => &self.n_name[..end],
None => &self.n_name,
})
}
}
}
/// A trait for generic access to `FileAux32` and `FileAux64`.
#[allow(missing_docs)]
pub trait FileAux: Debug + Pod {
fn x_fname(&self) -> &[u8; 8];
fn x_ftype(&self) -> u8;
fn x_auxtype(&self) -> Option<u8>;
/// Parse the x_fname field, which may be an inline string or a string table offset.
fn fname<'data, R: ReadRef<'data>>(
&'data self,
strings: StringTable<'data, R>,
) -> Result<&'data [u8]> {
let x_fname = self.x_fname();
if x_fname[0] == 0 {
// If the name starts with 0 then the last 4 bytes are a string table offset.
let offset = u32::from_be_bytes(x_fname[4..8].try_into().unwrap());
strings
.get(offset)
.read_error("Invalid XCOFF symbol name offset")
} else {
// The name is inline and padded with nulls.
Ok(match memchr::memchr(b'\0', x_fname) {
Some(end) => &x_fname[..end],
None => x_fname,
})
}
}
}
impl FileAux for xcoff::FileAux64 {
fn x_fname(&self) -> &[u8; 8] {
&self.x_fname
}
fn x_ftype(&self) -> u8 {
self.x_ftype
}
fn x_auxtype(&self) -> Option<u8> {
Some(self.x_auxtype)
}
}
impl FileAux for xcoff::FileAux32 {
fn x_fname(&self) -> &[u8; 8] {
&self.x_fname
}
fn x_ftype(&self) -> u8 {
self.x_ftype
}
fn x_auxtype(&self) -> Option<u8> {
None
}
}
/// A trait for generic access to `CsectAux32` and `CsectAux64`.
#[allow(missing_docs)]
pub trait CsectAux: Debug + Pod {
fn x_scnlen(&self) -> u64;
fn x_parmhash(&self) -> u32;
fn x_snhash(&self) -> u16;
fn x_smtyp(&self) -> u8;
fn x_smclas(&self) -> u8;
fn x_auxtype(&self) -> Option<u8>;
fn sym_type(&self) -> u8 {
self.x_smtyp() & 0x07
}
}
impl CsectAux for xcoff::CsectAux64 {
fn x_scnlen(&self) -> u64 {
self.x_scnlen_lo.get(BE) as u64 | ((self.x_scnlen_hi.get(BE) as u64) << 32)
}
fn x_parmhash(&self) -> u32 {
self.x_parmhash.get(BE)
}
fn x_snhash(&self) -> u16 {
self.x_snhash.get(BE)
}
fn x_smtyp(&self) -> u8 {
self.x_smtyp
}
fn x_smclas(&self) -> u8 {
self.x_smclas
}
fn x_auxtype(&self) -> Option<u8> {
Some(self.x_auxtype)
}
}
impl CsectAux for xcoff::CsectAux32 {
fn x_scnlen(&self) -> u64 {
self.x_scnlen.get(BE) as u64
}
fn x_parmhash(&self) -> u32 {
self.x_parmhash.get(BE)
}
fn x_snhash(&self) -> u16 {
self.x_snhash.get(BE)
}
fn x_smtyp(&self) -> u8 {
self.x_smtyp
}
fn x_smclas(&self) -> u8 {
self.x_smclas
}
fn x_auxtype(&self) -> Option<u8> {
None
}
}