diff options
Diffstat (limited to 'third_party/rust/object/src/read/xcoff/symbol.rs')
| -rw-r--r-- | third_party/rust/object/src/read/xcoff/symbol.rs | 634 |
1 files changed, 634 insertions, 0 deletions
diff --git a/third_party/rust/object/src/read/xcoff/symbol.rs b/third_party/rust/object/src/read/xcoff/symbol.rs new file mode 100644 index 0000000000..6738ad1714 --- /dev/null +++ b/third_party/rust/object/src/read/xcoff/symbol.rs @@ -0,0 +1,634 @@ +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::Pod; +use crate::read::util::StringTable; +use crate::{bytes_of, xcoff, Object, ObjectSection, SectionKind}; + +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 the file auxiliary symbol. + pub fn aux_file(&self, index: usize) -> Result<&'data Xcoff::FileAux> { + debug_assert!(self.symbol(index)?.has_aux_file()); + let aux_file = self.get::<Xcoff::FileAux>(index, 1)?; + 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 + 'data: 'file, + 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 + 'data: 'file, + 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 + 'data: 'file, + 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]> { + 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 => 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 { + aux_csect.x_scnlen() + } else { + 0 + } + } else { + 0 + } + } else { + 0 + } + } + + fn kind(&self) -> SymbolKind { + match self.symbol.n_sclass() { + xcoff::C_FILE => SymbolKind::File, + xcoff::C_NULL => SymbolKind::Null, + _ => self + .file + .section_by_index(SectionIndex((self.symbol.n_scnum() - 1) as usize)) + .map(|section| match section.kind() { + SectionKind::Data | SectionKind::UninitializedData => SymbolKind::Data, + SectionKind::UninitializedTls | SectionKind::Tls => SymbolKind::Tls, + SectionKind::Text => SymbolKind::Text, + _ => SymbolKind::Unknown, + }) + .unwrap_or(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> { + SymbolFlags::None + } +} + +/// 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>; +} + +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 + } +} |