mozilla-central/third_party/rust/object/src/write/coff/object.rs

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use alloc::vec::Vec;
use crate::pe as coff;
use crate::write::coff::writer;
use crate::write::util::*;
use crate::write::*;
#[derive(Default, Clone, Copy)]
struct SectionOffsets {
name: writer::Name,
offset: u32,
reloc_offset: u32,
selection: u8,
associative_section: u32,
}
#[derive(Default, Clone, Copy)]
struct SymbolOffsets {
name: writer::Name,
index: u32,
aux_count: u8,
}
/// Internal format to use for the `.drectve` section containing linker
/// directives for symbol exports.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum CoffExportStyle {
/// MSVC format supported by link.exe and LLD.
Msvc,
/// Gnu format supported by GNU LD and LLD.
Gnu,
}
impl<'a> Object<'a> {
pub(crate) fn coff_section_info(
&self,
section: StandardSection,
) -> (&'static [u8], &'static [u8], SectionKind, SectionFlags) {
match section {
StandardSection::Text => (&[], &b".text"[..], SectionKind::Text, SectionFlags::None),
StandardSection::Data => (&[], &b".data"[..], SectionKind::Data, SectionFlags::None),
StandardSection::ReadOnlyData
| StandardSection::ReadOnlyDataWithRel
| StandardSection::ReadOnlyString => (
&[],
&b".rdata"[..],
SectionKind::ReadOnlyData,
SectionFlags::None,
),
StandardSection::UninitializedData => (
&[],
&b".bss"[..],
SectionKind::UninitializedData,
SectionFlags::None,
),
// TLS sections are data sections with a special name.
StandardSection::Tls => (&[], &b".tls$"[..], SectionKind::Data, SectionFlags::None),
StandardSection::UninitializedTls => {
// Unsupported section.
(&[], &[], SectionKind::UninitializedTls, SectionFlags::None)
}
StandardSection::TlsVariables => {
// Unsupported section.
(&[], &[], SectionKind::TlsVariables, SectionFlags::None)
}
StandardSection::Common => {
// Unsupported section.
(&[], &[], SectionKind::Common, SectionFlags::None)
}
StandardSection::GnuProperty => {
// Unsupported section.
(&[], &[], SectionKind::Note, SectionFlags::None)
}
}
}
pub(crate) fn coff_subsection_name(&self, section: &[u8], value: &[u8]) -> Vec<u8> {
let mut name = section.to_vec();
name.push(b'$');
name.extend_from_slice(value);
name
}
pub(crate) fn coff_translate_relocation(&mut self, reloc: &mut Relocation) -> Result<()> {
let (mut kind, _encoding, size) = if let RelocationFlags::Generic {
kind,
encoding,
size,
} = reloc.flags
{
(kind, encoding, size)
} else {
return Ok(());
};
if kind == RelocationKind::GotRelative {
// Use a stub symbol for the relocation instead.
// This isn't really a GOT, but it's a similar purpose.
// TODO: need to handle DLL imports differently?
kind = RelocationKind::Relative;
reloc.symbol = self.coff_add_stub_symbol(reloc.symbol)?;
} else if kind == RelocationKind::PltRelative {
// Windows doesn't need a separate relocation type for
// references to functions in import libraries.
// For convenience, treat this the same as Relative.
kind = RelocationKind::Relative;
}
let typ = match self.architecture {
Architecture::I386 => match (kind, size) {
(RelocationKind::Absolute, 16) => coff::IMAGE_REL_I386_DIR16,
(RelocationKind::Relative, 16) => coff::IMAGE_REL_I386_REL16,
(RelocationKind::Absolute, 32) => coff::IMAGE_REL_I386_DIR32,
(RelocationKind::ImageOffset, 32) => coff::IMAGE_REL_I386_DIR32NB,
(RelocationKind::SectionIndex, 16) => coff::IMAGE_REL_I386_SECTION,
(RelocationKind::SectionOffset, 32) => coff::IMAGE_REL_I386_SECREL,
(RelocationKind::SectionOffset, 7) => coff::IMAGE_REL_I386_SECREL7,
(RelocationKind::Relative, 32) => coff::IMAGE_REL_I386_REL32,
_ => {
return Err(Error(format!("unimplemented relocation {:?}", reloc)));
}
},
Architecture::X86_64 => match (kind, size) {
(RelocationKind::Absolute, 64) => coff::IMAGE_REL_AMD64_ADDR64,
(RelocationKind::Absolute, 32) => coff::IMAGE_REL_AMD64_ADDR32,
(RelocationKind::ImageOffset, 32) => coff::IMAGE_REL_AMD64_ADDR32NB,
(RelocationKind::Relative, 32) => match reloc.addend {
-5 => coff::IMAGE_REL_AMD64_REL32_1,
-6 => coff::IMAGE_REL_AMD64_REL32_2,
-7 => coff::IMAGE_REL_AMD64_REL32_3,
-8 => coff::IMAGE_REL_AMD64_REL32_4,
-9 => coff::IMAGE_REL_AMD64_REL32_5,
_ => coff::IMAGE_REL_AMD64_REL32,
},
(RelocationKind::SectionIndex, 16) => coff::IMAGE_REL_AMD64_SECTION,
(RelocationKind::SectionOffset, 32) => coff::IMAGE_REL_AMD64_SECREL,
(RelocationKind::SectionOffset, 7) => coff::IMAGE_REL_AMD64_SECREL7,
_ => {
return Err(Error(format!("unimplemented relocation {:?}", reloc)));
}
},
Architecture::Arm => match (kind, size) {
(RelocationKind::Absolute, 32) => coff::IMAGE_REL_ARM_ADDR32,
(RelocationKind::ImageOffset, 32) => coff::IMAGE_REL_ARM_ADDR32NB,
(RelocationKind::Relative, 32) => coff::IMAGE_REL_ARM_REL32,
(RelocationKind::SectionIndex, 16) => coff::IMAGE_REL_ARM_SECTION,
(RelocationKind::SectionOffset, 32) => coff::IMAGE_REL_ARM_SECREL,
_ => {
return Err(Error(format!("unimplemented relocation {:?}", reloc)));
}
},
Architecture::Aarch64 => match (kind, size) {
(RelocationKind::Absolute, 32) => coff::IMAGE_REL_ARM64_ADDR32,
(RelocationKind::ImageOffset, 32) => coff::IMAGE_REL_ARM64_ADDR32NB,
(RelocationKind::SectionIndex, 16) => coff::IMAGE_REL_ARM64_SECTION,
(RelocationKind::SectionOffset, 32) => coff::IMAGE_REL_ARM64_SECREL,
(RelocationKind::Absolute, 64) => coff::IMAGE_REL_ARM64_ADDR64,
(RelocationKind::Relative, 32) => coff::IMAGE_REL_ARM64_REL32,
_ => {
return Err(Error(format!("unimplemented relocation {:?}", reloc)));
}
},
_ => {
return Err(Error(format!(
"unimplemented architecture {:?}",
self.architecture
)));
}
};
reloc.flags = RelocationFlags::Coff { typ };
Ok(())
}
pub(crate) fn coff_adjust_addend(&self, relocation: &mut Relocation) -> Result<bool> {
let typ = if let RelocationFlags::Coff { typ } = relocation.flags {
typ
} else {
return Err(Error(format!("invalid relocation flags {:?}", relocation)));
};
let offset = match self.architecture {
Architecture::Arm => {
if typ == coff::IMAGE_REL_ARM_REL32 {
4
} else {
0
}
}
Architecture::Aarch64 => {
if typ == coff::IMAGE_REL_ARM64_REL32 {
4
} else {
0
}
}
Architecture::I386 => {
if typ == coff::IMAGE_REL_I386_REL32 {
4
} else {
0
}
}
Architecture::X86_64 => match typ {
coff::IMAGE_REL_AMD64_REL32 => 4,
coff::IMAGE_REL_AMD64_REL32_1 => 5,
coff::IMAGE_REL_AMD64_REL32_2 => 6,
coff::IMAGE_REL_AMD64_REL32_3 => 7,
coff::IMAGE_REL_AMD64_REL32_4 => 8,
coff::IMAGE_REL_AMD64_REL32_5 => 9,
_ => 0,
},
_ => return Err(Error(format!("unimplemented relocation {:?}", relocation))),
};
relocation.addend += offset;
Ok(true)
}
pub(crate) fn coff_relocation_size(&self, reloc: &Relocation) -> Result<u8> {
let typ = if let RelocationFlags::Coff { typ } = reloc.flags {
typ
} else {
return Err(Error(format!("unexpected relocation for size {:?}", reloc)));
};
let size = match self.architecture {
Architecture::I386 => match typ {
coff::IMAGE_REL_I386_DIR16
| coff::IMAGE_REL_I386_REL16
| coff::IMAGE_REL_I386_SECTION => Some(16),
coff::IMAGE_REL_I386_DIR32
| coff::IMAGE_REL_I386_DIR32NB
| coff::IMAGE_REL_I386_SECREL
| coff::IMAGE_REL_I386_TOKEN
| coff::IMAGE_REL_I386_REL32 => Some(32),
_ => None,
},
Architecture::X86_64 => match typ {
coff::IMAGE_REL_AMD64_SECTION => Some(16),
coff::IMAGE_REL_AMD64_ADDR32
| coff::IMAGE_REL_AMD64_ADDR32NB
| coff::IMAGE_REL_AMD64_REL32
| coff::IMAGE_REL_AMD64_REL32_1
| coff::IMAGE_REL_AMD64_REL32_2
| coff::IMAGE_REL_AMD64_REL32_3
| coff::IMAGE_REL_AMD64_REL32_4
| coff::IMAGE_REL_AMD64_REL32_5
| coff::IMAGE_REL_AMD64_SECREL
| coff::IMAGE_REL_AMD64_TOKEN => Some(32),
coff::IMAGE_REL_AMD64_ADDR64 => Some(64),
_ => None,
},
Architecture::Arm => match typ {
coff::IMAGE_REL_ARM_SECTION => Some(16),
coff::IMAGE_REL_ARM_ADDR32
| coff::IMAGE_REL_ARM_ADDR32NB
| coff::IMAGE_REL_ARM_TOKEN
| coff::IMAGE_REL_ARM_REL32
| coff::IMAGE_REL_ARM_SECREL => Some(32),
_ => None,
},
Architecture::Aarch64 => match typ {
coff::IMAGE_REL_ARM64_SECTION => Some(16),
coff::IMAGE_REL_ARM64_ADDR32
| coff::IMAGE_REL_ARM64_ADDR32NB
| coff::IMAGE_REL_ARM64_SECREL
| coff::IMAGE_REL_ARM64_TOKEN
| coff::IMAGE_REL_ARM64_REL32 => Some(32),
coff::IMAGE_REL_ARM64_ADDR64 => Some(64),
_ => None,
},
_ => None,
};
size.ok_or_else(|| Error(format!("unsupported relocation for size {:?}", reloc)))
}
fn coff_add_stub_symbol(&mut self, symbol_id: SymbolId) -> Result<SymbolId> {
if let Some(stub_id) = self.stub_symbols.get(&symbol_id) {
return Ok(*stub_id);
}
let stub_size = self.architecture.address_size().unwrap().bytes();
let name = b".rdata$.refptr".to_vec();
let section_id = self.add_section(Vec::new(), name, SectionKind::ReadOnlyData);
let section = self.section_mut(section_id);
section.set_data(vec![0; stub_size as usize], u64::from(stub_size));
self.add_relocation(
section_id,
Relocation {
offset: 0,
symbol: symbol_id,
addend: 0,
flags: RelocationFlags::Generic {
kind: RelocationKind::Absolute,
encoding: RelocationEncoding::Generic,
size: stub_size * 8,
},
},
)?;
let mut name = b".refptr.".to_vec();
name.extend_from_slice(&self.symbol(symbol_id).name);
let stub_id = self.add_raw_symbol(Symbol {
name,
value: 0,
size: u64::from(stub_size),
kind: SymbolKind::Data,
scope: SymbolScope::Compilation,
weak: false,
section: SymbolSection::Section(section_id),
flags: SymbolFlags::None,
});
self.stub_symbols.insert(symbol_id, stub_id);
Ok(stub_id)
}
/// Appends linker directives to the `.drectve` section to tell the linker
/// to export all symbols with `SymbolScope::Dynamic`.
///
/// This must be called after all symbols have been defined.
pub fn add_coff_exports(&mut self, style: CoffExportStyle) {
assert_eq!(self.format, BinaryFormat::Coff);
let mut directives = vec![];
for symbol in &self.symbols {
if symbol.scope == SymbolScope::Dynamic {
match style {
CoffExportStyle::Msvc => directives.extend(b" /EXPORT:\""),
CoffExportStyle::Gnu => directives.extend(b" -export:\""),
}
directives.extend(&symbol.name);
directives.extend(b"\"");
if symbol.kind != SymbolKind::Text {
match style {
CoffExportStyle::Msvc => directives.extend(b",DATA"),
CoffExportStyle::Gnu => directives.extend(b",data"),
}
}
}
}
let drectve = self.add_section(vec![], b".drectve".to_vec(), SectionKind::Linker);
self.append_section_data(drectve, &directives, 1);
}
pub(crate) fn coff_write(&self, buffer: &mut dyn WritableBuffer) -> Result<()> {
let mut writer = writer::Writer::new(buffer);
// Add section strings to strtab.
let mut section_offsets = vec![SectionOffsets::default(); self.sections.len()];
for (index, section) in self.sections.iter().enumerate() {
section_offsets[index].name = writer.add_name(&section.name);
}
// Set COMDAT flags.
for comdat in &self.comdats {
let symbol = &self.symbols[comdat.symbol.0];
let comdat_section = match symbol.section {
SymbolSection::Section(id) => id.0,
_ => {
return Err(Error(format!(
"unsupported COMDAT symbol `{}` section {:?}",
symbol.name().unwrap_or(""),
symbol.section
)));
}
};
section_offsets[comdat_section].selection = match comdat.kind {
ComdatKind::NoDuplicates => coff::IMAGE_COMDAT_SELECT_NODUPLICATES,
ComdatKind::Any => coff::IMAGE_COMDAT_SELECT_ANY,
ComdatKind::SameSize => coff::IMAGE_COMDAT_SELECT_SAME_SIZE,
ComdatKind::ExactMatch => coff::IMAGE_COMDAT_SELECT_EXACT_MATCH,
ComdatKind::Largest => coff::IMAGE_COMDAT_SELECT_LARGEST,
ComdatKind::Newest => coff::IMAGE_COMDAT_SELECT_NEWEST,
ComdatKind::Unknown => {
return Err(Error(format!(
"unsupported COMDAT symbol `{}` kind {:?}",
symbol.name().unwrap_or(""),
comdat.kind
)));
}
};
for id in &comdat.sections {
let section = &self.sections[id.0];
if section.symbol.is_none() {
return Err(Error(format!(
"missing symbol for COMDAT section `{}`",
section.name().unwrap_or(""),
)));
}
if id.0 != comdat_section {
section_offsets[id.0].selection = coff::IMAGE_COMDAT_SELECT_ASSOCIATIVE;
section_offsets[id.0].associative_section = comdat_section as u32 + 1;
}
}
}
// Reserve symbol indices and add symbol strings to strtab.
let mut symbol_offsets = vec![SymbolOffsets::default(); self.symbols.len()];
for (index, symbol) in self.symbols.iter().enumerate() {
symbol_offsets[index].index = writer.reserve_symbol_index();
let mut name = &*symbol.name;
match symbol.kind {
SymbolKind::File => {
// Name goes in auxiliary symbol records.
symbol_offsets[index].aux_count = writer.reserve_aux_file_name(&symbol.name);
name = b".file";
}
SymbolKind::Section if symbol.section.id().is_some() => {
symbol_offsets[index].aux_count = writer.reserve_aux_section();
}
_ => {}
};
symbol_offsets[index].name = writer.add_name(name);
}
// Reserve file ranges.
writer.reserve_file_header();
writer.reserve_section_headers(self.sections.len() as u16);
for (index, section) in self.sections.iter().enumerate() {
section_offsets[index].offset = writer.reserve_section(section.data.len());
section_offsets[index].reloc_offset =
writer.reserve_relocations(section.relocations.len());
}
writer.reserve_symtab_strtab();
// Start writing.
writer.write_file_header(writer::FileHeader {
machine: match (self.architecture, self.sub_architecture) {
(Architecture::Arm, None) => coff::IMAGE_FILE_MACHINE_ARMNT,
(Architecture::Aarch64, None) => coff::IMAGE_FILE_MACHINE_ARM64,
(Architecture::Aarch64, Some(SubArchitecture::Arm64EC)) => {
coff::IMAGE_FILE_MACHINE_ARM64EC
}
(Architecture::I386, None) => coff::IMAGE_FILE_MACHINE_I386,
(Architecture::X86_64, None) => coff::IMAGE_FILE_MACHINE_AMD64,
_ => {
return Err(Error(format!(
"unimplemented architecture {:?} with sub-architecture {:?}",
self.architecture, self.sub_architecture
)));
}
},
time_date_stamp: 0,
characteristics: match self.flags {
FileFlags::Coff { characteristics } => characteristics,
_ => 0,
},
})?;
// Write section headers.
for (index, section) in self.sections.iter().enumerate() {
let mut characteristics = if let SectionFlags::Coff {
characteristics, ..
} = section.flags
{
characteristics
} else {
match section.kind {
SectionKind::Text => {
coff::IMAGE_SCN_CNT_CODE
| coff::IMAGE_SCN_MEM_EXECUTE
| coff::IMAGE_SCN_MEM_READ
}
SectionKind::Data => {
coff::IMAGE_SCN_CNT_INITIALIZED_DATA
| coff::IMAGE_SCN_MEM_READ
| coff::IMAGE_SCN_MEM_WRITE
}
SectionKind::UninitializedData => {
coff::IMAGE_SCN_CNT_UNINITIALIZED_DATA
| coff::IMAGE_SCN_MEM_READ
| coff::IMAGE_SCN_MEM_WRITE
}
SectionKind::ReadOnlyData
| SectionKind::ReadOnlyDataWithRel
| SectionKind::ReadOnlyString => {
coff::IMAGE_SCN_CNT_INITIALIZED_DATA | coff::IMAGE_SCN_MEM_READ
}
SectionKind::Debug
| SectionKind::DebugString
| SectionKind::Other
| SectionKind::OtherString => {
coff::IMAGE_SCN_CNT_INITIALIZED_DATA
| coff::IMAGE_SCN_MEM_READ
| coff::IMAGE_SCN_MEM_DISCARDABLE
}
SectionKind::Linker => coff::IMAGE_SCN_LNK_INFO | coff::IMAGE_SCN_LNK_REMOVE,
SectionKind::Common
| SectionKind::Tls
| SectionKind::UninitializedTls
| SectionKind::TlsVariables
| SectionKind::Note
| SectionKind::Unknown
| SectionKind::Metadata
| SectionKind::Elf(_) => {
return Err(Error(format!(
"unimplemented section `{}` kind {:?}",
section.name().unwrap_or(""),
section.kind
)));
}
}
};
if section_offsets[index].selection != 0 {
characteristics |= coff::IMAGE_SCN_LNK_COMDAT;
};
if section.relocations.len() > 0xffff {
characteristics |= coff::IMAGE_SCN_LNK_NRELOC_OVFL;
}
characteristics |= match section.align {
1 => coff::IMAGE_SCN_ALIGN_1BYTES,
2 => coff::IMAGE_SCN_ALIGN_2BYTES,
4 => coff::IMAGE_SCN_ALIGN_4BYTES,
8 => coff::IMAGE_SCN_ALIGN_8BYTES,
16 => coff::IMAGE_SCN_ALIGN_16BYTES,
32 => coff::IMAGE_SCN_ALIGN_32BYTES,
64 => coff::IMAGE_SCN_ALIGN_64BYTES,
128 => coff::IMAGE_SCN_ALIGN_128BYTES,
256 => coff::IMAGE_SCN_ALIGN_256BYTES,
512 => coff::IMAGE_SCN_ALIGN_512BYTES,
1024 => coff::IMAGE_SCN_ALIGN_1024BYTES,
2048 => coff::IMAGE_SCN_ALIGN_2048BYTES,
4096 => coff::IMAGE_SCN_ALIGN_4096BYTES,
8192 => coff::IMAGE_SCN_ALIGN_8192BYTES,
_ => {
return Err(Error(format!(
"unimplemented section `{}` align {}",
section.name().unwrap_or(""),
section.align
)));
}
};
writer.write_section_header(writer::SectionHeader {
name: section_offsets[index].name,
size_of_raw_data: section.size as u32,
pointer_to_raw_data: section_offsets[index].offset,
pointer_to_relocations: section_offsets[index].reloc_offset,
pointer_to_linenumbers: 0,
number_of_relocations: section.relocations.len() as u32,
number_of_linenumbers: 0,
characteristics,
});
}
// Write section data and relocations.
for section in &self.sections {
writer.write_section(&section.data);
if !section.relocations.is_empty() {
//debug_assert_eq!(section_offsets[index].reloc_offset, buffer.len());
writer.write_relocations_count(section.relocations.len());
for reloc in &section.relocations {
let typ = if let RelocationFlags::Coff { typ } = reloc.flags {
typ
} else {
return Err(Error("invalid relocation flags".into()));
};
writer.write_relocation(writer::Relocation {
virtual_address: reloc.offset as u32,
symbol: symbol_offsets[reloc.symbol.0].index,
typ,
});
}
}
}
// Write symbols.
for (index, symbol) in self.symbols.iter().enumerate() {
let section_number = match symbol.section {
SymbolSection::None => {
debug_assert_eq!(symbol.kind, SymbolKind::File);
coff::IMAGE_SYM_DEBUG as u16
}
SymbolSection::Undefined => coff::IMAGE_SYM_UNDEFINED as u16,
SymbolSection::Absolute => coff::IMAGE_SYM_ABSOLUTE as u16,
SymbolSection::Common => coff::IMAGE_SYM_UNDEFINED as u16,
SymbolSection::Section(id) => id.0 as u16 + 1,
};
let typ = if symbol.kind == SymbolKind::Text {
coff::IMAGE_SYM_DTYPE_FUNCTION << coff::IMAGE_SYM_DTYPE_SHIFT
} else {
coff::IMAGE_SYM_TYPE_NULL
};
let storage_class = match symbol.kind {
SymbolKind::File => coff::IMAGE_SYM_CLASS_FILE,
SymbolKind::Section => {
if symbol.section.id().is_some() {
coff::IMAGE_SYM_CLASS_STATIC
} else {
coff::IMAGE_SYM_CLASS_SECTION
}
}
SymbolKind::Label => coff::IMAGE_SYM_CLASS_LABEL,
SymbolKind::Text | SymbolKind::Data | SymbolKind::Tls => {
match symbol.section {
SymbolSection::None => {
return Err(Error(format!(
"missing section for symbol `{}`",
symbol.name().unwrap_or("")
)));
}
SymbolSection::Undefined | SymbolSection::Common => {
coff::IMAGE_SYM_CLASS_EXTERNAL
}
SymbolSection::Absolute | SymbolSection::Section(_) => {
match symbol.scope {
// TODO: does this need aux symbol records too?
_ if symbol.weak => coff::IMAGE_SYM_CLASS_WEAK_EXTERNAL,
SymbolScope::Unknown => {
return Err(Error(format!(
"unimplemented symbol `{}` scope {:?}",
symbol.name().unwrap_or(""),
symbol.scope
)));
}
SymbolScope::Compilation => coff::IMAGE_SYM_CLASS_STATIC,
SymbolScope::Linkage | SymbolScope::Dynamic => {
coff::IMAGE_SYM_CLASS_EXTERNAL
}
}
}
}
}
SymbolKind::Unknown => {
return Err(Error(format!(
"unimplemented symbol `{}` kind {:?}",
symbol.name().unwrap_or(""),
symbol.kind
)));
}
};
let number_of_aux_symbols = symbol_offsets[index].aux_count;
let value = if symbol.section == SymbolSection::Common {
symbol.size as u32
} else {
symbol.value as u32
};
writer.write_symbol(writer::Symbol {
name: symbol_offsets[index].name,
value,
section_number,
typ,
storage_class,
number_of_aux_symbols,
});
// Write auxiliary symbols.
match symbol.kind {
SymbolKind::File => {
writer.write_aux_file_name(&symbol.name, number_of_aux_symbols);
}
SymbolKind::Section if symbol.section.id().is_some() => {
debug_assert_eq!(number_of_aux_symbols, 1);
let section_index = symbol.section.id().unwrap().0;
let section = &self.sections[section_index];
writer.write_aux_section(writer::AuxSymbolSection {
length: section.size as u32,
number_of_relocations: section.relocations.len() as u32,
number_of_linenumbers: 0,
check_sum: if section.is_bss() {
0
} else {
checksum(section.data())
},
number: section_offsets[section_index].associative_section,
selection: section_offsets[section_index].selection,
});
}
_ => {
debug_assert_eq!(number_of_aux_symbols, 0);
}
}
}
writer.write_strtab();
debug_assert_eq!(writer.reserved_len(), writer.len());
Ok(())
}
}
// JamCRC
fn checksum(data: &[u8]) -> u32 {
let mut hasher = crc32fast::Hasher::new_with_initial(0xffff_ffff);
hasher.update(data);
!hasher.finalize()
}