| //! Helper for writing ELF files. |
| use alloc::string::String; |
| use alloc::vec::Vec; |
| use core::mem; |
| |
| use crate::elf; |
| use crate::endian::*; |
| use crate::pod; |
| use crate::write::string::{StringId, StringTable}; |
| use crate::write::util; |
| use crate::write::{Error, Result, WritableBuffer}; |
| |
| /// The index of an ELF section. |
| #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| pub struct SectionIndex(pub u32); |
| |
| /// The index of an ELF symbol. |
| #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] |
| pub struct SymbolIndex(pub u32); |
| |
| /// A helper for writing ELF files. |
| /// |
| /// Writing uses a two phase approach. The first phase builds up all of the information |
| /// that may need to be known ahead of time: |
| /// - build string tables |
| /// - reserve section indices |
| /// - reserve symbol indices |
| /// - reserve file ranges for headers and sections |
| /// |
| /// Some of the information has ordering requirements. For example, strings must be added |
| /// to string tables before reserving the file range for the string table. Symbol indices |
| /// must be reserved after reserving the section indices they reference. There are debug |
| /// asserts to check some of these requirements. |
| /// |
| /// The second phase writes everything out in order. Thus the caller must ensure writing |
| /// is in the same order that file ranges were reserved. There are debug asserts to assist |
| /// with checking this. |
| #[allow(missing_debug_implementations)] |
| pub struct Writer<'a> { |
| endian: Endianness, |
| is_64: bool, |
| is_mips64el: bool, |
| elf_align: usize, |
| |
| buffer: &'a mut dyn WritableBuffer, |
| len: usize, |
| |
| segment_offset: usize, |
| segment_num: u32, |
| |
| section_offset: usize, |
| section_num: u32, |
| |
| shstrtab: StringTable<'a>, |
| shstrtab_str_id: Option<StringId>, |
| shstrtab_index: SectionIndex, |
| shstrtab_offset: usize, |
| shstrtab_data: Vec<u8>, |
| |
| need_strtab: bool, |
| strtab: StringTable<'a>, |
| strtab_str_id: Option<StringId>, |
| strtab_index: SectionIndex, |
| strtab_offset: usize, |
| strtab_data: Vec<u8>, |
| |
| symtab_str_id: Option<StringId>, |
| symtab_index: SectionIndex, |
| symtab_offset: usize, |
| symtab_num: u32, |
| |
| need_symtab_shndx: bool, |
| symtab_shndx_str_id: Option<StringId>, |
| symtab_shndx_offset: usize, |
| symtab_shndx_data: Vec<u8>, |
| |
| need_dynstr: bool, |
| dynstr: StringTable<'a>, |
| dynstr_str_id: Option<StringId>, |
| dynstr_index: SectionIndex, |
| dynstr_offset: usize, |
| dynstr_data: Vec<u8>, |
| |
| dynsym_str_id: Option<StringId>, |
| dynsym_index: SectionIndex, |
| dynsym_offset: usize, |
| dynsym_num: u32, |
| |
| dynamic_str_id: Option<StringId>, |
| dynamic_offset: usize, |
| dynamic_num: usize, |
| |
| hash_str_id: Option<StringId>, |
| hash_offset: usize, |
| hash_size: usize, |
| |
| gnu_hash_str_id: Option<StringId>, |
| gnu_hash_offset: usize, |
| gnu_hash_size: usize, |
| |
| gnu_versym_str_id: Option<StringId>, |
| gnu_versym_offset: usize, |
| |
| gnu_verdef_str_id: Option<StringId>, |
| gnu_verdef_offset: usize, |
| gnu_verdef_size: usize, |
| gnu_verdef_count: u16, |
| gnu_verdef_remaining: u16, |
| gnu_verdaux_remaining: u16, |
| |
| gnu_verneed_str_id: Option<StringId>, |
| gnu_verneed_offset: usize, |
| gnu_verneed_size: usize, |
| gnu_verneed_count: u16, |
| gnu_verneed_remaining: u16, |
| gnu_vernaux_remaining: u16, |
| |
| gnu_attributes_str_id: Option<StringId>, |
| gnu_attributes_offset: usize, |
| gnu_attributes_size: usize, |
| } |
| |
| impl<'a> Writer<'a> { |
| /// Create a new `Writer` for the given endianness and ELF class. |
| pub fn new(endian: Endianness, is_64: bool, buffer: &'a mut dyn WritableBuffer) -> Self { |
| let elf_align = if is_64 { 8 } else { 4 }; |
| Writer { |
| endian, |
| is_64, |
| // Determined later. |
| is_mips64el: false, |
| elf_align, |
| |
| buffer, |
| len: 0, |
| |
| segment_offset: 0, |
| segment_num: 0, |
| |
| section_offset: 0, |
| section_num: 0, |
| |
| shstrtab: StringTable::default(), |
| shstrtab_str_id: None, |
| shstrtab_index: SectionIndex(0), |
| shstrtab_offset: 0, |
| shstrtab_data: Vec::new(), |
| |
| need_strtab: false, |
| strtab: StringTable::default(), |
| strtab_str_id: None, |
| strtab_index: SectionIndex(0), |
| strtab_offset: 0, |
| strtab_data: Vec::new(), |
| |
| symtab_str_id: None, |
| symtab_index: SectionIndex(0), |
| symtab_offset: 0, |
| symtab_num: 0, |
| |
| need_symtab_shndx: false, |
| symtab_shndx_str_id: None, |
| symtab_shndx_offset: 0, |
| symtab_shndx_data: Vec::new(), |
| |
| need_dynstr: false, |
| dynstr: StringTable::default(), |
| dynstr_str_id: None, |
| dynstr_index: SectionIndex(0), |
| dynstr_offset: 0, |
| dynstr_data: Vec::new(), |
| |
| dynsym_str_id: None, |
| dynsym_index: SectionIndex(0), |
| dynsym_offset: 0, |
| dynsym_num: 0, |
| |
| dynamic_str_id: None, |
| dynamic_offset: 0, |
| dynamic_num: 0, |
| |
| hash_str_id: None, |
| hash_offset: 0, |
| hash_size: 0, |
| |
| gnu_hash_str_id: None, |
| gnu_hash_offset: 0, |
| gnu_hash_size: 0, |
| |
| gnu_versym_str_id: None, |
| gnu_versym_offset: 0, |
| |
| gnu_verdef_str_id: None, |
| gnu_verdef_offset: 0, |
| gnu_verdef_size: 0, |
| gnu_verdef_count: 0, |
| gnu_verdef_remaining: 0, |
| gnu_verdaux_remaining: 0, |
| |
| gnu_verneed_str_id: None, |
| gnu_verneed_offset: 0, |
| gnu_verneed_size: 0, |
| gnu_verneed_count: 0, |
| gnu_verneed_remaining: 0, |
| gnu_vernaux_remaining: 0, |
| |
| gnu_attributes_str_id: None, |
| gnu_attributes_offset: 0, |
| gnu_attributes_size: 0, |
| } |
| } |
| |
| /// Return the current file length that has been reserved. |
| pub fn reserved_len(&self) -> usize { |
| self.len |
| } |
| |
| /// Return the current file length that has been written. |
| #[allow(clippy::len_without_is_empty)] |
| pub fn len(&self) -> usize { |
| self.buffer.len() |
| } |
| |
| /// Reserve a file range with the given size and starting alignment. |
| /// |
| /// Returns the aligned offset of the start of the range. |
| pub fn reserve(&mut self, len: usize, align_start: usize) -> usize { |
| if align_start > 1 { |
| self.len = util::align(self.len, align_start); |
| } |
| let offset = self.len; |
| self.len += len; |
| offset |
| } |
| |
| /// Write alignment padding bytes. |
| pub fn write_align(&mut self, align_start: usize) { |
| if align_start > 1 { |
| util::write_align(self.buffer, align_start); |
| } |
| } |
| |
| /// Write data. |
| /// |
| /// This is typically used to write section data. |
| pub fn write(&mut self, data: &[u8]) { |
| self.buffer.write_bytes(data); |
| } |
| |
| /// Reserve the file range up to the given file offset. |
| pub fn reserve_until(&mut self, offset: usize) { |
| debug_assert!(self.len <= offset); |
| self.len = offset; |
| } |
| |
| /// Write padding up to the given file offset. |
| pub fn pad_until(&mut self, offset: usize) { |
| debug_assert!(self.buffer.len() <= offset); |
| self.buffer.resize(offset); |
| } |
| |
| fn file_header_size(&self) -> usize { |
| if self.is_64 { |
| mem::size_of::<elf::FileHeader64<Endianness>>() |
| } else { |
| mem::size_of::<elf::FileHeader32<Endianness>>() |
| } |
| } |
| |
| /// Reserve the range for the file header. |
| /// |
| /// This must be at the start of the file. |
| pub fn reserve_file_header(&mut self) { |
| debug_assert_eq!(self.len, 0); |
| self.reserve(self.file_header_size(), 1); |
| } |
| |
| /// Write the file header. |
| /// |
| /// This must be at the start of the file. |
| /// |
| /// Fields that can be derived from known information are automatically set by this function. |
| pub fn write_file_header(&mut self, header: &FileHeader) -> Result<()> { |
| debug_assert_eq!(self.buffer.len(), 0); |
| |
| self.is_mips64el = |
| self.is_64 && self.endian.is_little_endian() && header.e_machine == elf::EM_MIPS; |
| |
| // Start writing. |
| self.buffer |
| .reserve(self.len) |
| .map_err(|_| Error(String::from("Cannot allocate buffer")))?; |
| |
| // Write file header. |
| let e_ident = elf::Ident { |
| magic: elf::ELFMAG, |
| class: if self.is_64 { |
| elf::ELFCLASS64 |
| } else { |
| elf::ELFCLASS32 |
| }, |
| data: if self.endian.is_little_endian() { |
| elf::ELFDATA2LSB |
| } else { |
| elf::ELFDATA2MSB |
| }, |
| version: elf::EV_CURRENT, |
| os_abi: header.os_abi, |
| abi_version: header.abi_version, |
| padding: [0; 7], |
| }; |
| |
| let e_ehsize = self.file_header_size() as u16; |
| |
| let e_phoff = self.segment_offset as u64; |
| let e_phentsize = if self.segment_num == 0 { |
| 0 |
| } else { |
| self.program_header_size() as u16 |
| }; |
| // TODO: overflow |
| let e_phnum = self.segment_num as u16; |
| |
| let e_shoff = self.section_offset as u64; |
| let e_shentsize = if self.section_num == 0 { |
| 0 |
| } else { |
| self.section_header_size() as u16 |
| }; |
| let e_shnum = if self.section_num >= elf::SHN_LORESERVE.into() { |
| 0 |
| } else { |
| self.section_num as u16 |
| }; |
| let e_shstrndx = if self.shstrtab_index.0 >= elf::SHN_LORESERVE.into() { |
| elf::SHN_XINDEX |
| } else { |
| self.shstrtab_index.0 as u16 |
| }; |
| |
| let endian = self.endian; |
| if self.is_64 { |
| let file = elf::FileHeader64 { |
| e_ident, |
| e_type: U16::new(endian, header.e_type), |
| e_machine: U16::new(endian, header.e_machine), |
| e_version: U32::new(endian, elf::EV_CURRENT.into()), |
| e_entry: U64::new(endian, header.e_entry), |
| e_phoff: U64::new(endian, e_phoff), |
| e_shoff: U64::new(endian, e_shoff), |
| e_flags: U32::new(endian, header.e_flags), |
| e_ehsize: U16::new(endian, e_ehsize), |
| e_phentsize: U16::new(endian, e_phentsize), |
| e_phnum: U16::new(endian, e_phnum), |
| e_shentsize: U16::new(endian, e_shentsize), |
| e_shnum: U16::new(endian, e_shnum), |
| e_shstrndx: U16::new(endian, e_shstrndx), |
| }; |
| self.buffer.write(&file) |
| } else { |
| let file = elf::FileHeader32 { |
| e_ident, |
| e_type: U16::new(endian, header.e_type), |
| e_machine: U16::new(endian, header.e_machine), |
| e_version: U32::new(endian, elf::EV_CURRENT.into()), |
| e_entry: U32::new(endian, header.e_entry as u32), |
| e_phoff: U32::new(endian, e_phoff as u32), |
| e_shoff: U32::new(endian, e_shoff as u32), |
| e_flags: U32::new(endian, header.e_flags), |
| e_ehsize: U16::new(endian, e_ehsize), |
| e_phentsize: U16::new(endian, e_phentsize), |
| e_phnum: U16::new(endian, e_phnum), |
| e_shentsize: U16::new(endian, e_shentsize), |
| e_shnum: U16::new(endian, e_shnum), |
| e_shstrndx: U16::new(endian, e_shstrndx), |
| }; |
| self.buffer.write(&file); |
| } |
| |
| Ok(()) |
| } |
| |
| fn program_header_size(&self) -> usize { |
| if self.is_64 { |
| mem::size_of::<elf::ProgramHeader64<Endianness>>() |
| } else { |
| mem::size_of::<elf::ProgramHeader32<Endianness>>() |
| } |
| } |
| |
| /// Reserve the range for the program headers. |
| pub fn reserve_program_headers(&mut self, num: u32) { |
| debug_assert_eq!(self.segment_offset, 0); |
| if num == 0 { |
| return; |
| } |
| self.segment_num = num; |
| self.segment_offset = |
| self.reserve(num as usize * self.program_header_size(), self.elf_align); |
| } |
| |
| /// Write alignment padding bytes prior to the program headers. |
| pub fn write_align_program_headers(&mut self) { |
| if self.segment_offset == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.segment_offset, self.buffer.len()); |
| } |
| |
| /// Write a program header. |
| pub fn write_program_header(&mut self, header: &ProgramHeader) { |
| let endian = self.endian; |
| if self.is_64 { |
| let header = elf::ProgramHeader64 { |
| p_type: U32::new(endian, header.p_type), |
| p_flags: U32::new(endian, header.p_flags), |
| p_offset: U64::new(endian, header.p_offset), |
| p_vaddr: U64::new(endian, header.p_vaddr), |
| p_paddr: U64::new(endian, header.p_paddr), |
| p_filesz: U64::new(endian, header.p_filesz), |
| p_memsz: U64::new(endian, header.p_memsz), |
| p_align: U64::new(endian, header.p_align), |
| }; |
| self.buffer.write(&header); |
| } else { |
| let header = elf::ProgramHeader32 { |
| p_type: U32::new(endian, header.p_type), |
| p_offset: U32::new(endian, header.p_offset as u32), |
| p_vaddr: U32::new(endian, header.p_vaddr as u32), |
| p_paddr: U32::new(endian, header.p_paddr as u32), |
| p_filesz: U32::new(endian, header.p_filesz as u32), |
| p_memsz: U32::new(endian, header.p_memsz as u32), |
| p_flags: U32::new(endian, header.p_flags), |
| p_align: U32::new(endian, header.p_align as u32), |
| }; |
| self.buffer.write(&header); |
| } |
| } |
| |
| /// Reserve the section index for the null section header. |
| /// |
| /// The null section header is usually automatically reserved, |
| /// but this can be used to force an empty section table. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_null_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.section_num, 0); |
| if self.section_num == 0 { |
| self.section_num = 1; |
| } |
| SectionIndex(0) |
| } |
| |
| /// Reserve a section table index. |
| /// |
| /// Automatically also reserves the null section header if required. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.section_offset, 0); |
| if self.section_num == 0 { |
| self.section_num = 1; |
| } |
| let index = self.section_num; |
| self.section_num += 1; |
| SectionIndex(index) |
| } |
| |
| fn section_header_size(&self) -> usize { |
| if self.is_64 { |
| mem::size_of::<elf::SectionHeader64<Endianness>>() |
| } else { |
| mem::size_of::<elf::SectionHeader32<Endianness>>() |
| } |
| } |
| |
| /// Reserve the range for the section headers. |
| /// |
| /// This function does nothing if no sections were reserved. |
| /// This must be called after [`Self::reserve_section_index`] |
| /// and other functions that reserve section indices. |
| pub fn reserve_section_headers(&mut self) { |
| debug_assert_eq!(self.section_offset, 0); |
| if self.section_num == 0 { |
| return; |
| } |
| self.section_offset = self.reserve( |
| self.section_num as usize * self.section_header_size(), |
| self.elf_align, |
| ); |
| } |
| |
| /// Write the null section header. |
| /// |
| /// This must be the first section header that is written. |
| /// This function does nothing if no sections were reserved. |
| pub fn write_null_section_header(&mut self) { |
| if self.section_num == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.section_offset, self.buffer.len()); |
| self.write_section_header(&SectionHeader { |
| name: None, |
| sh_type: 0, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: 0, |
| sh_size: if self.section_num >= elf::SHN_LORESERVE.into() { |
| self.section_num.into() |
| } else { |
| 0 |
| }, |
| sh_link: if self.shstrtab_index.0 >= elf::SHN_LORESERVE.into() { |
| self.shstrtab_index.0 |
| } else { |
| 0 |
| }, |
| // TODO: e_phnum overflow |
| sh_info: 0, |
| sh_addralign: 0, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Write a section header. |
| pub fn write_section_header(&mut self, section: &SectionHeader) { |
| let sh_name = if let Some(name) = section.name { |
| self.shstrtab.get_offset(name) as u32 |
| } else { |
| 0 |
| }; |
| let endian = self.endian; |
| if self.is_64 { |
| let section = elf::SectionHeader64 { |
| sh_name: U32::new(endian, sh_name), |
| sh_type: U32::new(endian, section.sh_type), |
| sh_flags: U64::new(endian, section.sh_flags), |
| sh_addr: U64::new(endian, section.sh_addr), |
| sh_offset: U64::new(endian, section.sh_offset), |
| sh_size: U64::new(endian, section.sh_size), |
| sh_link: U32::new(endian, section.sh_link), |
| sh_info: U32::new(endian, section.sh_info), |
| sh_addralign: U64::new(endian, section.sh_addralign), |
| sh_entsize: U64::new(endian, section.sh_entsize), |
| }; |
| self.buffer.write(§ion); |
| } else { |
| let section = elf::SectionHeader32 { |
| sh_name: U32::new(endian, sh_name), |
| sh_type: U32::new(endian, section.sh_type), |
| sh_flags: U32::new(endian, section.sh_flags as u32), |
| sh_addr: U32::new(endian, section.sh_addr as u32), |
| sh_offset: U32::new(endian, section.sh_offset as u32), |
| sh_size: U32::new(endian, section.sh_size as u32), |
| sh_link: U32::new(endian, section.sh_link), |
| sh_info: U32::new(endian, section.sh_info), |
| sh_addralign: U32::new(endian, section.sh_addralign as u32), |
| sh_entsize: U32::new(endian, section.sh_entsize as u32), |
| }; |
| self.buffer.write(§ion); |
| } |
| } |
| |
| /// Add a section name to the section header string table. |
| /// |
| /// This will be stored in the `.shstrtab` section. |
| /// |
| /// This must be called before [`Self::reserve_shstrtab`]. |
| pub fn add_section_name(&mut self, name: &'a [u8]) -> StringId { |
| debug_assert_eq!(self.shstrtab_offset, 0); |
| self.shstrtab.add(name) |
| } |
| |
| /// Reserve the range for the section header string table. |
| /// |
| /// This range is used for a section named `.shstrtab`. |
| /// |
| /// This function does nothing if no sections were reserved. |
| /// This must be called after [`Self::add_section_name`]. |
| /// and other functions that reserve section names and indices. |
| pub fn reserve_shstrtab(&mut self) { |
| debug_assert_eq!(self.shstrtab_offset, 0); |
| if self.section_num == 0 { |
| return; |
| } |
| // Start with null section name. |
| self.shstrtab_data = vec![0]; |
| self.shstrtab.write(1, &mut self.shstrtab_data); |
| self.shstrtab_offset = self.reserve(self.shstrtab_data.len(), 1); |
| } |
| |
| /// Write the section header string table. |
| /// |
| /// This function does nothing if the section was not reserved. |
| pub fn write_shstrtab(&mut self) { |
| if self.shstrtab_offset == 0 { |
| return; |
| } |
| debug_assert_eq!(self.shstrtab_offset, self.buffer.len()); |
| self.buffer.write_bytes(&self.shstrtab_data); |
| } |
| |
| /// Reserve the section index for the section header string table. |
| /// |
| /// This must be called before [`Self::reserve_shstrtab`] |
| /// and [`Self::reserve_section_headers`]. |
| pub fn reserve_shstrtab_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.shstrtab_index, SectionIndex(0)); |
| self.shstrtab_str_id = Some(self.add_section_name(&b".shstrtab"[..])); |
| self.shstrtab_index = self.reserve_section_index(); |
| self.shstrtab_index |
| } |
| |
| /// Write the section header for the section header string table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_shstrtab_section_header(&mut self) { |
| if self.shstrtab_index == SectionIndex(0) { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.shstrtab_str_id, |
| sh_type: elf::SHT_STRTAB, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: self.shstrtab_offset as u64, |
| sh_size: self.shstrtab_data.len() as u64, |
| sh_link: 0, |
| sh_info: 0, |
| sh_addralign: 1, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Add a string to the string table. |
| /// |
| /// This will be stored in the `.strtab` section. |
| /// |
| /// This must be called before [`Self::reserve_strtab`]. |
| pub fn add_string(&mut self, name: &'a [u8]) -> StringId { |
| debug_assert_eq!(self.strtab_offset, 0); |
| self.need_strtab = true; |
| self.strtab.add(name) |
| } |
| |
| /// Return true if `.strtab` is needed. |
| pub fn strtab_needed(&self) -> bool { |
| self.need_strtab |
| } |
| |
| /// Reserve the range for the string table. |
| /// |
| /// This range is used for a section named `.strtab`. |
| /// |
| /// This function does nothing if no strings or symbols were defined. |
| /// This must be called after [`Self::add_string`]. |
| pub fn reserve_strtab(&mut self) { |
| debug_assert_eq!(self.strtab_offset, 0); |
| if !self.need_strtab { |
| return; |
| } |
| // Start with null string. |
| self.strtab_data = vec![0]; |
| self.strtab.write(1, &mut self.strtab_data); |
| self.strtab_offset = self.reserve(self.strtab_data.len(), 1); |
| } |
| |
| /// Write the string table. |
| /// |
| /// This function does nothing if the section was not reserved. |
| pub fn write_strtab(&mut self) { |
| if self.strtab_offset == 0 { |
| return; |
| } |
| debug_assert_eq!(self.strtab_offset, self.buffer.len()); |
| self.buffer.write_bytes(&self.strtab_data); |
| } |
| |
| /// Reserve the section index for the string table. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_strtab_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.strtab_index, SectionIndex(0)); |
| self.strtab_str_id = Some(self.add_section_name(&b".strtab"[..])); |
| self.strtab_index = self.reserve_section_index(); |
| self.strtab_index |
| } |
| |
| /// Write the section header for the string table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_strtab_section_header(&mut self) { |
| if self.strtab_index == SectionIndex(0) { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.strtab_str_id, |
| sh_type: elf::SHT_STRTAB, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: self.strtab_offset as u64, |
| sh_size: self.strtab_data.len() as u64, |
| sh_link: 0, |
| sh_info: 0, |
| sh_addralign: 1, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Reserve the null symbol table entry. |
| /// |
| /// This will be stored in the `.symtab` section. |
| /// |
| /// The null symbol table entry is usually automatically reserved, |
| /// but this can be used to force an empty symbol table. |
| /// |
| /// This must be called before [`Self::reserve_symtab`]. |
| pub fn reserve_null_symbol_index(&mut self) -> SymbolIndex { |
| debug_assert_eq!(self.symtab_offset, 0); |
| debug_assert_eq!(self.symtab_num, 0); |
| self.symtab_num = 1; |
| // The symtab must link to a strtab. |
| self.need_strtab = true; |
| SymbolIndex(0) |
| } |
| |
| /// Reserve a symbol table entry. |
| /// |
| /// This will be stored in the `.symtab` section. |
| /// |
| /// `section_index` is used to determine whether `.symtab_shndx` is required. |
| /// |
| /// Automatically also reserves the null symbol if required. |
| /// Callers may assume that the returned indices will be sequential |
| /// starting at 1. |
| /// |
| /// This must be called before [`Self::reserve_symtab`] and |
| /// [`Self::reserve_symtab_shndx`]. |
| pub fn reserve_symbol_index(&mut self, section_index: Option<SectionIndex>) -> SymbolIndex { |
| debug_assert_eq!(self.symtab_offset, 0); |
| debug_assert_eq!(self.symtab_shndx_offset, 0); |
| if self.symtab_num == 0 { |
| self.symtab_num = 1; |
| // The symtab must link to a strtab. |
| self.need_strtab = true; |
| } |
| let index = self.symtab_num; |
| self.symtab_num += 1; |
| if let Some(section_index) = section_index { |
| if section_index.0 >= elf::SHN_LORESERVE.into() { |
| self.need_symtab_shndx = true; |
| } |
| } |
| SymbolIndex(index) |
| } |
| |
| /// Return the number of reserved symbol table entries. |
| /// |
| /// Includes the null symbol. |
| pub fn symbol_count(&self) -> u32 { |
| self.symtab_num |
| } |
| |
| fn symbol_size(&self) -> usize { |
| if self.is_64 { |
| mem::size_of::<elf::Sym64<Endianness>>() |
| } else { |
| mem::size_of::<elf::Sym32<Endianness>>() |
| } |
| } |
| |
| /// Reserve the range for the symbol table. |
| /// |
| /// This range is used for a section named `.symtab`. |
| /// This function does nothing if no symbols were reserved. |
| /// This must be called after [`Self::reserve_symbol_index`]. |
| pub fn reserve_symtab(&mut self) { |
| debug_assert_eq!(self.symtab_offset, 0); |
| if self.symtab_num == 0 { |
| return; |
| } |
| self.symtab_offset = self.reserve( |
| self.symtab_num as usize * self.symbol_size(), |
| self.elf_align, |
| ); |
| } |
| |
| /// Write the null symbol. |
| /// |
| /// This must be the first symbol that is written. |
| /// This function does nothing if no symbols were reserved. |
| pub fn write_null_symbol(&mut self) { |
| if self.symtab_num == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.symtab_offset, self.buffer.len()); |
| if self.is_64 { |
| self.buffer.write(&elf::Sym64::<Endianness>::default()); |
| } else { |
| self.buffer.write(&elf::Sym32::<Endianness>::default()); |
| } |
| |
| if self.need_symtab_shndx { |
| self.symtab_shndx_data.write_pod(&U32::new(self.endian, 0)); |
| } |
| } |
| |
| /// Write a symbol. |
| pub fn write_symbol(&mut self, sym: &Sym) { |
| let st_name = if let Some(name) = sym.name { |
| self.strtab.get_offset(name) as u32 |
| } else { |
| 0 |
| }; |
| let st_shndx = if let Some(section) = sym.section { |
| if section.0 >= elf::SHN_LORESERVE as u32 { |
| elf::SHN_XINDEX |
| } else { |
| section.0 as u16 |
| } |
| } else { |
| sym.st_shndx |
| }; |
| |
| let endian = self.endian; |
| if self.is_64 { |
| let sym = elf::Sym64 { |
| st_name: U32::new(endian, st_name), |
| st_info: sym.st_info, |
| st_other: sym.st_other, |
| st_shndx: U16::new(endian, st_shndx), |
| st_value: U64::new(endian, sym.st_value), |
| st_size: U64::new(endian, sym.st_size), |
| }; |
| self.buffer.write(&sym); |
| } else { |
| let sym = elf::Sym32 { |
| st_name: U32::new(endian, st_name), |
| st_info: sym.st_info, |
| st_other: sym.st_other, |
| st_shndx: U16::new(endian, st_shndx), |
| st_value: U32::new(endian, sym.st_value as u32), |
| st_size: U32::new(endian, sym.st_size as u32), |
| }; |
| self.buffer.write(&sym); |
| } |
| |
| if self.need_symtab_shndx { |
| let section_index = sym.section.unwrap_or(SectionIndex(0)); |
| self.symtab_shndx_data |
| .write_pod(&U32::new(self.endian, section_index.0)); |
| } |
| } |
| |
| /// Reserve the section index for the symbol table. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_symtab_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.symtab_index, SectionIndex(0)); |
| self.symtab_str_id = Some(self.add_section_name(&b".symtab"[..])); |
| self.symtab_index = self.reserve_section_index(); |
| self.symtab_index |
| } |
| |
| /// Return the section index of the symbol table. |
| pub fn symtab_index(&mut self) -> SectionIndex { |
| self.symtab_index |
| } |
| |
| /// Write the section header for the symbol table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_symtab_section_header(&mut self, num_local: u32) { |
| if self.symtab_index == SectionIndex(0) { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.symtab_str_id, |
| sh_type: elf::SHT_SYMTAB, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: self.symtab_offset as u64, |
| sh_size: self.symtab_num as u64 * self.symbol_size() as u64, |
| sh_link: self.strtab_index.0, |
| sh_info: num_local, |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: self.symbol_size() as u64, |
| }); |
| } |
| |
| /// Return true if `.symtab_shndx` is needed. |
| pub fn symtab_shndx_needed(&self) -> bool { |
| self.need_symtab_shndx |
| } |
| |
| /// Reserve the range for the extended section indices for the symbol table. |
| /// |
| /// This range is used for a section named `.symtab_shndx`. |
| /// This also reserves a section index. |
| /// |
| /// This function does nothing if extended section indices are not needed. |
| /// This must be called after [`Self::reserve_symbol_index`]. |
| pub fn reserve_symtab_shndx(&mut self) { |
| debug_assert_eq!(self.symtab_shndx_offset, 0); |
| if !self.need_symtab_shndx { |
| return; |
| } |
| self.symtab_shndx_offset = self.reserve(self.symtab_num as usize * 4, 4); |
| self.symtab_shndx_data.reserve(self.symtab_num as usize * 4); |
| } |
| |
| /// Write the extended section indices for the symbol table. |
| /// |
| /// This function does nothing if the section was not reserved. |
| pub fn write_symtab_shndx(&mut self) { |
| if self.symtab_shndx_offset == 0 { |
| return; |
| } |
| debug_assert_eq!(self.symtab_shndx_offset, self.buffer.len()); |
| debug_assert_eq!(self.symtab_num as usize * 4, self.symtab_shndx_data.len()); |
| self.buffer.write_bytes(&self.symtab_shndx_data); |
| } |
| |
| /// Reserve the section index for the extended section indices symbol table. |
| /// |
| /// You should check [`Self::symtab_shndx_needed`] before calling this |
| /// unless you have other means of knowing if this section is needed. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_symtab_shndx_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.symtab_shndx_str_id.is_none()); |
| self.symtab_shndx_str_id = Some(self.add_section_name(&b".symtab_shndx"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the extended section indices for the symbol table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_symtab_shndx_section_header(&mut self) { |
| if self.symtab_shndx_str_id.is_none() { |
| return; |
| } |
| let sh_size = if self.symtab_shndx_offset == 0 { |
| 0 |
| } else { |
| (self.symtab_num * 4) as u64 |
| }; |
| self.write_section_header(&SectionHeader { |
| name: self.symtab_shndx_str_id, |
| sh_type: elf::SHT_SYMTAB_SHNDX, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: self.symtab_shndx_offset as u64, |
| sh_size, |
| sh_link: self.symtab_index.0, |
| sh_info: 0, |
| sh_addralign: 4, |
| sh_entsize: 4, |
| }); |
| } |
| |
| /// Add a string to the dynamic string table. |
| /// |
| /// This will be stored in the `.dynstr` section. |
| /// |
| /// This must be called before [`Self::reserve_dynstr`]. |
| pub fn add_dynamic_string(&mut self, name: &'a [u8]) -> StringId { |
| debug_assert_eq!(self.dynstr_offset, 0); |
| self.need_dynstr = true; |
| self.dynstr.add(name) |
| } |
| |
| /// Get a string that was previously added to the dynamic string table. |
| /// |
| /// Panics if the string was not added. |
| pub fn get_dynamic_string(&self, name: &'a [u8]) -> StringId { |
| self.dynstr.get_id(name) |
| } |
| |
| /// Return true if `.dynstr` is needed. |
| pub fn dynstr_needed(&self) -> bool { |
| self.need_dynstr |
| } |
| |
| /// Reserve the range for the dynamic string table. |
| /// |
| /// This range is used for a section named `.dynstr`. |
| /// |
| /// This function does nothing if no dynamic strings or symbols were defined. |
| /// This must be called after [`Self::add_dynamic_string`]. |
| pub fn reserve_dynstr(&mut self) { |
| debug_assert_eq!(self.dynstr_offset, 0); |
| if !self.need_dynstr { |
| return; |
| } |
| // Start with null string. |
| self.dynstr_data = vec![0]; |
| self.dynstr.write(1, &mut self.dynstr_data); |
| self.dynstr_offset = self.reserve(self.dynstr_data.len(), 1); |
| } |
| |
| /// Write the dynamic string table. |
| /// |
| /// This function does nothing if the section was not reserved. |
| pub fn write_dynstr(&mut self) { |
| if self.dynstr_offset == 0 { |
| return; |
| } |
| debug_assert_eq!(self.dynstr_offset, self.buffer.len()); |
| self.buffer.write_bytes(&self.dynstr_data); |
| } |
| |
| /// Reserve the section index for the dynamic string table. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_dynstr_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.dynstr_index, SectionIndex(0)); |
| self.dynstr_str_id = Some(self.add_section_name(&b".dynstr"[..])); |
| self.dynstr_index = self.reserve_section_index(); |
| self.dynstr_index |
| } |
| |
| /// Return the section index of the dynamic string table. |
| pub fn dynstr_index(&mut self) -> SectionIndex { |
| self.dynstr_index |
| } |
| |
| /// Write the section header for the dynamic string table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_dynstr_section_header(&mut self, sh_addr: u64) { |
| if self.dynstr_index == SectionIndex(0) { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.dynstr_str_id, |
| sh_type: elf::SHT_STRTAB, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.dynstr_offset as u64, |
| sh_size: self.dynstr_data.len() as u64, |
| sh_link: 0, |
| sh_info: 0, |
| sh_addralign: 1, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Reserve the null dynamic symbol table entry. |
| /// |
| /// This will be stored in the `.dynsym` section. |
| /// |
| /// The null dynamic symbol table entry is usually automatically reserved, |
| /// but this can be used to force an empty dynamic symbol table. |
| /// |
| /// This must be called before [`Self::reserve_dynsym`]. |
| pub fn reserve_null_dynamic_symbol_index(&mut self) -> SymbolIndex { |
| debug_assert_eq!(self.dynsym_offset, 0); |
| debug_assert_eq!(self.dynsym_num, 0); |
| self.dynsym_num = 1; |
| // The symtab must link to a strtab. |
| self.need_dynstr = true; |
| SymbolIndex(0) |
| } |
| |
| /// Reserve a dynamic symbol table entry. |
| /// |
| /// This will be stored in the `.dynsym` section. |
| /// |
| /// Automatically also reserves the null symbol if required. |
| /// Callers may assume that the returned indices will be sequential |
| /// starting at 1. |
| /// |
| /// This must be called before [`Self::reserve_dynsym`]. |
| pub fn reserve_dynamic_symbol_index(&mut self) -> SymbolIndex { |
| debug_assert_eq!(self.dynsym_offset, 0); |
| if self.dynsym_num == 0 { |
| self.dynsym_num = 1; |
| // The symtab must link to a strtab. |
| self.need_dynstr = true; |
| } |
| let index = self.dynsym_num; |
| self.dynsym_num += 1; |
| SymbolIndex(index) |
| } |
| |
| /// Return the number of reserved dynamic symbols. |
| /// |
| /// Includes the null symbol. |
| pub fn dynamic_symbol_count(&mut self) -> u32 { |
| self.dynsym_num |
| } |
| |
| /// Reserve the range for the dynamic symbol table. |
| /// |
| /// This range is used for a section named `.dynsym`. |
| /// |
| /// This function does nothing if no dynamic symbols were reserved. |
| /// This must be called after [`Self::reserve_dynamic_symbol_index`]. |
| pub fn reserve_dynsym(&mut self) { |
| debug_assert_eq!(self.dynsym_offset, 0); |
| if self.dynsym_num == 0 { |
| return; |
| } |
| self.dynsym_offset = self.reserve( |
| self.dynsym_num as usize * self.symbol_size(), |
| self.elf_align, |
| ); |
| } |
| |
| /// Write the null dynamic symbol. |
| /// |
| /// This must be the first dynamic symbol that is written. |
| /// This function does nothing if no dynamic symbols were reserved. |
| pub fn write_null_dynamic_symbol(&mut self) { |
| if self.dynsym_num == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.dynsym_offset, self.buffer.len()); |
| if self.is_64 { |
| self.buffer.write(&elf::Sym64::<Endianness>::default()); |
| } else { |
| self.buffer.write(&elf::Sym32::<Endianness>::default()); |
| } |
| } |
| |
| /// Write a dynamic symbol. |
| pub fn write_dynamic_symbol(&mut self, sym: &Sym) { |
| let st_name = if let Some(name) = sym.name { |
| self.dynstr.get_offset(name) as u32 |
| } else { |
| 0 |
| }; |
| |
| let st_shndx = if let Some(section) = sym.section { |
| if section.0 >= elf::SHN_LORESERVE as u32 { |
| // TODO: we don't actually write out .dynsym_shndx yet. |
| // This is unlikely to be needed though. |
| elf::SHN_XINDEX |
| } else { |
| section.0 as u16 |
| } |
| } else { |
| sym.st_shndx |
| }; |
| |
| let endian = self.endian; |
| if self.is_64 { |
| let sym = elf::Sym64 { |
| st_name: U32::new(endian, st_name), |
| st_info: sym.st_info, |
| st_other: sym.st_other, |
| st_shndx: U16::new(endian, st_shndx), |
| st_value: U64::new(endian, sym.st_value), |
| st_size: U64::new(endian, sym.st_size), |
| }; |
| self.buffer.write(&sym); |
| } else { |
| let sym = elf::Sym32 { |
| st_name: U32::new(endian, st_name), |
| st_info: sym.st_info, |
| st_other: sym.st_other, |
| st_shndx: U16::new(endian, st_shndx), |
| st_value: U32::new(endian, sym.st_value as u32), |
| st_size: U32::new(endian, sym.st_size as u32), |
| }; |
| self.buffer.write(&sym); |
| } |
| } |
| |
| /// Reserve the section index for the dynamic symbol table. |
| /// |
| /// This must be called before [`Self::reserve_section_headers`]. |
| pub fn reserve_dynsym_section_index(&mut self) -> SectionIndex { |
| debug_assert_eq!(self.dynsym_index, SectionIndex(0)); |
| self.dynsym_str_id = Some(self.add_section_name(&b".dynsym"[..])); |
| self.dynsym_index = self.reserve_section_index(); |
| self.dynsym_index |
| } |
| |
| /// Return the section index of the dynamic symbol table. |
| pub fn dynsym_index(&mut self) -> SectionIndex { |
| self.dynsym_index |
| } |
| |
| /// Write the section header for the dynamic symbol table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_dynsym_section_header(&mut self, sh_addr: u64, num_local: u32) { |
| if self.dynsym_index == SectionIndex(0) { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.dynsym_str_id, |
| sh_type: elf::SHT_DYNSYM, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.dynsym_offset as u64, |
| sh_size: self.dynsym_num as u64 * self.symbol_size() as u64, |
| sh_link: self.dynstr_index.0, |
| sh_info: num_local, |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: self.symbol_size() as u64, |
| }); |
| } |
| |
| fn dyn_size(&self) -> usize { |
| if self.is_64 { |
| mem::size_of::<elf::Dyn64<Endianness>>() |
| } else { |
| mem::size_of::<elf::Dyn32<Endianness>>() |
| } |
| } |
| |
| /// Reserve the range for the `.dynamic` section. |
| /// |
| /// This function does nothing if `dynamic_num` is zero. |
| pub fn reserve_dynamic(&mut self, dynamic_num: usize) { |
| debug_assert_eq!(self.dynamic_offset, 0); |
| if dynamic_num == 0 { |
| return; |
| } |
| self.dynamic_num = dynamic_num; |
| self.dynamic_offset = self.reserve(dynamic_num * self.dyn_size(), self.elf_align); |
| } |
| |
| /// Write alignment padding bytes prior to the `.dynamic` section. |
| /// |
| /// This function does nothing if the section was not reserved. |
| pub fn write_align_dynamic(&mut self) { |
| if self.dynamic_offset == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.dynamic_offset, self.buffer.len()); |
| } |
| |
| /// Write a dynamic string entry. |
| pub fn write_dynamic_string(&mut self, tag: u32, id: StringId) { |
| self.write_dynamic(tag, self.dynstr.get_offset(id) as u64); |
| } |
| |
| /// Write a dynamic value entry. |
| pub fn write_dynamic(&mut self, d_tag: u32, d_val: u64) { |
| debug_assert!(self.dynamic_offset <= self.buffer.len()); |
| let endian = self.endian; |
| if self.is_64 { |
| let d = elf::Dyn64 { |
| d_tag: U64::new(endian, d_tag.into()), |
| d_val: U64::new(endian, d_val), |
| }; |
| self.buffer.write(&d); |
| } else { |
| let d = elf::Dyn32 { |
| d_tag: U32::new(endian, d_tag), |
| d_val: U32::new(endian, d_val as u32), |
| }; |
| self.buffer.write(&d); |
| } |
| debug_assert!( |
| self.dynamic_offset + self.dynamic_num * self.dyn_size() >= self.buffer.len() |
| ); |
| } |
| |
| /// Reserve the section index for the dynamic table. |
| pub fn reserve_dynamic_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.dynamic_str_id.is_none()); |
| self.dynamic_str_id = Some(self.add_section_name(&b".dynamic"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the dynamic table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_dynamic_section_header(&mut self, sh_addr: u64) { |
| if self.dynamic_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.dynamic_str_id, |
| sh_type: elf::SHT_DYNAMIC, |
| sh_flags: (elf::SHF_WRITE | elf::SHF_ALLOC).into(), |
| sh_addr, |
| sh_offset: self.dynamic_offset as u64, |
| sh_size: (self.dynamic_num * self.dyn_size()) as u64, |
| sh_link: self.dynstr_index.0, |
| sh_info: 0, |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: self.dyn_size() as u64, |
| }); |
| } |
| |
| fn rel_size(&self, is_rela: bool) -> usize { |
| if self.is_64 { |
| if is_rela { |
| mem::size_of::<elf::Rela64<Endianness>>() |
| } else { |
| mem::size_of::<elf::Rel64<Endianness>>() |
| } |
| } else { |
| if is_rela { |
| mem::size_of::<elf::Rela32<Endianness>>() |
| } else { |
| mem::size_of::<elf::Rel32<Endianness>>() |
| } |
| } |
| } |
| |
| /// Reserve a file range for a SysV hash section. |
| /// |
| /// `symbol_count` is the number of symbols in the hash, |
| /// not the total number of symbols. |
| pub fn reserve_hash(&mut self, bucket_count: u32, chain_count: u32) { |
| self.hash_size = mem::size_of::<elf::HashHeader<Endianness>>() |
| + bucket_count as usize * 4 |
| + chain_count as usize * 4; |
| self.hash_offset = self.reserve(self.hash_size, self.elf_align); |
| } |
| |
| /// Write a SysV hash section. |
| /// |
| /// `chain_count` is the number of symbols in the hash. |
| /// The argument to `hash` will be in the range `0..chain_count`. |
| pub fn write_hash<F>(&mut self, bucket_count: u32, chain_count: u32, hash: F) |
| where |
| F: Fn(u32) -> Option<u32>, |
| { |
| let mut buckets = vec![U32::new(self.endian, 0); bucket_count as usize]; |
| let mut chains = vec![U32::new(self.endian, 0); chain_count as usize]; |
| for i in 0..chain_count { |
| if let Some(hash) = hash(i) { |
| let bucket = hash % bucket_count; |
| chains[i as usize] = buckets[bucket as usize]; |
| buckets[bucket as usize] = U32::new(self.endian, i); |
| } |
| } |
| |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.hash_offset, self.buffer.len()); |
| self.buffer.write(&elf::HashHeader { |
| bucket_count: U32::new(self.endian, bucket_count), |
| chain_count: U32::new(self.endian, chain_count), |
| }); |
| self.buffer.write_slice(&buckets); |
| self.buffer.write_slice(&chains); |
| } |
| |
| /// Reserve the section index for the SysV hash table. |
| pub fn reserve_hash_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.hash_str_id.is_none()); |
| self.hash_str_id = Some(self.add_section_name(&b".hash"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the SysV hash table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_hash_section_header(&mut self, sh_addr: u64) { |
| if self.hash_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.hash_str_id, |
| sh_type: elf::SHT_HASH, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.hash_offset as u64, |
| sh_size: self.hash_size as u64, |
| sh_link: self.dynsym_index.0, |
| sh_info: 0, |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: 4, |
| }); |
| } |
| |
| /// Reserve a file range for a GNU hash section. |
| /// |
| /// `symbol_count` is the number of symbols in the hash, |
| /// not the total number of symbols. |
| pub fn reserve_gnu_hash(&mut self, bloom_count: u32, bucket_count: u32, symbol_count: u32) { |
| self.gnu_hash_size = mem::size_of::<elf::GnuHashHeader<Endianness>>() |
| + bloom_count as usize * self.elf_align |
| + bucket_count as usize * 4 |
| + symbol_count as usize * 4; |
| self.gnu_hash_offset = self.reserve(self.gnu_hash_size, self.elf_align); |
| } |
| |
| /// Write a GNU hash section. |
| /// |
| /// `symbol_count` is the number of symbols in the hash. |
| /// The argument to `hash` will be in the range `0..symbol_count`. |
| /// |
| /// This requires that symbols are already sorted by bucket. |
| pub fn write_gnu_hash<F>( |
| &mut self, |
| symbol_base: u32, |
| bloom_shift: u32, |
| bloom_count: u32, |
| bucket_count: u32, |
| symbol_count: u32, |
| hash: F, |
| ) where |
| F: Fn(u32) -> u32, |
| { |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.gnu_hash_offset, self.buffer.len()); |
| self.buffer.write(&elf::GnuHashHeader { |
| bucket_count: U32::new(self.endian, bucket_count), |
| symbol_base: U32::new(self.endian, symbol_base), |
| bloom_count: U32::new(self.endian, bloom_count), |
| bloom_shift: U32::new(self.endian, bloom_shift), |
| }); |
| |
| // Calculate and write bloom filter. |
| if self.is_64 { |
| let mut bloom_filters = vec![0; bloom_count as usize]; |
| for i in 0..symbol_count { |
| let h = hash(i); |
| bloom_filters[((h / 64) & (bloom_count - 1)) as usize] |= |
| 1 << (h % 64) | 1 << ((h >> bloom_shift) % 64); |
| } |
| for bloom_filter in bloom_filters { |
| self.buffer.write(&U64::new(self.endian, bloom_filter)); |
| } |
| } else { |
| let mut bloom_filters = vec![0; bloom_count as usize]; |
| for i in 0..symbol_count { |
| let h = hash(i); |
| bloom_filters[((h / 32) & (bloom_count - 1)) as usize] |= |
| 1 << (h % 32) | 1 << ((h >> bloom_shift) % 32); |
| } |
| for bloom_filter in bloom_filters { |
| self.buffer.write(&U32::new(self.endian, bloom_filter)); |
| } |
| } |
| |
| // Write buckets. |
| // |
| // This requires that symbols are already sorted by bucket. |
| let mut bucket = 0; |
| for i in 0..symbol_count { |
| let symbol_bucket = hash(i) % bucket_count; |
| while bucket < symbol_bucket { |
| self.buffer.write(&U32::new(self.endian, 0)); |
| bucket += 1; |
| } |
| if bucket == symbol_bucket { |
| self.buffer.write(&U32::new(self.endian, symbol_base + i)); |
| bucket += 1; |
| } |
| } |
| while bucket < bucket_count { |
| self.buffer.write(&U32::new(self.endian, 0)); |
| bucket += 1; |
| } |
| |
| // Write hash values. |
| for i in 0..symbol_count { |
| let mut h = hash(i); |
| if i == symbol_count - 1 || h % bucket_count != hash(i + 1) % bucket_count { |
| h |= 1; |
| } else { |
| h &= !1; |
| } |
| self.buffer.write(&U32::new(self.endian, h)); |
| } |
| } |
| |
| /// Reserve the section index for the GNU hash table. |
| pub fn reserve_gnu_hash_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.gnu_hash_str_id.is_none()); |
| self.gnu_hash_str_id = Some(self.add_section_name(&b".gnu.hash"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the GNU hash table. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_gnu_hash_section_header(&mut self, sh_addr: u64) { |
| if self.gnu_hash_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.gnu_hash_str_id, |
| sh_type: elf::SHT_GNU_HASH, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.gnu_hash_offset as u64, |
| sh_size: self.gnu_hash_size as u64, |
| sh_link: self.dynsym_index.0, |
| sh_info: 0, |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Reserve the range for the `.gnu.version` section. |
| /// |
| /// This function does nothing if no dynamic symbols were reserved. |
| pub fn reserve_gnu_versym(&mut self) { |
| debug_assert_eq!(self.gnu_versym_offset, 0); |
| if self.dynsym_num == 0 { |
| return; |
| } |
| self.gnu_versym_offset = self.reserve(self.dynsym_num as usize * 2, 2); |
| } |
| |
| /// Write the null symbol version entry. |
| /// |
| /// This must be the first symbol version that is written. |
| /// This function does nothing if no dynamic symbols were reserved. |
| pub fn write_null_gnu_versym(&mut self) { |
| if self.dynsym_num == 0 { |
| return; |
| } |
| util::write_align(self.buffer, 2); |
| debug_assert_eq!(self.gnu_versym_offset, self.buffer.len()); |
| self.write_gnu_versym(0); |
| } |
| |
| /// Write a symbol version entry. |
| pub fn write_gnu_versym(&mut self, versym: u16) { |
| self.buffer.write(&U16::new(self.endian, versym)); |
| } |
| |
| /// Reserve the section index for the `.gnu.version` section. |
| pub fn reserve_gnu_versym_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.gnu_versym_str_id.is_none()); |
| self.gnu_versym_str_id = Some(self.add_section_name(&b".gnu.version"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the `.gnu.version` section. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_gnu_versym_section_header(&mut self, sh_addr: u64) { |
| if self.gnu_versym_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.gnu_versym_str_id, |
| sh_type: elf::SHT_GNU_VERSYM, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.gnu_versym_offset as u64, |
| sh_size: self.dynsym_num as u64 * 2, |
| sh_link: self.dynsym_index.0, |
| sh_info: 0, |
| sh_addralign: 2, |
| sh_entsize: 2, |
| }); |
| } |
| |
| /// Reserve the range for the `.gnu.version_d` section. |
| pub fn reserve_gnu_verdef(&mut self, verdef_count: usize, verdaux_count: usize) { |
| debug_assert_eq!(self.gnu_verdef_offset, 0); |
| if verdef_count == 0 { |
| return; |
| } |
| self.gnu_verdef_size = verdef_count * mem::size_of::<elf::Verdef<Endianness>>() |
| + verdaux_count * mem::size_of::<elf::Verdaux<Endianness>>(); |
| self.gnu_verdef_offset = self.reserve(self.gnu_verdef_size, self.elf_align); |
| self.gnu_verdef_count = verdef_count as u16; |
| self.gnu_verdef_remaining = self.gnu_verdef_count; |
| } |
| |
| /// Write alignment padding bytes prior to a `.gnu.version_d` section. |
| pub fn write_align_gnu_verdef(&mut self) { |
| if self.gnu_verdef_offset == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.gnu_verdef_offset, self.buffer.len()); |
| } |
| |
| /// Write a version definition entry. |
| pub fn write_gnu_verdef(&mut self, verdef: &Verdef) { |
| debug_assert_ne!(self.gnu_verdef_remaining, 0); |
| self.gnu_verdef_remaining -= 1; |
| let vd_next = if self.gnu_verdef_remaining == 0 { |
| 0 |
| } else { |
| mem::size_of::<elf::Verdef<Endianness>>() as u32 |
| + verdef.aux_count as u32 * mem::size_of::<elf::Verdaux<Endianness>>() as u32 |
| }; |
| |
| self.gnu_verdaux_remaining = verdef.aux_count; |
| let vd_aux = if verdef.aux_count == 0 { |
| 0 |
| } else { |
| mem::size_of::<elf::Verdef<Endianness>>() as u32 |
| }; |
| |
| self.buffer.write(&elf::Verdef { |
| vd_version: U16::new(self.endian, verdef.version), |
| vd_flags: U16::new(self.endian, verdef.flags), |
| vd_ndx: U16::new(self.endian, verdef.index), |
| vd_cnt: U16::new(self.endian, verdef.aux_count), |
| vd_hash: U32::new(self.endian, elf::hash(self.dynstr.get_string(verdef.name))), |
| vd_aux: U32::new(self.endian, vd_aux), |
| vd_next: U32::new(self.endian, vd_next), |
| }); |
| self.write_gnu_verdaux(verdef.name); |
| } |
| |
| /// Write a version definition auxiliary entry. |
| pub fn write_gnu_verdaux(&mut self, name: StringId) { |
| debug_assert_ne!(self.gnu_verdaux_remaining, 0); |
| self.gnu_verdaux_remaining -= 1; |
| let vda_next = if self.gnu_verdaux_remaining == 0 { |
| 0 |
| } else { |
| mem::size_of::<elf::Verdaux<Endianness>>() as u32 |
| }; |
| self.buffer.write(&elf::Verdaux { |
| vda_name: U32::new(self.endian, self.dynstr.get_offset(name) as u32), |
| vda_next: U32::new(self.endian, vda_next), |
| }); |
| } |
| |
| /// Reserve the section index for the `.gnu.version_d` section. |
| pub fn reserve_gnu_verdef_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.gnu_verdef_str_id.is_none()); |
| self.gnu_verdef_str_id = Some(self.add_section_name(&b".gnu.version_d"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the `.gnu.version_d` section. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_gnu_verdef_section_header(&mut self, sh_addr: u64) { |
| if self.gnu_verdef_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.gnu_verdef_str_id, |
| sh_type: elf::SHT_GNU_VERDEF, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.gnu_verdef_offset as u64, |
| sh_size: self.gnu_verdef_size as u64, |
| sh_link: self.dynstr_index.0, |
| sh_info: self.gnu_verdef_count.into(), |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Reserve the range for the `.gnu.version_r` section. |
| pub fn reserve_gnu_verneed(&mut self, verneed_count: usize, vernaux_count: usize) { |
| debug_assert_eq!(self.gnu_verneed_offset, 0); |
| if verneed_count == 0 { |
| return; |
| } |
| self.gnu_verneed_size = verneed_count * mem::size_of::<elf::Verneed<Endianness>>() |
| + vernaux_count * mem::size_of::<elf::Vernaux<Endianness>>(); |
| self.gnu_verneed_offset = self.reserve(self.gnu_verneed_size, self.elf_align); |
| self.gnu_verneed_count = verneed_count as u16; |
| self.gnu_verneed_remaining = self.gnu_verneed_count; |
| } |
| |
| /// Write alignment padding bytes prior to a `.gnu.version_r` section. |
| pub fn write_align_gnu_verneed(&mut self) { |
| if self.gnu_verneed_offset == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.gnu_verneed_offset, self.buffer.len()); |
| } |
| |
| /// Write a version need entry. |
| pub fn write_gnu_verneed(&mut self, verneed: &Verneed) { |
| debug_assert_ne!(self.gnu_verneed_remaining, 0); |
| self.gnu_verneed_remaining -= 1; |
| let vn_next = if self.gnu_verneed_remaining == 0 { |
| 0 |
| } else { |
| mem::size_of::<elf::Verneed<Endianness>>() as u32 |
| + verneed.aux_count as u32 * mem::size_of::<elf::Vernaux<Endianness>>() as u32 |
| }; |
| |
| self.gnu_vernaux_remaining = verneed.aux_count; |
| let vn_aux = if verneed.aux_count == 0 { |
| 0 |
| } else { |
| mem::size_of::<elf::Verneed<Endianness>>() as u32 |
| }; |
| |
| self.buffer.write(&elf::Verneed { |
| vn_version: U16::new(self.endian, verneed.version), |
| vn_cnt: U16::new(self.endian, verneed.aux_count), |
| vn_file: U32::new(self.endian, self.dynstr.get_offset(verneed.file) as u32), |
| vn_aux: U32::new(self.endian, vn_aux), |
| vn_next: U32::new(self.endian, vn_next), |
| }); |
| } |
| |
| /// Write a version need auxiliary entry. |
| pub fn write_gnu_vernaux(&mut self, vernaux: &Vernaux) { |
| debug_assert_ne!(self.gnu_vernaux_remaining, 0); |
| self.gnu_vernaux_remaining -= 1; |
| let vna_next = if self.gnu_vernaux_remaining == 0 { |
| 0 |
| } else { |
| mem::size_of::<elf::Vernaux<Endianness>>() as u32 |
| }; |
| self.buffer.write(&elf::Vernaux { |
| vna_hash: U32::new(self.endian, elf::hash(self.dynstr.get_string(vernaux.name))), |
| vna_flags: U16::new(self.endian, vernaux.flags), |
| vna_other: U16::new(self.endian, vernaux.index), |
| vna_name: U32::new(self.endian, self.dynstr.get_offset(vernaux.name) as u32), |
| vna_next: U32::new(self.endian, vna_next), |
| }); |
| } |
| |
| /// Reserve the section index for the `.gnu.version_r` section. |
| pub fn reserve_gnu_verneed_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.gnu_verneed_str_id.is_none()); |
| self.gnu_verneed_str_id = Some(self.add_section_name(&b".gnu.version_r"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Write the section header for the `.gnu.version_r` section. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_gnu_verneed_section_header(&mut self, sh_addr: u64) { |
| if self.gnu_verneed_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.gnu_verneed_str_id, |
| sh_type: elf::SHT_GNU_VERNEED, |
| sh_flags: elf::SHF_ALLOC.into(), |
| sh_addr, |
| sh_offset: self.gnu_verneed_offset as u64, |
| sh_size: self.gnu_verneed_size as u64, |
| sh_link: self.dynstr_index.0, |
| sh_info: self.gnu_verneed_count.into(), |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Reserve the section index for the `.gnu.attributes` section. |
| pub fn reserve_gnu_attributes_section_index(&mut self) -> SectionIndex { |
| debug_assert!(self.gnu_attributes_str_id.is_none()); |
| self.gnu_attributes_str_id = Some(self.add_section_name(&b".gnu.attributes"[..])); |
| self.reserve_section_index() |
| } |
| |
| /// Reserve the range for the `.gnu.attributes` section. |
| pub fn reserve_gnu_attributes(&mut self, gnu_attributes_size: usize) { |
| debug_assert_eq!(self.gnu_attributes_offset, 0); |
| if gnu_attributes_size == 0 { |
| return; |
| } |
| self.gnu_attributes_size = gnu_attributes_size; |
| self.gnu_attributes_offset = self.reserve(self.gnu_attributes_size, self.elf_align); |
| } |
| |
| /// Write the section header for the `.gnu.attributes` section. |
| /// |
| /// This function does nothing if the section index was not reserved. |
| pub fn write_gnu_attributes_section_header(&mut self) { |
| if self.gnu_attributes_str_id.is_none() { |
| return; |
| } |
| self.write_section_header(&SectionHeader { |
| name: self.gnu_attributes_str_id, |
| sh_type: elf::SHT_GNU_ATTRIBUTES, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: self.gnu_attributes_offset as u64, |
| sh_size: self.gnu_attributes_size as u64, |
| sh_link: self.dynstr_index.0, |
| sh_info: 0, // TODO |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: 0, |
| }); |
| } |
| |
| /// Write the data for the `.gnu.attributes` section. |
| pub fn write_gnu_attributes(&mut self, data: &[u8]) { |
| if self.gnu_attributes_offset == 0 { |
| return; |
| } |
| util::write_align(self.buffer, self.elf_align); |
| debug_assert_eq!(self.gnu_attributes_offset, self.buffer.len()); |
| self.buffer.write_bytes(data); |
| } |
| |
| /// Reserve a file range for the given number of relocations. |
| /// |
| /// Returns the offset of the range. |
| pub fn reserve_relocations(&mut self, count: usize, is_rela: bool) -> usize { |
| self.reserve(count * self.rel_size(is_rela), self.elf_align) |
| } |
| |
| /// Write alignment padding bytes prior to a relocation section. |
| pub fn write_align_relocation(&mut self) { |
| util::write_align(self.buffer, self.elf_align); |
| } |
| |
| /// Write a relocation. |
| pub fn write_relocation(&mut self, is_rela: bool, rel: &Rel) { |
| let endian = self.endian; |
| if self.is_64 { |
| if is_rela { |
| let rel = elf::Rela64 { |
| r_offset: U64::new(endian, rel.r_offset), |
| r_info: elf::Rela64::r_info(endian, self.is_mips64el, rel.r_sym, rel.r_type), |
| r_addend: I64::new(endian, rel.r_addend), |
| }; |
| self.buffer.write(&rel); |
| } else { |
| let rel = elf::Rel64 { |
| r_offset: U64::new(endian, rel.r_offset), |
| r_info: elf::Rel64::r_info(endian, rel.r_sym, rel.r_type), |
| }; |
| self.buffer.write(&rel); |
| } |
| } else { |
| if is_rela { |
| let rel = elf::Rela32 { |
| r_offset: U32::new(endian, rel.r_offset as u32), |
| r_info: elf::Rel32::r_info(endian, rel.r_sym, rel.r_type as u8), |
| r_addend: I32::new(endian, rel.r_addend as i32), |
| }; |
| self.buffer.write(&rel); |
| } else { |
| let rel = elf::Rel32 { |
| r_offset: U32::new(endian, rel.r_offset as u32), |
| r_info: elf::Rel32::r_info(endian, rel.r_sym, rel.r_type as u8), |
| }; |
| self.buffer.write(&rel); |
| } |
| } |
| } |
| |
| /// Write the section header for a relocation section. |
| /// |
| /// `section` is the index of the section the relocations apply to, |
| /// or 0 if none. |
| /// |
| /// `symtab` is the index of the symbol table the relocations refer to, |
| /// or 0 if none. |
| /// |
| /// `offset` is the file offset of the relocations. |
| pub fn write_relocation_section_header( |
| &mut self, |
| name: StringId, |
| section: SectionIndex, |
| symtab: SectionIndex, |
| offset: usize, |
| count: usize, |
| is_rela: bool, |
| ) { |
| self.write_section_header(&SectionHeader { |
| name: Some(name), |
| sh_type: if is_rela { elf::SHT_RELA } else { elf::SHT_REL }, |
| sh_flags: elf::SHF_INFO_LINK.into(), |
| sh_addr: 0, |
| sh_offset: offset as u64, |
| sh_size: (count * self.rel_size(is_rela)) as u64, |
| sh_link: symtab.0, |
| sh_info: section.0, |
| sh_addralign: self.elf_align as u64, |
| sh_entsize: self.rel_size(is_rela) as u64, |
| }); |
| } |
| |
| /// Reserve a file range for a COMDAT section. |
| /// |
| /// `count` is the number of sections in the COMDAT group. |
| /// |
| /// Returns the offset of the range. |
| pub fn reserve_comdat(&mut self, count: usize) -> usize { |
| self.reserve((count + 1) * 4, 4) |
| } |
| |
| /// Write `GRP_COMDAT` at the start of the COMDAT section. |
| pub fn write_comdat_header(&mut self) { |
| util::write_align(self.buffer, 4); |
| self.buffer.write(&U32::new(self.endian, elf::GRP_COMDAT)); |
| } |
| |
| /// Write an entry in a COMDAT section. |
| pub fn write_comdat_entry(&mut self, entry: SectionIndex) { |
| self.buffer.write(&U32::new(self.endian, entry.0)); |
| } |
| |
| /// Write the section header for a COMDAT section. |
| pub fn write_comdat_section_header( |
| &mut self, |
| name: StringId, |
| symtab: SectionIndex, |
| symbol: SymbolIndex, |
| offset: usize, |
| count: usize, |
| ) { |
| self.write_section_header(&SectionHeader { |
| name: Some(name), |
| sh_type: elf::SHT_GROUP, |
| sh_flags: 0, |
| sh_addr: 0, |
| sh_offset: offset as u64, |
| sh_size: ((count + 1) * 4) as u64, |
| sh_link: symtab.0, |
| sh_info: symbol.0, |
| sh_addralign: 4, |
| sh_entsize: 4, |
| }); |
| } |
| |
| /// Return a helper for writing an attributes section. |
| pub fn attributes_writer(&self) -> AttributesWriter { |
| AttributesWriter::new(self.endian) |
| } |
| } |
| |
| /// A helper for writing an attributes section. |
| /// |
| /// Attributes have a variable length encoding, so it is awkward to write them in a |
| /// single pass. Instead, we build the entire attributes section data in memory, using |
| /// placeholders for unknown lengths that are filled in later. |
| #[allow(missing_debug_implementations)] |
| pub struct AttributesWriter { |
| endian: Endianness, |
| data: Vec<u8>, |
| subsection_offset: usize, |
| subsubsection_offset: usize, |
| } |
| |
| impl AttributesWriter { |
| /// Create a new `AttributesWriter` for the given endianness. |
| pub fn new(endian: Endianness) -> Self { |
| AttributesWriter { |
| endian, |
| data: vec![0x41], |
| subsection_offset: 0, |
| subsubsection_offset: 0, |
| } |
| } |
| |
| /// Start a new subsection with the given vendor name. |
| pub fn start_subsection(&mut self, vendor: &[u8]) { |
| debug_assert_eq!(self.subsection_offset, 0); |
| debug_assert_eq!(self.subsubsection_offset, 0); |
| self.subsection_offset = self.data.len(); |
| self.data.extend_from_slice(&[0; 4]); |
| self.data.extend_from_slice(vendor); |
| self.data.push(0); |
| } |
| |
| /// End the subsection. |
| /// |
| /// The subsection length is automatically calculated and written. |
| pub fn end_subsection(&mut self) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_eq!(self.subsubsection_offset, 0); |
| let length = self.data.len() - self.subsection_offset; |
| self.data[self.subsection_offset..][..4] |
| .copy_from_slice(pod::bytes_of(&U32::new(self.endian, length as u32))); |
| self.subsection_offset = 0; |
| } |
| |
| /// Start a new sub-subsection with the given tag. |
| pub fn start_subsubsection(&mut self, tag: u8) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_eq!(self.subsubsection_offset, 0); |
| self.subsubsection_offset = self.data.len(); |
| self.data.push(tag); |
| self.data.extend_from_slice(&[0; 4]); |
| } |
| |
| /// Write a section or symbol index to the sub-subsection. |
| /// |
| /// The user must also call this function to write the terminating 0 index. |
| pub fn write_subsubsection_index(&mut self, index: u32) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| util::write_uleb128(&mut self.data, u64::from(index)); |
| } |
| |
| /// Write raw index data to the sub-subsection. |
| /// |
| /// The terminating 0 index is automatically written. |
| pub fn write_subsubsection_indices(&mut self, indices: &[u8]) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| self.data.extend_from_slice(indices); |
| self.data.push(0); |
| } |
| |
| /// Write an attribute tag to the sub-subsection. |
| pub fn write_attribute_tag(&mut self, tag: u64) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| util::write_uleb128(&mut self.data, tag); |
| } |
| |
| /// Write an attribute integer value to the sub-subsection. |
| pub fn write_attribute_integer(&mut self, value: u64) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| util::write_uleb128(&mut self.data, value); |
| } |
| |
| /// Write an attribute string value to the sub-subsection. |
| /// |
| /// The value must not include the null terminator. |
| pub fn write_attribute_string(&mut self, value: &[u8]) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| self.data.extend_from_slice(value); |
| self.data.push(0); |
| } |
| |
| /// Write raw attribute data to the sub-subsection. |
| pub fn write_subsubsection_attributes(&mut self, attributes: &[u8]) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| self.data.extend_from_slice(attributes); |
| } |
| |
| /// End the sub-subsection. |
| /// |
| /// The sub-subsection length is automatically calculated and written. |
| pub fn end_subsubsection(&mut self) { |
| debug_assert_ne!(self.subsection_offset, 0); |
| debug_assert_ne!(self.subsubsection_offset, 0); |
| let length = self.data.len() - self.subsubsection_offset; |
| self.data[self.subsubsection_offset + 1..][..4] |
| .copy_from_slice(pod::bytes_of(&U32::new(self.endian, length as u32))); |
| self.subsubsection_offset = 0; |
| } |
| |
| /// Return the completed section data. |
| pub fn data(self) -> Vec<u8> { |
| debug_assert_eq!(self.subsection_offset, 0); |
| debug_assert_eq!(self.subsubsection_offset, 0); |
| self.data |
| } |
| } |
| |
| /// Native endian version of [`elf::FileHeader64`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct FileHeader { |
| pub os_abi: u8, |
| pub abi_version: u8, |
| pub e_type: u16, |
| pub e_machine: u16, |
| pub e_entry: u64, |
| pub e_flags: u32, |
| } |
| |
| /// Native endian version of [`elf::ProgramHeader64`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct ProgramHeader { |
| pub p_type: u32, |
| pub p_flags: u32, |
| pub p_offset: u64, |
| pub p_vaddr: u64, |
| pub p_paddr: u64, |
| pub p_filesz: u64, |
| pub p_memsz: u64, |
| pub p_align: u64, |
| } |
| |
| /// Native endian version of [`elf::SectionHeader64`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct SectionHeader { |
| pub name: Option<StringId>, |
| pub sh_type: u32, |
| pub sh_flags: u64, |
| pub sh_addr: u64, |
| pub sh_offset: u64, |
| pub sh_size: u64, |
| pub sh_link: u32, |
| pub sh_info: u32, |
| pub sh_addralign: u64, |
| pub sh_entsize: u64, |
| } |
| |
| /// Native endian version of [`elf::Sym64`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct Sym { |
| pub name: Option<StringId>, |
| pub section: Option<SectionIndex>, |
| pub st_info: u8, |
| pub st_other: u8, |
| pub st_shndx: u16, |
| pub st_value: u64, |
| pub st_size: u64, |
| } |
| |
| /// Unified native endian version of [`elf::Rel64`] and [`elf::Rela64`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct Rel { |
| pub r_offset: u64, |
| pub r_sym: u32, |
| pub r_type: u32, |
| pub r_addend: i64, |
| } |
| |
| /// Information required for writing [`elf::Verdef`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct Verdef { |
| pub version: u16, |
| pub flags: u16, |
| pub index: u16, |
| pub aux_count: u16, |
| /// The name for the first [`elf::Verdaux`] entry. |
| pub name: StringId, |
| } |
| |
| /// Information required for writing [`elf::Verneed`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct Verneed { |
| pub version: u16, |
| pub aux_count: u16, |
| pub file: StringId, |
| } |
| |
| /// Information required for writing [`elf::Vernaux`]. |
| #[allow(missing_docs)] |
| #[derive(Debug, Clone)] |
| pub struct Vernaux { |
| pub flags: u16, |
| pub index: u16, |
| pub name: StringId, |
| } |
