Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 518 insertions, 0 deletions

diff --git a/vendor/object/src/write/coff/writer.rs b/vendor/object/src/write/coff/writer.rs
new file mode 100644
index 0000000..8c7ada3
--- /dev/null
+++ b/vendor/object/src/write/coff/writer.rs
@@ -0,0 +1,518 @@
+//! Helper for writing COFF files.
+use alloc::string::String;
+use alloc::vec::Vec;
+use core::mem;
+
+use crate::endian::{LittleEndian as LE, U16Bytes, U32Bytes, U16, U32};
+use crate::pe;
+use crate::write::string::{StringId, StringTable};
+use crate::write::util;
+use crate::write::{Error, Result, WritableBuffer};
+
+/// A helper for writing COFF 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 table
+/// - 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 the string table before reserving the file range for the string table. 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> {
+    buffer: &'a mut dyn WritableBuffer,
+    len: usize,
+
+    section_num: u16,
+
+    symtab_offset: u32,
+    symtab_num: u32,
+
+    strtab: StringTable<'a>,
+    strtab_len: usize,
+    strtab_offset: u32,
+    strtab_data: Vec<u8>,
+}
+
+impl<'a> Writer<'a> {
+    /// Create a new `Writer`.
+    pub fn new(buffer: &'a mut dyn WritableBuffer) -> Self {
+        Writer {
+            buffer,
+            len: 0,
+
+            section_num: 0,
+
+            symtab_offset: 0,
+            symtab_num: 0,
+
+            strtab: StringTable::default(),
+            strtab_len: 0,
+            strtab_offset: 0,
+            strtab_data: Vec::new(),
+        }
+    }
+
+    /// 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) -> u32 {
+        if align_start > 1 {
+            self.len = util::align(self.len, align_start);
+        }
+        let offset = self.len;
+        self.len += len;
+        offset as u32
+    }
+
+    /// 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.
+    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);
+    }
+
+    /// 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(mem::size_of::<pe::ImageFileHeader>(), 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);
+
+        // Start writing.
+        self.buffer
+            .reserve(self.len)
+            .map_err(|_| Error(String::from("Cannot allocate buffer")))?;
+
+        // Write file header.
+        let header = pe::ImageFileHeader {
+            machine: U16::new(LE, header.machine),
+            number_of_sections: U16::new(LE, self.section_num),
+            time_date_stamp: U32::new(LE, header.time_date_stamp),
+            pointer_to_symbol_table: U32::new(LE, self.symtab_offset),
+            number_of_symbols: U32::new(LE, self.symtab_num),
+            size_of_optional_header: U16::default(),
+            characteristics: U16::new(LE, header.characteristics),
+        };
+        self.buffer.write(&header);
+
+        Ok(())
+    }
+
+    /// Reserve the range for the section headers.
+    pub fn reserve_section_headers(&mut self, section_num: u16) {
+        debug_assert_eq!(self.section_num, 0);
+        self.section_num = section_num;
+        self.reserve(
+            section_num as usize * mem::size_of::<pe::ImageSectionHeader>(),
+            1,
+        );
+    }
+
+    /// Write a section header.
+    pub fn write_section_header(&mut self, section: SectionHeader) {
+        let mut coff_section = pe::ImageSectionHeader {
+            name: [0; 8],
+            virtual_size: U32::default(),
+            virtual_address: U32::default(),
+            size_of_raw_data: U32::new(LE, section.size_of_raw_data),
+            pointer_to_raw_data: U32::new(LE, section.pointer_to_raw_data),
+            pointer_to_relocations: U32::new(LE, section.pointer_to_relocations),
+            pointer_to_linenumbers: U32::new(LE, section.pointer_to_linenumbers),
+            number_of_relocations: if section.number_of_relocations > 0xffff {
+                U16::new(LE, 0xffff)
+            } else {
+                U16::new(LE, section.number_of_relocations as u16)
+            },
+            number_of_linenumbers: U16::default(),
+            characteristics: U32::new(LE, section.characteristics),
+        };
+        match section.name {
+            Name::Short(name) => coff_section.name = name,
+            Name::Long(str_id) => {
+                let mut str_offset = self.strtab.get_offset(str_id);
+                if str_offset <= 9_999_999 {
+                    let mut name = [0; 7];
+                    let mut len = 0;
+                    if str_offset == 0 {
+                        name[6] = b'0';
+                        len = 1;
+                    } else {
+                        while str_offset != 0 {
+                            let rem = (str_offset % 10) as u8;
+                            str_offset /= 10;
+                            name[6 - len] = b'0' + rem;
+                            len += 1;
+                        }
+                    }
+                    coff_section.name = [0; 8];
+                    coff_section.name[0] = b'/';
+                    coff_section.name[1..][..len].copy_from_slice(&name[7 - len..]);
+                } else {
+                    debug_assert!(str_offset as u64 <= 0xf_ffff_ffff);
+                    coff_section.name[0] = b'/';
+                    coff_section.name[1] = b'/';
+                    for i in 0..6 {
+                        let rem = (str_offset % 64) as u8;
+                        str_offset /= 64;
+                        let c = match rem {
+                            0..=25 => b'A' + rem,
+                            26..=51 => b'a' + rem - 26,
+                            52..=61 => b'0' + rem - 52,
+                            62 => b'+',
+                            63 => b'/',
+                            _ => unreachable!(),
+                        };
+                        coff_section.name[7 - i] = c;
+                    }
+                }
+            }
+        }
+        self.buffer.write(&coff_section);
+    }
+
+    /// Reserve the range for the section data.
+    ///
+    /// Returns the aligned offset of the start of the range.
+    /// Does nothing and returns 0 if the length is zero.
+    pub fn reserve_section(&mut self, len: usize) -> u32 {
+        if len == 0 {
+            return 0;
+        }
+        // TODO: not sure what alignment is required here, but this seems to match LLVM
+        self.reserve(len, 4)
+    }
+
+    /// Write the alignment bytes prior to section data.
+    ///
+    /// This is unneeded if you are using `write_section` or `write_section_zeroes`
+    /// for the data.
+    pub fn write_section_align(&mut self) {
+        util::write_align(self.buffer, 4);
+    }
+
+    /// Write the section data.
+    ///
+    /// Writes alignment bytes prior to the data.
+    /// Does nothing if the data is empty.
+    pub fn write_section(&mut self, data: &[u8]) {
+        if data.is_empty() {
+            return;
+        }
+        self.write_section_align();
+        self.buffer.write_bytes(data);
+    }
+
+    /// Write the section data using zero bytes.
+    ///
+    /// Writes alignment bytes prior to the data.
+    /// Does nothing if the length is zero.
+    pub fn write_section_zeroes(&mut self, len: usize) {
+        if len == 0 {
+            return;
+        }
+        self.write_section_align();
+        self.buffer.resize(self.buffer.len() + len);
+    }
+
+    /// Reserve a file range for the given number of relocations.
+    ///
+    /// This will automatically reserve an extra relocation if there are more than 0xffff.
+    ///
+    /// Returns the offset of the range.
+    /// Does nothing and returns 0 if the count is zero.
+    pub fn reserve_relocations(&mut self, mut count: usize) -> u32 {
+        if count == 0 {
+            return 0;
+        }
+        if count > 0xffff {
+            count += 1;
+        }
+        self.reserve(count * mem::size_of::<pe::ImageRelocation>(), 1)
+    }
+
+    /// Write a relocation containing the count if required.
+    ///
+    /// This should be called before writing the first relocation for a section.
+    pub fn write_relocations_count(&mut self, count: usize) {
+        if count > 0xffff {
+            let coff_relocation = pe::ImageRelocation {
+                virtual_address: U32Bytes::new(LE, count as u32 + 1),
+                symbol_table_index: U32Bytes::new(LE, 0),
+                typ: U16Bytes::new(LE, 0),
+            };
+            self.buffer.write(&coff_relocation);
+        }
+    }
+
+    /// Write a relocation.
+    pub fn write_relocation(&mut self, reloc: Relocation) {
+        let coff_relocation = pe::ImageRelocation {
+            virtual_address: U32Bytes::new(LE, reloc.virtual_address),
+            symbol_table_index: U32Bytes::new(LE, reloc.symbol),
+            typ: U16Bytes::new(LE, reloc.typ),
+        };
+        self.buffer.write(&coff_relocation);
+    }
+
+    /// Reserve a symbol table entry.
+    ///
+    /// This must be called before [`Self::reserve_symtab_strtab`].
+    pub fn reserve_symbol_index(&mut self) -> u32 {
+        debug_assert_eq!(self.symtab_offset, 0);
+        let index = self.symtab_num;
+        self.symtab_num += 1;
+        index
+    }
+
+    /// Reserve a number of symbol table entries.
+    pub fn reserve_symbol_indices(&mut self, count: u32) {
+        debug_assert_eq!(self.symtab_offset, 0);
+        self.symtab_num += count;
+    }
+
+    /// Write a symbol table entry.
+    pub fn write_symbol(&mut self, symbol: Symbol) {
+        let mut coff_symbol = pe::ImageSymbol {
+            name: [0; 8],
+            value: U32Bytes::new(LE, symbol.value),
+            section_number: U16Bytes::new(LE, symbol.section_number),
+            typ: U16Bytes::new(LE, symbol.typ),
+            storage_class: symbol.storage_class,
+            number_of_aux_symbols: symbol.number_of_aux_symbols,
+        };
+        match symbol.name {
+            Name::Short(name) => coff_symbol.name = name,
+            Name::Long(str_id) => {
+                let str_offset = self.strtab.get_offset(str_id);
+                coff_symbol.name[4..8].copy_from_slice(&u32::to_le_bytes(str_offset as u32));
+            }
+        }
+        self.buffer.write(&coff_symbol);
+    }
+
+    /// Reserve auxiliary symbols for a file name.
+    ///
+    /// Returns the number of auxiliary symbols required.
+    ///
+    /// This must be called before [`Self::reserve_symtab_strtab`].
+    pub fn reserve_aux_file_name(&mut self, name: &[u8]) -> u8 {
+        debug_assert_eq!(self.symtab_offset, 0);
+        let aux_count = (name.len() + pe::IMAGE_SIZEOF_SYMBOL - 1) / pe::IMAGE_SIZEOF_SYMBOL;
+        self.symtab_num += aux_count as u32;
+        aux_count as u8
+    }
+
+    /// Write auxiliary symbols for a file name.
+    pub fn write_aux_file_name(&mut self, name: &[u8], aux_count: u8) {
+        let aux_len = aux_count as usize * pe::IMAGE_SIZEOF_SYMBOL;
+        debug_assert!(aux_len >= name.len());
+        let old_len = self.buffer.len();
+        self.buffer.write_bytes(name);
+        self.buffer.resize(old_len + aux_len);
+    }
+
+    /// Reserve an auxiliary symbol for a section.
+    ///
+    /// Returns the number of auxiliary symbols required.
+    ///
+    /// This must be called before [`Self::reserve_symtab_strtab`].
+    pub fn reserve_aux_section(&mut self) -> u8 {
+        debug_assert_eq!(self.symtab_offset, 0);
+        self.symtab_num += 1;
+        1
+    }
+
+    /// Write an auxiliary symbol for a section.
+    pub fn write_aux_section(&mut self, section: AuxSymbolSection) {
+        let aux = pe::ImageAuxSymbolSection {
+            length: U32Bytes::new(LE, section.length),
+            number_of_relocations: if section.number_of_relocations > 0xffff {
+                U16Bytes::new(LE, 0xffff)
+            } else {
+                U16Bytes::new(LE, section.number_of_relocations as u16)
+            },
+            number_of_linenumbers: U16Bytes::new(LE, section.number_of_linenumbers),
+            check_sum: U32Bytes::new(LE, section.check_sum),
+            number: U16Bytes::new(LE, section.number as u16),
+            selection: section.selection,
+            reserved: 0,
+            high_number: U16Bytes::new(LE, (section.number >> 16) as u16),
+        };
+        self.buffer.write(&aux);
+    }
+
+    /// Return the number of reserved symbol table entries.
+    pub fn symbol_count(&self) -> u32 {
+        self.symtab_num
+    }
+
+    /// Add a string to the string table.
+    ///
+    /// This must be called before [`Self::reserve_symtab_strtab`].
+    pub fn add_string(&mut self, name: &'a [u8]) -> StringId {
+        debug_assert_eq!(self.strtab_offset, 0);
+        self.strtab.add(name)
+    }
+
+    /// Add a section or symbol name to the string table if required.
+    ///
+    /// This must be called before [`Self::reserve_symtab_strtab`].
+    pub fn add_name(&mut self, name: &'a [u8]) -> Name {
+        if name.len() > 8 {
+            Name::Long(self.add_string(name))
+        } else {
+            let mut short_name = [0; 8];
+            short_name[..name.len()].copy_from_slice(name);
+            Name::Short(short_name)
+        }
+    }
+
+    /// Reserve the range for the symbol table and string table.
+    ///
+    /// This must be called after functions that reserve symbol
+    /// indices or add strings.
+    pub fn reserve_symtab_strtab(&mut self) {
+        debug_assert_eq!(self.symtab_offset, 0);
+        self.symtab_offset = self.reserve(self.symtab_num as usize * pe::IMAGE_SIZEOF_SYMBOL, 1);
+
+        debug_assert_eq!(self.strtab_offset, 0);
+        // First 4 bytes of strtab are the length.
+        self.strtab.write(4, &mut self.strtab_data);
+        self.strtab_len = self.strtab_data.len() + 4;
+        self.strtab_offset = self.reserve(self.strtab_len, 1);
+    }
+
+    /// Write the string table.
+    pub fn write_strtab(&mut self) {
+        debug_assert_eq!(self.strtab_offset, self.buffer.len() as u32);
+        self.buffer
+            .write_bytes(&u32::to_le_bytes(self.strtab_len as u32));
+        self.buffer.write_bytes(&self.strtab_data);
+    }
+}
+
+/// Shortened and native endian version of [`pe::ImageFileHeader`].
+#[allow(missing_docs)]
+#[derive(Debug, Default, Clone)]
+pub struct FileHeader {
+    pub machine: u16,
+    pub time_date_stamp: u32,
+    pub characteristics: u16,
+}
+
+/// A section or symbol name.
+#[derive(Debug, Clone, Copy)]
+pub enum Name {
+    /// An inline name.
+    Short([u8; 8]),
+    /// An id of a string table entry.
+    Long(StringId),
+}
+
+impl Default for Name {
+    fn default() -> Name {
+        Name::Short([0; 8])
+    }
+}
+
+// From isn't useful.
+#[allow(clippy::from_over_into)]
+impl<'a> Into<Name> for &'a [u8; 8] {
+    fn into(self) -> Name {
+        Name::Short(*self)
+    }
+}
+
+/// Native endian version of [`pe::ImageSectionHeader`].
+#[allow(missing_docs)]
+#[derive(Debug, Default, Clone)]
+pub struct SectionHeader {
+    pub name: Name,
+    pub size_of_raw_data: u32,
+    pub pointer_to_raw_data: u32,
+    pub pointer_to_relocations: u32,
+    pub pointer_to_linenumbers: u32,
+    /// This will automatically be clamped if there are more than 0xffff.
+    pub number_of_relocations: u32,
+    pub number_of_linenumbers: u16,
+    pub characteristics: u32,
+}
+
+/// Native endian version of [`pe::ImageSymbol`].
+#[allow(missing_docs)]
+#[derive(Debug, Default, Clone)]
+pub struct Symbol {
+    pub name: Name,
+    pub value: u32,
+    pub section_number: u16,
+    pub typ: u16,
+    pub storage_class: u8,
+    pub number_of_aux_symbols: u8,
+}
+
+/// Native endian version of [`pe::ImageAuxSymbolSection`].
+#[allow(missing_docs)]
+#[derive(Debug, Default, Clone)]
+pub struct AuxSymbolSection {
+    pub length: u32,
+    /// This will automatically be clamped if there are more than 0xffff.
+    pub number_of_relocations: u32,
+    pub number_of_linenumbers: u16,
+    pub check_sum: u32,
+    pub number: u32,
+    pub selection: u8,
+}
+
+/// Native endian version of [`pe::ImageRelocation`].
+#[allow(missing_docs)]
+#[derive(Debug, Default, Clone)]
+pub struct Relocation {
+    pub virtual_address: u32,
+    pub symbol: u32,
+    pub typ: u16,
+}