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Merge pull request #23 from ChrisDenton/rename
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Make the null import descriptor name unique to the import library
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@bjorn3
bjorn3 authored Aug 19, 2024
2 parents c61dc95 + 870962c commit b54f093
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Showing 3 changed files with 63 additions and 77 deletions.
2 changes: 1 addition & 1 deletion src/archive_writer.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -542,7 +542,7 @@ fn write_ec_symbols<W: Write + Seek>(w: &mut W, sym_map: &SymMap) -> io::Result<

fn is_import_descriptor(name: &[u8]) -> bool {
name.starts_with(coff_import_file::IMPORT_DESCRIPTOR_PREFIX)
|| name == coff_import_file::NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME
|| name.starts_with(coff_import_file::NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME)
|| (name.starts_with(coff_import_file::NULL_THUNK_DATA_PREFIX)
&& name.ends_with(coff_import_file::NULL_THUNK_DATA_SUFFIX))
}
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78 changes: 31 additions & 47 deletions src/coff_import_file.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -10,13 +10,12 @@ use std::path::PathBuf;
use std::str::from_utf8;

use object::pe::{
ImageAuxSymbolSection, ImageFileHeader, ImageImportDescriptor, ImageRelocation,
ImageSectionHeader, ImageSymbol, ImportObjectHeader, IMAGE_COMDAT_SELECT_ANY,
IMAGE_FILE_32BIT_MACHINE, IMAGE_REL_AMD64_ADDR32NB, IMAGE_REL_ARM64_ADDR32NB,
IMAGE_REL_ARM_ADDR32NB, IMAGE_REL_I386_DIR32NB, IMAGE_SCN_ALIGN_2BYTES, IMAGE_SCN_ALIGN_4BYTES,
IMAGE_SCN_ALIGN_8BYTES, IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_LNK_COMDAT,
IMAGE_SCN_LNK_INFO, IMAGE_SCN_LNK_REMOVE, IMAGE_SCN_MEM_READ, IMAGE_SCN_MEM_WRITE,
IMAGE_SYM_CLASS_EXTERNAL, IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_SECTION,
ImageFileHeader, ImageImportDescriptor, ImageRelocation, ImageSectionHeader, ImageSymbol,
ImportObjectHeader, IMAGE_FILE_32BIT_MACHINE, IMAGE_REL_AMD64_ADDR32NB,
IMAGE_REL_ARM64_ADDR32NB, IMAGE_REL_ARM_ADDR32NB, IMAGE_REL_I386_DIR32NB,
IMAGE_SCN_ALIGN_2BYTES, IMAGE_SCN_ALIGN_4BYTES, IMAGE_SCN_ALIGN_8BYTES,
IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_LNK_INFO, IMAGE_SCN_LNK_REMOVE, IMAGE_SCN_MEM_READ,
IMAGE_SCN_MEM_WRITE, IMAGE_SYM_CLASS_EXTERNAL, IMAGE_SYM_CLASS_NULL, IMAGE_SYM_CLASS_SECTION,
IMAGE_SYM_CLASS_STATIC, IMAGE_SYM_CLASS_WEAK_EXTERNAL, IMAGE_WEAK_EXTERN_SEARCH_ALIAS,
};
use object::pod::bytes_of;
Expand All @@ -27,6 +26,7 @@ use crate::{write_archive_to_stream, ArchiveKind, NewArchiveMember, DEFAULT_OBJE

pub(crate) const IMPORT_DESCRIPTOR_PREFIX: &[u8] = b"__IMPORT_DESCRIPTOR_";
pub(crate) const NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME: &[u8] = b"__NULL_IMPORT_DESCRIPTOR";
pub(crate) const NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME_PREFIX: &[u8] = b"__NULL_IMPORT_DESCRIPTOR_";
pub(crate) const NULL_THUNK_DATA_PREFIX: &[u8] = b"\x7f";
pub(crate) const NULL_THUNK_DATA_SUFFIX: &[u8] = b"_NULL_THUNK_DATA";

Expand Down Expand Up @@ -209,10 +209,11 @@ struct ObjectFactory<'a> {
import_name: &'a str,
import_descriptor_symbol_name: Vec<u8>,
null_thunk_symbol_name: Vec<u8>,
null_import_descriptor_symbol_name: Vec<u8>,
}

impl<'a> ObjectFactory<'a> {
fn new(s: &'a str, m: MachineTypes) -> Result<Self> {
fn new(s: &'a str, m: MachineTypes, whole_archive_compat: bool) -> Result<Self> {
let import_as_path = PathBuf::from(s);
let library = import_as_path
.file_stem()
Expand All @@ -239,6 +240,15 @@ impl<'a> ObjectFactory<'a> {
.chain(NULL_THUNK_DATA_SUFFIX)
.copied()
.collect(),
null_import_descriptor_symbol_name: if whole_archive_compat {
NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME_PREFIX
.iter()
.chain(library)
.copied()
.collect()
} else {
NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME.into()
},
})
}

Expand Down Expand Up @@ -439,7 +449,7 @@ impl<'a> ObjectFactory<'a> {
size_of::<u32>()
+ self.import_descriptor_symbol_name.len()
+ 1
+ NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME.len()
+ self.null_import_descriptor_symbol_name.len()
+ 1,
);
buffer.write_all(bytes_of(&symbol_table))?;
Expand All @@ -449,7 +459,7 @@ impl<'a> ObjectFactory<'a> {
&mut buffer,
&[
&self.import_descriptor_symbol_name,
NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME,
&self.null_import_descriptor_symbol_name,
&self.null_thunk_symbol_name,
],
)?;
Expand All @@ -464,14 +474,11 @@ impl<'a> ObjectFactory<'a> {
/// Creates a NULL import descriptor. This is a small object file whcih
/// contains a NULL import descriptor. It is used to terminate the imports
/// from a specific DLL.
///
/// If `comdat` is set to true, the NULL import descriptor's section (`.idata$3`) will be
/// turned into a COMDAT section.
fn create_null_import_descriptor(&self, comdat: bool) -> Result<NewArchiveMember<'_>> {
fn create_null_import_descriptor(&self) -> Result<NewArchiveMember<'_>> {
let mut buffer = Vec::new();

const NUMBER_OF_SECTIONS: usize = 1;
let number_of_symbols = if comdat { 3 } else { 1 };
const NUMBER_OF_SYMBOLS: usize = 1;

// COFF Header
let header = ImageFileHeader {
Expand All @@ -481,7 +488,7 @@ impl<'a> ObjectFactory<'a> {
pointer_to_symbol_table: u32!((size_of::<ImageFileHeader>() + (NUMBER_OF_SECTIONS * size_of::<ImageSectionHeader>()) +
// .idata$3
size_of::<ImageImportDescriptor>()).try_into().unwrap()),
number_of_symbols: u32!(number_of_symbols.try_into().unwrap()),
number_of_symbols: u32!(NUMBER_OF_SYMBOLS.try_into().unwrap()),
size_of_optional_header: u16!(0),
characteristics: u16!(if self.is_64_bit() {
0
Expand Down Expand Up @@ -510,7 +517,6 @@ impl<'a> ObjectFactory<'a> {
| IMAGE_SCN_CNT_INITIALIZED_DATA
| IMAGE_SCN_MEM_READ
| IMAGE_SCN_MEM_WRITE
| if comdat { IMAGE_SCN_LNK_COMDAT } else { 0 }
),
}];
buffer.write_all(bytes_of(&section_table))?;
Expand All @@ -526,41 +532,19 @@ impl<'a> ObjectFactory<'a> {
buffer.write_all(bytes_of(&import_descriptor))?;

// Symbol Table
if comdat {
let symbol = ImageSymbol {
name: *b".idata$3",
value: u32!(0),
section_number: u16!(1),
typ: u16!(0),
storage_class: IMAGE_SYM_CLASS_STATIC,
number_of_aux_symbols: 1,
};
let aux = ImageAuxSymbolSection {
length: u32!(size_of::<ImageImportDescriptor>().try_into().unwrap()),
number_of_relocations: u16!(0),
number_of_linenumbers: u16!(0),
check_sum: u32!(0),
selection: IMAGE_COMDAT_SELECT_ANY,
number: u16!(0),
reserved: 0,
high_number: u16!(0),
};
buffer.write_all(bytes_of(&symbol))?;
buffer.write_all(bytes_of(&aux))?;
}
let mut null_descriptor_symbol = ImageSymbol {
let mut symbol_table: [_; NUMBER_OF_SYMBOLS] = [ImageSymbol {
name: [0; 8],
value: u32!(0),
section_number: u16!(1),
typ: u16!(0),
storage_class: IMAGE_SYM_CLASS_EXTERNAL,
number_of_aux_symbols: 0,
};
set_name_to_string_table_entry(&mut null_descriptor_symbol, size_of::<u32>());
buffer.write_all(bytes_of(&null_descriptor_symbol))?;
}];
set_name_to_string_table_entry(&mut symbol_table[0], size_of::<u32>());
buffer.write_all(bytes_of(&symbol_table))?;

// String Table
write_string_table(&mut buffer, &[NULL_IMPORT_DESCRIPTOR_SYMBOL_NAME])?;
write_string_table(&mut buffer, &[&self.null_import_descriptor_symbol_name])?;

Ok(NewArchiveMember::new(
buffer.into_boxed_slice(),
Expand Down Expand Up @@ -853,20 +837,20 @@ pub fn write_import_library<W: Write + Seek>(
exports: &[COFFShortExport],
machine: MachineTypes,
mingw: bool,
comdat: bool,
whole_archive_compat: bool,
) -> Result<()> {
let native_machine = if machine == MachineTypes::ARM64EC {
MachineTypes::ARM64
} else {
machine
};

let of = ObjectFactory::new(import_name, native_machine)?;
let of = ObjectFactory::new(import_name, native_machine, whole_archive_compat)?;
let mut members = Vec::new();

members.push(of.create_import_descriptor()?);

members.push(of.create_null_import_descriptor(comdat)?);
members.push(of.create_null_import_descriptor()?);

members.push(of.create_null_thunk()?);

Expand Down
60 changes: 31 additions & 29 deletions tests/import_library.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,10 +5,10 @@ use std::process::Command;

use ar_archive_writer::{ArchiveKind, COFFShortExport, MachineTypes};
use common::{create_archive_with_ar_archive_writer, create_archive_with_llvm_ar};
use object::coff::CoffHeader;
use object::coff::CoffFile;
use object::pe::ImageFileHeader;
use object::read::archive::ArchiveFile;
use object::{bytes_of, Architecture, Object, SubArchitecture, U32Bytes};
use object::{bytes_of, Architecture, Object, ObjectSection, ObjectSymbol, SubArchitecture};
use pretty_assertions::assert_eq;

mod common;
Expand Down Expand Up @@ -305,43 +305,45 @@ fn compare_comdat(archive_writer_bytes: &[u8], llvm_bytes: &[u8]) {
let archive_member = archive_member.unwrap();
let llvm_member = llvm_member.unwrap();

// skip the EC symbols table.
if archive_member.name() == b"/<ECSYMBOLS>/" {
continue;
}

if archive_member.size() != llvm_member.size() {
// Ensure that the member header is the same except for the file size.
let mut llvm_file_header = *llvm_member.header().unwrap();
llvm_file_header.size = *b"163 ";
llvm_file_header.size = archive_member.header().unwrap().size;
assert_eq!(
bytes_of(archive_member.header().unwrap()),
bytes_of(&llvm_file_header)
);

// Ensure that the LLVM generated object contains .idata$3
object::File::parse(llvm_member.data(llvm_bytes).unwrap())
.unwrap()
.section_by_name_bytes(b".idata$3")
.unwrap();

// Ensure the COFF file headers are the same except for the symbol count.
let llvm_data = llvm_member.data(llvm_bytes).unwrap();
// Make sure they are both COFF files with the same sections and symbols,
// except for the different naming for the null import descriptor.
let archive_data = archive_member.data(archive_writer_bytes).unwrap();
let mut offset = 0;
let mut header = *ImageFileHeader::parse(llvm_data, &mut offset).unwrap();
header.number_of_symbols = U32Bytes::from_bytes(3_u32.to_le_bytes());
assert_eq!(
&archive_data[..size_of::<ImageFileHeader>()],
bytes_of(&header)
);
let llvm_data = llvm_member.data(llvm_bytes).unwrap();
let archive_file = CoffFile::<_, ImageFileHeader>::parse(archive_data).unwrap();
let llvm_file = CoffFile::<_, ImageFileHeader>::parse(llvm_data).unwrap();

// The rest of the object file will always be the same as `expected`
// for all import files no matter the platform.
let expected = [
46, 105, 100, 97, 116, 97, 36, 51, 0, 0, 0, 0, 0, 0, 0, 0, 20, 0, 0, 0, 60, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 64, 16, 48, 192, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 46, 105, 100, 97, 116, 97, 36, 51, 0, 0, 0, 0, 1,
0, 0, 0, 3, 1, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0,
4, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 29, 0, 0, 0, 95, 95, 78, 85, 76, 76, 95,
73, 77, 80, 79, 82, 84, 95, 68, 69, 83, 67, 82, 73, 80, 84, 79, 82, 0,
];
assert_eq!(&archive_data[size_of::<ImageFileHeader>()..], &expected);
for (archive_section, llvm_section) in archive_file.sections().zip(llvm_file.sections())
{
assert_eq!(archive_section.data(), llvm_section.data());
}
for (archive_symbol, llvm_symbol) in archive_file.symbols().zip(llvm_file.symbols()) {
if llvm_symbol.name().unwrap() == "__NULL_IMPORT_DESCRIPTOR" {
assert!(archive_symbol
.name()
.unwrap()
.starts_with("__NULL_IMPORT_DESCRIPTOR_"));
} else {
assert_eq!(archive_symbol.name(), llvm_symbol.name());
}
let archive_coff_symbol = archive_symbol.coff_symbol();
let mut llvm_coff_symbol = *llvm_symbol.coff_symbol();
llvm_coff_symbol.name = archive_coff_symbol.name;
assert_eq!(bytes_of(archive_coff_symbol), bytes_of(&llvm_coff_symbol));
}
} else {
assert_eq!(
bytes_of(archive_member.header().unwrap()),
Expand Down

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