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Avoid a temporary file when processing macOS fat archives
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alex committed Dec 3, 2022
1 parent 047c7cc commit bd8e476
Showing 1 changed file with 34 additions and 36 deletions.
70 changes: 34 additions & 36 deletions compiler/rustc_codegen_ssa/src/back/archive.rs
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ use tempfile::Builder as TempFileBuilder;

use std::error::Error;
use std::fs::File;
use std::io::{self, Write};
use std::io;
use std::path::{Path, PathBuf};

// Re-exporting for rustc_codegen_llvm::back::archive
Expand Down Expand Up @@ -116,51 +116,42 @@ impl<'a> ArArchiveBuilder<'a> {
}
}

fn try_filter_fat_archs(
fn try_filter_fat_archs<'a>(
archs: object::read::Result<&[impl FatArch]>,
target_arch: object::Architecture,
archive_path: &Path,
archive_map_data: &[u8],
) -> io::Result<Option<PathBuf>> {
archive_map_data: &'a [u8],
) -> io::Result<Option<(&'a [u8], u64)>> {
let archs = archs.map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;

let desired = match archs.iter().filter(|a| a.architecture() == target_arch).next() {
Some(a) => a,
None => return Ok(None),
};

let (mut new_f, extracted_path) = tempfile::Builder::new()
.suffix(archive_path.file_name().unwrap())
.tempfile()?
.keep()
.unwrap();

new_f.write_all(
Ok(Some((
desired.data(archive_map_data).map_err(|e| io::Error::new(io::ErrorKind::Other, e))?,
)?;

Ok(Some(extracted_path))
desired.offset().into(),
)))
}

pub fn try_extract_macho_fat_archive(
pub fn try_extract_macho_fat_archive<'a>(
sess: &Session,
archive_path: &Path,
) -> io::Result<Option<PathBuf>> {
let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
archive_bytes: &'a [u8],
) -> io::Result<Option<(&'a [u8], u64)>> {
let target_arch = match sess.target.arch.as_ref() {
"aarch64" => object::Architecture::Aarch64,
"x86_64" => object::Architecture::X86_64,
_ => return Ok(None),
};

match object::macho::FatHeader::parse(&*archive_map) {
match object::macho::FatHeader::parse(archive_bytes) {
Ok(h) if h.magic.get(object::endian::BigEndian) == object::macho::FAT_MAGIC => {
let archs = object::macho::FatHeader::parse_arch32(&*archive_map);
try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
let archs = object::macho::FatHeader::parse_arch32(archive_bytes);
try_filter_fat_archs(archs, target_arch, archive_bytes)
}
Ok(h) if h.magic.get(object::endian::BigEndian) == object::macho::FAT_MAGIC_64 => {
let archs = object::macho::FatHeader::parse_arch64(&*archive_map);
try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
let archs = object::macho::FatHeader::parse_arch64(archive_bytes);
try_filter_fat_archs(archs, target_arch, archive_bytes)
}
// Not a FatHeader at all, just return None.
_ => Ok(None),
Expand All @@ -173,21 +164,24 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
archive_path: &Path,
mut skip: Box<dyn FnMut(&str) -> bool + 'static>,
) -> io::Result<()> {
let mut archive_path = archive_path.to_path_buf();
if self.sess.target.llvm_target.contains("-apple-macosx") {
if let Some(new_archive_path) =
try_extract_macho_fat_archive(&self.sess, &archive_path)?
{
archive_path = new_archive_path
}
}

let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
if self.src_archives.iter().any(|archive| archive.0 == archive_path) {
return Ok(());
}

let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
let archive = ArchiveFile::parse(&*archive_map)
let (archive_bytes, offset) = if self.sess.target.llvm_target.contains("-apple-macosx") {
if let Some((sub_archive, archive_offset)) =
try_extract_macho_fat_archive(&self.sess, &*archive_map)?
{
(sub_archive, Some(archive_offset))
} else {
(&*archive_map, None)
}
} else {
(&*archive_map, None)
};

let archive = ArchiveFile::parse(&*archive_bytes)
.map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
let archive_index = self.src_archives.len();

Expand All @@ -196,9 +190,13 @@ impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
let file_name = String::from_utf8(entry.name().to_vec())
.map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
if !skip(&file_name) {
let mut range = entry.file_range();
if let Some(offset) = offset {
range.0 += offset;
}
self.entries.push((
file_name.into_bytes(),
ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
ArchiveEntry::FromArchive { archive_index, file_range: range },
));
}
}
Expand Down

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