//! Reading and writing of the rustc metadata for rlibs and dylibs
-use std::convert::TryFrom;
use std::fs::File;
+use std::ops::Deref;
use std::path::Path;
use rustc_codegen_ssa::METADATA_FILENAME;
-use rustc_data_structures::owning_ref::OwningRef;
+use rustc_data_structures::owning_ref::{OwningRef, StableAddress};
use rustc_data_structures::rustc_erase_owner;
use rustc_data_structures::sync::MetadataRef;
use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoader};
pub(crate) struct CraneliftMetadataLoader;
+struct StableMmap(memmap2::Mmap);
+
+impl Deref for StableMmap {
+ type Target = [u8];
+
+ fn deref(&self) -> &[u8] {
+ &*self.0
+ }
+}
+
+unsafe impl StableAddress for StableMmap {}
+
+fn load_metadata_with(
+ path: &Path,
+ f: impl for<'a> FnOnce(&'a [u8]) -> Result<&'a [u8], String>,
+) -> Result<MetadataRef, String> {
+ let file = File::open(path).map_err(|e| format!("{:?}", e))?;
+ let data = unsafe { memmap2::MmapOptions::new().map_copy_read_only(&file) }
+ .map_err(|e| format!("{:?}", e))?;
+ let metadata = OwningRef::new(StableMmap(data)).try_map(f)?;
+ return Ok(rustc_erase_owner!(metadata.map_owner_box()));
+}
+
impl MetadataLoader for CraneliftMetadataLoader {
fn get_rlib_metadata(&self, _target: &Target, path: &Path) -> Result<MetadataRef, String> {
- let mut archive = ar::Archive::new(File::open(path).map_err(|e| format!("{:?}", e))?);
- // Iterate over all entries in the archive:
- while let Some(entry_result) = archive.next_entry() {
- let mut entry = entry_result.map_err(|e| format!("{:?}", e))?;
- if entry.header().identifier() == METADATA_FILENAME.as_bytes() {
- let mut buf = Vec::with_capacity(
- usize::try_from(entry.header().size())
- .expect("Rlib metadata file too big to load into memory."),
- );
- ::std::io::copy(&mut entry, &mut buf).map_err(|e| format!("{:?}", e))?;
- let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(buf);
- return Ok(rustc_erase_owner!(buf.map_owner_box()));
+ load_metadata_with(path, |data| {
+ let archive = object::read::archive::ArchiveFile::parse(&*data)
+ .map_err(|e| format!("{:?}", e))?;
+
+ for entry_result in archive.members() {
+ let entry = entry_result.map_err(|e| format!("{:?}", e))?;
+ if entry.name() == METADATA_FILENAME.as_bytes() {
+ return Ok(entry.data());
+ }
}
- }
- Err("couldn't find metadata entry".to_string())
+ Err("couldn't find metadata entry".to_string())
+ })
}
fn get_dylib_metadata(&self, _target: &Target, path: &Path) -> Result<MetadataRef, String> {
use object::{Object, ObjectSection};
- let file = std::fs::read(path).map_err(|e| format!("read:{:?}", e))?;
- let file = object::File::parse(&file).map_err(|e| format!("parse: {:?}", e))?;
- let buf = file
- .section_by_name(".rustc")
- .ok_or("no .rustc section")?
- .data()
- .map_err(|e| format!("failed to read .rustc section: {:?}", e))?
- .to_owned();
- let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(buf);
- Ok(rustc_erase_owner!(buf.map_owner_box()))
+
+ load_metadata_with(path, |data| {
+ let file = object::File::parse(&data).map_err(|e| format!("parse: {:?}", e))?;
+ file.section_by_name(".rustc")
+ .ok_or("no .rustc section")?
+ .data()
+ .map_err(|e| format!("failed to read .rustc section: {:?}", e))
+ })
}
}