compiler/rustc_codegen_cranelift/src/archive.rs

   1 //! Creation of ar archives like for the lib and staticlib crate type
   2
   3 use std::collections::BTreeMap;
   4 use std::fs::File;
   5 use std::io::{self, Read, Seek};
   6 use std::path::{Path, PathBuf};
   7
   8 use rustc_codegen_ssa::back::archive::ArchiveBuilder;
   9 use rustc_session::Session;
  10
  11 use object::read::archive::ArchiveFile;
  12 use object::{Object, ObjectSymbol, ReadCache};
  13
  14 #[derive(Debug)]
  15 enum ArchiveEntry {
  16     FromArchive { archive_index: usize, file_range: (u64, u64) },
  17     File(PathBuf),
  18 }
  19
  20 pub(crate) struct ArArchiveBuilder<'a> {
  21     sess: &'a Session,
  22     dst: PathBuf,
  23     use_gnu_style_archive: bool,
  24     no_builtin_ranlib: bool,
  25
  26     src_archives: Vec<File>,
  27     // Don't use `HashMap` here, as the order is important. `rust.metadata.bin` must always be at
  28     // the end of an archive for linkers to not get confused.
  29     entries: Vec<(Vec<u8>, ArchiveEntry)>,
  30 }
  31
  32 impl<'a> ArchiveBuilder<'a> for ArArchiveBuilder<'a> {
  33     fn new(sess: &'a Session, output: &Path) -> Self {
  34         ArArchiveBuilder {
  35             sess,
  36             dst: output.to_path_buf(),
  37             use_gnu_style_archive: sess.target.archive_format == "gnu",
  38             // FIXME fix builtin ranlib on macOS
  39             no_builtin_ranlib: sess.target.is_like_osx,
  40
  41             src_archives: vec![],
  42             entries: vec![],
  43         }
  44     }
  45
  46     fn add_file(&mut self, file: &Path) {
  47         self.entries.push((
  48             file.file_name().unwrap().to_str().unwrap().to_string().into_bytes(),
  49             ArchiveEntry::File(file.to_owned()),
  50         ));
  51     }
  52
  53     fn add_archive<F>(&mut self, archive_path: &Path, mut skip: F) -> std::io::Result<()>
  54     where
  55         F: FnMut(&str) -> bool + 'static,
  56     {
  57         let read_cache = ReadCache::new(std::fs::File::open(&archive_path)?);
  58         let archive = ArchiveFile::parse(&read_cache).unwrap();
  59         let archive_index = self.src_archives.len();
  60
  61         for entry in archive.members() {
  62             let entry = entry.map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
  63             let file_name = String::from_utf8(entry.name().to_vec())
  64                 .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
  65             if !skip(&file_name) {
  66                 self.entries.push((
  67                     file_name.into_bytes(),
  68                     ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
  69                 ));
  70             }
  71         }
  72
  73         self.src_archives.push(read_cache.into_inner());
  74         Ok(())
  75     }
  76
  77     fn build(mut self) -> bool {
  78         enum BuilderKind {
  79             Bsd(ar::Builder<File>),
  80             Gnu(ar::GnuBuilder<File>),
  81         }
  82
  83         let sess = self.sess;
  84
  85         let mut symbol_table = BTreeMap::new();
  86
  87         let mut entries = Vec::new();
  88
  89         for (mut entry_name, entry) in self.entries {
  90             // FIXME only read the symbol table of the object files to avoid having to keep all
  91             // object files in memory at once, or read them twice.
  92             let data = match entry {
  93                 ArchiveEntry::FromArchive { archive_index, file_range } => {
  94                     // FIXME read symbols from symtab
  95                     let src_read_cache = &mut self.src_archives[archive_index];
  96
  97                     src_read_cache.seek(io::SeekFrom::Start(file_range.0)).unwrap();
  98                     let mut data = std::vec::from_elem(0, usize::try_from(file_range.1).unwrap());
  99                     src_read_cache.read_exact(&mut data).unwrap();
 100
 101                     data
 102                 }
 103                 ArchiveEntry::File(file) => std::fs::read(file).unwrap_or_else(|err| {
 104                     sess.fatal(&format!(
 105                         "error while reading object file during archive building: {}",
 106                         err
 107                     ));
 108                 }),
 109             };
 110
 111             if !self.no_builtin_ranlib {
 112                 if symbol_table.contains_key(&entry_name) {
 113                     // The ar crate can't handle creating a symbol table in case of multiple archive
 114                     // members with the same name. Work around this by prepending a number until we
 115                     // get a unique name.
 116                     for i in 1.. {
 117                         let new_name = format!("{}_", i)
 118                             .into_bytes()
 119                             .into_iter()
 120                             .chain(entry_name.iter().copied())
 121                             .collect::<Vec<_>>();
 122                         if !symbol_table.contains_key(&new_name) {
 123                             entry_name = new_name;
 124                             break;
 125                         }
 126                     }
 127                 }
 128
 129                 match object::File::parse(&*data) {
 130                     Ok(object) => {
 131                         symbol_table.insert(
 132                             entry_name.to_vec(),
 133                             object
 134                                 .symbols()
 135                                 .filter_map(|symbol| {
 136                                     if symbol.is_undefined() || symbol.is_local() {
 137                                         None
 138                                     } else {
 139                                         symbol.name().map(|name| name.as_bytes().to_vec()).ok()
 140                                     }
 141                                 })
 142                                 .collect::<Vec<_>>(),
 143                         );
 144                     }
 145                     Err(err) => {
 146                         let err = err.to_string();
 147                         if err == "Unknown file magic" {
 148                             // Not an object file; skip it.
 149                         } else {
 150                             sess.fatal(&format!(
 151                                 "error parsing `{}` during archive creation: {}",
 152                                 String::from_utf8_lossy(&entry_name),
 153                                 err
 154                             ));
 155                         }
 156                     }
 157                 }
 158             }
 159
 160             entries.push((entry_name, data));
 161         }
 162
 163         let mut builder = if self.use_gnu_style_archive {
 164             BuilderKind::Gnu(
 165                 ar::GnuBuilder::new(
 166                     File::create(&self.dst).unwrap_or_else(|err| {
 167                         sess.fatal(&format!(
 168                             "error opening destination during archive building: {}",
 169                             err
 170                         ));
 171                     }),
 172                     entries.iter().map(|(name, _)| name.clone()).collect(),
 173                     ar::GnuSymbolTableFormat::Size32,
 174                     symbol_table,
 175                 )
 176                 .unwrap(),
 177             )
 178         } else {
 179             BuilderKind::Bsd(
 180                 ar::Builder::new(
 181                     File::create(&self.dst).unwrap_or_else(|err| {
 182                         sess.fatal(&format!(
 183                             "error opening destination during archive building: {}",
 184                             err
 185                         ));
 186                     }),
 187                     symbol_table,
 188                 )
 189                 .unwrap(),
 190             )
 191         };
 192
 193         let any_members = !entries.is_empty();
 194
 195         // Add all files
 196         for (entry_name, data) in entries.into_iter() {
 197             let header = ar::Header::new(entry_name, data.len() as u64);
 198             match builder {
 199                 BuilderKind::Bsd(ref mut builder) => builder.append(&header, &mut &*data).unwrap(),
 200                 BuilderKind::Gnu(ref mut builder) => builder.append(&header, &mut &*data).unwrap(),
 201             }
 202         }
 203
 204         // Finalize archive
 205         std::mem::drop(builder);
 206
 207         if self.no_builtin_ranlib {
 208             let ranlib = crate::toolchain::get_toolchain_binary(self.sess, "ranlib");
 209
 210             // Run ranlib to be able to link the archive
 211             let status = std::process::Command::new(ranlib)
 212                 .arg(self.dst)
 213                 .status()
 214                 .expect("Couldn't run ranlib");
 215
 216             if !status.success() {
 217                 self.sess.fatal(&format!("Ranlib exited with code {:?}", status.code()));
 218             }
 219         }
 220
 221         any_members
 222     }
 223
 224     fn sess(&self) -> &Session {
 225         self.sess
 226     }
 227
 228     fn create_dll_import_lib(
 229         _sess: &Session,
 230         _lib_name: &str,
 231         _dll_imports: &[rustc_session::cstore::DllImport],
 232         _tmpdir: &Path,
 233     ) -> PathBuf {
 234         bug!("creating dll imports is not supported");
 235     }
 236 }