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, input: Option<&Path>) -> Self {
  34         let (src_archives, entries) = if let Some(input) = input {
  35             let read_cache = ReadCache::new(File::open(input).unwrap());
  36             let archive = ArchiveFile::parse(&read_cache).unwrap();
  37             let mut entries = Vec::new();
  38
  39             for entry in archive.members() {
  40                 let entry = entry.unwrap();
  41                 entries.push((
  42                     entry.name().to_vec(),
  43                     ArchiveEntry::FromArchive { archive_index: 0, file_range: entry.file_range() },
  44                 ));
  45             }
  46
  47             (vec![read_cache.into_inner()], entries)
  48         } else {
  49             (vec![], Vec::new())
  50         };
  51
  52         ArArchiveBuilder {
  53             sess,
  54             dst: output.to_path_buf(),
  55             use_gnu_style_archive: sess.target.archive_format == "gnu",
  56             // FIXME fix builtin ranlib on macOS
  57             no_builtin_ranlib: sess.target.is_like_osx,
  58
  59             src_archives,
  60             entries,
  61         }
  62     }
  63
  64     fn src_files(&mut self) -> Vec<String> {
  65         self.entries.iter().map(|(name, _)| String::from_utf8(name.clone()).unwrap()).collect()
  66     }
  67
  68     fn remove_file(&mut self, name: &str) {
  69         let index = self
  70             .entries
  71             .iter()
  72             .position(|(entry_name, _)| entry_name == name.as_bytes())
  73             .expect("Tried to remove file not existing in src archive");
  74         self.entries.remove(index);
  75     }
  76
  77     fn add_file(&mut self, file: &Path) {
  78         self.entries.push((
  79             file.file_name().unwrap().to_str().unwrap().to_string().into_bytes(),
  80             ArchiveEntry::File(file.to_owned()),
  81         ));
  82     }
  83
  84     fn add_archive<F>(&mut self, archive_path: &Path, mut skip: F) -> std::io::Result<()>
  85     where
  86         F: FnMut(&str) -> bool + 'static,
  87     {
  88         let read_cache = ReadCache::new(std::fs::File::open(&archive_path)?);
  89         let archive = ArchiveFile::parse(&read_cache).unwrap();
  90         let archive_index = self.src_archives.len();
  91
  92         for entry in archive.members() {
  93             let entry = entry.map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
  94             let file_name = String::from_utf8(entry.name().to_vec())
  95                 .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
  96             if !skip(&file_name) {
  97                 self.entries.push((
  98                     file_name.into_bytes(),
  99                     ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
 100                 ));
 101             }
 102         }
 103
 104         self.src_archives.push(read_cache.into_inner());
 105         Ok(())
 106     }
 107
 108     fn build(mut self) {
 109         enum BuilderKind {
 110             Bsd(ar::Builder<File>),
 111             Gnu(ar::GnuBuilder<File>),
 112         }
 113
 114         let sess = self.sess;
 115
 116         let mut symbol_table = BTreeMap::new();
 117
 118         let mut entries = Vec::new();
 119
 120         for (mut entry_name, entry) in self.entries {
 121             // FIXME only read the symbol table of the object files to avoid having to keep all
 122             // object files in memory at once, or read them twice.
 123             let data = match entry {
 124                 ArchiveEntry::FromArchive { archive_index, file_range } => {
 125                     // FIXME read symbols from symtab
 126                     let src_read_cache = &mut self.src_archives[archive_index];
 127
 128                     src_read_cache.seek(io::SeekFrom::Start(file_range.0)).unwrap();
 129                     let mut data = std::vec::from_elem(0, usize::try_from(file_range.1).unwrap());
 130                     src_read_cache.read_exact(&mut data).unwrap();
 131
 132                     data
 133                 }
 134                 ArchiveEntry::File(file) => std::fs::read(file).unwrap_or_else(|err| {
 135                     sess.fatal(&format!(
 136                         "error while reading object file during archive building: {}",
 137                         err
 138                     ));
 139                 }),
 140             };
 141
 142             if !self.no_builtin_ranlib {
 143                 if symbol_table.contains_key(&entry_name) {
 144                     // The ar crate can't handle creating a symbol table in case of multiple archive
 145                     // members with the same name. Work around this by prepending a number until we
 146                     // get a unique name.
 147                     for i in 1.. {
 148                         let new_name = format!("{}_", i)
 149                             .into_bytes()
 150                             .into_iter()
 151                             .chain(entry_name.iter().copied())
 152                             .collect::<Vec<_>>();
 153                         if !symbol_table.contains_key(&new_name) {
 154                             entry_name = new_name;
 155                             break;
 156                         }
 157                     }
 158                 }
 159
 160                 match object::File::parse(&*data) {
 161                     Ok(object) => {
 162                         symbol_table.insert(
 163                             entry_name.to_vec(),
 164                             object
 165                                 .symbols()
 166                                 .filter_map(|symbol| {
 167                                     if symbol.is_undefined() || symbol.is_local() {
 168                                         None
 169                                     } else {
 170                                         symbol.name().map(|name| name.as_bytes().to_vec()).ok()
 171                                     }
 172                                 })
 173                                 .collect::<Vec<_>>(),
 174                         );
 175                     }
 176                     Err(err) => {
 177                         let err = err.to_string();
 178                         if err == "Unknown file magic" {
 179                             // Not an object file; skip it.
 180                         } else {
 181                             sess.fatal(&format!(
 182                                 "error parsing `{}` during archive creation: {}",
 183                                 String::from_utf8_lossy(&entry_name),
 184                                 err
 185                             ));
 186                         }
 187                     }
 188                 }
 189             }
 190
 191             entries.push((entry_name, data));
 192         }
 193
 194         let mut builder = if self.use_gnu_style_archive {
 195             BuilderKind::Gnu(
 196                 ar::GnuBuilder::new(
 197                     File::create(&self.dst).unwrap_or_else(|err| {
 198                         sess.fatal(&format!(
 199                             "error opening destination during archive building: {}",
 200                             err
 201                         ));
 202                     }),
 203                     entries.iter().map(|(name, _)| name.clone()).collect(),
 204                     ar::GnuSymbolTableFormat::Size32,
 205                     symbol_table,
 206                 )
 207                 .unwrap(),
 208             )
 209         } else {
 210             BuilderKind::Bsd(
 211                 ar::Builder::new(
 212                     File::create(&self.dst).unwrap_or_else(|err| {
 213                         sess.fatal(&format!(
 214                             "error opening destination during archive building: {}",
 215                             err
 216                         ));
 217                     }),
 218                     symbol_table,
 219                 )
 220                 .unwrap(),
 221             )
 222         };
 223
 224         // Add all files
 225         for (entry_name, data) in entries.into_iter() {
 226             let header = ar::Header::new(entry_name, data.len() as u64);
 227             match builder {
 228                 BuilderKind::Bsd(ref mut builder) => builder.append(&header, &mut &*data).unwrap(),
 229                 BuilderKind::Gnu(ref mut builder) => builder.append(&header, &mut &*data).unwrap(),
 230             }
 231         }
 232
 233         // Finalize archive
 234         std::mem::drop(builder);
 235
 236         if self.no_builtin_ranlib {
 237             let ranlib = crate::toolchain::get_toolchain_binary(self.sess, "ranlib");
 238
 239             // Run ranlib to be able to link the archive
 240             let status = std::process::Command::new(ranlib)
 241                 .arg(self.dst)
 242                 .status()
 243                 .expect("Couldn't run ranlib");
 244
 245             if !status.success() {
 246                 self.sess.fatal(&format!("Ranlib exited with code {:?}", status.code()));
 247             }
 248         }
 249     }
 250
 251     fn inject_dll_import_lib(
 252         &mut self,
 253         _lib_name: &str,
 254         _dll_imports: &[rustc_session::cstore::DllImport],
 255         _tmpdir: &rustc_data_structures::temp_dir::MaybeTempDir,
 256     ) {
 257         bug!("injecting dll imports is not supported");
 258     }
 259 }