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