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