compiler/rustc_codegen_llvm/src/back/archive.rs

   1 //! A helper class for dealing with static archives
   2
   3 use std::env;
   4 use std::ffi::{c_char, c_void, CStr, CString, OsString};
   5 use std::io;
   6 use std::mem;
   7 use std::path::{Path, PathBuf};
   8 use std::ptr;
   9 use std::str;
  10
  11 use crate::common;
  12 use crate::errors::{
  13     DlltoolFailImportLibrary, ErrorCallingDllTool, ErrorCreatingImportLibrary, ErrorWritingDEFFile,
  14 };
  15 use crate::llvm::archive_ro::{ArchiveRO, Child};
  16 use crate::llvm::{self, ArchiveKind, LLVMMachineType, LLVMRustCOFFShortExport};
  17 use rustc_codegen_ssa::back::archive::{
  18     get_native_object_symbols, try_extract_macho_fat_archive, ArArchiveBuilder,
  19     ArchiveBuildFailure, ArchiveBuilder, ArchiveBuilderBuilder, UnknownArchiveKind,
  20 };
  21
  22 use rustc_session::cstore::DllImport;
  23 use rustc_session::Session;
  24
  25 /// Helper for adding many files to an archive.
  26 #[must_use = "must call build() to finish building the archive"]
  27 pub(crate) struct LlvmArchiveBuilder<'a> {
  28     sess: &'a Session,
  29     additions: Vec<Addition>,
  30 }
  31
  32 enum Addition {
  33     File { path: PathBuf, name_in_archive: String },
  34     Archive { path: PathBuf, archive: ArchiveRO, skip: Box<dyn FnMut(&str) -> bool> },
  35 }
  36
  37 impl Addition {
  38     fn path(&self) -> &Path {
  39         match self {
  40             Addition::File { path, .. } | Addition::Archive { path, .. } => path,
  41         }
  42     }
  43 }
  44
  45 fn is_relevant_child(c: &Child<'_>) -> bool {
  46     match c.name() {
  47         Some(name) => !name.contains("SYMDEF"),
  48         None => false,
  49     }
  50 }
  51
  52 /// Map machine type strings to values of LLVM's MachineTypes enum.
  53 fn llvm_machine_type(cpu: &str) -> LLVMMachineType {
  54     match cpu {
  55         "x86_64" => LLVMMachineType::AMD64,
  56         "x86" => LLVMMachineType::I386,
  57         "aarch64" => LLVMMachineType::ARM64,
  58         "arm" => LLVMMachineType::ARM,
  59         _ => panic!("unsupported cpu type {}", cpu),
  60     }
  61 }
  62
  63 impl<'a> ArchiveBuilder<'a> for LlvmArchiveBuilder<'a> {
  64     fn add_archive(
  65         &mut self,
  66         archive: &Path,
  67         skip: Box<dyn FnMut(&str) -> bool + 'static>,
  68     ) -> io::Result<()> {
  69         let mut archive = archive.to_path_buf();
  70         if self.sess.target.llvm_target.contains("-apple-macosx") {
  71             if let Some(new_archive) = try_extract_macho_fat_archive(&self.sess, &archive)? {
  72                 archive = new_archive
  73             }
  74         }
  75         let archive_ro = match ArchiveRO::open(&archive) {
  76             Ok(ar) => ar,
  77             Err(e) => return Err(io::Error::new(io::ErrorKind::Other, e)),
  78         };
  79         if self.additions.iter().any(|ar| ar.path() == archive) {
  80             return Ok(());
  81         }
  82         self.additions.push(Addition::Archive {
  83             path: archive,
  84             archive: archive_ro,
  85             skip: Box::new(skip),
  86         });
  87         Ok(())
  88     }
  89
  90     /// Adds an arbitrary file to this archive
  91     fn add_file(&mut self, file: &Path) {
  92         let name = file.file_name().unwrap().to_str().unwrap();
  93         self.additions
  94             .push(Addition::File { path: file.to_path_buf(), name_in_archive: name.to_owned() });
  95     }
  96
  97     /// Combine the provided files, rlibs, and native libraries into a single
  98     /// `Archive`.
  99     fn build(mut self: Box<Self>, output: &Path) -> bool {
 100         match self.build_with_llvm(output) {
 101             Ok(any_members) => any_members,
 102             Err(e) => self.sess.emit_fatal(ArchiveBuildFailure { error: e }),
 103         }
 104     }
 105 }
 106
 107 pub struct LlvmArchiveBuilderBuilder;
 108
 109 impl ArchiveBuilderBuilder for LlvmArchiveBuilderBuilder {
 110     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder<'a> + 'a> {
 111         // FIXME use ArArchiveBuilder on most targets again once reading thin archives is
 112         // implemented
 113         if true || sess.target.arch == "wasm32" || sess.target.arch == "wasm64" {
 114             Box::new(LlvmArchiveBuilder { sess, additions: Vec::new() })
 115         } else {
 116             Box::new(ArArchiveBuilder::new(sess, get_llvm_object_symbols))
 117         }
 118     }
 119
 120     fn create_dll_import_lib(
 121         &self,
 122         sess: &Session,
 123         lib_name: &str,
 124         dll_imports: &[DllImport],
 125         tmpdir: &Path,
 126         is_direct_dependency: bool,
 127     ) -> PathBuf {
 128         let name_suffix = if is_direct_dependency { "_imports" } else { "_imports_indirect" };
 129         let output_path = {
 130             let mut output_path: PathBuf = tmpdir.to_path_buf();
 131             output_path.push(format!("{}{}", lib_name, name_suffix));
 132             output_path.with_extension("lib")
 133         };
 134
 135         let target = &sess.target;
 136         let mingw_gnu_toolchain = common::is_mingw_gnu_toolchain(target);
 137
 138         let import_name_and_ordinal_vector: Vec<(String, Option<u16>)> = dll_imports
 139             .iter()
 140             .map(|import: &DllImport| {
 141                 if sess.target.arch == "x86" {
 142                     (
 143                         common::i686_decorated_name(import, mingw_gnu_toolchain, false),
 144                         import.ordinal(),
 145                     )
 146                 } else {
 147                     (import.name.to_string(), import.ordinal())
 148                 }
 149             })
 150             .collect();
 151
 152         if mingw_gnu_toolchain {
 153             // The binutils linker used on -windows-gnu targets cannot read the import
 154             // libraries generated by LLVM: in our attempts, the linker produced an .EXE
 155             // that loaded but crashed with an AV upon calling one of the imported
 156             // functions. Therefore, use binutils to create the import library instead,
 157             // by writing a .DEF file to the temp dir and calling binutils's dlltool.
 158             let def_file_path =
 159                 tmpdir.join(format!("{}{}", lib_name, name_suffix)).with_extension("def");
 160
 161             let def_file_content = format!(
 162                 "EXPORTS\n{}",
 163                 import_name_and_ordinal_vector
 164                     .into_iter()
 165                     .map(|(name, ordinal)| {
 166                         match ordinal {
 167                             Some(n) => format!("{} @{} NONAME", name, n),
 168                             None => name,
 169                         }
 170                     })
 171                     .collect::<Vec<String>>()
 172                     .join("\n")
 173             );
 174
 175             match std::fs::write(&def_file_path, def_file_content) {
 176                 Ok(_) => {}
 177                 Err(e) => {
 178                     sess.emit_fatal(ErrorWritingDEFFile { error: e });
 179                 }
 180             };
 181
 182             // --no-leading-underscore: For the `import_name_type` feature to work, we need to be
 183             // able to control the *exact* spelling of each of the symbols that are being imported:
 184             // hence we don't want `dlltool` adding leading underscores automatically.
 185             let dlltool = find_binutils_dlltool(sess);
 186             let result = std::process::Command::new(dlltool)
 187                 .args([
 188                     "-d",
 189                     def_file_path.to_str().unwrap(),
 190                     "-D",
 191                     lib_name,
 192                     "-l",
 193                     output_path.to_str().unwrap(),
 194                     "--no-leading-underscore",
 195                 ])
 196                 .output();
 197
 198             match result {
 199                 Err(e) => {
 200                     sess.emit_fatal(ErrorCallingDllTool { error: e });
 201                 }
 202                 Ok(output) if !output.status.success() => {
 203                     sess.emit_fatal(DlltoolFailImportLibrary {
 204                         stdout: String::from_utf8_lossy(&output.stdout),
 205                         stderr: String::from_utf8_lossy(&output.stderr),
 206                     })
 207                 }
 208                 _ => {}
 209             }
 210         } else {
 211             // we've checked for \0 characters in the library name already
 212             let dll_name_z = CString::new(lib_name).unwrap();
 213
 214             let output_path_z = rustc_fs_util::path_to_c_string(&output_path);
 215
 216             trace!("invoking LLVMRustWriteImportLibrary");
 217             trace!("  dll_name {:#?}", dll_name_z);
 218             trace!("  output_path {}", output_path.display());
 219             trace!(
 220                 "  import names: {}",
 221                 dll_imports
 222                     .iter()
 223                     .map(|import| import.name.to_string())
 224                     .collect::<Vec<_>>()
 225                     .join(", "),
 226             );
 227
 228             // All import names are Rust identifiers and therefore cannot contain \0 characters.
 229             // FIXME: when support for #[link_name] is implemented, ensure that the import names
 230             // still don't contain any \0 characters. Also need to check that the names don't
 231             // contain substrings like " @" or "NONAME" that are keywords or otherwise reserved
 232             // in definition files.
 233             let cstring_import_name_and_ordinal_vector: Vec<(CString, Option<u16>)> =
 234                 import_name_and_ordinal_vector
 235                     .into_iter()
 236                     .map(|(name, ordinal)| (CString::new(name).unwrap(), ordinal))
 237                     .collect();
 238
 239             let ffi_exports: Vec<LLVMRustCOFFShortExport> = cstring_import_name_and_ordinal_vector
 240                 .iter()
 241                 .map(|(name_z, ordinal)| LLVMRustCOFFShortExport::new(name_z.as_ptr(), *ordinal))
 242                 .collect();
 243             let result = unsafe {
 244                 crate::llvm::LLVMRustWriteImportLibrary(
 245                     dll_name_z.as_ptr(),
 246                     output_path_z.as_ptr(),
 247                     ffi_exports.as_ptr(),
 248                     ffi_exports.len(),
 249                     llvm_machine_type(&sess.target.arch) as u16,
 250                     !sess.target.is_like_msvc,
 251                 )
 252             };
 253
 254             if result == crate::llvm::LLVMRustResult::Failure {
 255                 sess.emit_fatal(ErrorCreatingImportLibrary {
 256                     lib_name,
 257                     error: llvm::last_error().unwrap_or("unknown LLVM error".to_string()),
 258                 });
 259             }
 260         };
 261
 262         output_path
 263     }
 264 }
 265
 266 // The object crate doesn't know how to get symbols for LLVM bitcode and COFF bigobj files.
 267 // As such we need to use LLVM for them.
 268 #[deny(unsafe_op_in_unsafe_fn)]
 269 fn get_llvm_object_symbols(
 270     buf: &[u8],
 271     f: &mut dyn FnMut(&[u8]) -> io::Result<()>,
 272 ) -> io::Result<bool> {
 273     let is_bitcode = unsafe { llvm::LLVMRustIsBitcode(buf.as_ptr(), buf.len()) };
 274
 275     // COFF bigobj file, msvc LTO file or import library. See
 276     // https://github.com/llvm/llvm-project/blob/453f27bc9/llvm/lib/BinaryFormat/Magic.cpp#L38-L51
 277     let is_unsupported_windows_obj_file = buf.get(0..4) == Some(b"\0\0\xFF\xFF");
 278
 279     if is_bitcode || is_unsupported_windows_obj_file {
 280         let mut state = Box::new(f);
 281
 282         let err = unsafe {
 283             llvm::LLVMRustGetSymbols(
 284                 buf.as_ptr(),
 285                 buf.len(),
 286                 &mut *state as *mut &mut _ as *mut c_void,
 287                 callback,
 288                 error_callback,
 289             )
 290         };
 291
 292         if err.is_null() {
 293             return Ok(true);
 294         } else {
 295             return Err(unsafe { *Box::from_raw(err as *mut io::Error) });
 296         }
 297
 298         unsafe extern "C" fn callback(
 299             state: *mut c_void,
 300             symbol_name: *const c_char,
 301         ) -> *mut c_void {
 302             let f = unsafe { &mut *(state as *mut &mut dyn FnMut(&[u8]) -> io::Result<()>) };
 303             match f(unsafe { CStr::from_ptr(symbol_name) }.to_bytes()) {
 304                 Ok(()) => std::ptr::null_mut(),
 305                 Err(err) => Box::into_raw(Box::new(err)) as *mut c_void,
 306             }
 307         }
 308
 309         unsafe extern "C" fn error_callback(error: *const c_char) -> *mut c_void {
 310             let error = unsafe { CStr::from_ptr(error) };
 311             Box::into_raw(Box::new(io::Error::new(
 312                 io::ErrorKind::Other,
 313                 format!("LLVM error: {}", error.to_string_lossy()),
 314             ))) as *mut c_void
 315         }
 316     } else {
 317         get_native_object_symbols(buf, f)
 318     }
 319 }
 320
 321 impl<'a> LlvmArchiveBuilder<'a> {
 322     fn build_with_llvm(&mut self, output: &Path) -> io::Result<bool> {
 323         let kind = &*self.sess.target.archive_format;
 324         let kind = kind
 325             .parse::<ArchiveKind>()
 326             .map_err(|_| kind)
 327             .unwrap_or_else(|kind| self.sess.emit_fatal(UnknownArchiveKind { kind }));
 328
 329         let mut additions = mem::take(&mut self.additions);
 330         let mut strings = Vec::new();
 331         let mut members = Vec::new();
 332
 333         let dst = CString::new(output.to_str().unwrap())?;
 334
 335         unsafe {
 336             for addition in &mut additions {
 337                 match addition {
 338                     Addition::File { path, name_in_archive } => {
 339                         let path = CString::new(path.to_str().unwrap())?;
 340                         let name = CString::new(name_in_archive.clone())?;
 341                         members.push(llvm::LLVMRustArchiveMemberNew(
 342                             path.as_ptr(),
 343                             name.as_ptr(),
 344                             None,
 345                         ));
 346                         strings.push(path);
 347                         strings.push(name);
 348                     }
 349                     Addition::Archive { archive, skip, .. } => {
 350                         for child in archive.iter() {
 351                             let child = child.map_err(string_to_io_error)?;
 352                             if !is_relevant_child(&child) {
 353                                 continue;
 354                             }
 355                             let child_name = child.name().unwrap();
 356                             if skip(child_name) {
 357                                 continue;
 358                             }
 359
 360                             // It appears that LLVM's archive writer is a little
 361                             // buggy if the name we pass down isn't just the
 362                             // filename component, so chop that off here and
 363                             // pass it in.
 364                             //
 365                             // See LLVM bug 25877 for more info.
 366                             let child_name =
 367                                 Path::new(child_name).file_name().unwrap().to_str().unwrap();
 368                             let name = CString::new(child_name)?;
 369                             let m = llvm::LLVMRustArchiveMemberNew(
 370                                 ptr::null(),
 371                                 name.as_ptr(),
 372                                 Some(child.raw),
 373                             );
 374                             members.push(m);
 375                             strings.push(name);
 376                         }
 377                     }
 378                 }
 379             }
 380
 381             let r = llvm::LLVMRustWriteArchive(
 382                 dst.as_ptr(),
 383                 members.len() as libc::size_t,
 384                 members.as_ptr() as *const &_,
 385                 true,
 386                 kind,
 387             );
 388             let ret = if r.into_result().is_err() {
 389                 let err = llvm::LLVMRustGetLastError();
 390                 let msg = if err.is_null() {
 391                     "failed to write archive".into()
 392                 } else {
 393                     String::from_utf8_lossy(CStr::from_ptr(err).to_bytes())
 394                 };
 395                 Err(io::Error::new(io::ErrorKind::Other, msg))
 396             } else {
 397                 Ok(!members.is_empty())
 398             };
 399             for member in members {
 400                 llvm::LLVMRustArchiveMemberFree(member);
 401             }
 402             ret
 403         }
 404     }
 405 }
 406
 407 fn string_to_io_error(s: String) -> io::Error {
 408     io::Error::new(io::ErrorKind::Other, format!("bad archive: {}", s))
 409 }
 410
 411 fn find_binutils_dlltool(sess: &Session) -> OsString {
 412     assert!(sess.target.options.is_like_windows && !sess.target.options.is_like_msvc);
 413     if let Some(dlltool_path) = &sess.opts.unstable_opts.dlltool {
 414         return dlltool_path.clone().into_os_string();
 415     }
 416
 417     let mut tool_name: OsString = if sess.host.arch != sess.target.arch {
 418         // We are cross-compiling, so we need the tool with the prefix matching our target
 419         if sess.target.arch == "x86" {
 420             "i686-w64-mingw32-dlltool"
 421         } else {
 422             "x86_64-w64-mingw32-dlltool"
 423         }
 424     } else {
 425         // We are not cross-compiling, so we just want `dlltool`
 426         "dlltool"
 427     }
 428     .into();
 429
 430     if sess.host.options.is_like_windows {
 431         // If we're compiling on Windows, add the .exe suffix
 432         tool_name.push(".exe");
 433     }
 434
 435     // NOTE: it's not clear how useful it is to explicitly search PATH.
 436     for dir in env::split_paths(&env::var_os("PATH").unwrap_or_default()) {
 437         let full_path = dir.join(&tool_name);
 438         if full_path.is_file() {
 439             return full_path.into_os_string();
 440         }
 441     }
 442
 443     // The user didn't specify the location of the dlltool binary, and we weren't able
 444     // to find the appropriate one on the PATH. Just return the name of the tool
 445     // and let the invocation fail with a hopefully useful error message.
 446     tool_name
 447 }