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