compiler/rustc_codegen_ssa/src/back/archive.rs - rust-lang/rust - Git at Google

 use std::env;
 use std::error::Error;
 use std::ffi::OsString;
 use std::fs::{self, File};
 use std::io::{self, BufWriter, Write};
 use std::path::{Path, PathBuf};

 use ar_archive_writer::{
     ArchiveKind, COFFShortExport, MachineTypes, NewArchiveMember, write_archive_to_stream,
 };
 pub use ar_archive_writer::{DEFAULT_OBJECT_READER, ObjectReader};
 use object::read::archive::ArchiveFile;
 use object::read::macho::FatArch;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_data_structures::memmap::Mmap;
 use rustc_fs_util::TempDirBuilder;
 use rustc_metadata::EncodedMetadata;
 use rustc_session::Session;
 use rustc_span::Symbol;
 use tracing::trace;

 use super::metadata::{create_compressed_metadata_file, search_for_section};
 use crate::common;
 // Re-exporting for rustc_codegen_llvm::back::archive
 pub use crate::errors::{ArchiveBuildFailure, ExtractBundledLibsError, UnknownArchiveKind};
 use crate::errors::{
     DlltoolFailImportLibrary, ErrorCallingDllTool, ErrorCreatingImportLibrary, ErrorWritingDEFFile,
 };

 /// An item to be included in an import library.
 /// This is a slimmed down version of `COFFShortExport` from `ar-archive-writer`.
 pub struct ImportLibraryItem {
     /// The name to be exported.
     pub name: String,
     /// The ordinal to be exported, if any.
     pub ordinal: Option<u16>,
     /// The original, decorated name if `name` is not decorated.
     pub symbol_name: Option<String>,
     /// True if this is a data export, false if it is a function export.
     pub is_data: bool,
 }

 impl From<ImportLibraryItem> for COFFShortExport {
     fn from(item: ImportLibraryItem) -> Self {
         COFFShortExport {
             name: item.name,
             ext_name: None,
             symbol_name: item.symbol_name,
             alias_target: None,
             ordinal: item.ordinal.unwrap_or(0),
             noname: item.ordinal.is_some(),
             data: item.is_data,
             private: false,
             constant: false,
         }
     }
 }

 pub trait ArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a>;

     fn create_dylib_metadata_wrapper(
         &self,
         sess: &Session,
         metadata: &EncodedMetadata,
         symbol_name: &str,
     ) -> Vec<u8> {
         create_compressed_metadata_file(sess, metadata, symbol_name)
     }

     /// Creates a DLL Import Library <https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-creation#creating-an-import-library>.
     /// and returns the path on disk to that import library.
     /// This functions doesn't take `self` so that it can be called from
     /// `linker_with_args`, which is specialized on `ArchiveBuilder` but
     /// doesn't take or create an instance of that type.
     fn create_dll_import_lib(
         &self,
         sess: &Session,
         lib_name: &str,
         items: Vec<ImportLibraryItem>,
         output_path: &Path,
     ) {
         if common::is_mingw_gnu_toolchain(&sess.target) {
             // The binutils linker used on -windows-gnu targets cannot read the import
             // libraries generated by LLVM: in our attempts, the linker produced an .EXE
             // that loaded but crashed with an AV upon calling one of the imported
             // functions. Therefore, use binutils to create the import library instead,
             // by writing a .DEF file to the temp dir and calling binutils's dlltool.
             create_mingw_dll_import_lib(sess, lib_name, items, output_path);
         } else {
             trace!("creating import library");
             trace!("  dll_name {:#?}", lib_name);
             trace!("  output_path {}", output_path.display());
             trace!(
                 "  import names: {}",
                 items
                     .iter()
                     .map(|ImportLibraryItem { name, .. }| name.clone())
                     .collect::<Vec<_>>()
                     .join(", "),
             );

             // All import names are Rust identifiers and therefore cannot contain \0 characters.
             // FIXME: when support for #[link_name] is implemented, ensure that the import names
             // still don't contain any \0 characters. Also need to check that the names don't
             // contain substrings like " @" or "NONAME" that are keywords or otherwise reserved
             // in definition files.

             let mut file = match fs::File::create_new(&output_path) {
                 Ok(file) => file,
                 Err(error) => sess
                     .dcx()
                     .emit_fatal(ErrorCreatingImportLibrary { lib_name, error: error.to_string() }),
             };

             let exports = items.into_iter().map(Into::into).collect::<Vec<_>>();
             let machine = match &*sess.target.arch {
                 "x86_64" => MachineTypes::AMD64,
                 "x86" => MachineTypes::I386,
                 "aarch64" => MachineTypes::ARM64,
                 "arm64ec" => MachineTypes::ARM64EC,
                 "arm" => MachineTypes::ARMNT,
                 cpu => panic!("unsupported cpu type {cpu}"),
             };

             if let Err(error) = ar_archive_writer::write_import_library(
                 &mut file,
                 lib_name,
                 &exports,
                 machine,
                 !sess.target.is_like_msvc,
                 // Enable compatibility with MSVC's `/WHOLEARCHIVE` flag.
                 // Without this flag a duplicate symbol error would be emitted
                 // when linking a rust staticlib using `/WHOLEARCHIVE`.
                 // See #129020
                 true,
             ) {
                 sess.dcx()
                     .emit_fatal(ErrorCreatingImportLibrary { lib_name, error: error.to_string() });
             }
         }
     }

     fn extract_bundled_libs<'a>(
         &'a self,
         rlib: &'a Path,
         outdir: &Path,
         bundled_lib_file_names: &FxIndexSet<Symbol>,
     ) -> Result<(), ExtractBundledLibsError<'a>> {
         let archive_map = unsafe {
             Mmap::map(
                 File::open(rlib)
                     .map_err(|e| ExtractBundledLibsError::OpenFile { rlib, error: Box::new(e) })?,
             )
             .map_err(|e| ExtractBundledLibsError::MmapFile { rlib, error: Box::new(e) })?
         };
         let archive = ArchiveFile::parse(&*archive_map)
             .map_err(|e| ExtractBundledLibsError::ParseArchive { rlib, error: Box::new(e) })?;

         for entry in archive.members() {
             let entry = entry
                 .map_err(|e| ExtractBundledLibsError::ReadEntry { rlib, error: Box::new(e) })?;
             let data = entry
                 .data(&*archive_map)
                 .map_err(|e| ExtractBundledLibsError::ArchiveMember { rlib, error: Box::new(e) })?;
             let name = std::str::from_utf8(entry.name())
                 .map_err(|e| ExtractBundledLibsError::ConvertName { rlib, error: Box::new(e) })?;
             if !bundled_lib_file_names.contains(&Symbol::intern(name)) {
                 continue; // We need to extract only native libraries.
             }
             let data = search_for_section(rlib, data, ".bundled_lib").map_err(|e| {
                 ExtractBundledLibsError::ExtractSection { rlib, error: Box::<dyn Error>::from(e) }
             })?;
             std::fs::write(&outdir.join(&name), data)
                 .map_err(|e| ExtractBundledLibsError::WriteFile { rlib, error: Box::new(e) })?;
         }
         Ok(())
     }
 }

 fn create_mingw_dll_import_lib(
     sess: &Session,
     lib_name: &str,
     items: Vec<ImportLibraryItem>,
     output_path: &Path,
 ) {
     let def_file_path = output_path.with_extension("def");

     let def_file_content = format!(
         "EXPORTS\n{}",
         items
             .into_iter()
             .map(|ImportLibraryItem { name, ordinal, .. }| {
                 match ordinal {
                     Some(n) => format!("{name} @{n} NONAME"),
                     None => name,
                 }
             })
             .collect::<Vec<String>>()
             .join("\n")
     );

     match std::fs::write(&def_file_path, def_file_content) {
         Ok(_) => {}
         Err(e) => {
             sess.dcx().emit_fatal(ErrorWritingDEFFile { error: e });
         }
     };

     // --no-leading-underscore: For the `import_name_type` feature to work, we need to be
     // able to control the *exact* spelling of each of the symbols that are being imported:
     // hence we don't want `dlltool` adding leading underscores automatically.
     let dlltool = find_binutils_dlltool(sess);
     let temp_prefix = {
         let mut path = PathBuf::from(&output_path);
         path.pop();
         path.push(lib_name);
         path
     };
     // dlltool target architecture args from:
     // https://github.com/llvm/llvm-project-release-prs/blob/llvmorg-15.0.6/llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp#L69
     let (dlltool_target_arch, dlltool_target_bitness) = match sess.target.arch.as_ref() {
         "x86_64" => ("i386:x86-64", "--64"),
         "x86" => ("i386", "--32"),
         "aarch64" => ("arm64", "--64"),
         "arm" => ("arm", "--32"),
         _ => panic!("unsupported arch {}", sess.target.arch),
     };
     let mut dlltool_cmd = std::process::Command::new(&dlltool);
     dlltool_cmd
         .arg("-d")
         .arg(def_file_path)
         .arg("-D")
         .arg(lib_name)
         .arg("-l")
         .arg(&output_path)
         .arg("-m")
         .arg(dlltool_target_arch)
         .arg("-f")
         .arg(dlltool_target_bitness)
         .arg("--no-leading-underscore")
         .arg("--temp-prefix")
         .arg(temp_prefix);

     match dlltool_cmd.output() {
         Err(e) => {
             sess.dcx().emit_fatal(ErrorCallingDllTool {
                 dlltool_path: dlltool.to_string_lossy(),
                 error: e,
             });
         }
         // dlltool returns '0' on failure, so check for error output instead.
         Ok(output) if !output.stderr.is_empty() => {
             sess.dcx().emit_fatal(DlltoolFailImportLibrary {
                 dlltool_path: dlltool.to_string_lossy(),
                 dlltool_args: dlltool_cmd
                     .get_args()
                     .map(|arg| arg.to_string_lossy())
                     .collect::<Vec<_>>()
                     .join(" "),
                 stdout: String::from_utf8_lossy(&output.stdout),
                 stderr: String::from_utf8_lossy(&output.stderr),
             })
         }
         _ => {}
     }
 }

 fn find_binutils_dlltool(sess: &Session) -> OsString {
     assert!(sess.target.options.is_like_windows && !sess.target.options.is_like_msvc);
     if let Some(dlltool_path) = &sess.opts.cg.dlltool {
         return dlltool_path.clone().into_os_string();
     }

     let tool_name: OsString = if sess.host.options.is_like_windows {
         // If we're compiling on Windows, always use "dlltool.exe".
         "dlltool.exe"
     } else {
         // On other platforms, use the architecture-specific name.
         match sess.target.arch.as_ref() {
             "x86_64" => "x86_64-w64-mingw32-dlltool",
             "x86" => "i686-w64-mingw32-dlltool",
             "aarch64" => "aarch64-w64-mingw32-dlltool",

             // For non-standard architectures (e.g., aarch32) fallback to "dlltool".
             _ => "dlltool",
         }
     }
     .into();

     // NOTE: it's not clear how useful it is to explicitly search PATH.
     for dir in env::split_paths(&env::var_os("PATH").unwrap_or_default()) {
         let full_path = dir.join(&tool_name);
         if full_path.is_file() {
             return full_path.into_os_string();
         }
     }

     // The user didn't specify the location of the dlltool binary, and we weren't able
     // to find the appropriate one on the PATH. Just return the name of the tool
     // and let the invocation fail with a hopefully useful error message.
     tool_name
 }

 pub trait ArchiveBuilder {
     fn add_file(&mut self, path: &Path);

     fn add_archive(
         &mut self,
         archive: &Path,
         skip: Box<dyn FnMut(&str) -> bool + 'static>,
     ) -> io::Result<()>;

     fn build(self: Box<Self>, output: &Path) -> bool;
 }

 pub struct ArArchiveBuilderBuilder;

 impl ArchiveBuilderBuilder for ArArchiveBuilderBuilder {
     fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a> {
         Box::new(ArArchiveBuilder::new(sess, &DEFAULT_OBJECT_READER))
     }
 }

 #[must_use = "must call build() to finish building the archive"]
 pub struct ArArchiveBuilder<'a> {
     sess: &'a Session,
     object_reader: &'static ObjectReader,

     src_archives: Vec<(PathBuf, Mmap)>,
     // Don't use an `HashMap` here, as the order is important. `lib.rmeta` needs
     // to be at the end of an archive in some cases for linkers to not get confused.
     entries: Vec<(Vec<u8>, ArchiveEntry)>,
 }

 #[derive(Debug)]
 enum ArchiveEntry {
     FromArchive { archive_index: usize, file_range: (u64, u64) },
     File(PathBuf),
 }

 impl<'a> ArArchiveBuilder<'a> {
     pub fn new(sess: &'a Session, object_reader: &'static ObjectReader) -> ArArchiveBuilder<'a> {
         ArArchiveBuilder { sess, object_reader, src_archives: vec![], entries: vec![] }
     }
 }

 fn try_filter_fat_archs(
     archs: &[impl FatArch],
     target_arch: object::Architecture,
     archive_path: &Path,
     archive_map_data: &[u8],
 ) -> io::Result<Option<PathBuf>> {
     let desired = match archs.iter().find(|a| a.architecture() == target_arch) {
         Some(a) => a,
         None => return Ok(None),
     };

     let (mut new_f, extracted_path) = tempfile::Builder::new()
         .suffix(archive_path.file_name().unwrap())
         .tempfile()?
         .keep()
         .unwrap();

     new_f.write_all(
         desired.data(archive_map_data).map_err(|e| io::Error::new(io::ErrorKind::Other, e))?,
     )?;

     Ok(Some(extracted_path))
 }

 pub fn try_extract_macho_fat_archive(
     sess: &Session,
     archive_path: &Path,
 ) -> io::Result<Option<PathBuf>> {
     let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
     let target_arch = match sess.target.arch.as_ref() {
         "aarch64" => object::Architecture::Aarch64,
         "x86_64" => object::Architecture::X86_64,
         _ => return Ok(None),
     };

     if let Ok(h) = object::read::macho::MachOFatFile32::parse(&*archive_map) {
         let archs = h.arches();
         try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
     } else if let Ok(h) = object::read::macho::MachOFatFile64::parse(&*archive_map) {
         let archs = h.arches();
         try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
     } else {
         // Not a FatHeader at all, just return None.
         Ok(None)
     }
 }

 impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
     fn add_archive(
         &mut self,
         archive_path: &Path,
         mut skip: Box<dyn FnMut(&str) -> bool + 'static>,
     ) -> io::Result<()> {
         let mut archive_path = archive_path.to_path_buf();
         if self.sess.target.llvm_target.contains("-apple-macosx")
             && let Some(new_archive_path) = try_extract_macho_fat_archive(self.sess, &archive_path)?
         {
             archive_path = new_archive_path
         }

         if self.src_archives.iter().any(|archive| archive.0 == archive_path) {
             return Ok(());
         }

         let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
         let archive = ArchiveFile::parse(&*archive_map)
             .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
         let archive_index = self.src_archives.len();

         for entry in archive.members() {
             let entry = entry.map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
             let file_name = String::from_utf8(entry.name().to_vec())
                 .map_err(|err| io::Error::new(io::ErrorKind::InvalidData, err))?;
             if !skip(&file_name) {
                 if entry.is_thin() {
                     let member_path = archive_path.parent().unwrap().join(Path::new(&file_name));
                     self.entries.push((file_name.into_bytes(), ArchiveEntry::File(member_path)));
                 } else {
                     self.entries.push((
                         file_name.into_bytes(),
                         ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
                     ));
                 }
             }
         }

         self.src_archives.push((archive_path, archive_map));
         Ok(())
     }

     /// Adds an arbitrary file to this archive
     fn add_file(&mut self, file: &Path) {
         self.entries.push((
             file.file_name().unwrap().to_str().unwrap().to_string().into_bytes(),
             ArchiveEntry::File(file.to_owned()),
         ));
     }

     /// Combine the provided files, rlibs, and native libraries into a single
     /// `Archive`.
     fn build(self: Box<Self>, output: &Path) -> bool {
         let sess = self.sess;
         match self.build_inner(output) {
             Ok(any_members) => any_members,
             Err(error) => {
                 sess.dcx().emit_fatal(ArchiveBuildFailure { path: output.to_owned(), error })
             }
         }
     }
 }

 impl<'a> ArArchiveBuilder<'a> {
     fn build_inner(self, output: &Path) -> io::Result<bool> {
         let archive_kind = match &*self.sess.target.archive_format {
             "gnu" => ArchiveKind::Gnu,
             "bsd" => ArchiveKind::Bsd,
             "darwin" => ArchiveKind::Darwin,
             "coff" => ArchiveKind::Coff,
             "aix_big" => ArchiveKind::AixBig,
             kind => {
                 self.sess.dcx().emit_fatal(UnknownArchiveKind { kind });
             }
         };

         let mut entries = Vec::new();

         for (entry_name, entry) in self.entries {
             let data =
                 match entry {
                     ArchiveEntry::FromArchive { archive_index, file_range } => {
                         let src_archive = &self.src_archives[archive_index];

                         let data = &src_archive.1
                             [file_range.0 as usize..file_range.0 as usize + file_range.1 as usize];

                         Box::new(data) as Box<dyn AsRef<[u8]>>
                     }
                     ArchiveEntry::File(file) => unsafe {
                         Box::new(
                             Mmap::map(File::open(file).map_err(|err| {
                                 io_error_context("failed to open object file", err)
                             })?)
                             .map_err(|err| io_error_context("failed to map object file", err))?,
                         ) as Box<dyn AsRef<[u8]>>
                     },
                 };

             entries.push(NewArchiveMember {
                 buf: data,
                 object_reader: self.object_reader,
                 member_name: String::from_utf8(entry_name).unwrap(),
                 mtime: 0,
                 uid: 0,
                 gid: 0,
                 perms: 0o644,
             })
         }

         // Write to a temporary file first before atomically renaming to the final name.
         // This prevents programs (including rustc) from attempting to read a partial archive.
         // It also enables writing an archive with the same filename as a dependency on Windows as
         // required by a test.
         // The tempfile crate currently uses 0o600 as mode for the temporary files and directories
         // it creates. We need it to be the default mode for back compat reasons however. (See
         // #107495) To handle this we are telling tempfile to create a temporary directory instead
         // and then inside this directory create a file using File::create.
         let archive_tmpdir = TempDirBuilder::new()
             .suffix(".temp-archive")
             .tempdir_in(output.parent().unwrap_or_else(|| Path::new("")))
             .map_err(|err| {
                 io_error_context("couldn't create a directory for the temp file", err)
             })?;
         let archive_tmpfile_path = archive_tmpdir.path().join("tmp.a");
         let archive_tmpfile = File::create_new(&archive_tmpfile_path)
             .map_err(|err| io_error_context("couldn't create the temp file", err))?;

         let mut archive_tmpfile = BufWriter::new(archive_tmpfile);
         write_archive_to_stream(
             &mut archive_tmpfile,
             &entries,
             archive_kind,
             false,
             /* is_ec = */ self.sess.target.arch == "arm64ec",
         )?;
         archive_tmpfile.flush()?;
         drop(archive_tmpfile);

         let any_entries = !entries.is_empty();
         drop(entries);
         // Drop src_archives to unmap all input archives, which is necessary if we want to write the
         // output archive to the same location as an input archive on Windows.
         drop(self.src_archives);

         fs::rename(archive_tmpfile_path, output)
             .map_err(|err| io_error_context("failed to rename archive file", err))?;
         archive_tmpdir
             .close()
             .map_err(|err| io_error_context("failed to remove temporary directory", err))?;

         Ok(any_entries)
     }
 }

 fn io_error_context(context: &str, err: io::Error) -> io::Error {
     io::Error::new(io::ErrorKind::Other, format!("{context}: {err}"))
 }
	use std::env;
	use std::error::Error;
	use std::ffi::OsString;
	use std::fs::{self, File};
	use std::io::{self, BufWriter, Write};
	use std::path::{Path, PathBuf};

	use ar_archive_writer::{
	ArchiveKind, COFFShortExport, MachineTypes, NewArchiveMember, write_archive_to_stream,
	};
	pub use ar_archive_writer::{DEFAULT_OBJECT_READER, ObjectReader};
	use object::read::archive::ArchiveFile;
	use object::read::macho::FatArch;
	use rustc_data_structures::fx::FxIndexSet;
	use rustc_data_structures::memmap::Mmap;
	use rustc_fs_util::TempDirBuilder;
	use rustc_metadata::EncodedMetadata;
	use rustc_session::Session;
	use rustc_span::Symbol;
	use tracing::trace;

	use super::metadata::{create_compressed_metadata_file, search_for_section};
	use crate::common;
	// Re-exporting for rustc_codegen_llvm::back::archive
	pub use crate::errors::{ArchiveBuildFailure, ExtractBundledLibsError, UnknownArchiveKind};
	use crate::errors::{
	DlltoolFailImportLibrary, ErrorCallingDllTool, ErrorCreatingImportLibrary, ErrorWritingDEFFile,
	};

	/// An item to be included in an import library.
	/// This is a slimmed down version of `COFFShortExport` from `ar-archive-writer`.
	pub struct ImportLibraryItem {
	/// The name to be exported.
	pub name: String,
	/// The ordinal to be exported, if any.
	pub ordinal: Option<u16>,
	/// The original, decorated name if `name` is not decorated.
	pub symbol_name: Option<String>,
	/// True if this is a data export, false if it is a function export.
	pub is_data: bool,
	}

	impl From<ImportLibraryItem> for COFFShortExport {
	fn from(item: ImportLibraryItem) -> Self {
	COFFShortExport {
	name: item.name,
	ext_name: None,
	symbol_name: item.symbol_name,
	alias_target: None,
	ordinal: item.ordinal.unwrap_or(0),
	noname: item.ordinal.is_some(),
	data: item.is_data,
	private: false,
	constant: false,
	}
	}
	}

	pub trait ArchiveBuilderBuilder {
	fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a>;

	fn create_dylib_metadata_wrapper(
	&self,
	sess: &Session,
	metadata: &EncodedMetadata,
	symbol_name: &str,
	) -> Vec<u8> {
	create_compressed_metadata_file(sess, metadata, symbol_name)
	}

	/// Creates a DLL Import Library <https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-creation#creating-an-import-library>.
	/// and returns the path on disk to that import library.
	/// This functions doesn't take `self` so that it can be called from
	/// `linker_with_args`, which is specialized on `ArchiveBuilder` but
	/// doesn't take or create an instance of that type.
	fn create_dll_import_lib(
	&self,
	sess: &Session,
	lib_name: &str,
	items: Vec<ImportLibraryItem>,
	output_path: &Path,
	) {
	if common::is_mingw_gnu_toolchain(&sess.target) {
	// The binutils linker used on -windows-gnu targets cannot read the import
	// libraries generated by LLVM: in our attempts, the linker produced an .EXE
	// that loaded but crashed with an AV upon calling one of the imported
	// functions. Therefore, use binutils to create the import library instead,
	// by writing a .DEF file to the temp dir and calling binutils's dlltool.
	create_mingw_dll_import_lib(sess, lib_name, items, output_path);
	} else {
	trace!("creating import library");
	trace!(" dll_name {:#?}", lib_name);
	trace!(" output_path {}", output_path.display());
	trace!(
	" import names: {}",
	items
	.iter()
	.map(\|ImportLibraryItem { name, .. }\| name.clone())
	.collect::<Vec<_>>()
	.join(", "),
	);

	// All import names are Rust identifiers and therefore cannot contain \0 characters.
	// FIXME: when support for #[link_name] is implemented, ensure that the import names
	// still don't contain any \0 characters. Also need to check that the names don't
	// contain substrings like " @" or "NONAME" that are keywords or otherwise reserved
	// in definition files.

	let mut file = match fs::File::create_new(&output_path) {
	Ok(file) => file,
	Err(error) => sess
	.dcx()
	.emit_fatal(ErrorCreatingImportLibrary { lib_name, error: error.to_string() }),
	};

	let exports = items.into_iter().map(Into::into).collect::<Vec<_>>();
	let machine = match &*sess.target.arch {
	"x86_64" => MachineTypes::AMD64,
	"x86" => MachineTypes::I386,
	"aarch64" => MachineTypes::ARM64,
	"arm64ec" => MachineTypes::ARM64EC,
	"arm" => MachineTypes::ARMNT,
	cpu => panic!("unsupported cpu type {cpu}"),
	};

	if let Err(error) = ar_archive_writer::write_import_library(
	&mut file,
	lib_name,
	&exports,
	machine,
	!sess.target.is_like_msvc,
	// Enable compatibility with MSVC's `/WHOLEARCHIVE` flag.
	// Without this flag a duplicate symbol error would be emitted
	// when linking a rust staticlib using `/WHOLEARCHIVE`.
	// See #129020
	true,
	) {
	sess.dcx()
	.emit_fatal(ErrorCreatingImportLibrary { lib_name, error: error.to_string() });
	}
	}
	}

	fn extract_bundled_libs<'a>(
	&'a self,
	rlib: &'a Path,
	outdir: &Path,
	bundled_lib_file_names: &FxIndexSet<Symbol>,
	) -> Result<(), ExtractBundledLibsError<'a>> {
	let archive_map = unsafe {
	Mmap::map(
	File::open(rlib)
	.map_err(\|e\| ExtractBundledLibsError::OpenFile { rlib, error: Box::new(e) })?,
	)
	.map_err(\|e\| ExtractBundledLibsError::MmapFile { rlib, error: Box::new(e) })?
	};
	let archive = ArchiveFile::parse(&*archive_map)
	.map_err(\|e\| ExtractBundledLibsError::ParseArchive { rlib, error: Box::new(e) })?;

	for entry in archive.members() {
	let entry = entry
	.map_err(\|e\| ExtractBundledLibsError::ReadEntry { rlib, error: Box::new(e) })?;
	let data = entry
	.data(&*archive_map)
	.map_err(\|e\| ExtractBundledLibsError::ArchiveMember { rlib, error: Box::new(e) })?;
	let name = std::str::from_utf8(entry.name())
	.map_err(\|e\| ExtractBundledLibsError::ConvertName { rlib, error: Box::new(e) })?;
	if !bundled_lib_file_names.contains(&Symbol::intern(name)) {
	continue; // We need to extract only native libraries.
	}
	let data = search_for_section(rlib, data, ".bundled_lib").map_err(\|e\| {
	ExtractBundledLibsError::ExtractSection { rlib, error: Box::<dyn Error>::from(e) }
	})?;
	std::fs::write(&outdir.join(&name), data)
	.map_err(\|e\| ExtractBundledLibsError::WriteFile { rlib, error: Box::new(e) })?;
	}
	Ok(())
	}
	}

	fn create_mingw_dll_import_lib(
	sess: &Session,
	lib_name: &str,
	items: Vec<ImportLibraryItem>,
	output_path: &Path,
	) {
	let def_file_path = output_path.with_extension("def");

	let def_file_content = format!(
	"EXPORTS\n{}",
	items
	.into_iter()
	.map(\|ImportLibraryItem { name, ordinal, .. }\| {
	match ordinal {
	Some(n) => format!("{name} @{n} NONAME"),
	None => name,
	}
	})
	.collect::<Vec<String>>()
	.join("\n")
	);

	match std::fs::write(&def_file_path, def_file_content) {
	Ok(_) => {}
	Err(e) => {
	sess.dcx().emit_fatal(ErrorWritingDEFFile { error: e });
	}
	};

	// --no-leading-underscore: For the `import_name_type` feature to work, we need to be
	// able to control the exact spelling of each of the symbols that are being imported:
	// hence we don't want `dlltool` adding leading underscores automatically.
	let dlltool = find_binutils_dlltool(sess);
	let temp_prefix = {
	let mut path = PathBuf::from(&output_path);
	path.pop();
	path.push(lib_name);
	path
	};
	// dlltool target architecture args from:
	// https://github.com/llvm/llvm-project-release-prs/blob/llvmorg-15.0.6/llvm/lib/ToolDrivers/llvm-dlltool/DlltoolDriver.cpp#L69
	let (dlltool_target_arch, dlltool_target_bitness) = match sess.target.arch.as_ref() {
	"x86_64" => ("i386:x86-64", "--64"),
	"x86" => ("i386", "--32"),
	"aarch64" => ("arm64", "--64"),
	"arm" => ("arm", "--32"),
	_ => panic!("unsupported arch {}", sess.target.arch),
	};
	let mut dlltool_cmd = std::process::Command::new(&dlltool);
	dlltool_cmd
	.arg("-d")
	.arg(def_file_path)
	.arg("-D")
	.arg(lib_name)
	.arg("-l")
	.arg(&output_path)
	.arg("-m")
	.arg(dlltool_target_arch)
	.arg("-f")
	.arg(dlltool_target_bitness)
	.arg("--no-leading-underscore")
	.arg("--temp-prefix")
	.arg(temp_prefix);

	match dlltool_cmd.output() {
	Err(e) => {
	sess.dcx().emit_fatal(ErrorCallingDllTool {
	dlltool_path: dlltool.to_string_lossy(),
	error: e,
	});
	}
	// dlltool returns '0' on failure, so check for error output instead.
	Ok(output) if !output.stderr.is_empty() => {
	sess.dcx().emit_fatal(DlltoolFailImportLibrary {
	dlltool_path: dlltool.to_string_lossy(),
	dlltool_args: dlltool_cmd
	.get_args()
	.map(\|arg\| arg.to_string_lossy())
	.collect::<Vec<_>>()
	.join(" "),
	stdout: String::from_utf8_lossy(&output.stdout),
	stderr: String::from_utf8_lossy(&output.stderr),
	})
	}
	_ => {}
	}
	}

	fn find_binutils_dlltool(sess: &Session) -> OsString {
	assert!(sess.target.options.is_like_windows && !sess.target.options.is_like_msvc);
	if let Some(dlltool_path) = &sess.opts.cg.dlltool {
	return dlltool_path.clone().into_os_string();
	}

	let tool_name: OsString = if sess.host.options.is_like_windows {
	// If we're compiling on Windows, always use "dlltool.exe".
	"dlltool.exe"
	} else {
	// On other platforms, use the architecture-specific name.
	match sess.target.arch.as_ref() {
	"x86_64" => "x86_64-w64-mingw32-dlltool",
	"x86" => "i686-w64-mingw32-dlltool",
	"aarch64" => "aarch64-w64-mingw32-dlltool",

	// For non-standard architectures (e.g., aarch32) fallback to "dlltool".
	_ => "dlltool",
	}
	}
	.into();

	// NOTE: it's not clear how useful it is to explicitly search PATH.
	for dir in env::split_paths(&env::var_os("PATH").unwrap_or_default()) {
	let full_path = dir.join(&tool_name);
	if full_path.is_file() {
	return full_path.into_os_string();
	}
	}

	// The user didn't specify the location of the dlltool binary, and we weren't able
	// to find the appropriate one on the PATH. Just return the name of the tool
	// and let the invocation fail with a hopefully useful error message.
	tool_name
	}

	pub trait ArchiveBuilder {
	fn add_file(&mut self, path: &Path);

	fn add_archive(
	&mut self,
	archive: &Path,
	skip: Box<dyn FnMut(&str) -> bool + 'static>,
	) -> io::Result<()>;

	fn build(self: Box<Self>, output: &Path) -> bool;
	}

	pub struct ArArchiveBuilderBuilder;

	impl ArchiveBuilderBuilder for ArArchiveBuilderBuilder {
	fn new_archive_builder<'a>(&self, sess: &'a Session) -> Box<dyn ArchiveBuilder + 'a> {
	Box::new(ArArchiveBuilder::new(sess, &DEFAULT_OBJECT_READER))
	}
	}

	#[must_use = "must call build() to finish building the archive"]
	pub struct ArArchiveBuilder<'a> {
	sess: &'a Session,
	object_reader: &'static ObjectReader,

	src_archives: Vec<(PathBuf, Mmap)>,
	// Don't use an `HashMap` here, as the order is important. `lib.rmeta` needs
	// to be at the end of an archive in some cases for linkers to not get confused.
	entries: Vec<(Vec<u8>, ArchiveEntry)>,
	}

	#[derive(Debug)]
	enum ArchiveEntry {
	FromArchive { archive_index: usize, file_range: (u64, u64) },
	File(PathBuf),
	}

	impl<'a> ArArchiveBuilder<'a> {
	pub fn new(sess: &'a Session, object_reader: &'static ObjectReader) -> ArArchiveBuilder<'a> {
	ArArchiveBuilder { sess, object_reader, src_archives: vec![], entries: vec![] }
	}
	}

	fn try_filter_fat_archs(
	archs: &[impl FatArch],
	target_arch: object::Architecture,
	archive_path: &Path,
	archive_map_data: &[u8],
	) -> io::Result<Option<PathBuf>> {
	let desired = match archs.iter().find(\|a\| a.architecture() == target_arch) {
	Some(a) => a,
	None => return Ok(None),
	};

	let (mut new_f, extracted_path) = tempfile::Builder::new()
	.suffix(archive_path.file_name().unwrap())
	.tempfile()?
	.keep()
	.unwrap();

	new_f.write_all(
	desired.data(archive_map_data).map_err(\|e\| io::Error::new(io::ErrorKind::Other, e))?,
	)?;

	Ok(Some(extracted_path))
	}

	pub fn try_extract_macho_fat_archive(
	sess: &Session,
	archive_path: &Path,
	) -> io::Result<Option<PathBuf>> {
	let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
	let target_arch = match sess.target.arch.as_ref() {
	"aarch64" => object::Architecture::Aarch64,
	"x86_64" => object::Architecture::X86_64,
	_ => return Ok(None),
	};

	if let Ok(h) = object::read::macho::MachOFatFile32::parse(&*archive_map) {
	let archs = h.arches();
	try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
	} else if let Ok(h) = object::read::macho::MachOFatFile64::parse(&*archive_map) {
	let archs = h.arches();
	try_filter_fat_archs(archs, target_arch, archive_path, &*archive_map)
	} else {
	// Not a FatHeader at all, just return None.
	Ok(None)
	}
	}

	impl<'a> ArchiveBuilder for ArArchiveBuilder<'a> {
	fn add_archive(
	&mut self,
	archive_path: &Path,
	mut skip: Box<dyn FnMut(&str) -> bool + 'static>,
	) -> io::Result<()> {
	let mut archive_path = archive_path.to_path_buf();
	if self.sess.target.llvm_target.contains("-apple-macosx")
	&& let Some(new_archive_path) = try_extract_macho_fat_archive(self.sess, &archive_path)?
	{
	archive_path = new_archive_path
	}

	if self.src_archives.iter().any(\|archive\| archive.0 == archive_path) {
	return Ok(());
	}

	let archive_map = unsafe { Mmap::map(File::open(&archive_path)?)? };
	let archive = ArchiveFile::parse(&*archive_map)
	.map_err(\|err\| io::Error::new(io::ErrorKind::InvalidData, err))?;
	let archive_index = self.src_archives.len();

	for entry in archive.members() {
	let entry = entry.map_err(\|err\| io::Error::new(io::ErrorKind::InvalidData, err))?;
	let file_name = String::from_utf8(entry.name().to_vec())
	.map_err(\|err\| io::Error::new(io::ErrorKind::InvalidData, err))?;
	if !skip(&file_name) {
	if entry.is_thin() {
	let member_path = archive_path.parent().unwrap().join(Path::new(&file_name));
	self.entries.push((file_name.into_bytes(), ArchiveEntry::File(member_path)));
	} else {
	self.entries.push((
	file_name.into_bytes(),
	ArchiveEntry::FromArchive { archive_index, file_range: entry.file_range() },
	));
	}
	}
	}

	self.src_archives.push((archive_path, archive_map));
	Ok(())
	}

	/// Adds an arbitrary file to this archive
	fn add_file(&mut self, file: &Path) {
	self.entries.push((
	file.file_name().unwrap().to_str().unwrap().to_string().into_bytes(),
	ArchiveEntry::File(file.to_owned()),
	));
	}

	/// Combine the provided files, rlibs, and native libraries into a single
	/// `Archive`.
	fn build(self: Box<Self>, output: &Path) -> bool {
	let sess = self.sess;
	match self.build_inner(output) {
	Ok(any_members) => any_members,
	Err(error) => {
	sess.dcx().emit_fatal(ArchiveBuildFailure { path: output.to_owned(), error })
	}
	}
	}
	}

	impl<'a> ArArchiveBuilder<'a> {
	fn build_inner(self, output: &Path) -> io::Result<bool> {
	let archive_kind = match &*self.sess.target.archive_format {
	"gnu" => ArchiveKind::Gnu,
	"bsd" => ArchiveKind::Bsd,
	"darwin" => ArchiveKind::Darwin,
	"coff" => ArchiveKind::Coff,
	"aix_big" => ArchiveKind::AixBig,
	kind => {
	self.sess.dcx().emit_fatal(UnknownArchiveKind { kind });
	}
	};

	let mut entries = Vec::new();

	for (entry_name, entry) in self.entries {
	let data =
	match entry {
	ArchiveEntry::FromArchive { archive_index, file_range } => {
	let src_archive = &self.src_archives[archive_index];

	let data = &src_archive.1
	[file_range.0 as usize..file_range.0 as usize + file_range.1 as usize];

	Box::new(data) as Box<dyn AsRef<[u8]>>
	}
	ArchiveEntry::File(file) => unsafe {
	Box::new(
	Mmap::map(File::open(file).map_err(\|err\| {
	io_error_context("failed to open object file", err)
	})?)
	.map_err(\|err\| io_error_context("failed to map object file", err))?,
	) as Box<dyn AsRef<[u8]>>
	},
	};

	entries.push(NewArchiveMember {
	buf: data,
	object_reader: self.object_reader,
	member_name: String::from_utf8(entry_name).unwrap(),
	mtime: 0,
	uid: 0,
	gid: 0,
	perms: 0o644,
	})
	}

	// Write to a temporary file first before atomically renaming to the final name.
	// This prevents programs (including rustc) from attempting to read a partial archive.
	// It also enables writing an archive with the same filename as a dependency on Windows as
	// required by a test.
	// The tempfile crate currently uses 0o600 as mode for the temporary files and directories
	// it creates. We need it to be the default mode for back compat reasons however. (See
	// #107495) To handle this we are telling tempfile to create a temporary directory instead
	// and then inside this directory create a file using File::create.
	let archive_tmpdir = TempDirBuilder::new()
	.suffix(".temp-archive")
	.tempdir_in(output.parent().unwrap_or_else(\|\| Path::new("")))
	.map_err(\|err\| {
	io_error_context("couldn't create a directory for the temp file", err)
	})?;
	let archive_tmpfile_path = archive_tmpdir.path().join("tmp.a");
	let archive_tmpfile = File::create_new(&archive_tmpfile_path)
	.map_err(\|err\| io_error_context("couldn't create the temp file", err))?;

	let mut archive_tmpfile = BufWriter::new(archive_tmpfile);
	write_archive_to_stream(
	&mut archive_tmpfile,
	&entries,
	archive_kind,
	false,
	/* is_ec = */ self.sess.target.arch == "arm64ec",
	)?;
	archive_tmpfile.flush()?;
	drop(archive_tmpfile);

	let any_entries = !entries.is_empty();
	drop(entries);
	// Drop src_archives to unmap all input archives, which is necessary if we want to write the
	// output archive to the same location as an input archive on Windows.
	drop(self.src_archives);

	fs::rename(archive_tmpfile_path, output)
	.map_err(\|err\| io_error_context("failed to rename archive file", err))?;
	archive_tmpdir
	.close()
	.map_err(\|err\| io_error_context("failed to remove temporary directory", err))?;

	Ok(any_entries)
	}
	}

	fn io_error_context(context: &str, err: io::Error) -> io::Error {
	io::Error::new(io::ErrorKind::Other, format!("{context}: {err}"))
	}