rustc.nix

{
  lib,
  stdenv,
  removeReferencesTo,
  pkgsBuildBuild,
  pkgsBuildHost,
  pkgsBuildTarget,
  targetPackages,
  llvmShared,
  llvmSharedForBuild,
  llvmSharedForHost,
  llvmSharedForTarget,
  llvmPackages,
  runCommandLocal,
  fetchurl,
  file,
  python3,
  darwin,
  cargo,
  cmake,
  rustc,
  rustfmt,
  pkg-config,
  openssl,
  xz,
  zlib,
  bintools,
  libiconv,
  which,
  libffi,
  withBundledLLVM ? false,
  enableRustcDev ? true,
  version,
  sha256,
  patches ? [ ],
  fd,
  ripgrep,
  wezterm,
  firefox,
  thunderbird,
  # This only builds std for target and reuses the rustc from build.
  fastCross,
  lndir,
  makeWrapper,
}:

let
  inherit (lib)
    optionals
    optional
    optionalString
    concatStringsSep
    ;
  inherit (darwin.apple_sdk.frameworks) Security;
  useLLVM = stdenv.targetPlatform.useLLVM or false;
in
stdenv.mkDerivation (finalAttrs: {
  pname = "${targetPackages.stdenv.cc.targetPrefix}rustc";
  inherit version;

  src = fetchurl {
    url = "https://static.rust-lang.org/dist/rustc-${version}-src.tar.gz";
    inherit sha256;
    # See https://nixos.org/manual/nixpkgs/stable/#using-git-bisect-on-the-rust-compiler
    passthru.isReleaseTarball = true;
  };

  hardeningDisable = optionals stdenv.cc.isClang [
    # remove once https://github.com/NixOS/nixpkgs/issues/318674 is
    # addressed properly
    "zerocallusedregs"
  ];

  __darwinAllowLocalNetworking = true;

  # rustc complains about modified source files otherwise
  dontUpdateAutotoolsGnuConfigScripts = true;

  # Running the default `strip -S` command on Darwin corrupts the
  # .rlib files in "lib/".
  #
  # See https://github.com/NixOS/nixpkgs/pull/34227
  #
  # Running `strip -S` when cross compiling can harm the cross rlibs.
  # See: https://github.com/NixOS/nixpkgs/pull/56540#issuecomment-471624656
  stripDebugList = [ "bin" ];

  # The Rust pkg-config crate does not support prefixed pkg-config executables[1],
  # but it does support checking these idiosyncratic PKG_CONFIG_${TRIPLE}
  # environment variables.
  # [1]: https://github.com/rust-lang/pkg-config-rs/issues/53
  "PKG_CONFIG_${builtins.replaceStrings [ "-" ] [ "_" ] stdenv.buildPlatform.rust.rustcTarget}" =
    "${pkgsBuildHost.stdenv.cc.targetPrefix}pkg-config";

  NIX_LDFLAGS = toString (
    # when linking stage1 libstd: cc: undefined reference to `__cxa_begin_catch'
    # This doesn't apply to cross-building for FreeBSD because the host
    # uses libstdc++, but the target (used for building std) uses libc++
    optional (
      stdenv.hostPlatform.isLinux && !withBundledLLVM && !stdenv.targetPlatform.isFreeBSD && !useLLVM
    ) "--push-state --as-needed -lstdc++ --pop-state"
    ++
      optional
        (stdenv.hostPlatform.isLinux && !withBundledLLVM && !stdenv.targetPlatform.isFreeBSD && useLLVM)
        "--push-state --as-needed -L${llvmPackages.libcxx}/lib -lc++ -lc++abi -lLLVM-${lib.versions.major llvmPackages.llvm.version} --pop-state"
    ++ optional (stdenv.hostPlatform.isDarwin && !withBundledLLVM) "-lc++ -lc++abi"
    ++ optional stdenv.hostPlatform.isFreeBSD "-rpath ${llvmPackages.libunwind}/lib"
    ++ optional stdenv.hostPlatform.isDarwin "-rpath ${llvmSharedForHost.lib}/lib"
  );

  # Increase codegen units to introduce parallelism within the compiler.
  RUSTFLAGS = "-Ccodegen-units=10";
  RUSTDOCFLAGS = "-A rustdoc::broken-intra-doc-links";

  # We need rust to build rust. If we don't provide it, configure will try to download it.
  # Reference: https://github.com/rust-lang/rust/blob/master/src/bootstrap/configure.py
  configureFlags =
    let
      prefixForStdenv = stdenv: "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}";
      ccPrefixForStdenv =
        stdenv: "${prefixForStdenv stdenv}${if (stdenv.cc.isClang or false) then "clang" else "cc"}";
      cxxPrefixForStdenv =
        stdenv: "${prefixForStdenv stdenv}${if (stdenv.cc.isClang or false) then "clang++" else "c++"}";
      setBuild = "--set=target.${stdenv.buildPlatform.rust.rustcTarget}";
      setHost = "--set=target.${stdenv.hostPlatform.rust.rustcTarget}";
      setTarget = "--set=target.${stdenv.targetPlatform.rust.rustcTarget}";
      ccForBuild = ccPrefixForStdenv pkgsBuildBuild.targetPackages.stdenv;
      cxxForBuild = cxxPrefixForStdenv pkgsBuildBuild.targetPackages.stdenv;
      ccForHost = ccPrefixForStdenv pkgsBuildHost.targetPackages.stdenv;
      cxxForHost = cxxPrefixForStdenv pkgsBuildHost.targetPackages.stdenv;
      ccForTarget = ccPrefixForStdenv pkgsBuildTarget.targetPackages.stdenv;
      cxxForTarget = cxxPrefixForStdenv pkgsBuildTarget.targetPackages.stdenv;
    in
    [
      "--sysconfdir=${placeholder "out"}/etc"
      "--release-channel=stable"
      "--set=build.rustc=${rustc}/bin/rustc"
      "--set=build.cargo=${cargo}/bin/cargo"
    ]
    ++ lib.optionals (!(finalAttrs.src.passthru.isReleaseTarball or false)) [
      # release tarballs vendor the rustfmt source; when
      # git-bisect'ing from upstream's git repo we must prevent
      # attempts to download the missing source tarball
      "--set=build.rustfmt=${rustfmt}/bin/rustfmt"
    ]
    ++ [
      "--tools=rustc,rustdoc,rust-analyzer-proc-macro-srv"
      "--enable-rpath"
      "--enable-vendor"
      # For Nixpkgs it makes more sense to use stdenv's linker than
      # letting rustc build its own.
      "--disable-lld"
      "--build=${stdenv.buildPlatform.rust.rustcTargetSpec}"
      "--host=${stdenv.hostPlatform.rust.rustcTargetSpec}"
      # std is built for all platforms in --target.
      "--target=${
        concatStringsSep "," (
          [
            stdenv.targetPlatform.rust.rustcTargetSpec

            # Other targets that don't need any extra dependencies to build.
          ]
          ++ optionals (!fastCross) [
            "wasm32-unknown-unknown"

            # (build!=target): When cross-building a compiler we need to add
            # the build platform as well so rustc can compile build.rs
            # scripts.
          ]
          ++ optionals (stdenv.buildPlatform != stdenv.targetPlatform && !fastCross) [
            stdenv.buildPlatform.rust.rustcTargetSpec

            # (host!=target): When building a cross-targeting compiler we
            # need to add the host platform as well so rustc can compile
            # build.rs scripts.
          ]
          ++ optionals (stdenv.hostPlatform != stdenv.targetPlatform && !fastCross) [
            stdenv.hostPlatform.rust.rustcTargetSpec
          ]
        )
      }"

      "${setBuild}.cc=${ccForBuild}"
      "${setHost}.cc=${ccForHost}"
      "${setTarget}.cc=${ccForTarget}"

      "${setBuild}.linker=${ccForBuild}"
      "${setHost}.linker=${ccForHost}"
      "${setTarget}.linker=${ccForTarget}"

      "${setBuild}.cxx=${cxxForBuild}"
      "${setHost}.cxx=${cxxForHost}"
      "${setTarget}.cxx=${cxxForTarget}"

      "${setBuild}.crt-static=${lib.boolToString stdenv.buildPlatform.isStatic}"
      "${setHost}.crt-static=${lib.boolToString stdenv.hostPlatform.isStatic}"
      "${setTarget}.crt-static=${lib.boolToString stdenv.targetPlatform.isStatic}"
    ]
    ++ optionals (!withBundledLLVM) [
      "--enable-llvm-link-shared"
      "${setBuild}.llvm-config=${llvmSharedForBuild.dev}/bin/llvm-config"
      "${setHost}.llvm-config=${llvmSharedForHost.dev}/bin/llvm-config"
      "${setTarget}.llvm-config=${llvmSharedForTarget.dev}/bin/llvm-config"
    ]
    ++ optionals fastCross [
      # Since fastCross only builds std, it doesn't make sense (and
      # doesn't work) to build a linker.
      "--disable-llvm-bitcode-linker"
    ]
    ++ optionals (stdenv.targetPlatform.isLinux && !(stdenv.targetPlatform.useLLVM or false)) [
      "--enable-profiler" # build libprofiler_builtins
    ]
    ++ optionals stdenv.buildPlatform.isMusl [
      "${setBuild}.musl-root=${pkgsBuildBuild.targetPackages.stdenv.cc.libc}"
    ]
    ++ optionals stdenv.hostPlatform.isMusl [
      "${setHost}.musl-root=${pkgsBuildHost.targetPackages.stdenv.cc.libc}"
    ]
    ++ optionals stdenv.targetPlatform.isMusl [
      "${setTarget}.musl-root=${pkgsBuildTarget.targetPackages.stdenv.cc.libc}"
    ]
    ++ optionals stdenv.targetPlatform.rust.isNoStdTarget [
      "--disable-docs"
    ]
    ++ optionals (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isx86_64) [
      # https://github.com/rust-lang/rust/issues/92173
      "--set rust.jemalloc"
    ]
    ++ optionals (useLLVM && !stdenv.targetPlatform.isFreeBSD) [
      # https://github.com/NixOS/nixpkgs/issues/311930
      "--llvm-libunwind=${if withBundledLLVM then "in-tree" else "system"}"
      "--enable-use-libcxx"
    ];

  # if we already have a rust compiler for build just compile the target std
  # library and reuse compiler
  buildPhase =
    if fastCross then
      "
    runHook preBuild

    mkdir -p build/${stdenv.hostPlatform.rust.rustcTargetSpec}/stage0-{std,rustc}/${stdenv.hostPlatform.rust.rustcTargetSpec}/release/
    ln -s ${rustc.unwrapped}/lib/rustlib/${stdenv.hostPlatform.rust.rustcTargetSpec}/libstd-*.so build/${stdenv.hostPlatform.rust.rustcTargetSpec}/stage0-std/${stdenv.hostPlatform.rust.rustcTargetSpec}/release/libstd.so
    ln -s ${rustc.unwrapped}/lib/rustlib/${stdenv.hostPlatform.rust.rustcTargetSpec}/librustc_driver-*.so build/${stdenv.hostPlatform.rust.rustcTargetSpec}/stage0-rustc/${stdenv.hostPlatform.rust.rustcTargetSpec}/release/librustc.so
    ln -s ${rustc.unwrapped}/bin/rustc build/${stdenv.hostPlatform.rust.rustcTargetSpec}/stage0-rustc/${stdenv.hostPlatform.rust.rustcTargetSpec}/release/rustc-main
    touch build/${stdenv.hostPlatform.rust.rustcTargetSpec}/stage0-std/${stdenv.hostPlatform.rust.rustcTargetSpec}/release/.libstd.stamp
    touch build/${stdenv.hostPlatform.rust.rustcTargetSpec}/stage0-rustc/${stdenv.hostPlatform.rust.rustcTargetSpec}/release/.librustc.stamp
    python ./x.py --keep-stage=0 --stage=1 build library

    runHook postBuild
  "
    else
      null;

  installPhase =
    if fastCross then
      ''
        runHook preInstall

        python ./x.py --keep-stage=0 --stage=1 install library/std
        mkdir -v $out/bin $doc $man
        ln -s ${rustc.unwrapped}/bin/{rustc,rustdoc} $out/bin
        rm -rf -v $out/lib/rustlib/{manifest-rust-std-,}${stdenv.hostPlatform.rust.rustcTargetSpec}
        ln -s ${rustc.unwrapped}/lib/rustlib/{manifest-rust-std-,}${stdenv.hostPlatform.rust.rustcTargetSpec} $out/lib/rustlib/
        echo rust-std-${stdenv.hostPlatform.rust.rustcTargetSpec} >> $out/lib/rustlib/components
        lndir ${rustc.doc} $doc
        lndir ${rustc.man} $man

        runHook postInstall
      ''
    else
      null;

  # the rust build system complains that nix alters the checksums
  dontFixLibtool = true;

  inherit patches;

  postPatch =
    ''
      patchShebangs src/etc

      # rust-lld is the name rustup uses for its bundled lld, so that it
      # doesn't conflict with any system lld.  This is not an
      # appropriate default for Nixpkgs, where there is no rust-lld.
      substituteInPlace compiler/rustc_target/src/spec/*/*.rs \
        --replace-quiet '"rust-lld"' '"lld"'

      ${optionalString (!withBundledLLVM) "rm -rf src/llvm"}

      # Useful debugging parameter
      # export VERBOSE=1
    ''
    + lib.optionalString (stdenv.hostPlatform.isDarwin || stdenv.targetPlatform.isDarwin) ''
      # Replace hardcoded path to strip with llvm-strip
      # https://github.com/NixOS/nixpkgs/issues/299606
      substituteInPlace compiler/rustc_codegen_ssa/src/back/link.rs \
        --replace-fail "/usr/bin/strip" "${lib.getExe' llvmShared "llvm-strip"}"
    ''
    + lib.optionalString (stdenv.hostPlatform.isDarwin && stdenv.hostPlatform.isx86_64) ''
      # See https://github.com/jemalloc/jemalloc/issues/1997
      # Using a value of 48 should work on both emulated and native x86_64-darwin.
      export JEMALLOC_SYS_WITH_LG_VADDR=48
    ''
    + lib.optionalString (!(finalAttrs.src.passthru.isReleaseTarball or false)) ''
      mkdir .cargo
      cat > .cargo/config.toml <<\EOF
      [source.crates-io]
      replace-with = "vendored-sources"
      [source.vendored-sources]
      directory = "vendor"
      EOF
    ''
    + lib.optionalString (stdenv.hostPlatform.isFreeBSD) ''
      # lzma-sys bundles an old version of xz that doesn't build
      # on modern FreeBSD, use the system one instead
      substituteInPlace src/bootstrap/src/core/build_steps/tool.rs \
          --replace 'cargo.env("LZMA_API_STATIC", "1");' ' '
    '';

  # rustc unfortunately needs cmake to compile llvm-rt but doesn't
  # use it for the normal build. This disables cmake in Nix.
  dontUseCmakeConfigure = true;

  depsBuildBuild = [
    pkgsBuildHost.stdenv.cc
    pkg-config
  ];
  depsBuildTarget = lib.optionals stdenv.targetPlatform.isMinGW [ bintools ];

  nativeBuildInputs =
    [
      file
      python3
      rustc
      cmake
      which
      libffi
      removeReferencesTo
      pkg-config
      xz
    ]
    ++ optionals fastCross [
      lndir
      makeWrapper
    ];

  buildInputs =
    [ openssl ]
    ++ optionals stdenv.hostPlatform.isDarwin [
      libiconv
      Security
      zlib
    ]
    ++ optional (!withBundledLLVM) llvmShared.lib
    ++ optional (useLLVM && !withBundledLLVM && !stdenv.targetPlatform.isFreeBSD) [
      llvmPackages.libunwind
      # Hack which is used upstream https://github.com/gentoo/gentoo/blob/master/dev-lang/rust/rust-1.78.0.ebuild#L284
      (runCommandLocal "libunwind-libgcc" { } ''
        mkdir -p $out/lib
        ln -s ${llvmPackages.libunwind}/lib/libunwind.so $out/lib/libgcc_s.so
        ln -s ${llvmPackages.libunwind}/lib/libunwind.so $out/lib/libgcc_s.so.1
      '')
    ];

  outputs = [
    "out"
    "man"
    "doc"
  ];
  setOutputFlags = false;

  postInstall =
    lib.optionalString (enableRustcDev && !fastCross) ''
      # install rustc-dev components. Necessary to build rls, clippy...
      python x.py dist rustc-dev
      tar xf build/dist/rustc-dev*tar.gz
      cp -r rustc-dev*/rustc-dev*/lib/* $out/lib/
      rm $out/lib/rustlib/install.log
      for m in $out/lib/rustlib/manifest-rust*
      do
        sort --output=$m < $m
      done

    ''
    + ''
      # remove references to llvm-config in lib/rustlib/x86_64-unknown-linux-gnu/codegen-backends/librustc_codegen_llvm-llvm.so
      # and thus a transitive dependency on ncurses
      find $out/lib -name "*.so" -type f -exec remove-references-to -t ${llvmShared} '{}' '+'

      # remove uninstall script that doesn't really make sense for Nix.
      rm $out/lib/rustlib/uninstall.sh
    '';

  configurePlatforms = [ ];

  enableParallelBuilding = true;

  setupHooks = ./setup-hook.sh;

  requiredSystemFeatures = [ "big-parallel" ];

  passthru = {
    llvm = llvmShared;
    inherit llvmPackages;
    inherit (rustc) tier1TargetPlatforms targetPlatforms badTargetPlatforms;
    tests = {
      inherit fd ripgrep wezterm;
    } // lib.optionalAttrs stdenv.hostPlatform.isLinux { inherit firefox thunderbird; };
  };

  meta = with lib; {
    homepage = "https://www.rust-lang.org/";
    description = "Safe, concurrent, practical language";
    maintainers = with maintainers; [ havvy ] ++ teams.rust.members;
    license = [
      licenses.mit
      licenses.asl20
    ];
    platforms = rustc.tier1TargetPlatforms;
    # If rustc can't target a platform, we also can't build rustc for
    # that platform.
    badPlatforms = rustc.badTargetPlatforms;
  };
})