nixpkgs/pkgs/build-support/rust/default.nix

{ stdenv, cacert, git, cargo, rustc, fetchcargo, buildPackages, windows }:

{ name ? "${args.pname}-${args.version}"
, cargoSha256 ? "unset"
, src ? null
, srcs ? null
, cargoPatches ? []
, patches ? []
, sourceRoot ? null
, logLevel ? ""
, buildInputs ? []
, nativeBuildInputs ? []
, cargoUpdateHook ? ""
, cargoDepsHook ? ""
, cargoBuildFlags ? []
, # Set to true to verify if the cargo dependencies are up to date.
  # This will change the value of cargoSha256.
  verifyCargoDeps ? false
, buildType ? "release"
, meta ? {}
, target ? null

, cargoVendorDir ? null
, ... } @ args:

assert cargoVendorDir == null -> cargoSha256 != "unset";
assert buildType == "release" || buildType == "debug";

let
  cargoDeps = if cargoVendorDir == null
    then fetchcargo {
        inherit name src srcs sourceRoot cargoUpdateHook;
        copyLockfile = verifyCargoDeps;
        patches = cargoPatches;
        sha256 = cargoSha256;
      }
    else null;

  setupVendorDir = if cargoVendorDir == null
    then ''
      unpackFile "$cargoDeps"
      cargoDepsCopy=$(stripHash $(basename $cargoDeps))
      chmod -R +w "$cargoDepsCopy"
    ''
    else ''
      cargoDepsCopy="$sourceRoot/${cargoVendorDir}"
    '';

  hostConfig = stdenv.hostPlatform.config;

  rustHostConfig = {
    x86_64-pc-mingw32 = "x86_64-pc-windows-gnu";
  }.${hostConfig} or hostConfig;
  rustTarget = if target == null then rustHostConfig else target;

  ccForBuild="${buildPackages.stdenv.cc}/bin/${buildPackages.stdenv.cc.targetPrefix}cc";
  cxxForBuild="${buildPackages.stdenv.cc}/bin/${buildPackages.stdenv.cc.targetPrefix}c++";
  ccForHost="${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";
  cxxForHost="${stdenv.cc}/bin/${stdenv.cc.targetPrefix}c++";
  releaseDir = "target/${rustTarget}/${buildType}";
in

stdenv.mkDerivation (args // {
  inherit cargoDeps;

  patchRegistryDeps = ./patch-registry-deps;

  nativeBuildInputs = nativeBuildInputs ++ [ cacert git cargo rustc ];
  buildInputs = buildInputs ++ stdenv.lib.optional stdenv.hostPlatform.isMinGW windows.pthreads;

  patches = cargoPatches ++ patches;

  PKG_CONFIG_ALLOW_CROSS =
    if stdenv.buildPlatform != stdenv.hostPlatform then 1 else 0;

  postUnpack = ''
    eval "$cargoDepsHook"

    ${setupVendorDir}

    mkdir .cargo
    config="$(pwd)/$cargoDepsCopy/.cargo/config";
    if [[ ! -e $config ]]; then
      config=${./fetchcargo-default-config.toml};
    fi;
    substitute $config .cargo/config \
      --subst-var-by vendor "$(pwd)/$cargoDepsCopy"

    cat >> .cargo/config <<'EOF'
    [target."${stdenv.buildPlatform.config}"]
    "linker" = "${ccForBuild}"
    ${stdenv.lib.optionalString (stdenv.buildPlatform.config != stdenv.hostPlatform.config) ''
    [target."${rustTarget}"]
    "linker" = "${ccForHost}"
    ${# https://github.com/rust-lang/rust/issues/46651#issuecomment-433611633
      stdenv.lib.optionalString (stdenv.hostPlatform.isMusl && stdenv.hostPlatform.isAarch64) ''
    "rustflags" = [ "-C", "target-feature=+crt-static", "-C", "link-arg=-lgcc" ]
    ''}
    ''}
    EOF

    unset cargoDepsCopy
    export RUST_LOG=${logLevel}
  '' + stdenv.lib.optionalString verifyCargoDeps ''
    if ! diff source/Cargo.lock $cargoDeps/Cargo.lock ; then
      echo
      echo "ERROR: cargoSha256 is out of date."
      echo
      echo "Cargo.lock is not the same in $cargoDeps."
      echo
      echo "To fix the issue:"
      echo '1. Use "1111111111111111111111111111111111111111111111111111" as the cargoSha256 value'
      echo "2. Build the derivation and wait it to fail with a hash mismatch"
      echo "3. Copy the 'got: sha256:' value back into the cargoSha256 field"
      echo

      exit 1
    fi
  '' + (args.postUnpack or "");

  configurePhase = args.configurePhase or ''
    runHook preConfigure
    runHook postConfigure
  '';

  buildPhase = with builtins; args.buildPhase or ''
    runHook preBuild

    (
    set -x
    env \
      "CC_${stdenv.buildPlatform.config}"="${ccForBuild}" \
      "CXX_${stdenv.buildPlatform.config}"="${cxxForBuild}" \
      "CC_${stdenv.hostPlatform.config}"="${ccForHost}" \
      "CXX_${stdenv.hostPlatform.config}"="${cxxForHost}" \
      cargo build \
        ${stdenv.lib.optionalString (buildType == "release") "--release"} \
        --target ${rustTarget} \
        --frozen ${concatStringsSep " " cargoBuildFlags}
    )

    # rename the output dir to a architecture independent one
    mapfile -t targets < <(find "$NIX_BUILD_TOP" -type d | grep '${releaseDir}$')
    for target in "''${targets[@]}"; do
      rm -rf "$target/../../${buildType}"
      ln -srf "$target" "$target/../../"
    done

    runHook postBuild
  '';

  checkPhase = args.checkPhase or ''
    runHook preCheck
    echo "Running cargo test"
    cargo test
    runHook postCheck
  '';

  doCheck = args.doCheck or true;

  inherit releaseDir;

  installPhase = args.installPhase or ''
    runHook preInstall
    mkdir -p $out/bin $out/lib

    find $releaseDir \
      -maxdepth 1 \
      -type f \
      -executable ! \( -regex ".*\.\(so.[0-9.]+\|so\|a\|dylib\)" \) \
      -print0 | xargs -r -0 cp -t $out/bin
    find $releaseDir \
      -maxdepth 1 \
      -regex ".*\.\(so.[0-9.]+\|so\|a\|dylib\)" \
      -print0 | xargs -r -0 cp -t $out/lib
    rmdir --ignore-fail-on-non-empty $out/lib $out/bin
    runHook postInstall
  '';

  passthru = { inherit cargoDeps; } // (args.passthru or {});

  meta = {
    # default to Rust's platforms
    platforms = rustc.meta.platforms;
  } // meta;
})