naersk/config.nix

{ lib, libb, builtinz, arg }:
let
  allowFun = attrs0: attrName: default:
    if builtins.hasAttr attrName attrs0 then
      if lib.isFunction attrs0.${attrName} then
        attrs0.${attrName} default
      else
        let
          finalTy = builtins.typeOf default;
          actualTy = builtins.typeOf attrs0.${attrName};
        in
          throw "${attrName} should be a function from ${finalTy} to ${finalTy}, but is a ${actualTy}"
    else default;
  mkAttrs = attrs0: rec
  {
    # The name of the derivation.
    name = attrs0.name or null;
    # The version of the derivation.
    version = attrs0.version or null;
    # Used by `naersk` as source input to the derivation. When `root` is not
    # set, `src` is also used to discover the `Cargo.toml` and `Cargo.lock`.
    src = attrs0.src or null;
    # Used by `naersk` to read the `Cargo.toml` and `Cargo.lock` files. May
    # be different from `src`. When `src` is not set, `root` is (indirectly)
    # used as `src`.
    root = attrs0.root or null;

    # The command to use for the build.
    cargoBuild =
      allowFun attrs0 "cargoBuild"
        ''cargo $cargo_options build $cargo_build_options >> $cargo_build_output_json'';

    # Options passed to cargo build, i.e. `cargo build <OPTS>`. These options
    # can be accessed during the build through the environment variable
    # `cargo_build_options`. <br/>
    # Note: naersk relies on the `--out-dir out` option and the
    # `--message-format` option. The `$cargo_message_format` variable is set
    # based on the cargo version.<br/>
    # Note: these values are not (shell) escaped, meaning that you can use
    # environment variables but must be careful when introducing e.g. spaces. <br/>
    cargoBuildOptions =
      allowFun attrs0 "cargoBuildOptions" [ "$cargo_release" ''-j "$NIX_BUILD_CORES"'' "--out-dir" "out" "--message-format=$cargo_message_format" ];

    # When true, `checkPhase` is run.
    doCheck = attrs0.doCheck or true;

    # The commands to run in the `checkPhase`.
    cargoTestCommands =
      allowFun attrs0 "cargoTestCommands" [ ''cargo $cargo_options test $cargo_test_options'' ];

    # Options passed to cargo test, i.e. `cargo test <OPTS>`. These options
    # can be accessed during the build through the environment variable
    # `cargo_test_options`. <br/>
    # Note: these values are not (shell) escaped, meaning that you can use
    # environment variables but must be careful when introducing e.g. spaces. <br/>
    cargoTestOptions =
      allowFun attrs0 "cargoTestOptions" [ "$cargo_release" ''-j "$NIX_BUILD_CORES"'' ];

    # Extra `buildInputs` to all derivations.
    buildInputs = attrs0.buildInputs or [];

    # Options passed to all cargo commands, i.e. `cargo <OPTS> ...`. These
    # options can be accessed during the build through the environment variable
    # `cargo_options`. <br/>
    # Note: these values are not (shell) escaped, meaning that you can use
    # environment variables but must be careful when introducing e.g. spaces. <br/>
    cargoOptions =
      allowFun attrs0 "cargoOptions" [ "-Z" "unstable-options" ];

    # When true, `cargo doc` is run and a new output `doc` is generated.
    doDoc = attrs0.doDoc or false;
    # When true, all cargo builds are run with `--release`. The environment
    # variable `cargo_release` is set to `--release` iff this option is set.
    release = attrs0.release or true;
    # An override for all derivations involved in the build.
    override = attrs0.override or (x: x);
    # When true, no intermediary (dependency-only) build is run. Enabling
    # `singleStep` greatly reduces the incrementality of the builds.
    singleStep = attrs0.singleStep or false;
    # The targets to build if the `Cargo.toml` is a virtual manifest.
    targets = attrs0.targets or null;
    # When true, the resulting binaries are copied to `$out/bin`. <br/>
    # Note: this relies on cargo's `--message-format` argument, set in the
    # default `cargoBuildOptions`.
    copyBins = attrs0.copyBins or true;

    # A [`jq`](https://stedolan.github.io/jq) filter for selecting which build
    # artifacts to release. This is run on cargo's
    # [`--message-format`](https://doc.rust-lang.org/cargo/reference/external-tools.html#json-messages)
    # JSON output. <br/>
    # The value is written to the `cargo_bins_jq_filter` variable.
    copyBinsFilter = attrs0.copyBinsFilter or
      ''select(.reason == "compiler-artifact" and .executable != null and .profile.test == false)'';
    # When true, the documentation is generated in a different output, `doc`.
    copyDocsToSeparateOutput = attrs0.copyDocsToSeparateOutput or true;
    # When true, the build fails if the documentation step fails; otherwise
    # the failure is ignored.
    doDocFail = attrs0.doDocFail or false;
    # When true, references to the nix store are removed from the generated
    # documentation.
    removeReferencesToSrcFromDocs = attrs0.removeReferencesToSrcFromDocs or true;
    # When true, the build output of intermediary builds is compressed with
    # [`Zstandard`](https://facebook.github.io/zstd/). This reduces the size
    # of closures.
    compressTarget = attrs0.compressTarget or true;
    # When true, the `target/` directory is copied to `$out`.
    copyTarget = attrs0.copyTarget or false;
    # Whether to use the `fromTOML` built-in or not. When set to `false` the
    # python package `remarshal` is used instead (in a derivation) and the
    # JSON output is read with `builtins.fromJSON`.
    # This is a workaround for old versions of Nix. May be used safely from
    # Nix 2.3 onwards where all bugs in `builtins.fromTOML` seem to have been
    # fixed.
    usePureFromTOML = attrs0.usePureFromTOML or true;
  };

  argIsAttrs =
    if lib.isDerivation arg then false
    else if lib.isString arg then false
    else if builtins.typeOf arg == "path" then false
    else if builtins.hasAttr "outPath" arg then false
    else true;

  # if the argument is not an attribute set, then assume it's the 'root'.

  attrs =
    if argIsAttrs
    then mkAttrs arg
    else mkAttrs { root = arg; };

  # we differentiate 'src' and 'root'. 'src' is used as source for the build;
  # 'root' is used to find files like 'Cargo.toml'. As often as possible 'root'
  # should be a "path" to avoid reading values from the nix-store.
  # Below we try to come up with some good values for src and root if they're
  # not defined.
  sr =
    let
      hasRoot = ! isNull attrs.root;
      hasSrc = ! isNull attrs.src;
      isPath = x: builtins.typeOf x == "path";
      root = attrs.root;
      src = attrs.src;
    in
      # src: yes, root: no
      if hasSrc && ! hasRoot then
        if isPath src then
          { src = lib.cleanSource src; root = src; }
        else { inherit src; root = src; }
        # src: yes, root: yes
      else if hasRoot && hasSrc then
        { inherit src root; }
        # src: no, root: yes
      else if hasRoot && ! hasSrc then
        if isPath root then
          { inherit root; src = lib.cleanSource root; }
        else
          { inherit root; src = root; }
        # src: no, root: yes
      else throw "please specify either 'src' or 'root'";

  usePureFromTOML = attrs.usePureFromTOML;
  readTOML = builtinz.readTOML usePureFromTOML;

  # config used during build the prebuild and the final build
  buildConfig = {
    inherit (attrs)
      buildInputs
      release
      override
      cargoOptions
      compressTarget

      cargoBuild
      cargoBuildOptions
      copyBins
      copyBinsFilter
      copyTarget

      doCheck
      cargoTestCommands
      cargoTestOptions

      doDoc
      doDocFail
      copyDocsToSeparateOutput
      removeReferencesToSrcFromDocs
      ;

    # The list of _all_ crates (incl. transitive dependencies) with name,
    # version and sha256 of the crate
    # Example:
    #   [ { name = "wabt", version = "2.0.6", sha256 = "..." } ]
    crateDependencies = libb.mkVersions buildPlanConfig.cargolock;
  };

  # config used when planning the builds
  buildPlanConfig = rec {
    inherit (sr) src root;
    # Whether we skip pre-building the deps
    isSingleStep = attrs.singleStep;

    # The members we want to build
    # (list of directory names)
    wantedMembers =
      lib.mapAttrsToList (member: _cargotoml: member) wantedMemberCargotomls;

    # Member path to cargotoml
    # (attrset from directory name to Nix object)
    wantedMemberCargotomls =
      let
        pred =
          if ! isWorkspace
          then (_member: _cargotoml: true)
          else
            if ! isNull attrs.targets
            then (_member: cargotoml: lib.elem cargotoml.package.name attrs.targets)
            else (member: _cargotoml: member != ".");
      in
        lib.filterAttrs pred cargotomls;

    # All cargotomls, from path to nix object
    # (attrset from directory name to Nix object)
    cargotomls =
      let
        readTOML = builtinz.readTOML usePureFromTOML;
      in
        { "." = toplevelCargotoml; } // lib.optionalAttrs isWorkspace
          (
            lib.listToAttrs
              (
                map
                  (
                    member:
                      {
                        name = member;
                        value = readTOML (root + "/${member}/Cargo.toml");
                      }
                  )
                  members
              )
          );

    # The cargo members
    members =
      let
        # the members, as listed in the virtual manifest
        listedMembers = toplevelCargotoml.workspace.members or [];

        # this turns members like "foo/*" into [ "foo/bar" "foo/baz" ]
        # as in https://github.com/rust-analyzer/rust-analyzer/blob/b2ed130ffd9c79de26249a1dfb2a8312d6af12b3/Cargo.toml#L2
        expandMember = member:
          if lib.hasSuffix "/*" member
          then
            let
              rootDir = lib.removeSuffix "/*" member;
              subdirs = builtins.attrNames (builtins.readDir (root + "/${rootDir}"));
            in
              map (subdir: "${rootDir}/${subdir}") subdirs
          else [ member ];

      in
        lib.concatMap expandMember listedMembers;

    patchedSources =
      let
        mkRelative = po:
          if lib.hasPrefix "/" po.path
          then throw "'${toString src}/Cargo.toml' contains the absolute path '${toString po.path}' which is not allowed under a [patch] section by naersk. Please make it relative to '${toString src}'"
          else src + "/" + po.path;
      in
        lib.optionals (builtins.hasAttr "patch" toplevelCargotoml)
          (
            map mkRelative
              (
                lib.collect (as: lib.isAttrs as && builtins.hasAttr "path" as)
                  toplevelCargotoml.patch
              )
          );

    # Are we building a workspace (or is this a simple crate) ?
    isWorkspace = builtins.hasAttr "workspace" toplevelCargotoml;

    # The top level Cargo.toml, either a workspace or package
    toplevelCargotoml = readTOML (root + "/Cargo.toml");

    # The cargo lock
    cargolock = readTOML (root + "/Cargo.lock");

    packageName =
      if ! isNull attrs.name
      then attrs.name
      else toplevelCargotoml.package.name or
        (if isWorkspace then "rust-workspace" else "rust-package");

    packageVersion =
      if ! isNull attrs.version
      then attrs.version
      else toplevelCargotoml.package.version or "unknown";
  };
in
buildPlanConfig // { inherit buildConfig; }