depot/pkgs/development/julia-modules/default.nix

{
  callPackage,
  fetchgit,
  fontconfig,
  git,
  lib,
  makeWrapper,
  python3,
  runCommand,
  system,
  writeText,
  writeTextFile,

  # Artifacts dependencies
  fetchurl,
  glibc,
  pkgs,
  stdenv,

  julia,

  # Special registry which is equal to JuliaRegistries/General, but every Versions.toml
  # entry is augmented with a Nix sha256 hash
  augmentedRegistry ? callPackage ./registry.nix { },

  # Other overridable arguments
  extraLibs ? [ ],
  juliaCpuTarget ? null,
  makeTransitiveDependenciesImportable ? false, # Used to support symbol indexing
  makeWrapperArgs ? "",
  packageOverrides ? { },
  precompile ? true,
  setDefaultDepot ? true,
}:

packageNames:

let
  util = callPackage ./util.nix { };

  # Some Julia packages require access to Python. Provide a Nixpkgs version so it
  # doesn't try to install its own.
  pythonToUse =
    let
      extraPythonPackages = (
        (callPackage ./extra-python-packages.nix { inherit python3; }).getExtraPythonPackages packageNames
      );
    in
    (
      if extraPythonPackages == [ ] then
        python3
      else
        util.addPackagesToPython python3 (map (pkg: lib.getAttr pkg python3.pkgs) extraPythonPackages)
    );

  # Start by wrapping Julia so it has access to Python and any other extra libs.
  # Also, prevent various packages (CondaPkg.jl, PythonCall.jl) from trying to do network calls.
  juliaWrapped =
    runCommand "julia-${julia.version}-wrapped"
      {
        nativeBuildInputs = [ makeWrapper ];
        inherit makeWrapperArgs;
      }
      ''
        mkdir -p $out/bin
        makeWrapper ${julia}/bin/julia $out/bin/julia \
          --suffix LD_LIBRARY_PATH : "${lib.makeLibraryPath extraLibs}" \
          --set FONTCONFIG_FILE ${fontconfig.out}/etc/fonts/fonts.conf \
          --set PYTHONHOME "${pythonToUse}" \
          --prefix PYTHONPATH : "${pythonToUse}/${pythonToUse.sitePackages}" \
          --set PYTHON ${pythonToUse}/bin/python $makeWrapperArgs \
          --set JULIA_CONDAPKG_OFFLINE yes \
          --set JULIA_CONDAPKG_BACKEND Null \
          --set JULIA_PYTHONCALL_EXE "@PyCall"
      '';

  # If our closure ends up with certain packages, add others.
  packageImplications = {
    # Because we want to put PythonCall in PyCall mode so it doesn't try to download
    # Python packages
    PythonCall = [ "PyCall" ];
  };

  # Invoke Julia resolution logic to determine the full dependency closure
  packageOverridesRepoified = lib.mapAttrs util.repoifySimple packageOverrides;
  closureYaml = callPackage ./package-closure.nix {
    inherit
      augmentedRegistry
      julia
      packageNames
      packageImplications
      ;
    packageOverrides = packageOverridesRepoified;
  };

  # Generate a Nix file consisting of a map from dependency UUID --> package info with fetchgit call:
  # {
  #   "77ba4419-2d1f-58cd-9bb1-8ffee604a2e3" = {
  #     src = fetchgit {...};
  #     name = "...";
  #     version = "...";
  #     treehash = "...";
  #   };
  #   ...
  # }
  dependencies =
    runCommand "julia-sources.nix"
      {
        buildInputs = [
          (python3.withPackages (
            ps: with ps; [
              toml
              pyyaml
            ]
          ))
          git
        ];
      }
      ''
        python ${./python}/sources_nix.py \
          "${augmentedRegistry}" \
          '${lib.generators.toJSON { } packageOverridesRepoified}' \
          "${closureYaml}" \
          "$out"
      '';

  # Import the Nix file from the previous step (IFD) and turn each dependency repo into
  # a dummy Git repository, as Julia expects. Format the results as a YAML map from
  # dependency UUID -> Nix store location:
  # {
  #   "77ba4419-2d1f-58cd-9bb1-8ffee604a2e3":"/nix/store/...-NaNMath.jl-0877504",
  #   ...
  # }
  # This is also the point where we apply the packageOverrides.
  dependencyUuidToInfo = import dependencies { inherit fetchgit; };
  fillInOverrideSrc =
    uuid: info:
    if lib.hasAttr info.name packageOverrides then
      (info // { src = lib.getAttr info.name packageOverrides; })
    else
      info;
  dependencyUuidToRepo = lib.mapAttrs util.repoifyInfo (
    lib.mapAttrs fillInOverrideSrc dependencyUuidToInfo
  );
  dependencyUuidToRepoYaml = writeTextFile {
    name = "dependency-uuid-to-repo.yml";
    text = lib.generators.toYAML { } dependencyUuidToRepo;
  };

  # Given the augmented registry, closure info yaml, and dependency path yaml, construct a complete
  # Julia registry containing all the necessary packages
  dependencyUuidToInfoYaml = writeTextFile {
    name = "dependency-uuid-to-info.yml";
    text = lib.generators.toYAML { } dependencyUuidToInfo;
  };
  fillInOverrideSrc' =
    uuid: info:
    if lib.hasAttr info.name packageOverridesRepoified then
      (info // { src = lib.getAttr info.name packageOverridesRepoified; })
    else
      info;
  overridesOnly = lib.mapAttrs fillInOverrideSrc' (
    lib.filterAttrs (uuid: info: info.src == null) dependencyUuidToInfo
  );
  minimalRegistry =
    runCommand "minimal-julia-registry"
      {
        buildInputs = [
          (python3.withPackages (
            ps: with ps; [
              toml
              pyyaml
            ]
          ))
          git
        ];
      }
      ''
        python ${./python}/minimal_registry.py \
          "${augmentedRegistry}" \
          "${closureYaml}" \
          '${lib.generators.toJSON { } overridesOnly}' \
          "${dependencyUuidToRepoYaml}" \
          "$out"
      '';

  # Next, deal with artifacts. Scan each artifacts file individually and generate a Nix file that
  # produces the desired Overrides.toml.
  artifactsNix =
    runCommand "julia-artifacts.nix"
      {
        buildInputs = [
          (python3.withPackages (
            ps: with ps; [
              toml
              pyyaml
            ]
          ))
        ];
      }
      ''
        python ${./python}/extract_artifacts.py \
          "${dependencyUuidToRepoYaml}" \
          "${closureYaml}" \
          "${juliaWrapped}/bin/julia" \
          "${
            if lib.versionAtLeast julia.version "1.7" then ./extract_artifacts.jl else ./extract_artifacts_16.jl
          }" \
          '${lib.generators.toJSON { } (import ./extra-libs.nix)}' \
          '${lib.generators.toJSON { } (stdenv.hostPlatform.isDarwin)}' \
          "$out"
      '';

  # Import the artifacts Nix to build Overrides.toml (IFD)
  artifacts = import artifactsNix (
    {
      inherit
        lib
        fetchurl
        pkgs
        stdenv
        ;
    }
    // lib.optionalAttrs (!stdenv.targetPlatform.isDarwin) {
      inherit glibc;
    }
  );
  overridesJson = writeTextFile {
    name = "Overrides.json";
    text = lib.generators.toJSON { } artifacts;
  };
  overridesToml =
    runCommand "Overrides.toml" { buildInputs = [ (python3.withPackages (ps: with ps; [ toml ])) ]; }
      ''
        python ${./python}/format_overrides.py \
          "${overridesJson}" \
          "$out"
      '';

  # Build a Julia project and depot. The project contains Project.toml/Manifest.toml, while the
  # depot contains package build products (including the precompiled libraries, if precompile=true)
  projectAndDepot = callPackage ./depot.nix {
    inherit
      closureYaml
      extraLibs
      juliaCpuTarget
      overridesToml
      packageImplications
      precompile
      ;
    julia = juliaWrapped;
    registry = minimalRegistry;
    packageNames =
      if makeTransitiveDependenciesImportable then
        lib.mapAttrsToList (uuid: info: info.name) dependencyUuidToInfo
      else
        packageNames;
  };

in

runCommand "julia-${julia.version}-env"
  {
    nativeBuildInputs = [ makeWrapper ];

    passthru = {
      inherit julia;
      inherit juliaWrapped;
      inherit (julia) pname version meta;

      # Expose the steps we used along the way in case the user wants to use them, for example to build
      # expressions and build them separately to avoid IFD.
      inherit dependencies;
      inherit closureYaml;
      inherit dependencyUuidToInfoYaml;
      inherit dependencyUuidToRepoYaml;
      inherit minimalRegistry;
      inherit artifactsNix;
      inherit overridesJson;
      inherit overridesToml;
      inherit projectAndDepot;
    };
  }
  (
    ''
      mkdir -p $out/bin
      makeWrapper ${juliaWrapped}/bin/julia $out/bin/julia \
        --suffix JULIA_DEPOT_PATH : "${projectAndDepot}/depot" \
        --set-default JULIA_PROJECT "${projectAndDepot}/project" \
        --set-default JULIA_LOAD_PATH '@:${projectAndDepot}/project/Project.toml:@v#.#:@stdlib'
    ''
    + lib.optionalString setDefaultDepot ''
      sed -i '2 i\JULIA_DEPOT_PATH=''${JULIA_DEPOT_PATH-"$HOME/.julia"}' $out/bin/julia
    ''
  )