core/pkgs/build-support/rust/build-rust-crate/build-crate.nix

{ lib, stdenv, mkRustcDepArgs, mkRustcFeatureArgs, needUnstableCLI }:

{ crateName, dependencies, crateFeatures, crateRenames, libName, release
, libPath, crateType, metadata, crateBin, hasCrateBin, extraRustcOpts, verbose
, colors, buildTests, codegenUnits }:

let
  baseRustcOpts = [
    (if release then "-C opt-level=3" else "-C debuginfo=2")
    "-C codegen-units=${toString codegenUnits}"
    "--remap-path-prefix=$NIX_BUILD_TOP=/"
    (mkRustcDepArgs dependencies crateRenames)
    (mkRustcFeatureArgs crateFeatures)
  ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
    "--target"
    stdenv.hostPlatform.rust.rustcTargetSpec
  ] ++ lib.optionals (needUnstableCLI dependencies) [ "-Z" "unstable-options" ]
    ++ extraRustcOpts
    # since rustc 1.42 the "proc_macro" crate is part of the default crate prelude
    # https://github.com/rust-lang/cargo/commit/4d64eb99a4#diff-7f98585dbf9d30aa100c8318e2c77e79R1021-R1022
    ++ lib.optional (lib.elem "proc-macro" crateType) "--extern proc_macro";
  rustcMeta = "-C metadata=${metadata} -C extra-filename=-${metadata}";

  # build the final rustc arguments that can be different between different
  # crates
  libRustcOpts = lib.concatStringsSep " " (baseRustcOpts ++ [ rustcMeta ]
    ++ (map (x: "--crate-type ${x}") crateType));

  binRustcOpts = lib.concatStringsSep " "
    ([ "-C linker=${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc" ]
      ++ baseRustcOpts);

  build_bin = if buildTests then "build_bin_test" else "build_bin";
in ''
  runHook preBuild

  # configure & source common build functions
  LIB_RUSTC_OPTS="${libRustcOpts}"
  BIN_RUSTC_OPTS="${binRustcOpts}"
  LIB_EXT="${stdenv.hostPlatform.extensions.sharedLibrary or ""}"
  LIB_PATH="${libPath}"
  LIB_NAME="${libName}"

  CRATE_NAME='${lib.replaceStrings [ "-" ] [ "_" ] libName}'

  setup_link_paths

  if [[ -e "$LIB_PATH" ]]; then
     build_lib "$LIB_PATH"
     ${lib.optionalString buildTests ''build_lib_test "$LIB_PATH"''}
  elif [[ -e src/lib.rs ]]; then
     build_lib src/lib.rs
     ${lib.optionalString buildTests "build_lib_test src/lib.rs"}
  fi



  ${lib.optionalString (lib.length crateBin > 0) (lib.concatMapStringsSep "\n"
    (bin:
      let
        haveRequiredFeature = if bin ? requiredFeatures then
        # Check that all element in requiredFeatures are also present in crateFeatures
          lib.intersectLists bin.requiredFeatures crateFeatures
          == bin.requiredFeatures
        else
          true;
      in if haveRequiredFeature then ''
        mkdir -p target/bin
        BIN_NAME='${bin.name or crateName}'
        ${if !bin ? path then ''
          BIN_PATH=""
          search_for_bin_path "$BIN_NAME"
        '' else ''
          BIN_PATH='${bin.path}'
        ''}
          ${build_bin} "$BIN_NAME" "$BIN_PATH"
      '' else ''
        echo Binary ${
          bin.name or crateName
        } not compiled due to not having all of the required features -- ${
          lib.escapeShellArg (builtins.toJSON bin.requiredFeatures)
        } -- enabled.
      '') crateBin)}

  ${lib.optionalString buildTests ''
    # When tests are enabled build all the files in the `tests` directory as
    # test binaries.
    if [ -d tests ]; then
      # find all the .rs files (or symlinks to those) in the tests directory, no subdirectories
      find tests -maxdepth 1 \( -type f -o -type l \) -a -name '*.rs' -print0 | while IFS= read -r -d ''' file; do
        mkdir -p target/bin
        build_bin_test_file "$file"
      done

      # find all the subdirectories of tests/ that contain a main.rs file as
      # that is also a test according to cargo
      find tests/ -mindepth 1 -maxdepth 2 \( -type f -o -type l \) -a -name 'main.rs' -print0 | while IFS= read -r -d ''' file; do
        mkdir -p target/bin
        build_bin_test_file "$file"
      done

    fi
  ''}

  # If crateBin is empty and hasCrateBin is not set then we must try to
  # detect some kind of bin target based on some files that might exist.
  ${lib.optionalString (lib.length crateBin == 0 && !hasCrateBin) ''
    if [[ -e src/main.rs ]]; then
      mkdir -p target/bin
      ${build_bin} ${crateName} src/main.rs
    fi
    for i in src/bin/*.rs; do #*/
      mkdir -p target/bin
      ${build_bin} "$(basename $i .rs)" "$i"
    done
  ''}
  # Remove object files to avoid "wrong ELF type"
  find target -type f -name "*.o" -print0 | xargs -0 rm -f
  runHook postBuild
''