depot/third_party/nixpkgs/pkgs/development/compilers/llvm/common/libclc.nix

{ lib, stdenv, version, runCommand, monorepoSrc, llvm, buildPackages, buildLlvmTools, ninja, cmake, python3 }:

stdenv.mkDerivation rec {
  pname = "libclc";
  inherit version;

  src = runCommand "${pname}-src-${version}" {} ''
    mkdir -p "$out"
    cp -r ${monorepoSrc}/cmake "$out"
    cp -r ${monorepoSrc}/${pname} "$out"
  '';

  sourceRoot = "${src.name}/${pname}";

  outputs = [ "out" "dev" ];

  patches = [
    ./libclc/libclc-gnu-install-dirs.patch
  ];

  # cmake expects all required binaries to be in the same place, so it will not be able to find clang without the patch
  postPatch = ''
    substituteInPlace CMakeLists.txt \
      --replace 'find_program( LLVM_CLANG clang PATHS ''${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH )' \
                'find_program( LLVM_CLANG clang PATHS "${buildLlvmTools.clang.cc}/bin" NO_DEFAULT_PATH )' \
      --replace 'find_program( LLVM_AS llvm-as PATHS ''${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH )' \
                'find_program( LLVM_AS llvm-as PATHS "${buildLlvmTools.llvm}/bin" NO_DEFAULT_PATH )' \
      --replace 'find_program( LLVM_LINK llvm-link PATHS ''${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH )' \
                'find_program( LLVM_LINK llvm-link PATHS "${buildLlvmTools.llvm}/bin" NO_DEFAULT_PATH )' \
      --replace 'find_program( LLVM_OPT opt PATHS ''${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH )' \
                'find_program( LLVM_OPT opt PATHS "${buildLlvmTools.llvm}/bin" NO_DEFAULT_PATH )' \
      --replace 'find_program( LLVM_SPIRV llvm-spirv PATHS ''${LLVM_TOOLS_BINARY_DIR} NO_DEFAULT_PATH )' \
                'find_program( LLVM_SPIRV llvm-spirv PATHS "${buildPackages.spirv-llvm-translator.override { inherit (buildLlvmTools) llvm; }}/bin" NO_DEFAULT_PATH )'
  '' + lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) ''
    substituteInPlace CMakeLists.txt \
      --replace 'COMMAND prepare_builtins' 'COMMAND ${buildLlvmTools.libclc.dev}/bin/prepare_builtins'
  '';

  nativeBuildInputs = [ cmake ninja python3 ];
  buildInputs = [ llvm ];
  strictDeps = true;

  postInstall = ''
    install -Dt $dev/bin prepare_builtins
  '';

  meta = with lib; {
    homepage = "http://libclc.llvm.org/";
    description = "Implementation of the library requirements of the OpenCL C programming language";
    mainProgram = "prepare_builtins";
    license = licenses.mit;
    platforms = platforms.all;
  };
}