Commit e53cfeee authored by Jonas Rembser's avatar Jonas Rembser
Browse files

root: enable `clad` for automatic differentiation in ROOT 

Clad is a clang plugin that can be used in Cling to create gradients of
C++ functions.

It is included in ROOT via `ExternalProject_Add`:

https://github.com/root-project/root/blob/master/interpreter/cling/tools/plugins/clad/CMakeLists.txt

Clad is used for example in RooFit to create analytical gradients of
likelihoods.
parent 35bbca41

pkgs/applications/science/misc/root/default.nix

+24 −1
Original line number Diff line number Diff line 
{ stdenv

, lib

, callPackage

, fetchgit

, fetchurl

, fetchpatch

, makeWrapper
@@ -68,6 +69,12 @@ stdenv.mkDerivation rec { 
    hash = "sha256-MA237RtnjtL7ljXKZ1khoZRcfCED2oQAM7STCR9VcAw=";

  };



  clad_src = fetchgit {

    url = "https://github.com/vgvassilev/clad";

    rev = "refs/tags/v1.4"; # Make sure that this is the same tag as in the ROOT build files!

    hash = "sha256-OI9PaS7kQ/ewD5Soe3gG5FZdlR6qG6Y3mfHwi5dj1sI=";

  };



  nativeBuildInputs = [ makeWrapper cmake pkg-config git ];

  propagatedBuildInputs = [

    nlohmann_json
@@ -131,6 +138,23 @@ stdenv.mkDerivation rec { 
    substituteInPlace cmake/modules/SearchInstalledSoftware.cmake \

      --replace 'set(lcgpackages ' '#set(lcgpackages '



    # We have to bypass the connection check, because it would disable clad.

    # This should probably be fixed upstream with a flag to disable the

    # connectivity check!

    substituteInPlace CMakeLists.txt \

      --replace 'if(NO_CONNECTION)' 'if(FALSE)'

    substituteInPlace interpreter/cling/tools/plugins/CMakeLists.txt \

      --replace 'if(NOT DEFINED NO_CONNECTION OR NOT NO_CONNECTION)' 'if(TRUE)'

    # Make sure that clad is not downloaded when building

    substituteInPlace interpreter/cling/tools/plugins/clad/CMakeLists.txt \

      --replace 'UPDATE_COMMAND ""' 'SOURCE_DIR ${clad_src} DOWNLOAD_COMMAND "" UPDATE_COMMAND ""'

    # Make sure that clad is finding the right llvm version

    substituteInPlace interpreter/cling/tools/plugins/clad/CMakeLists.txt \

      --replace '-DLLVM_DIR=''${LLVM_BINARY_DIR}' '-DLLVM_DIR=${llvm_13.dev}/lib/cmake/llvm'

    # Fix that will also be upstream in ROOT 6.32. TODO: remove it when updating to 6.32

    substituteInPlace interpreter/cling/tools/plugins/clad/CMakeLists.txt \

      --replace 'set(_CLAD_LIBRARY_PATH ''${clad_install_dir}/plugins/lib)' 'set(_CLAD_LIBRARY_PATH ''${CMAKE_CURRENT_BINARY_DIR}/clad-prefix/src/clad-build/lib''${LLVM_LIBDIR_SUFFIX})'



    substituteInPlace interpreter/llvm-project/clang/tools/driver/CMakeLists.txt \

      --replace 'add_clang_symlink(''${link} clang)' ""
@@ -155,7 +179,6 @@ stdenv.mkDerivation rec { 
    "-DCMAKE_INSTALL_LIBDIR=lib"

    "-DCMAKE_INSTALL_INCLUDEDIR=include"

    "-Dbuiltin_llvm=OFF"

    "-Dclad=OFF"

    "-Dfail-on-missing=ON"

    "-Dfitsio=OFF"

    "-Dgnuinstall=ON"