fex: Add support for library forwarding (#413255)

  xxHash,

  fmt,

  nasm,

  buildEnv,

  writeText,

  pkgsCross,

  libclang,

  libllvm,

  alsa-lib,

  libdrm,

  libGL,

  wayland,

  xorg,

}:

let

  # Headers required to build the ThunkLibs subtree

  libForwardingInputs = lib.map lib.getInclude [

    alsa-lib

    libdrm

    libGL

    wayland

    xorg.libX11

    xorg.libxcb

    xorg.libXrandr

    xorg.libXrender

    xorg.xorgproto

  ];

  pkgsCross32 = pkgsCross.gnu32;

  pkgsCross64 = pkgsCross.gnu64;

  devRootFS = buildEnv {

    name = "fex-dev-rootfs";

    paths = [

      pkgsCross64.stdenv.cc.libc_dev

      pkgsCross32.stdenv.cc.libc_dev

      pkgsCross64.stdenv.cc.cc

      pkgsCross32.stdenv.cc.cc

    ]

    ++ libForwardingInputs;

    ignoreCollisions = true;

    pathsToLink = [

      "/include"

      "/lib"

    ];

    postBuild = ''

      mkdir -p $out/usr

      ln -s $out/include $out/usr/

    '';

  };

  toolchain32 = writeText "toolchain_nix_x86_32.txt" ''

    set(CMAKE_EXE_LINKER_FLAGS_INIT "-fuse-ld=lld")

    set(CMAKE_MODULE_LINKER_FLAGS_INIT "-fuse-ld=lld")

    set(CMAKE_SHARED_LINKER_FLAGS_INIT "-fuse-ld=lld")

    set(CMAKE_SYSTEM_PROCESSOR i686)

    set(CMAKE_C_COMPILER clang)

    set(CMAKE_CXX_COMPILER clang++)

    set(CMAKE_C_COMPILER ${pkgsCross32.buildPackages.clang}/bin/i686-unknown-linux-gnu-clang)

    set(CMAKE_CXX_COMPILER ${pkgsCross32.buildPackages.clang}/bin/i686-unknown-linux-gnu-clang++)

    set(CLANG_FLAGS "-nodefaultlibs -nostartfiles -target i686-linux-gnu -msse2 -mfpmath=sse --sysroot=${devRootFS} -iwithsysroot/usr/include")

    set(CMAKE_C_FLAGS "''${CMAKE_C_FLAGS} ''${CLANG_FLAGS}")

    set(CMAKE_CXX_FLAGS "''${CMAKE_CXX_FLAGS} ''${CLANG_FLAGS}")

  '';

  toolchain = writeText "toolchain_nix_x86_64.txt" ''

    set(CMAKE_EXE_LINKER_FLAGS_INIT "-fuse-ld=lld")

    set(CMAKE_MODULE_LINKER_FLAGS_INIT "-fuse-ld=lld")

    set(CMAKE_SHARED_LINKER_FLAGS_INIT "-fuse-ld=lld")

    set(CMAKE_SYSTEM_PROCESSOR x86_64)

    set(CMAKE_C_COMPILER clang)

    set(CMAKE_CXX_COMPILER clang++)

    set(CMAKE_C_COMPILER ${pkgsCross64.buildPackages.clang}/bin/x86_64-unknown-linux-gnu-clang)

    set(CMAKE_CXX_COMPILER ${pkgsCross64.buildPackages.clang}/bin/x86_64-unknown-linux-gnu-clang++)

    set(CLANG_FLAGS "-nodefaultlibs -nostartfiles -target x86_64-linux-gnu --sysroot=${devRootFS} -iwithsysroot/usr/include")

    set(CMAKE_C_FLAGS "''${CMAKE_C_FLAGS} ''${CLANG_FLAGS}")

    set(CMAKE_CXX_FLAGS "''${CMAKE_CXX_FLAGS} ''${CLANG_FLAGS}")

  '';

in

llvmPackages.stdenv.mkDerivation (finalAttrs: {

  pname = "fex";

  version = "2508.1";

    '';

  };

  postPatch = ''

    substituteInPlace ThunkLibs/GuestLibs/CMakeLists.txt ThunkLibs/HostLibs/CMakeLists.txt \

      --replace-fail "/usr/include/libdrm" "${devRootFS}/include/libdrm" \

      --replace-fail "/usr/include/wayland" "${devRootFS}/include/wayland"

    # Add include paths for thunkgen invocation

    substituteInPlace ThunkLibs/HostLibs/CMakeLists.txt \

      --replace-fail "-- " "-- $(cat ${llvmPackages.stdenv.cc}/nix-support/libc-cflags) $(cat ${llvmPackages.stdenv.cc}/nix-support/libcxx-cxxflags) ${

        lib.concatMapStrings (x: "-isystem " + x + "/include ") libForwardingInputs

      }"

    substituteInPlace ThunkLibs/GuestLibs/CMakeLists.txt \

      --replace-fail "-- " "-- $(cat ${llvmPackages.stdenv.cc}/nix-support/libcxx-cxxflags) "

    # Patch any references to library wrapper paths

    substituteInPlace FEXCore/Source/Interface/Config/Config.json.in \

      --replace-fail "ThunkGuestLibs" "UnusedThunkGuestLibs" \

      --replace-fail "ThunkHostLibs" "UnusedThunkHostLibs"

    substituteInPlace FEXCore/Source/Interface/Config/Config.cpp \

      --replace-fail "FEXCore::Config::CONFIG_THUNKGUESTLIBS" "FEXCore::Config::CONFIG_UNUSEDTHUNKGUESTLIBS" \

      --replace-fail "FEXCore::Config::CONFIG_THUNKHOSTLIBS" "FEXCore::Config::CONFIG_UNUSEDTHUNKHOSTLIBS"

    substituteInPlace Source/Tools/LinuxEmulation/VDSO_Emulation.cpp \

      --replace-fail "FEX_CONFIG_OPT(ThunkGuestLibs, THUNKGUESTLIBS);" "auto ThunkGuestLibs = []() { return \"$out/share/fex-emu/GuestThunks/\"; };"

    substituteInPlace Source/Tools/LinuxEmulation/LinuxSyscalls/FileManagement.h \

      --replace-fail "FEX_CONFIG_OPT(ThunkGuestLibs, THUNKGUESTLIBS);" "fextl::string ThunkGuestLibs() { return \"$out/share/fex-emu/GuestThunks/\"; }"

    substituteInPlace Source/Tools/LinuxEmulation/Thunks.cpp \

      --replace-fail "FEX_CONFIG_OPT(ThunkHostLibsPath, THUNKHOSTLIBS);" "fextl::string ThunkHostLibsPath() { return \"$out/lib/fex-emu/HostThunks/\"; }"

    substituteInPlace Source/Tools/FEXConfig/main.qml \

      --replace-fail "config: \"Thunk" "config: \"UnusedThunk" \

      --replace-fail "title: qsTr(\"Library forwarding:\")" "visible: false; title: qsTr(\"Library forwarding:\")"

  '';

  nativeBuildInputs = [

    cmake

    ninja

  buildInputs = [

    xxHash

    fmt

    pkgsCross64.buildPackages.clang

    pkgsCross32.buildPackages.clang

    libclang

    libllvm

  ]

  ++ libForwardingInputs

  ++ (with qt5; [

    qtbase

    qtdeclarative

    (lib.cmakeBool "ENABLE_ASSERTIONS" false)

    (lib.cmakeFeature "OVERRIDE_VERSION" finalAttrs.version)

    (lib.cmakeBool "BUILD_TESTS" finalAttrs.finalPackage.doCheck)

    (lib.cmakeBool "BUILD_THUNKS" true)

    (lib.cmakeFeature "X86_32_TOOLCHAIN_FILE" "${toolchain32}")

    (lib.cmakeFeature "X86_64_TOOLCHAIN_FILE" "${toolchain}")

    (lib.cmakeFeature "X86_DEV_ROOTFS" "${devRootFS}")

  ];

  strictDeps = true;