Flake for LLVM Build

llvm.nix

{
  description = "LLVM Build Flake";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
  };

  outputs = { self, nixpkgs, ... }:
  let
    system = "x86_64-linux";
    pkgs = nixpkgs.legacyPackages.${system};

    conanOverride = pkgs.conan.overridePythonAttrs (oldAttrs: {
      doCheck = false;
    });

    devPackages = with pkgs; [
      automake
      autoconf
      ccache
      cmake
      conanOverride
      gperf
      gnumake
      libtool
      nasm
      m4
      perl
      python3
      ruby_3_4
      rake
      stdenv
    ];

    buildStdenv = with pkgs; overrideCC stdenv pkgs.llvmPackages.clangUseLLVM;

    in {
      devShells.${system}.default = pkgs.mkShell.override {
        stdenv = buildStdenv;
      }
    {
      packages = with pkgs.llvmPackages; [
        bintools
        clang-tools
        lldb
        lld
        llvm
      ] ++ devPackages;

      hardeningDisable = [ "all" ];
      impureUseNativeOptimizations = true;

      NIX_ENFORCE_NO_NATIVE = false;
      NIX_HARDENING_DISABLE = true;
      LLVM_ROOT = "${buildStdenv.cc}";
      LLVM_LIB = "${buildStdenv.cc.libcxx}/lib";
    };
  };
}