Compile with Clang / LLVM

base.nix

@@ -79,13 +79,12 @@
   STACKPROTECTOR = yes;
   STACKPROTECTOR_STRONG = yes;
 
-  LTO_CLANG_FULL = option yes;
+  LTO_CLANG_FULL = yes;
+  CFI_CLANG = yes;
 
   VMAP_STACK = yes;
   RANDOMIZE_KSTACK_OFFSET_DEFAULT = yes;
 
-  GCC_PLUGINS = yes;
-
   BLK_DEV_WRITE_MOUNTED = yes;
   BLK_WBT = yes;
   BLK_WBT_MQ = yes;
@@ -325,8 +324,6 @@
 
   BUG_ON_DATA_CORRUPTION = yes;
 
-  RANDSTRUCT_PERFORMANCE = option yes;
-
   CRYPTO_ZSTD = yes;
 
   SWIOTLB_DYNAMIC = yes;

linux-hardened.nix

@@ -4,11 +4,16 @@ let
     lib
     buildEnv
     buildLinux
+    buildPackages
     fetchFromGitHub
-    gccStdenv
+    overrideCC
     runCommand;
 
   kernel = let
+    inherit (pkgs.llvmPackages_latest)
+      llvm clang-unwrapped lld
+      clang bintools;
+
     args = {
       inherit (pkgs) lib hostPlatform;
     };
@@ -34,9 +39,28 @@ let
     };
 
     defconfig = "allnoconfig";
-      extraMakeFlags = [ "KCFLAGS=-march=${arch}" ];
     enableCommonConfig = false;
 
+    extraMakeFlags = [
+      "LLVM=1"
+
+      "HOSTCC=${clang}/bin/clang"
+      "HOSTCXX=${clang}/bin/clang++"
+      "HOSTLD=${bintools}/bin/ld.lld"
+      "HOSTAR=${bintools}/bin/ar"
+
+      "CC=${clang-unwrapped}/bin/clang"
+      "LD=${lld}/bin/ld.lld"
+      "AR=${llvm}/bin/llvm-ar"
+      "NM=${llvm}/bin/llvm-nm"
+      "OBJCOPY=${llvm}/bin/llvm-objcopy"
+      "OBJDUMP=${llvm}/bin/llvm-objdump"
+      "READELF=${llvm}/bin/llvm-readelf"
+      "STRIP=${llvm}/bin/llvm-strip"
+
+      "KCFLAGS=-march=${arch}"
+    ];
+
     structuredExtraConfig =
       (import ./base.nix args) //
       (import config args) //
@@ -50,7 +74,6 @@ let
     };
 
     isHardened = true;
-      stdenv = gccStdenv;
   };
 in kernel.overrideAttrs (base: {
   installFlags = base.installFlags or [ ] ++ [ "INSTALL_MOD_PATH=$(out)" ];