Selectively build packages with LLVM

flake.nix

@@ -98,7 +98,10 @@
         localSystem = builtins.currentSystem or platform;
         crossSystem = platform;
         overlays = [ self.overlays.default ];
-        config.allowUnsupportedSystem = true;
+        config = {
+          allowUnsupportedSystem = true;
+          replaceStdenv = { pkgs }: self.lib.stdenv pkgs;
+        };
       });
 
     packages = eachSystem (system: platform:

lib/stdenv.nix

@@ -0,0 +1,42 @@
+{ ... }: pkgs:
+
+let
+  inherit (lib) optionalAttrs optionals toList;
+  inherit (pkgs) lib stdenv;
+  inherit (stdenv) targetPlatform;
+in pkgs.addAttrsToDerivation (prevAttrs: let
+  overrideAlloc = prevAttrs.overrideAlloc or true;
+
+  inputs = optionals overrideAlloc [ pkgs.mimalloc ];
+
+  cflags = [ "-pipe" ];
+  ldflags = [
+    "-O2"
+    "--hash-style=gnu"
+  ] ++ optionals overrideAlloc [ "-lmimalloc" ];
+
+  rustflags = [
+    "-C" "opt-level=2"
+    "-C" "linker-flavor=ld.lld"
+    "-C" "lto"
+    "-C" "linker-plugin-lto"
+    "-C" "link-arg=--icf=safe"
+    "-C" "link-arg=--lto-O2"
+  ] ++ optionals (targetPlatform.isx86_64 && targetPlatform ? gcc.arch) [
+    "-C" "target-cpu=${targetPlatform.gcc.arch}"
+  ] ++ (map (flag: [ "-C" "link-arg=${flag}" ]) ldflags |> lib.flatten);
+in {
+  buildInputs = prevAttrs.buildInputs or [ ] ++ inputs;
+
+  env = prevAttrs.env or { } // optionalAttrs (!prevAttrs ? NIX_CFLAGS_COMPILE) {
+    NIX_CFLAGS_COMPILE = toList prevAttrs.env.NIX_CFLAGS_COMPILE or [ ] ++ cflags |> toString;
+  } // optionalAttrs (prevAttrs ? env.NIX_LDFLAGS) {
+    NIX_LDFLAGS = toList prevAttrs.NIX_LDFLAGS or [ ] ++ ldflags |> toString;
+  };
+
+  NIX_RUSTFLAGS = prevAttrs.NIX_RUSTFLAGS or [ ] ++ rustflags;
+} // optionalAttrs (prevAttrs ? NIX_CFLAGS_COMPILE) {
+  NIX_CFLAGS_COMPILE = toList prevAttrs.NIX_CFLAGS_COMPILE or [ ] ++ cflags;
+} // optionalAttrs (!prevAttrs ? env.NIX_LDFLAGS) {
+  NIX_LDFLAGS = toList prevAttrs.NIX_LDFLAGS or [ ] ++ ldflags;
+}) stdenv

overlay/default.nix

@@ -7,6 +7,7 @@ nixpkgs.lib.composeManyExtensions [
   colmena.overlays.default
   rust-overlay.overlays.default
   niri.overlays.niri
+  self.overlays.llvm
   self.overlays.mimalloc
   self.overlays.modern-minimal
   self.overlays.fixes

overlay/fixes.nix

@@ -4,6 +4,10 @@ let
   inherit (lib) toList;
   inherit (prev.stdenv) hostPlatform;
 in {
+  git = prev.git.overrideAttrs {
+    doInstallCheck = false;
+  };
+
   numactl = prev.numactl.overrideAttrs (prevAttrs: {
     patches = prevAttrs.patches or [ ] ++ [
       (final.fetchpatch {

overlay/llvm.nix

@@ -0,0 +1,142 @@
+{ nixpkgs, ... }: final: prev:
+
+let
+  inherit (nixpkgs) lib;
+  inherit (lib) optionalAttrs toList;
+  inherit (final.llvmPackages_latest) clangUseLLVM bintools;
+
+  stdenv = final.overrideCC final.stdenv (clangUseLLVM.override { inherit bintools; });
+  cflags = [ "-flto" ];
+  ldflags = [ "--icf=safe" "--lto-O2" ];
+
+  override = pkg: (pkg.overrideAttrs (prevAttrs: {  
+    env = prevAttrs.env or { } // optionalAttrs (!prevAttrs ? NIX_CFLAGS_COMPILE) {
+      NIX_CFLAGS_COMPILE = toList prevAttrs.env.NIX_CFLAGS_COMPILE or [ ] ++ cflags |> toString;
+    } // optionalAttrs (prevAttrs ? env.NIX_LDFLAGS) {
+      NIX_LDFLAGS = toList prevAttrs.NIX_LDFLAGS or [ ] ++ ldflags |> toString;
+    };
+  } // optionalAttrs (prevAttrs ? NIX_CFLAGS_COMPILE) {
+    NIX_CFLAGS_COMPILE = toList prevAttrs.env.NIX_CFLAGS_COMPILE or [ ] ++ cflags;
+  } // optionalAttrs (!prevAttrs ? env.NIX_LDFLAGS) {
+    NIX_LDFLAGS = toList prevAttrs.NIX_LDFLAGS or [ ] ++ ldflags;
+  })).override { inherit stdenv; };
+in lib.genAttrs [
+  "alsa-lib"
+  "at-spi2-atk"
+  "bluez"
+  "cairo"
+  "celt"
+  "colord"
+  "cryptsetup"
+  "cups"
+  "dav1d"
+  "dbus"
+  "dbus-broker"
+  "dconf"
+  "fdk-aac"
+  "ffmpeg"
+  "ffmpeg-headless"
+  "firefox-unwrapped"
+  "flac"
+  "flite"
+  "fontconfig"
+  "freetype"
+  "fribidi"
+  "fprintd"
+  "fwupd"
+  "gdk-pixbuf"
+  "geoclue2"
+  "ghostscript"
+  "giflib"
+  "gjs"
+  "glib"
+  "glslang"
+  "gtk2"
+  "gtk3"
+  "gtk4"
+  "gtkmm"
+  "gumbo"
+  "haproxy"
+  "harfbuzz"
+  "imlib2"
+  "inkscape"
+  "iwd"
+  "jasper"
+  "jbig2dec"
+  "kitty"
+  "ladspa"
+  "lame"
+  "lcms2"
+  "libaom"
+  "libass"
+  "libblockdev"
+  "libde256"
+  "libdrm"
+  "libepoxy"
+  "libevdev"
+  "libevent"
+  "libexif"
+  "libglvnd"
+  "libheif"
+  "libinput"
+  "libjpeg"
+  "libmng"
+  "libmpeg2"
+  "libogg"
+  "libopus"
+  "libnotify"
+  "libpng"
+  "libpng-apng"
+  "libpulseaudio"
+  "librsvg"
+  "libsndfile"
+  "libtheora"
+  "libtiff"
+  "libusb"
+  "libva"
+  "libva-minimal"
+  "libvorbis"
+  "libvpx"
+  "libxkbcommon"
+  "libwebp"
+  "mesa"
+  "mimalloc"
+  "mpv"
+  "nix"
+  "nsncd"
+  "openh264"
+  "openjpeg"
+  "openssh"
+  "pango"
+  "pcre"
+  "pipewire"
+  "pixman"
+  "polkit"
+  "poppler"
+  "qemu-user"
+  "rtkit"
+  "sbc"
+  "sioyek"
+  "speex"
+  "spdlog"
+  "svt-av1"
+  "swaylock"
+  "swaylock-effects"
+  "systemd"
+  "thunderbird-unwrapped"
+  "udisks"
+  "v4l-utils"
+  "vulkan-headers"
+  "vulkan-loader"
+  "waybar"
+  "wayland"
+  "wayland-protocols"
+  "wayland-scanner"
+  "wireplumber"
+  "wlroots"
+  "woff2"
+  "x264"
+  "x265"
+  "xvidcore"
+] (pkg: override prev.${pkg})
+

overlay/mimalloc.nix

@@ -4,6 +4,7 @@ let
   inherit (nixpkgs) lib;
 in {
   mimalloc = (prev.mimalloc.overrideAttrs (prevAttrs: {
+    overrideAlloc = false;
     postPatch = prevAttrs.postPatch or "" + ''
       sed -E -i \
         -e 's/(\{ )1(, UNINIT, MI_OPTION_LEGACY\(purge_decommits,reset_decommits\) \})/\10\2/' \
@@ -33,10 +34,6 @@ in {
 
   fractal = prev.fractal.overrideAttrs (prevAttrs: {
     nativeBuildInputs = prevAttrs.nativeBuildInputs or [ ] ++ [ final.makeBinaryWrapper ];
-    buildInputs = prevAttrs.buildInputs or [ ] ++ [ final.mimalloc ];
-
-    NIX_RUSTFLAGS = lib.toList prevAttrs.NIX_RUSTFLAGS or [ ] ++ [ "-C" "link-arg=-lmimalloc" ];
-    
     postInstall = prevAttrs.postInstall or "" + ''
       wrapProgram "$out/bin/fractal" \
         --set MIMALLOC_RESERVE_HUGE_OS_PAGES 1
@@ -47,47 +44,8 @@ in {
     mpv = final.mpv-unwrapped;
     extraMakeWrapperArgs = [ "--set" "MIMALLOC_RESERVE_HUGE_OS_PAGES" "1" ];
   };
-} // lib.genAttrs [
-  "bat"
-  "bottom"
-  "cryptsetup"
-  "dbus-broker"
-  "erlang"
-  "fd"
-  "firefox-unwrapped"
-  "fuzzel"
-  "helix"
-  "kitty"
-  "mako"
-  "mpv-unwrapped"
-  "niri"
-  "nix"
-  "nushell"
-  "openssh"
-  "pipewire"
-  "pueue"
-  "ripgrep"
-  "sd"
-  "sioyek"
-  "sudo-rs"
-  "systemd"
-  "swayidle"
-  "swaylock"
-  "swaylock-effects"
-  "thunderbird-unwrapped"
-  "uutils-coreutils"
-  "uutils-coreutils-noprefix"
-  "waybar"
-  "wirepluber"
-  "xdg-desktop-portal-gnome"
-  "xdg-desktop-portal-gtk"
-] (pkg: prev.${pkg}.overrideAttrs (prevAttrs: {
-  buildInputs = prevAttrs.buildInputs or [ ] ++ [ final.mimalloc ];
-  env = prevAttrs.env or { } // lib.optionalAttrs (prevAttrs ? env.NIX_LDFLAGS) {
-    NIX_LDFLAGS = toString (lib.toList prevAttrs.env.NIX_LDFLAGS or [ ] ++ [ "-lmimalloc" ]);
-  };
 
-  NIX_RUSTFLAGS = lib.toList prevAttrs.NIX_RUSTFLAGS or [ ] ++ [ "-C" "link-arg=-lmimalloc" ];
-} // lib.optionalAttrs (!prevAttrs ? env.NIX_LDFLAGS) {
-  NIX_LDFLAGS = lib.toList prevAttrs.NIX_LDFLAGS or [ ] ++ [ "-lmimalloc" ];
-}))
+  perl = prev.perl.overrideAttrs {
+    overrideAlloc = false;
+  };
+}