3 files changed, 59 insertions, 0 deletions
diff --git a/nix/overlays.nix b/nix/overlays.nix
new file mode 100644
index 00000000..12e0e86d
--- /dev/null
+++ b/nix/overlays.nix
@@ -0,0 +1,14 @@
+{ config, ... }:
+{
+  overlays =
+    let
+      paths = [
+        ./overlays
+      ];
+    in with builtins;
+      concatMap (path:
+        (map (n: import (path + ("/" + n)))
+          (filter (n: match ".*\\.nix" n != null ||
+                      pathExists (path + ("/" + n + "/default.nix")))
+            (attrNames (readDir path))))) paths;
+}
diff --git a/nix/sources.nix b/nix/sources.nix
new file mode 100644
index 00000000..3e90ca06
--- /dev/null
+++ b/nix/sources.nix
@@ -0,0 +1,16 @@
+{
+  nixpkgs = {
+    unstable = builtins.fetchGit {
+      url = "https://github.com/NixOS/nixpkgs.git";
+      rev = "cf7475d2061ac3ada4b226571a4a1bb91420b578";
+    };
+    stable = builtins.fetchGit {
+      url = "https://github.com/NixOS/nixpkgs.git";
+      rev = "c11f75bd73e8264bbca6f4bc969ccc39cd371196";
+    };
+  };
+  home-manager = builtins.fetchGit {
+    url = "https://github.com/nix-community/home-manager.git";
+    rev = "275d1b52126674764f0f3d15c73c2add511bd310";
+  };
+}
diff --git a/nix/utils.nix b/nix/utils.nix
new file mode 100644
index 00000000..9848a785
--- /dev/null
+++ b/nix/utils.nix
@@ -0,0 +1,29 @@
+{ pkgs, ... }:
+# https://stackoverflow.com/questions/42136197/how-to-override-compile-flags-for-a-single-package-in-nixos
+let
+  overrideWithFlags = pkg: flags:
+    pkgs.lib.overrideDerivation pkg (old:
+      let
+        newflags = pkgs.lib.foldl' (acc: x: "${acc} ${x}") "" flags;
+        oldflags = if (pkgs.lib.hasAttr "NIX_CFLAGS_COMPILE" old)
+                   then "${old.NIX_CFLAGS_COMPILE}"
+                   else "";
+      in
+        {
+          NIX_CFLAGS_COMPILE = "${oldflags} ${newflags}";
+        });
+in
+{
+  overrideWithFlags = overrideWithFlags;
+  optimizeForThisHost = pkg:
+    overrideWithFlags pkg [ "-O3" "-march=native" "-fPIC" ];
+
+  withDebugSymbols = pkg:
+    overrideWithFlags pkg [ "-DDEBUG" ];
+
+  importDirs = path: with builtins;
+    map (n: import (path + ("/" + n)))
+      (filter (n: match ".*\\.nix" n != null ||
+                  pathExists (path + ("/" + n + "/default.nix")))
+        (attrNames (readDir path)));
+}