From 33f9ff0778560d82470f736a3d8cf397d4239673 Mon Sep 17 00:00:00 2001
From: Amos Wenger <amos@bearcove.net>
Date: Mon, 11 Mar 2024 10:33:11 +0100
Subject: [PATCH] Add flake to have the toolchain anywhere

---
 .envrc              |   1 +
 .gitignore          |   2 +-
 flake.lock          | 106 ++++++++++++++++++++++++++++++++++++++++++++
 flake.nix           |  75 +++++++++++++++++++++++++++++++
 rust-toolchain.toml |   1 +
 5 files changed, 184 insertions(+), 1 deletion(-)
 create mode 100644 .envrc
 create mode 100644 flake.lock
 create mode 100644 flake.nix

diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..3550a30
--- /dev/null
+++ b/.envrc
@@ -0,0 +1 @@
+use flake
diff --git a/.gitignore b/.gitignore
index 85b7ea2..5400fb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
 /target
-/Cargo.lock
 *coverage*
+.direnv
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..8fcc935
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,106 @@
+{
+  "nodes": {
+    "crane": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1710003968,
+        "narHash": "sha256-g8+K+mLiNG5uch35Oy9oDQBAmGSkCcqrd0Jjme7xiG0=",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "rev": "10484f86201bb94bd61ecc5335b1496794fedb78",
+        "type": "github"
+      },
+      "original": {
+        "owner": "ipetkov",
+        "repo": "crane",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1710146030,
+        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1709961763,
+        "narHash": "sha256-6H95HGJHhEZtyYA3rIQpvamMKAGoa8Yh2rFV29QnuGw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "3030f185ba6a4bf4f18b87f345f104e6a6961f34",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "crane": "crane",
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "rust-overlay": {
+      "inputs": {
+        "flake-utils": [
+          "flake-utils"
+        ],
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1710123130,
+        "narHash": "sha256-EoGL/WSM1M2L099Q91mPKO/FRV2iu2ZLOEp3y5sLfiE=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "73aca260afe5d41d3ebce932c8d896399c9d5174",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..68a3782
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,75 @@
+{
+  inputs = {
+    flake-utils = { url = "github:numtide/flake-utils"; };
+    nixpkgs = { url = "github:NixOS/nixpkgs/nixos-unstable"; };
+    rust-overlay =
+      {
+        url = "github:oxalica/rust-overlay";
+        inputs = {
+          nixpkgs.follows = "nixpkgs";
+          flake-utils.follows = "flake-utils";
+        };
+      };
+    crane = {
+      url = "github:ipetkov/crane";
+      inputs = {
+        nixpkgs.follows = "nixpkgs";
+      };
+    };
+  };
+  outputs =
+    { self, nixpkgs, flake-utils, rust-overlay, crane }:
+    flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [ (import rust-overlay) ];
+      };
+      rustToolchain = pkgs.pkgsBuildHost.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+      craneLib = (crane.mkLib pkgs).overrideToolchain rustToolchain;
+      src = craneLib.cleanCargoSource (craneLib.path ./.);
+
+      buildInputs = with pkgs; [ pkgs.stdenv.cc.cc ];
+      nativeBuildInputs = with pkgs; [
+        rustToolchain
+        clang
+        mold
+        curl
+      ]
+      ++ lib.optionals pkgs.stdenv.isLinux [ autoPatchelfHook ]
+      ++ lib.optionals pkgs.stdenv.isDarwin
+        (with pkgs.darwin.apple_sdk.frameworks; [
+          CoreFoundation
+          CoreServices
+          SystemConfiguration
+          Security
+        ]);
+      commonArgs = {
+        pname = "ktls";
+        version = "latest";
+        strictDeps = true;
+        dontStrip = true;
+        # workaround for https://github.com/NixOS/nixpkgs/issues/166205
+        env = with pkgs; lib.optionalAttrs stdenv.cc.isClang {
+          NIX_LDFLAGS = "-l${stdenv.cc.libcxx.cxxabi.libName}";
+        };
+        inherit src buildInputs nativeBuildInputs;
+      };
+      cargoArtifacts = craneLib.buildDepsOnly commonArgs;
+      bin = craneLib.buildPackage (commonArgs // {
+        inherit cargoArtifacts;
+      });
+    in
+    with pkgs;
+    {
+      packages = {
+        inherit bin;
+        default = bin;
+      };
+      devShells.default = mkShell {
+        inputsFrom = [ bin ];
+        packages = with pkgs; [ just nixpkgs-fmt ];
+      };
+    }
+    );
+}
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 292fe49..d24f9dc 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,2 +1,3 @@
 [toolchain]
 channel = "stable"
+components = ["llvm-tools", "clippy", "rust-src"]