refactor(flake): cross packages for each system

Ovyerus · Jul 10, 2024 · 6f6fe33 · 6f6fe33
1 parent adf7cdf
commit 6f6fe33
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diff --git a/flake.lock b/flake.lock
diff --git a/flake.nix b/flake.nix
@@ -3,43 +3,86 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-
-    crane = {
-      url = "github:ipetkov/crane";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
-
-    rust-overlay = {
-      url = "github:oxalica/rust-overlay";
-      inputs.nixpkgs.follows = "nixpkgs";
-    };
+    fenix.url = "github:nix-community/fenix";
+    naersk.url = "github:nix-community/naersk/master";
   };
 
   outputs = {
+    fenix,
     nixpkgs,
-    rust-overlay,
-    crane,
+    naersk,
     ...
   }: let
-    forSystems = fn:
-      nixpkgs.lib.genAttrs [
-        "aarch64-linux"
-        "aarch64-darwin"
-        "x86_64-darwin"
-        "x86_64-linux"
-      ] (system: fn nixpkgs.legacyPackages.${system});
-    defaultForSystems = fn: forSystems (pkgs: {default = fn pkgs;});
-
-    mkBandsnatch = pkgs: let
-      rustBin = rust-overlay.lib.mkRustBin {} pkgs;
-      craneLib = (crane.mkLib pkgs).overrideToolchain (p: rustBin.stable.latest.default);
+    buildTargets = {
+      "x86_64-linux" = "x86_64-unknown-linux-musl";
+      "aarch64-linux" = "aarch64-unknown-linux-musl";
+      "x86_64-darwin" = "x86_64-apple-darwin";
+      "aarch64-darwin" = "aarch64-apple-darwin";
+    };
+
+    systems = builtins.attrNames buildTargets;
+
+    # forSystems [...system] (system: ...)
+    forSystems = systems: fn:
+      nixpkgs.lib.genAttrs systems (system: fn system);
+
+    # crossForSystems [...system] (hostSystem: targetSystem: ...)
+    crossForSystems = systems: fn:
+      forSystems systems (
+        hostSystem:
+          builtins.foldl'
+          (acc: targetSystem:
+            acc
+            // {
+              "cross-${targetSystem}" = fn hostSystem targetSystem;
+            })
+          {default = fn hostSystem hostSystem;}
+          systems
+      );
+
+    mkBandsnatch = hostSystem: targetSystem: let
+      rustTarget = buildTargets.${targetSystem};
+      pkgs = import nixpkgs {system = hostSystem;};
+      pkgsCross = import nixpkgs {
+        system = hostSystem;
+        crossSystem.config = rustTarget;
+      };
+      fenixPkgs = fenix.packages.${hostSystem};
+      toolchain = fenixPkgs.combine [
+        fenixPkgs.stable.rustc
+        fenixPkgs.stable.cargo
+        fenixPkgs.targets.${rustTarget}.stable.rust-std
+      ];
+
+      naersk-lib = pkgs.callPackage naersk {
+        cargo = toolchain;
+        rustc = toolchain;
+      };
+      TARGET_CC = "${pkgsCross.stdenv.cc}/bin/${pkgsCross.stdenv.cc.targetPrefix}cc";
     in
-      pkgs.callPackage ./package.nix {inherit craneLib;};
+      naersk-lib.buildPackage {
+        src = ./.;
+        strictDeps = true;
+        doCheck = false;
+
+        inherit TARGET_CC;
+
+        CARGO_BUILD_TARGET = rustTarget;
+        CARGO_BUILD_RUSTFLAGS = [
+          "-C"
+          "target-feature=+crt-static"
+          "-C"
+          "linker=${TARGET_CC}"
+        ];
+      };
   in {
-    packages = defaultForSystems mkBandsnatch;
+    packages = crossForSystems systems mkBandsnatch;
 
-    devShells = defaultForSystems (
-      pkgs: pkgs.mkShell {inputsFrom = [(mkBandsnatch pkgs)];}
+    devShells = forSystems systems (
+      system: let
+        pkgs = nixpkgs.legacyPackages.${system};
+        fenixPkgs = fenix.packages.${system};
+      in {default = pkgs.mkShell {nativeBuildInputs = [fenixPkgs.stable.toolchain];};}
     );
   };
 }