[nix] Flake

.envrc

@@ -1 +1 @@
-# use flake
+use flake

.github/workflows/common.yml

@@ -32,6 +32,7 @@ jobs:
   format:
     name: Format
     runs-on: ubuntu-22.04
+    if: "!contains(github.event.head_commit.message, '[skip format]')"
     steps:
     - name: Checkout
       uses: actions/checkout@v3
@@ -61,9 +62,11 @@ jobs:
       working-directory: ${{ inputs.workdir }}
       shell: bash
       run: ./format.sh && git diff --exit-code
+
   build:
     name: Build
     runs-on: ubuntu-22.04
+    if: "!contains(github.event.head_commit.message, '[skip build]')"
     steps:
     - name: Checkout
       uses: actions/checkout@v3
@@ -103,26 +106,106 @@ jobs:
     - name: Benchmark Test
       shell: bash
       run: ./utils/bench.py ${{ inputs.workdir }} --default --frames 10
+
   nix:
     name: Nix
     runs-on: ubuntu-22.04
+    if: ${{ !contains(github.event.head_commit.message, '[skip nix]') }}
+    outputs:
+      flake_status: ${{ steps.early.outputs.flake_status }}
+      shell_status: ${{ steps.early.outputs.shell_status }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - id: early
+        name: Check if nix files exist
+        shell: bash
+        working-directory: ${{ inputs.workdir }}
+        run: |
+          flake_status="skip"
+          if [ -f "derivation.nix" ]; then
+            flake_status="found"
+          fi
+          echo "flake_status=${flake_status}" >> "${GITHUB_OUTPUT}"
+
+          shell_status="skip"
+          if [ -f "shell.nix" ]; then
+            shell_status="found"
+          fi
+          echo "shell_status=${shell_status}" >> "${GITHUB_OUTPUT}"
+
+  nix-flake:
+    name: Nix Flake
+    runs-on: ubuntu-22.04
+    needs: nix
+    if: ${{ !contains(github.event.head_commit.message, '[skip nix flake]') && needs.nix.outputs.flake_status == 'found' }}
     steps:
     - name: Checkout
       uses: actions/checkout@v3
       with:
         submodules: recursive
     - name: Set Up Build Cache
       uses: actions/cache@v3
+      id: nix-cache
       with:
-        path: |
-          /nix
-        key: ${{ inputs.workdir }}-nix-${{ hashFiles(format('{0}/shell.nix', inputs.workdir)) }}
-        restore-keys: ${{ inputs.workdir }}-nix-
+        path: /tmp/nix-store.nar
+        key: ${{ runner.os }}-${{ inputs.workdir }}-nix-store.nar-${{ hashFiles('flake.nix', 'flake.lock', format('{0}/derivation.nix', inputs.workdir)) }}
+        restore-keys: ${{ runner.os }}-${{ inputs.workdir }}-nix-store.nar-
     - name: Install Deps
       uses: cachix/install-nix-action@v15
       with:
         nix_path: nixpkgs=channel:nixos-22.11
-    - name: Run
+      # see: https://github.com/cachix/install-nix-action/issues/56#issuecomment-1300421537
+    - name: "Import Nix Store Cache"
+      if: "steps.nix-cache.outputs.cache-hit == 'true'"
+      run: "nix-store --import < /tmp/nix-store.nar"
+    - name: Flake Build
+      shell: bash
+      run: |
+        nix eval .#packages --impure --raw \
+            --apply '(import ./utils/get-builds-for-lang.nix { lang = "${{ inputs.workdir }}"; attr = "packages"; })' \
+          | xargs nix build -L
+    - name: Flake Run
+      shell: bash
+      run: |
+        nix eval .#packages --impure --raw \
+            --apply '(import ./utils/get-builds-for-lang.nix { lang = "${{ inputs.workdir }}"; prefix = ".#"; })' \
+          | xargs -I{} nix run {} -- --help
+    - name: Flake Shell
+      shell: bash
+      working-directory: ${{ inputs.workdir }}
+      run: nix develop ..#${{ inputs.workdir }} --command bash -c './build.sh && ./rosettaboy-release --help'
+    - name: Flake Checks
+      shell: bash
+      run: |
+        nix eval .#checks --impure --raw \
+            --apply '(import ./utils/get-builds-for-lang.nix { lang = "${{ inputs.workdir }}"; attr = "checks"; })' \
+          | xargs nix build -L
+    - name: "Export Nix Store Cache"
+      shell: bash
+      # we could add devShells here but it might fill the cache fast...
+      run: |
+        nix eval .#packages --impure --raw \
+            --apply '(import ./utils/get-builds-for-lang.nix { lang = "${{ inputs.workdir }}"; attr = "packages"; })' \
+          | xargs -I{} bash -c "nix eval --raw {}; echo" \
+          | xargs nix-store -qR \
+          | xargs nix-store --export > /tmp/nix-store.nar
+
+  nix-shell:
+    name: Nix Shell
+    runs-on: ubuntu-22.04
+    needs: nix
+    if: ${{ !contains(github.event.head_commit.message, '[skip nix flake]') && needs.nix.outputs.shell_status == 'found' }}
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+      with:
+        submodules: recursive
+    - name: Install Nix
+      uses: cachix/install-nix-action@v15
+      with:
+        nix_path: nixpkgs=channel:nixos-22.11
+    - name: Run Shell
       shell: bash
       working-directory: ${{ inputs.workdir }}
       run: nix-shell --pure --run './build.sh && ./rosettaboy-release --help'

.github/workflows/nim.yml

@@ -22,4 +22,4 @@ jobs:
     with:
       workdir: nim
       with-nim: stable
-      build-pkgs: libsdl2-dev
+      build-pkgs: libsdl2-dev

README.md

@@ -70,7 +70,7 @@ If you have either Nix or Docker available, you can run `./utils/shell.sh` to cr
 
 If you prefer Docker, you can use `./utils/shell-docker.sh` instead.
 
-If you prefer Nix, you can manually run `nix-shell` instead. When run in an implemention's directory, `nix-shell` will only provide what is needed for that language, and when run in the project root it will provide everything needed for all languages.
+If you prefer Nix, you can manually run `nix develop` or `nix-shell` instead. When run with an implementation as an argument, e.g.  `nix develop .#py`, it will only provide what is needed for that language, and when run in the project root it will provide everything needed for all languages. Alternatively, there is also an integration with [nix-direnv](https://github.com/nix-community/nix-direnv).
 
 
 Benchmarks

c/.envrc

@@ -0,0 +1 @@
+../utils/.envrc

c/derivation.nix

@@ -1,41 +1,44 @@
-{ lib
-, stdenv
-, cmake
-, SDL2
-, autoPatchelfHook
-, pkg-config
-, valgrind ? null
-, clang-tools ? null
-, nixpkgs-fmt ? null
-, ltoSupport ? false
-, debugSupport ? false
+{
+ lib,
+ stdenv,
+ cmake,
+ SDL2,
+ pkg-config,
+ cleanSource,
+ clang-tools ? null,
+ ltoSupport ? false,
+ debugSupport ? false
 }:
 
 let
-  devTools = [ clang-tools nixpkgs-fmt valgrind ];
+  devTools = [ clang-tools ];
 in
 
-stdenv.mkDerivation {
+stdenv.mkDerivation rec {
   name = "rosettaboy-c";
-
-  src = ./.;
+  src = cleanSource {
+    inherit name;
+    src = ./.;
+    extraRules = ''
+      .clang-format
+    '';
+  };
 
   passthru = { inherit devTools; };
 
   enableParallelBuilding = true;
 
   buildInputs = [ SDL2 ];
-  nativeBuildInputs = [ autoPatchelfHook cmake pkg-config ]
-    ++ lib.optionals debugSupport devTools;
+  nativeBuildInputs = [ cmake pkg-config ];
 
   cmakeFlags = [ ]
     ++ lib.optional debugSupport "-DCMAKE_BUILD_TYPE=Debug"
     ++ lib.optional (!debugSupport) "-DCMAKE_BUILD_TYPE=Release"
     ++ lib.optional ltoSupport "-DENABLE_LTO=On"
   ;
 
-  meta = with lib; {
-    description = "rosettaboy-c";
-    mainProgram = "rosettaboy-c";
+  meta = {
+    description = name;
+    mainProgram = name;
   };
 }

cpp/.gitignore

@@ -10,3 +10,4 @@ CMakeFiles
 Makefile
 cmake_install.cmake
 rosettaboy-cpp
+/result*

cpp/CMakeLists.txt

@@ -8,9 +8,13 @@ option(ENABLE_LTO "enable LTO" OFF)
 include(CheckIPOSupported)
 check_ipo_supported(RESULT supported OUTPUT error)
 
+include(GNUInstallDirs)
+
 include_directories(/usr/local/include/)
 
 add_executable(rosettaboy-cpp src/main.cpp src/args.cpp src/cpu.cpp src/cart.cpp src/gameboy.cpp src/gpu.cpp src/consts.h src/cart.h src/cpu.h src/gpu.h src/args.h src/apu.cpp src/apu.h src/ram.cpp src/ram.h src/buttons.cpp src/buttons.h src/clock.cpp src/clock.h)
+install(TARGETS rosettaboy-cpp
+        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
 if( ENABLE_LTO AND supported )
     message(STATUS "IPO / LTO enabled")

cpp/derivation.nix

@@ -0,0 +1,41 @@
+{
+  lib,
+  stdenv,
+  cmake,
+  SDL2,
+  fmt_8,
+  pkg-config,
+  cleanSource,
+  clang-format ? null,
+  ltoSupport ? false,
+  debugSupport ? false,
+}:
+
+stdenv.mkDerivation rec {
+  name = "rosettaboy-cpp";
+  src = cleanSource {
+    inherit name;
+    src = ./.;
+    extraRules = ''
+      .clang-format
+    '';
+  };
+
+  buildInputs = [ SDL2 fmt_8 ];
+  nativeBuildInputs = [ cmake pkg-config ];
+
+  passthru = {
+    devTools = [ clang-format ];
+  };
+
+  cmakeFlags = [ ]
+    ++ lib.optional debugSupport "-DCMAKE_BUILD_TYPE=Debug"
+    ++ lib.optional (!debugSupport) "-DCMAKE_BUILD_TYPE=Release"
+    ++ lib.optional ltoSupport "-DENABLE_LTO=On"
+  ;
+
+  meta = {
+    description = name;
+    mainProgram = name;
+  };
+}

default.nix

@@ -0,0 +1,10 @@
+(import
+  (
+    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
+    fetchTarball {
+      url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+      sha256 = lock.nodes.flake-compat.locked.narHash;
+    }
+  )
+  { src = ./.; }
+).defaultNix