From ed5146dcfc4795d56fd5101c39d7de9789baab26 Mon Sep 17 00:00:00 2001
From: TimePath <andrew.hardaker1995@gmail.com>
Date: Wed, 2 Aug 2017 21:29:06 +1000
Subject: [PATCH] nix: create a composed shell derivation

---
 CMakeLists.txt | 19 +++++++-----
 default.nix    | 82 ++++++++++++++++++++++++++++----------------------
 2 files changed, 57 insertions(+), 44 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 704c5439..4116f5cd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,17 +4,20 @@ project(xonotic)
 option(DOWNLOAD_MAPS "Download new maps from the build server" ON)
 option(BUILD_RELEASE "Package a release" OFF)
 
-macro(subproject id name)
-    if (EXISTS "${PROJECT_SOURCE_DIR}/${name}/CMakeLists.txt" AND NOT DEFINED ENV{XON_NO_${id}})
+function(subproject id name)
+    if ($ENV{XON_NO_${id}})
+        return()
+    endif ()
+    if (EXISTS "${PROJECT_SOURCE_DIR}/${name}/CMakeLists.txt")
         add_subdirectory(${name} ${ARGN})
     endif ()
-endmacro()
+endfunction()
 
-subproject(DAEMON  daemon)
-subproject(PKI     d0_blind_id)
-subproject(DP      darkplaces)
-subproject(DATA    data/xonotic-data.pk3dir)
-subproject(QCC     gmqcc)
+subproject(DAEMON daemon)
+subproject(PKI d0_blind_id)
+subproject(DP darkplaces)
+subproject(DATA data/xonotic-data.pk3dir)
+subproject(QCC gmqcc)
 subproject(RADIANT netradiant)
 
 if (DOWNLOAD_MAPS)
diff --git a/default.nix b/default.nix
index 418fb88d..69485127 100644
--- a/default.nix
+++ b/default.nix
@@ -1,25 +1,18 @@
-# nix-shell -A xonotic
+# nix-shell -A shell
 # --argstr cc clang
 {
     nixpkgs ? <nixpkgs>,
     pkgs ? (import nixpkgs) {},
-    cc ? null,
+    cc ? null
 }:
 with pkgs;
 let
     VERSION = "0.8.2";
-    stdenv = if (cc != null) then overrideCC pkgs.stdenv pkgs."${cc}" else pkgs.stdenv;
     targets = rec {
-        xonotic = stdenv.mkDerivation rec {
+        xonotic = mkDerivation { pki = true; dp = true; data = true; } rec {
             name = "xonotic-${version}";
             version = VERSION;
 
-            XON_NO_DAEMON = true;
-            XON_NO_RADIANT = true;
-
-            XON_NO_QCC = true;
-            QCC = "${gmqcc}/gmqcc";
-
             src = lib.sourceFilesBySuffices ./. [
                 ".txt" ".cmake" ".in"
                 ".c" ".cpp" ".h"
@@ -28,11 +21,9 @@ let
                 ".sh"
             ];
 
-            enableParallelBuilding = true;
-
-            cmakeFlags = [
-                "-DDOWNLOAD_MAPS=0"
-            ];
+            env = {
+                QCC = "${gmqcc}/gmqcc";
+            };
 
             nativeBuildInputs = [
                 cmake   # for building
@@ -40,6 +31,10 @@ let
                 # unzip # for downloading maps
             ];
 
+            cmakeFlags = [
+                "-DDOWNLOAD_MAPS=0"
+            ];
+
             buildInputs = [
                 openssl # for d0_blind_id
                 SDL2    # for darkplaces
@@ -59,10 +54,6 @@ let
                 libvorbis
             ];
 
-            shellHook = ''
-                export LD_LIBRARY_PATH=''${LD_LIBRARY_PATH:+$LD_LIBRARY_PATH:}${lib.makeLibraryPath runtimeInputs}
-            '';
-
             installPhase = ''
                 mkdir $out
 
@@ -79,43 +70,33 @@ let
             dontPatchELF = true;
         };
 
-        gmqcc = stdenv.mkDerivation rec {
+        gmqcc = mkDerivation { qcc = true; } rec {
             name = "gmqcc-${version}";
             version = "xonotic-${VERSION}";
 
             src = ./gmqcc;
 
-            enableParallelBuilding = true;
-
             installPhase = ''
                 mkdir $out
                 cp -r . $out
             '';
         };
 
-        netradiant = stdenv.mkDerivation rec {
+        netradiant = mkDerivation { radiant = true; } rec {
             name = "netradiant-${version}";
             version = VERSION;
 
-            XON_NO_DAEMON = true;
-            XON_NO_DP = true;
-            XON_NO_PKI = true;
-            XON_NO_QCC = true;
-            XON_NO_DATA = true;
-
             src = ./netradiant;
 
-            enableParallelBuilding = true;
-
-            cmakeFlags = [
-                "-DDOWNLOAD_MAPS=0"
-            ];
-
             nativeBuildInputs = [
                 cmake   # for building
                 git     # for versioning
             ];
 
+            cmakeFlags = [
+                "-DDOWNLOAD_MAPS=0"
+            ];
+
             buildInputs = [
                 pkgconfig
                 glib
@@ -141,4 +122,33 @@ let
             ];
         };
     };
-in targets
+    stdenv = if (cc != null) then overrideCC pkgs.stdenv pkgs."${cc}" else pkgs.stdenv;
+    mkEnableTargets = args: {
+        XON_NO_PKI = !args?pki;
+        XON_NO_DP = !args?dp;
+        XON_NO_DATA = !args?data;
+        XON_NO_QCC = !args?qcc;
+        XON_NO_RADIANT = !args?radiant;
+    };
+    mkDerivation = targets: {env ? {}, shellHook ? "", runtimeInputs ? [], ...}@args:
+        stdenv.mkDerivation (
+            (mkEnableTargets targets)
+            // { enableParallelBuilding = true; }
+            // (removeAttrs args ["env" "shellHook" "runtimeInputs"])  # passthru
+            // env
+            // {
+                shellHook = ''
+                    ${shellHook}
+                    ${lib.concatStringsSep "\n" (lib.mapAttrsToList (n: v: "export ${n}=${v}") env)}
+                    export LD_LIBRARY_PATH=''${LD_LIBRARY_PATH:+$LD_LIBRARY_PATH:}${lib.makeLibraryPath runtimeInputs}
+                '';
+            }
+        );
+    shell = let inputs = (lib.mapAttrsToList (n: v: v) targets); in stdenv.mkDerivation (rec {
+        name = "xon-shell";
+        XON_NO_DAEMON = true;
+        nativeBuildInputs = builtins.map (it: it.nativeBuildInputs) inputs;
+        buildInputs = builtins.map (it: it.buildInputs) inputs;
+        shellHook = builtins.map (it: it.shellHook) (builtins.filter (it: it?shellHook) inputs);
+    });
+in { inherit shell; } // targets
-- 
2.39.2