mps: add darwin support (#368808)

pkgs/by-name/mp/mps/package.nix

@@ -4,35 +4,64 @@
   fetchFromGitHub,
   autoreconfHook,
   sqlite,
+  xcbuildHook,
 }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (finalAttrs: {
   pname = "mps";
   version = "1.118.0";
 
   src = fetchFromGitHub {
     owner = "Ravenbrook";
     repo = "mps";
-    tag = "release-${version}";
+    tag = "release-${finalAttrs.version}";
     hash = "sha256-3ql3jWLccgnQHKf23B1en+nJ9rxqmHcWd7aBr93YER0=";
   };
 
-  postPatch = ''
+  sourceRoot = lib.optionalString stdenv.hostPlatform.isDarwin "${finalAttrs.src.name}/code";
+
+  postPatch = lib.optionalString stdenv.hostPlatform.isLinux ''
     # Disable -Werror to avoid biuld failure on fresh toolchains like
     # gcc-13.
-    substituteInPlace code/gc.gmk --replace-fail '-Werror ' ' '
-    substituteInPlace code/gp.gmk --replace-fail '-Werror ' ' '
-    substituteInPlace code/ll.gmk --replace-fail '-Werror ' ' '
+    substituteInPlace code/gc.gmk \
+      --replace-fail "-Werror " " "
+    substituteInPlace code/gp.gmk \
+      --replace-fail "-Werror " " "
+    substituteInPlace code/ll.gmk \
+      --replace-fail "-Werror " " "
   '';
 
-  nativeBuildInputs = [ autoreconfHook ];
+  nativeBuildInputs =
+    (lib.optionals stdenv.hostPlatform.isLinux [ autoreconfHook ])
+    ++ (lib.optionals stdenv.hostPlatform.isDarwin [ xcbuildHook ]);
+
   buildInputs = [ sqlite ];
 
+  xcbuildFlags = lib.optionals stdenv.hostPlatform.isDarwin [
+    "-configuration"
+    "Release"
+    "-project"
+    "mps.xcodeproj"
+    # "-scheme"
+    # "mps"
+    "OTHER_CFLAGS='-Wno-error=unused-but-set-variable'"
+  ];
+
+  installPhase = lib.optionalString stdenv.hostPlatform.isDarwin ''
+    runHook preInstall
+
+    install -Dm644 Products/Release/libmps.a $out/lib/libmps.a
+    mkdir $out/include
+    cp mps*.h $out/include/
+
+    runHook postInstall
+  '';
+
   meta = {
     description = "Flexible memory management and garbage collection library";
     homepage = "https://www.ravenbrook.com/project/mps";
     license = lib.licenses.sleepycat;
-    platforms = lib.platforms.linux;
+    platforms = lib.platforms.linux ++ lib.platforms.darwin;
     maintainers = [ lib.maintainers.thoughtpolice ];
   };
-}
+})