Add callCabal2nix to haskell packages

Closes #22191. (cherry picked from commit 05ee547) Signed-off-by: Domen Kožar <domen@dev.si>
NixOS · Feb 3, 2017 · 74f24c7 · 74f24c7
1 parent e67d70f
commit 74f24c7
Showing 1 changed file with 26 additions and 12 deletions.
diff --git a/pkgs/development/haskell-modules/default.nix b/pkgs/development/haskell-modules/default.nix
@@ -52,18 +52,26 @@ let
         inherit packages;
       };
 
-      hackage2nix = name: version: pkgs.stdenv.mkDerivation {
-        name = "cabal2nix-${name}-${version}";
-        buildInputs = [ pkgs.cabal2nix ];
-        phases = ["installPhase"];
-        LANG = "en_US.UTF-8";
-        LOCALE_ARCHIVE = pkgs.lib.optionalString pkgs.stdenv.isLinux "${pkgs.glibcLocales}/lib/locale/locale-archive";
-        installPhase = ''
-          export HOME="$TMP"
-          mkdir $out
-          hash=$(sed -e 's/.*"SHA256":"//' -e 's/".*$//' ${all-cabal-hashes}/${name}/${version}/${name}.json)
-          cabal2nix --compiler=${self.ghc.name} --system=${stdenv.system} --sha256=$hash ${all-cabal-hashes}/${name}/${version}/${name}.cabal >$out/default.nix
-        '';
+      haskellSrc2nix = { name, src, sha256 ? null }:
+        let
+          sha256Arg = if isNull sha256 then "" else ''--sha256="${sha256}"'';
+        in pkgs.stdenv.mkDerivation {
+          name = "cabal2nix-${name}";
+          buildInputs = [ pkgs.cabal2nix ];
+          phases = ["installPhase"];
+          LANG = "en_US.UTF-8";
+          LOCALE_ARCHIVE = pkgs.lib.optionalString pkgs.stdenv.isLinux "${pkgs.glibcLocales}/lib/locale/locale-archive";
+          installPhase = ''
+            export HOME="$TMP"
+            mkdir -p "$out"
+            cabal2nix --compiler=${self.ghc.name} --system=${stdenv.system} ${sha256Arg} "${src}" > "$out/default.nix"
+          '';
+      };
+
+      hackage2nix = name: version: haskellSrc2nix {
+        name   = "${name}-${version}";
+        sha256 = ''$(sed -e 's/.*"SHA256":"//' -e 's/".*$//' "${all-cabal-hashes}/${name}/${version}/${name}.json")'';
+        src    = "${all-cabal-hashes}/${name}/${version}/${name}.cabal";
       };
 
     in
@@ -73,6 +81,12 @@ let
 
         callHackage = name: version: self.callPackage (hackage2nix name version);
 
+        # Creates a Haskell package from a source package by calling cabal2nix on the source.
+        callCabal2nix = src: self.callPackage (haskellSrc2nix {
+          inherit src;
+          name = src.name;
+        });
+
         ghcWithPackages = selectFrom: withPackages (selectFrom self);
 
         ghcWithHoogle = selectFrom: