pkgs/top-level/all-packages.nix: prefer makeOverridable over getPkgConfig to customize GNU plot

Changed 'gnuplot' expression to allow for argument overriding instead of
relying on getPkgConfig. While I was at it, I also simplified the actual build
expression a bit.

svn path=/nixpkgs/trunk/; revision=21864

2 files changed, 7 insertions, 15 deletions

diff --git a/pkgs/tools/graphics/gnuplot/default.nix b/pkgs/tools/graphics/gnuplot/default.nix
index c10777f66ab2..003169415d39 100644
--- a/pkgs/tools/graphics/gnuplot/default.nix
+++ b/pkgs/tools/graphics/gnuplot/default.nix
@@ -10,16 +10,9 @@
 , pango ? null
 , cairo ? null
 , pkgconfig ? null
-, x11Support ? false
 , readline
 }:
 
-assert x11Support -> ((libX11 != null) &&
-    (libXt != null) && (libXpm != null) &&
-    (libXaw != null));
-
-assert (wxGTK != null) -> x11Support;
-
 stdenv.mkDerivation {
   name = "gnuplot-4.4.0";
   src = fetchurl {
@@ -27,9 +20,10 @@ stdenv.mkDerivation {
     sha256 = "0akb2lzxa3b0j4nr6anr0mhsk10b1fcnixk8vk9aa82rl1a2rph0";
   };
 
-  configureFlags = if x11Support then ["--with-x"] else ["--without-x"];
+  configureFlags = if (libX11 != null) then ["--with-x"] else ["--without-x"];
 
-  buildInputs = [zlib gd texinfo readline emacs lua texLive] ++
-    (if x11Support then [libX11 libXt libXpm libXaw] else []) ++
-    (if wxGTK != null then [wxGTK pango cairo pkgconfig] else []);
+  buildInputs = [
+    zlib gd texinfo readline emacs lua texLive libX11 libXt libXpm libXaw
+    wxGTK pango cairo pkgconfig
+  ];
 }
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index d6589c12f156..1835c4afb9f5 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -817,11 +817,9 @@ let
       openldap bzip2 libusb curl;
   };
 
-  gnuplot = import ../tools/graphics/gnuplot {
-    inherit fetchurl stdenv zlib gd texinfo readline emacs;
+  gnuplot = makeOverridable (import ../tools/graphics/gnuplot) {
+    inherit fetchurl stdenv zlib gd texinfo readline emacs wxGTK;
     inherit (xlibs) libX11 libXt libXaw libXpm;
-    x11Support = getPkgConfig "gnuplot" "x11" false;
-    wxGTK = if getPkgConfig "gnuplot" "wxGtk" false then wxGTK else null;
     inherit (gtkLibs) pango;
     inherit cairo pkgconfig;
   };