Merge 'mingw-w64' and 'darwin' into cross-win-osx.

Both branches have quite a lot in common, so it's time for a merge and
do the cleanups with respect to both implementations and also generalize
both implementations as much as possible.

This also closes #1876.

Conflicts:
	pkgs/development/interpreters/lua-5/5.2.nix
	pkgs/development/libraries/SDL/default.nix
	pkgs/development/libraries/glew/default.nix
	pkgs/top-level/all-packages.nix

pkgs/development/libraries/SDL/default.nix

@@ -7,21 +7,13 @@
 
 # OSS is no longer supported, for it's much crappier than ALSA and
 # PulseAudio.
-assert alsaSupport || pulseaudioSupport;
+assert !(stdenv ? cross) -> alsaSupport || pulseaudioSupport;
 
 assert openglSupport -> (mesa != null && x11Support);
 assert x11Support -> (x11 != null && libXrandr != null);
 assert alsaSupport -> alsaLib != null;
 assert pulseaudioSupport -> pulseaudio != null;
 
-let
-  configureFlagsFun = attrs: ''
-        --disable-oss --disable-video-x11-xme
-        --disable-x11-shared --disable-alsa-shared --enable-rpath --disable-pulseaudio-shared
-        --disable-osmesa-shared
-        ${if alsaSupport then "--with-alsa-prefix=${attrs.alsaLib}/lib" else ""}
-      '';
-in
 stdenv.mkDerivation rec {
   version = "1.2.15";
   name    = "SDL-${version}";
@@ -32,20 +24,46 @@ stdenv.mkDerivation rec {
   };
 
   # Since `libpulse*.la' contain `-lgdbm', PulseAudio must be propagated.
-  propagatedBuildInputs = stdenv.lib.optionals x11Support [ x11 libXrandr ] ++
+  propagatedNativeBuildInputs =
+    stdenv.lib.optionals x11Support [ x11 libXrandr ] ++
     stdenv.lib.optional pulseaudioSupport pulseaudio;
 
-  buildInputs = [ pkgconfig audiofile ] ++
+  buildInputs = let
+    notMingw = !(stdenv ? cross) || stdenv.cross.libc != "msvcrt";
+  in stdenv.lib.optional notMingw audiofile;
+
+  nativeBuildInputs = [ pkgconfig ] ++
     stdenv.lib.optional openglSupport [ mesa ] ++
     stdenv.lib.optional alsaSupport alsaLib;
 
   # XXX: By default, SDL wants to dlopen() PulseAudio, in which case
   # we must arrange to add it to its RPATH; however, `patchelf' seems
   # to fail at doing this, hence `--disable-pulseaudio-shared'.
-  configureFlags = configureFlagsFun { inherit alsaLib; };
+  configureFlags = [
+    "--disable-oss"
+    "--disable-video-x11-xme"
+    "--disable-x11-shared"
+    "--disable-alsa-shared"
+    "--enable-rpath"
+    "--disable-pulseaudio-shared"
+    "--disable-osmesa-shared"
+  ] ++ stdenv.lib.optionals (stdenv ? cross) ([
+    "--without-x"
+  ] ++ stdenv.lib.optional alsaSupport "--with-alsa-prefix=${alsaLib}/lib");
 
-  crossAttrs = {
-      configureFlags = configureFlagsFun { alsaLib = alsaLib.crossDrv; };
+  crossAttrs =stdenv.lib.optionalAttrs (stdenv.cross.libc == "libSystem") {
+    patches = let
+      f = rev: sha256: fetchurl {
+        url = "http://hg.libsdl.org/SDL/raw-rev/${rev}";
+        inherit sha256;
+      };
+    in [
+      (f "e9466ead70e5" "0ygir3k83d0vxp7s3k48jn3j8n2bnv9wm6613wpx3ybnjrxabrip")
+      (f "bbfb41c13a87" "17v29ybjifvka19m8qf14rjc43nfdwk9v9inaizznarhb17amlnv")
+    ];
+    postPatch = ''
+      sed -i -e 's/ *-fpascal-strings//' configure
+    '';
   };
 
   passthru = {inherit openglSupport;};