ghostscript: reduce size significantly, /cc #8990

- Don't use static bin/gs.
- Split docs into a separate output.
- Split fonts into another derivation, so they're not reinstalled when
  something changes.
- Drop --disable-sse2
  https://github.com/NixOS/nixpkgs/commit/e723c512c#commitcomment-12361078
- Some cleanups.

pkgs/misc/ghostscript/default.nix

@@ -7,16 +7,14 @@
 
 assert x11Support -> x11 != null;
 assert cupsSupport -> cups != null;
-
-stdenv.mkDerivation rec {
-  name = "ghostscript-9.15";
-
-  src = fetchurl {
-    url = "http://downloads.ghostscript.com/public/${name}.tar.bz2";
+let
+  version = "9.15";
   sha256 = "0p1isp6ssfay141klirn7n9s8b546vcz6paksfmksbwy0ljsypg6";
-  };
 
-  fonts = [
+  fonts = stdenv.mkDerivation {
+    name = "ghostscript-fonts";
+
+    srcs = [
       (fetchurl {
         url = "mirror://sourceforge/gs-fonts/ghostscript-fonts-std-8.11.tar.gz";
         sha256 = "00f4l10xd826kak51wsmaz69szzm2wp8a41jasr4jblz25bg7dhf";
@@ -28,6 +26,25 @@ stdenv.mkDerivation rec {
       # ... add other fonts here
     ];
 
+    installPhase = ''
+      mkdir "$out"
+      mv -v * "$out/"
+    '';
+  };
+
+in
+stdenv.mkDerivation rec {
+  name = "ghostscript-${version}";
+
+  src = fetchurl {
+    url = "http://downloads.ghostscript.com/public/${name}.tar.bz2";
+    inherit sha256;
+  };
+
+  patches = [ ./urw-font-files.patch ];
+
+  outputs = [ "out" "doc" ];
+
   enableParallelBuilding = true;
 
   buildInputs =
@@ -40,38 +57,34 @@ stdenv.mkDerivation rec {
     # [] # maybe sometimes jpeg2000 support
     ;
 
-  patches = [ ./urw-font-files.patch ];
-
   makeFlags = [ "cups_serverroot=$(out)" "cups_serverbin=$(out)/lib/cups" ];
 
-  configureFlags =
-    [ "--with-system-libtiff" "--disable-sse2"
-      "--enable-dynamic"
-      (if x11Support then "--with-x" else "--without-x")
-      (if cupsSupport then "--enable-cups" else "--disable-cups")
-    ];
-
-  doCheck = true;
-
-  installTargets="install soinstall";
-
-  #CFLAGS = "-fPIC";
-  #NIX_LDFLAGS =
-  #  "-lz -rpath${ if stdenv.isDarwin then " " else "="}${freetype}/lib";
-
   preConfigure = ''
     rm -rf jpeg libpng zlib jasper expat tiff lcms{,2} jbig2dec openjpeg freetype cups/libs
 
     sed "s@if ( test -f \$(INCLUDE)[^ ]* )@if ( true )@; s@INCLUDE=/usr/include@INCLUDE=/no-such-path@" -i base/unix-aux.mak
   '';
 
-  postInstall = ''
-    # ToDo: web says the fonts should be already included
-    for i in $fonts; do
-      (cd $out/share/ghostscript && tar xvfz $i)
-    done
+  configureFlags =
+    [ "--with-system-libtiff"
+      "--enable-dynamic"
+      (if x11Support then "--with-x" else "--without-x")
+      (if cupsSupport then "--enable-cups" else "--disable-cups")
+    ];
 
-    rm -rf $out/lib/cups/filter/{gstopxl,gstoraster}
+  doCheck = true;
+
+  # don't build/install statically linked bin/gs
+  buildFlags = "so";
+  installTargets="soinstall";
+
+  postInstall = ''
+    ln -s gsc "$out"/bin/gs
+
+    mkdir -p "$doc/share/ghostscript/${version}"
+    mv "$out/share/ghostscript/${version}"/{doc,examples} "$doc/share/ghostscript/${version}/"
+
+    ln -s "${fonts}" "$out/share/ghostscript/fonts"
   '';
 
   meta = {