rtags: fix for clang/libc++ 4

This also fixes a missing header in the SDK that rtags needs to work
properly. The underlying cause is that C++ headers got shuffled around a
lot in libc++ 3.8 (I believe) and became more standards-compliant, which
led to a lot of C-compatible passthrough header files being added to it
like math.h, which defines some C++-compatible versions of standard
functions like signbit, while #include_next'ing the system math.h. In
this case, including the SDK was stuffing another math.h in front of the
libc++ shim, which led to all sorts of mysterious failures.

pkgs/development/tools/rtags/default.nix

@@ -5,15 +5,11 @@ stdenv.mkDerivation rec {
   version = "2.8-p1";
 
   buildInputs = [ cmake llvmPackages.llvm openssl llvmPackages.clang emacs ]
-    ++ lib.optionals stdenv.isDarwin [ apple_sdk.sdk apple_sdk.frameworks.CoreServices ];
+    ++ lib.optionals stdenv.isDarwin [ apple_sdk.libs.xpc apple_sdk.frameworks.CoreServices ];
 
   preConfigure = ''
     export LIBCLANG_CXXFLAGS="-isystem ${llvmPackages.clang.cc}/include $(llvm-config --cxxflags) -fexceptions" \
-           LIBCLANG_LIBDIR="${llvmPackages.clang.cc}/lib" \
-
-  '' + lib.optionalString stdenv.isDarwin ''
-    export CXXFLAGS="-isysroot ${apple_sdk.sdk}/" \
-           MACOSX_DEPLOYMENT_TARGET="10.9"
+           LIBCLANG_LIBDIR="${llvmPackages.clang.cc}/lib"
   '';
 
   src = fetchgit {
@@ -24,11 +20,11 @@ stdenv.mkDerivation rec {
     sha256 = "0g9sgc763c5d695hjffhis19sbaqk8z4884szljf7kbrjxl17y78";
   };
 
+  enableParallelBuilding = true;
+
   meta = {
     description = "C/C++ client-server indexer based on clang";
-
     homepage = https://github.com/andersbakken/rtags;
-
     license = stdenv.lib.licenses.gpl3;
     platforms = stdenv.lib.platforms.allBut [ "i686-linux" ];
   };

pkgs/os-specific/darwin/apple-sdk/default.nix

@@ -157,6 +157,7 @@ in rec {
         mkdir -p $out/include
         pushd $out/include >/dev/null
         ln -s "${sdk}/include/xpc"
+        ln -s "${sdk}/include/launch.h"
         popd >/dev/null
       '';
     };