libc++abi: Don't set dylib install name to /usr/lib

This caused users of libc++abi to use the system libc++abi.

pkgs/development/libraries/libc++abi/darwin.patch

@@ -0,0 +1,17 @@
+diff -ru -x '*~' libcxxabi-orig/lib/buildit libcxxabi/lib/buildit
+--- libcxxabi-orig/lib/buildit	2014-09-18 16:54:14.000000000 +0200
++++ libcxxabi/lib/buildit	2014-09-24 13:22:27.000000000 +0200
+@@ -51,12 +51,8 @@
+         -dynamiclib -nodefaultlibs  \
+         -current_version ${RC_ProjectSourceVersion} \
+         -compatibility_version 1 \
+-        -install_name /usr/lib/libc++abi.dylib \
++        -install_name $out/lib/libc++abi.dylib \
+         -lSystem"
+-	if [ -f "${SDKROOT}/usr/local/lib/libCrashReporterClient.a" ]
+-	then
+-		LDSHARED_FLAGS+=" -lCrashReporterClient"
+-	fi
+     ;;
+   *-*-mingw*)
+     # FIXME: removing libgcc and libsupc++ dependencies means porting libcxxrt and LLVM/compiler-rt

pkgs/development/libraries/libc++abi/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, libcxx, libunwind, coreutils, gnused }:
+{ lib, stdenv, fetchurl, libcxx, libunwind, coreutils, gnused }:
 
 let rev = "199626"; in
 
@@ -10,6 +10,8 @@ stdenv.mkDerivation {
     sha256 = "09wr6qwgmdzbmgfkdzfhph9giy0zd6fp3s017fcfy4g0prjn5s4c";
   };
 
+  patches = [ ./no-stdc++.patch ./darwin.patch ];
+
   NIX_CFLAGS_LINK = "-L${libunwind}/lib -lunwind";
 
   buildInputs = [ coreutils ];
@@ -17,7 +19,7 @@ stdenv.mkDerivation {
   postUnpack = ''
     unpackFile ${libcxx.src}
     export NIX_CFLAGS_COMPILE="-I${libunwind}/include -I$PWD/include -I$(readlink -f libcxx-*)/include"
-  '' + stdenv.lib.optionalString stdenv.isDarwin ''
+  '' + lib.optionalString stdenv.isDarwin ''
     export TRIPLE=x86_64-apple-darwin
   '';
 
@@ -35,8 +37,6 @@ stdenv.mkDerivation {
       ln -s libc++abi.so.1.0 $out/lib/libc++abi.so.1
     '';
 
-  patchPhase = "${gnused}/bin/sed -e s,-lstdc++,, -i lib/buildit";
-
   buildPhase = "(cd lib; ./buildit)";
 
   meta = {

pkgs/development/libraries/libc++abi/no-stdc++.patch

@@ -0,0 +1,12 @@
+diff -ru -x '*~' libcxxabi-orig/lib/buildit libcxxabi/lib/buildit
+--- libcxxabi-orig/lib/buildit	2014-09-18 16:54:14.000000000 +0200
++++ libcxxabi/lib/buildit	2014-09-24 13:22:27.000000000 +0200
+@@ -70,7 +66,7 @@
+     SOEXT=so
+     LDSHARED_FLAGS="-o libc++abi.so.1.0 \
+         -shared -nodefaultlibs -Wl,-soname,libc++abi.so.1 \
+-        -lpthread -lrt -lc -lstdc++"
++        -lpthread -lrt -lc"
+     ;;
+ esac
+