Only set the C++ preprocessor if C++ is enabled

svn path=/nixpkgs/trunk/; revision=26669

pkgs/development/compilers/gcc-4.6/builder.sh

@@ -8,7 +8,9 @@ mkdir $NIX_FIXINC_DUMMY
 # libstdc++ needs this; otherwise it will use /lib/cpp, which is a Bad
 # Thing.
 export CPP="gcc -E"
-export CXXCPP="gcc -E"
+if test "$langCC" = "1"; then
+  export CXXCPP="gcc -E" #We only want this if C++ is enabled
+fi
 
 if test "$staticCompiler" = "1"; then
     EXTRA_LDFLAGS="-static"

pkgs/development/compilers/gcc-4.6/default.nix

@@ -200,7 +200,7 @@ stdenv.mkDerivation ({
     else null;
 
   inherit noSysDirs profiledCompiler staticCompiler langJava crossStageStatic
-    libcCross crossMingw;
+    libcCross crossMingw langCC;
 
   buildNativeInputs = [ texinfo which ]
     ++ optional (perl != null) perl;