Big fixes in the cross build:

- Before this changes, cflags and ldflags for the native and the cross compiler
  got mixed. Not all the gcc-wrapper/gcc-cross-wrapper variables are
  independant now, but enough, I think.
- Fixed the generic stdenv expression, which did a big mess on buildInputs and
  buildNativeInputs. Now it distinguishes when there is a stdenvCross or not.
  Maybe we should have a single stdenv and forget about the stdenvCross
  adapter - this could end in a stdenv a bit complex, but simpler than the
  generic stdenv + adapter.
- Added basic support in pkgconfig for cross-builds: a single PKG_CONFIG_PATH
  now works for both the cross and the native compilers, but I think this
  should work well for most cases I can think of.
- I tried to fix the guile expression to cross-biuld; guile is built, but not
  its manual, so the derivation still fails. Guile requires patching to
  cross-build, as far as I understnad.
- Made the glibcCross build to be done through the usage of a
  gcc-cross-wrapper over the gcc-cross-stage-static, instead of using it
  directly.
- Trying to make physfs (a neverball dependency) cross build.
- Updated the gcc expression to support building a cross compiler without getting
  derivation variables mixed with those of the stdenvCross.

svn path=/nixpkgs/branches/stdenv-updates/; revision=18534

pkgs/development/tools/build-managers/cmake/setup-hook.sh

@@ -32,6 +32,13 @@ cmakeConfigurePhase()
         cmakeFlags="-DCMAKE_INSTALL_PREFIX=$prefix $cmakeFlags"
     fi
 
+    if test -n "$crossConfig"; then
+        # By now it supports linux builds only. We should set the proper
+        # CMAKE_SYSTEM_NAME otherwise.
+        # http://www.cmake.org/Wiki/CMake_Cross_Compiling
+        cmakeFlags="-DCMAKE_CXX_COMPILER=$crossConfig-g++ -DCMAKE_C_COMPILER=$crossConfig-gcc $cmakeFlags"
+    fi
+
     echo "cmake flags: $cmakeFlags ${cmakeFlagsArray[@]}"
 
     cmake ${cmakeDir:-.} $cmakeFlags ${cmakeFlagsArray[@]}
@@ -43,4 +50,8 @@ if test -z "$dontUseCmakeConfigure"; then
     configurePhase=cmakeConfigurePhase
 fi
 
-envHooks=(${envHooks[@]} addCMakeParams)
+if test -n "$crossConfig"; then
+    crossEnvHooks=(${crossEnvHooks[@]} addCMakeParams)
+else
+    envHooks=(${envHooks[@]} addCMakeParams)
+fi