build OpenSceneGraph 3.0.1 for iOS

I'm trying to build the OpenSceneGraph for iOS as specified in the README file.

cmake -G Xcode \
-D OSG_BUILD_PLATFORM_IPHONE:BOOL=ON \
开发者_如何学JAVA-D CMAKE_CXX_FLAGS:STRING="-ftree-vectorize -fvisibility-inlines-hidden -mno-thumb -arch armv6 -pipe -no-cpp-precomp -miphoneos-version-min=3.2 -mno-thumb" \
-D BUILD_OSG_APPLICATIONS:BOOL=OFF \
-D OSG_BUILD_FRAMEWORKS:BOOL=OFF \
-D OSG_WINDOWING_SYSTEM:STRING=IOS \
-D OSG_BUILD_PLATFORM_IPHONE:BOOL=ON \
-D CMAKE_OSX_ARCHITECTURES:STRING="armv6;armv7" \
-D CMAKE_OSX_SYSROOT:STRING=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk \
-D OSG_GL1_AVAILABLE:BOOL=OFF \
-D OSG_GL2_AVAILABLE:BOOL=OFF \
-D OSG_GLES1_AVAILABLE:BOOL=ON \
-D OSG_GL_DISPLAYLISTS_AVAILABLE:BOOL=OFF \
-D OSG_GL_FIXED_FUNCTION_AVAILABLE:BOOL=ON \
-D OSG_GL_LIBRARY_STATIC:BOOL=OFF \
-D OSG_GL_MATRICES_AVAILABLE:BOOL=ON \
-D OSG_GL_VERTEX_ARRAY_FUNCS_AVAILABLE:BOOL=ON \
-D OSG_GL_VERTEX_FUNCS_AVAILABLE:BOOL=OFF \
-D DYNAMIC_OPENSCENEGRAPH:BOOL=OFF \
-D DYNAMIC_OPENTHREADS:BOOL=OFF .

But I'm getting following error.

-- The C compiler identification is GNU
-- The CXX compiler identification is unknown
-- Checking whether C compiler has -isysroot
-- Checking whether C compiler has -isysroot - yes
-- Checking whether C compiler supports OSX deployment target flag
-- Checking whether C compiler supports OSX deployment target flag - yes
-- Check for working C compiler using: Xcode
-- Check for working C compiler using: Xcode -- broken
CMake Error at /opt/local/share/cmake-2.8/Modules/CMakeTestCCompiler.cmake:52 (MESSAGE):
  The C compiler "/usr/bin/gcc" is not able to compile a simple test program.

  It fails with the following output:

   Change Dir: /Volumes/MY_DATA/AugmentedReality/osg/OpenSceneGraph-3.0.1/CMakeFiles/CMakeTmp

  Run Build Command:/opt/local/bin/cmakexbuild -project
  CMAKE_TRY_COMPILE.xcodeproj build -target cmTryCompileExec -configuration
  Debug

  === BUILD NATIVE TARGET cmTryCompileExec OF PROJECT CMAKE_TRY_COMPILE WITH
  CONFIGURATION Debug ===

  Check dependencies

  target specifies product type 'com.apple.product-type.tool', but there's no
  such product type for the 'iphoneos' platform

  ** BUILD FAILED **

  The following build commands failed:

    Check dependencies

  (1 failure)

  CMake will not be able to correctly generate this project.
Call Stack (most recent call first):
  CMakeLists.txt:30 (PROJECT)

-- Configuring incomplete, errors occurred!

What might cause this and how do I solve it?

I'm trying to do the same thing and get a similar error. I found the following post indicating cmake is not yet compatible with Xcode 4 when building for iOS:

http://forum.openscenegraph.org/viewtopic.php?t=9034