This is the default that's produced. Doesn't seem to have anything that's mac specific.

hxcpp_config.xml

<!--

  This file will get included twice - once at the beginning - once at the end.

  The first time though, the "vars" section is parsed, and this is where you can
   set variables to control the setup of the standard compilers and install paths etc.

  The second time, the "exes" section is parsed, and you can modify the linkers/compilers
   by adding flags to these executables.
  
-->

<xml>

  <!-- This section is parses at the beginning of the build .... -->
  <section id="vars">

     <!-- Use this to control the SDK used when compiling for iphone/iphonesim, and the
           default is not found, or you wish to use a specific version -->
     <!-- <set name="IPHONE_VER" value="4.2" /> -->

     <!-- If you put all your SDKs in one directory, then you can just set this
          single variable.  If you put them in exactly this place, then you should not
          need to setup anything ! -->
     <set name="SDK_ROOT" value="c:\SDKs\" unless="SDK_ROOT" if="windows" />
     <set name="SDK_ROOT" value="${HOME}/SDKs/" unless="SDK_ROOT" />


     <!-- ANDROID_NDK_ROOT is required for building android binaries. See:
            http://developer.android.com/sdk/ndk/index.html -->
     <set name="ANDROID_NDK_ROOT" value="${SDK_ROOT}/android-ndk-r6" unless="ANDROID_NDK_ROOT" />

     <!-- ant is required to build android packages. See:
            http://ant.apache.org/bindownload.cgi -->
     <set name="ANT_HOME" value="${SDK_ROOT}/ant" unless="ANT_HOME" />

     <!-- The ANDROID_SDK is required for building androis packages. See
            http://developer.android.com/sdk/index.html -->
     <set name="ANDROID_SDK" value="${SDK_ROOT}/android-sdk" unless="ANDROID_SDK" />

     <!-- The Java development kit (which should include the java runtime) is
         also required for android dev. Make sure to get the 32 bit version! -->

     <set name="JAVA_HOME" value="${SDK_ROOT}/java_jdk" unless="JAVA_HOME" />



     <!-- If you want to control how many compilers get spawned .
          The default will use the number of processors.
          Reducing this to 1 can help deciphering error messages. -->
     <!-- <set name="HXCPP_COMPILE_THREADS" value="1" /> -->

     <!-- Add this if your compiler does not support precompiled headers -->
     <!-- <set name="NO_PRECOMPILED_HEADERS" value="1"/> -->

     <!-- Older versions of gcc do not suport the @file syntax for an obj file list
          and precompiled headers.  Set this if you have these issues -->
     <!-- <set name="GCC_OLD" value="1" /> -->


     <!-- Skip the "stripping" phase.  This will leave extra symbols in you exe, which
          may allow reverse engineering and larger file sizes.  You might want to do
          this to debug some problems though. -->
     <!-- <set name="nostrip" value="1" /> -->

     <!-- Let the system detect the latest version of MSVC on windows
          (otherwise must setup the environment yourself) -->
     <!-- Disable with <set name="NO_AUTO_MSVC" value="1" /> -->
     <!-- To disable specific versions: <setenv name="VS110COMNTOOLS" value="disable" /> -->


  </section>


  <!-- Use this section to add flags to the compilers and linkers -->
  <section id="exes">

     <!-- Compiling on windows ... -->
     <compiler id="MSVC" if="windows">
        <!-- Example adding a build flag -->
        <flag value = "-Ie:/VS8//PlatformSDK/Include"/>
     </compiler>

     <!-- Linking on windows ... -->
     <linker id="dll" if="windows">
        <!-- Add library paths for windows (DirectX needed for building NME) -->
        <flag value = "-libpath:e:\VS8\DirectXSDK\Lib\x86"/>
        <flag value = "-libpath:e:/VS8/PlatformSDK/Lib"/>
     </linker>

     <!-- And for linking executables -->
     <linker id="exe" if="windows">
        <flag value = "-libpath:e:/VS8/PlatformSDK/Lib"/>
     </linker>

  </section>

</xml>