[CMake] Detecting Mac OS X Version

[Mike Jackson]

On Oct 31, 2007, at 1:26 PM, James Bigler wrote:

> Sean McBride wrote:
>> On 10/31/07 9:28 AM, Mike Jackson said:
>>> Would someone have an example of detecting the specific version  
>>> of OS  X that cmake is running on? I would like add values based  
>>> on OS X  version.
>>>
>>> IF (OS_X_VERSION matches "10.5")
>>>   ......
>>> ENDIF (OS_X_VERSION matches "10.5")
>>>
>>> or something to that effect..
>> Mike,
>> I'm curious... in what situation does it matter which version of  
>> the OS
>> is being run?  Wouldn't it be better to check which SDK is being  
>> used? Or the deployment version?
>
> Is there an easy way to determine the deployment version of the  
> integrated X environment?
>
> OSX 10.5 changed to using Xorg instead of XFree86 and some of the  
> paths have changed.  As well there is some confusion with the  
> linker when trying to link the X version of libGL.  Here's what one  
> of our developers said about it:
>
> "The main issue is linkpaths, OSX has two GL libraries that seem to  
> conflict and with the default CMake settings it picks up the wrong  
> library. Basically CMake does not write out the proper linking  
> instructions. To fix this for Leopard, a hack is added that adds  
> the OpenGL libraries to the LINK_FLAGS variables, which circumvents  
> the parsing of filenames in -Lpath -llibname, the latter will cause  
> OSX to find the OpenGL version in the frameworks. Currently CMake  
> does not have an option to include paths directly, hence we hacked  
> it to make it work."
>
> 738··IF·(APPLE_LEOPARD)
> 739····SET·(GL_LIBRARY·""·CACHE·INTERNAL·"OpenGL·Libs"·FORCE)
> 740····SET·(GL_LINK·"·/usr/X11R6/lib/libGL.dylib·/usr/X11R6/lib/ 
> libGLU.dylib·- 
> framework·AGL"·CACHE·INTERNAL·"Link·options·for·OpenGL·libs"·FORCE)
> 741····SET·(X_LIBRARY·""·CACHE·INTERNAL·"OpenGL·Libs"·FORCE)
> 742····SET·(X_LINK·"·/usr/X11R6/lib/libX11.dylib·/usr/X11R6/lib/ 
> libXext.dylib·- 
> framework·Carbon"·CACHE·INTERNAL·"Link·options·for·X11·libs"·FORCE)
> 743
> 744··ELSE·(APPLE_LEOPARD)
> 745····SET·(GL_LIBRARY·/usr/X11R6/lib/libGL.dylib·/usr/X11R6/lib/ 
> libGLU.dylib·"-framework·AGL"·CACHE·INTERNAL·"OpenGL·Libs")
> 746····SET· 
> (GL_LINK·""·CACHE·INTERNAL·"Link·options·for·OpenGL·libs"·FORCE)
> 747····SET·(X_LINK·""·CACHE·INTERNAL·"Link·options·for·X·libs"·FORCE)
> 748····SET·(SCIRUN_INCLUDE_ADDITIONAL·${SCIRUN_INCLUDE_ADDITIONAL}·$ 
> {GL_INCLUDE})····
> 749··ENDIF·(APPLE_LEOPARD)
>
> 87··IF(APPLE_LEOPARD)
> 88····SET_TARGET_PROPERTIES(Core_Events·PROPERTIES·LINK_FLAGS··"$ 
> {GL_LINK}·${X_LINK}")
> 89··ENDIF(APPLE_LEOPARD)
>
> James

I was having the same problem that james was having with ParaView  
2.6.1. Here is the solution that I came up with based from a web page;

#-- Put the following in ${ParaView_SOURCE_DIR}/CMake/ 
OSXLeopardX11OpenGL.cmake
IF ( OSX_LEOPARD_OPENGL_FIX )
   IF (APPLE)
     IF (VTK_USE_X)
       #IF(CMAKE_COMPILER_IS_GNUCXX)
         SET (CMAKE_EXE_LINKER_FLAGS  "-Wl,-dylib_file,/System/ 
Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib:/ 
System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/ 
libGL.dylib" )

         SET (CMAKE_SHARED_LINKER_FLAGS  "-Wl,-dylib_file,/System/ 
Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib:/ 
System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/ 
libGL.dylib")
        # ENDIF(CMAKE_COMPILER_IS_GNUCXX)
     ENDIF (VTK_USE_X)
   ENDIF (APPLE)
ENDIF ( OSX_LEOPARD_OPENGL_FIX )

In the Top Level CmakeLists.txt file insert a new option into the OS  
X section:
   OPTION(OSX_LEOPARD_OPENGL_FIX "Adds Linker arguments needed to  
correctly select the X11 OpenGL Library" TRUE)
# ----------------- End OS X 10.5 X11 Patch  
----------------------------------

http://wiki.finkproject.org/index.php/ 
Fink:Packaging:Preparing_for_10.5#OpenGL_Bug

Also, X11 move to the X.org code base for Leopard and there are LOTS  
of problems so far. The XDarwin maintainer has just released a new  
binary for Leopard users that starts to fix some of the problems.

http://lists.apple.com/archives/X11-users/2007/Oct/msg00123.html

http://lists.apple.com/archives/X11-users/2007/Oct/msg00201.html

So the reason I want to know is that this work-around may only be  
needed for 10.5.0 or certain versions of X11. Certainly do not need  
it for 10.4.

I guess I could look for a certain version of X11 on Leopard? But the  
real thing is the linker issue so I think this issue may be here to  
stay. Just a guess. I know nothing about any of this. I just need  
ParaView to work on Leopard.

-- 
Mike Jackson   Senior Research Engineer
Innovative Management & Technology Services