[CMake] Weirdness with shared library, RPATH policy on MacOS

[Michael Wild]

On 13. Aug, 2010, at 16:32 , Chris Wolf wrote:

> 
> 
> On 8/13/10 10:23 AM, Chris Wolf wrote:
>> 
>> 
>> On 8/13/10 9:29 AM, Michael Wild wrote:
>>> 
>>> On 13. Aug, 2010, at 15:25 , Chris Wolf wrote:
>>> 
>>>> 
>>>> I have confirmed that the RPATH handling, as documented here:
>>>> 
>>>> http://www.cmake.org/Wiki/CMake_RPATH_handling
>>>> 
>>>> Is only accurate for the Linux case and *NOT* for MacOS.  
>>>> 
>>>> Here is the summary of my findings:
>>>> 
>>>> "Default RPATH":
>>>> http://www.cmake.org/Wiki/CMake_RPATH_handling#Default_RPATH_settings
>>>> 
>>>> link in build: full build path rpath
>>>> link on install: installed executable will have no rpath
>>>> 
>>>> Linux: yes - works as documented, must set LD_LIBRARY_PATH for installed
>>>>            executable to find shared lib in non-standard install dir
>>>> 
>>>> MacOS: no -  installed executable rpath is still set to full build rpath,
>>>>            (was supposed to be empty rpath) 
>>>>            must set LD_LIBRARY_PATH for installed
>>>>            executable to find shared lib in non-standard install dir
>>>> 
>>>> 
>>>> 
>>>> "Always Use RPATH":
>>>> http://www.cmake.org/Wiki/CMake_RPATH_handling#Always_full_RPATH
>>>> 
>>>> Linux: yes - works as documented, build executable uses build rpath, 
>>>>      installed executable uses installed rpath
>>>> 
>>>> MacOS: no - installed executable rpath is still set to full build rpath
>>>>      (was supposed to be installed lib rpath)
>>>>      must set LD_LIBRARY_PATH for installed
>>>>      executable to find shared lib in non-standard install dir
>>>> 
>>>> 
>>>> 
>>>> "No relinking and full RPATH for the install tree":
>>>> http://www.cmake.org/Wiki/CMake_RPATH_handling#No_relinking_and_full_RPATH_for_the_install_tree
>>>> 
>>>> 
>>>> Linux: yes - works as documented; to run executable in build tree, must 
>>>>      set LD_LIBRARY_PATH=. 
>>>> 
>>>> MacOS: no - executable has no RPATH for build tree, (as expected)
>>>>      although executable finds library in current working directory (build)
>>>>      installed executable *also* has no RPATH; (was supposed to be installed lib rpath)
>>>>      must set DYLD_LIBRARY_PATH for installed
>>>>      executable to find shared lib in non-standard install dir.
>>>>      otool -L shows no RPATH in both executable cases
>>>> 
>>>> 
>>>> I would like to get scenario #2 or #3 working on MacOS.
>>>> 
>>>> Thanks,
>>>> 
>>>> -Chris
>>>> 
>>> 
>>> AFAIK RPATH settings are irrelevant on Mac OS X, since it is always used. 
>>> And the relevant target property is INSTALL_NAME_DIR, initialized by the variable CMAKE_INSTALL_NAME_DIR.
>>> 
>>> Michael
>> 
>> When you write, "RPATH settings are irrelevant on Mac OS X, since it is always used.",
>> does "it" refer to "RPATH"?  If so then how could the settings be irrelevant?
>> 
>> If the RPATH settings were irrelevant on MacOS, then the documentation should say so
>> and/or CMake should block, or flag as error, application of these settings in the MacOS case.
>> But I'm thinking that these settings *are* relevant since they do have some effect on
>> the executable lib search behavior.
>> 
>> As I mentioned, I tried setting both INSTALL_NAME_DIR and CMAKE_INSTALL_NAME_DIR and these did not 
>> have any effect.  I have not found documentation for them other then forum postings, such as:
>> 
>> http://www.cmake.org/pipermail/cmake/2006-June/009758.html
>> http://www.cmake.org/pipermail/cmake/2006-October/011527.html
>> etc...
>> 
>> 
> 
> I want to amend my last statement: I have not found documentation for 
> INSTALL_NAME_DIR and CMAKE_INSTALL_NAME_DIR in CMake's *manual* - 
> actually, there is a small paragraph, which mentions these settings
> without explaining how to use them:
> 
> http://www.cmake.org/cmake/help/cmake-2-8-docs.html#command:set_target_properties
> 
>  -Chris

http://www.cmake.org/cmake/help/cmake-2-8-docs.html#prop_tgt:INSTALL_NAME_DIR
http://www.cmake.org/cmake/help/cmake-2-8-docs.html#variable:CMAKE_INSTALL_NAME_DIR

Sometimes hitting the "find next" button really helps...

Michael