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

[Michael Wild]

On 13.08.2010, at 18:33, Chris Wolf <cw10025 at gmail.com> wrote:

> 
> 
> On 8/13/10 11:21 AM, Michael Wild wrote:
>> 
>> 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
>> 
>> 
> 
> Although I appreciate you taking time to reply to my inquiries, 
> this particular response is not really helpful - those two links you refer too 
> merely summarize what the first link I referred to says.  
> 
> Have you actually built shared libraries on MacOS with CMake?  If so, maybe an example
> of yours would be more helpful.
> 
> Thanks,
> 
>   -Chris

Sure, http://repo.or.cz/w/freefoam.git/shortlog/refs/heads/pu, but it's pretty complex...

Michael