[petsc-dev] [petsc-maint #49264] PETScDLxxx link error

[Barry Smith]

On Jul 10, 2010, at 1:06 PM, Satish Balay wrote:

> Ok - I'll reverted the change now. Will see if the problem
> reappears. The primary reason it came up was due to compilers not
> returning error codes. [this issue is to be fixed differently - with
> an explicit compiler check]
> 
> The puzzling part for me is - why is this 'functionality' check done
> in checkdynamcilinker. And what does it actually mean on bgl/xt3 to
> have PetscDLOpen().

   Presumably on those machines the tests fail and so PETSc does not actually use dlopen() in the code.

   I guess your questions is "why does PetscDLOpen() get built (as any empty stub) when dlopen() or friends does not exist? Why not just not build those routines?" 

   This would be fine, the source code would need slight adjustment of #ifdef to wrap the whole functions depending on what exists; only a slight pain because of the two cases, Windows and Unix.

    Barry

> 
> Satish
> 
> 
> On Sat, 10 Jul 2010, Barry Smith wrote:
> 
>> 
>> 
>> On Jul 10, 2010, at 12:03 PM, Satish Balay wrote:
>> 
>>> On Fri, 9 Jul 2010, Barry Smith wrote:
>>> 
>>>> On Jul 9, 2010, at 6:58 PM, Satish Balay wrote:
>>>> 
>>>>> I'm gussing its related to the checkDynamicLinker() change I pushed
>>>>> yesterday. But I don't understand the issue completely. [why is petsc
>>>>> looking for dlopen - when --with-dynamic is not used].
>>>> 
>>>>  Someone a while ago asked for support to use dynamic libraries for other stuff even if PETSc is not using dynamic libraries for itself. We've had this support for a while now. In other words even if PETSc is not using dynamic libraries configure should still do all the dynamic library checking.
>>> 
>>> I think we should have a configure flag to enable this part of the
>>> functonality [so there is some control on it - and not automatically
>>> do this.]
>>> 
>> 
>>   The PetscDLOpen() etc part of PETSc works the same as other things in PETSc. If ../configure detects certain things are available: in this case LoadLibrary() and friends in Windows and dlopen() and friends in Unix then PETSc is built to use them otherwise these things are not compiled in for PETSc. So every thing should be honkey-dorry and "just work".  
>> 
>>   Could you please explain exactly what goes wrong here (if ./configure doesn't detect dlopen() fine, PETSc won't build with it, so not an error). Is it that ./configure is buggy and crashes when doing checks when it shouldn't crash? If so, then we should fix configure to not crash, only if it is not fixable then we should provide an option to prevent the crashes.
>> 
>>   Barry
>> 
>> 
>>> Wrt the issue Glenn is seeing - I see configure was run on Jul-09 -
>>> but make was run on Jul-07. So rebuilding the libraries should fix the
>>> problem.
>>> 
>>> configure.log:#define PETSC_VERSION_DATE_HG "Fri Jul 09 15:12:56 2010 -0500"
>>> make.log:#define PETSC_VERSION_DATE_HG "Wed Jul 07 15:57:21 2010 -0500"
>>> 
>>> Satish
>>> 
>>>> 
>>>>  Barry
>>>> 
>>>>> 
>>>>> Will check on this later. For now - perhaps you can comment out the
>>>>> following lines from config/BuildSystem/config/setCompilers.py
>>>>> 
>>>>> +    if not self.framework.argDB['with-dynamic']:
>>>>> +      return
>>>>> 
>>>>> Satish
>>>>> 
>>>>> On Fri, 9 Jul 2010, Hammond, Glenn wrote:
>>>>> 
>>>>>> PETSc,
>>>>>> 
>>>>>> 
>>>>>> When linking PFLOTRAN on Jaguar, I get the following error (same errors with 'make test'.  
>>>>>> 
>>>>>> Suggestions?  
>>>>>> 
>>>>>> Thanks,
>>>>>> 
>>>>>> Glenn
>>>>>> 
>>>>>> /ccs/proj/geo002/petsc-dev/cray-xt4-pgi_fast/lib/libpetsc.a(dlimpl.o): In function `PetscDLOpen':
>>>>>> ./dlimpl.c:57: undefined reference to `dlerror'
>>>>>> ./dlimpl.c:57: undefined reference to `dlopen'
>>>>>> ./dlimpl.c:128: undefined reference to `dlerror'
>>>>>> /ccs/proj/geo002/petsc-dev/cray-xt4-pgi_fast/lib/libpetsc.a(dlimpl.o): In function `PetscDLClose':
>>>>>> ./dlimpl.c:153: undefined reference to `dlerror'
>>>>>> ./dlimpl.c:153: undefined reference to `dlclose'
>>>>>> ./dlimpl.c:199: undefined reference to `dlerror'
>>>>>> /ccs/proj/geo002/petsc-dev/cray-xt4-pgi_fast/lib/libpetsc.a(dlimpl.o): In function `PetscDLSym':
>>>>>> ./dlimpl.c:231: undefined reference to `dlerror'
>>>>>> ./dlimpl.c:231: undefined reference to `dlsym'
>>>>>> ./dlimpl.c:231: undefined reference to `dlerror'
>>>>>> /usr/bin/ld.x: link errors found, deleting executable `pflotran'
>>>>>> cmake: *** [pflotran] Error 2
>>>>>> 
>>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>> 
>> 
> 
>