Re: gprof/sprof and shared libraries...again

["H . J . Lu" <hjl at lucon dot org>]

On Thu, Apr 04, 2002 at 09:00:40AM -0500, Braman, Paul wrote:
> 
> This discussion seems to creep up from time to time but I haven't seen
> anyone post positive results (that I can replicate).
> 
> Our RedHat installation here at work is a slightly modified 7.2 (we have a
> RedHat contractor on-site who's coordinating our setup).  I can't seem to
> get a profile for a shared library the way I think I should.
> 
> First off, what I expect as output from my work is not a profile of the
> calls *in* the library, but a profile of the calls *to* the library.  (The
> linker knows what calls are being made to the library and should be able to
> put timing information around those calls.)
> 

Then, you need to compile your work with -g.

> I've got a small library with one function, libprof.so.  I've got a small
> main that calls an internal function once and a function from the library
> once.  I can get a profile for the call to the internal function just fine,
> but nothing I've done has generated information for a call to the function
> in the library.
> 
> Commands I am running...
> 
>     export LD_PROFILE=libprof.so
>     export LD_PROFILE_OUTPUT=/home/user/proftest
>     g++ -g -fPIC -c -o prof.lo prof.cpp
>     g++ --shared -o libprof.so prof.lo
>     g++ -g -pg -I/home/user/proftest -c -o ptest.o ptest.cpp
>     g++ -pg -o ptest ptest.o -L/home/user/proftest -lprof \
>         -Xlinker -rpath -Xlinker /home/user/proftest
>     /home/user/ptest
> 

It profiles libprof.so. That is the calls made from libprof.so.


H.J.