[CMake] Dynamic libraries and library dependencies

[Alan W. Irwin]

On 2007-01-31 20:25+0100 Stefan Buschmann wrote:

> So, is there a way to solve this without having to add the library path to 
> every dependent project (which would in fact make the library abstraction 
> useless)?

Let me try to give you a general answer that I think should apply to your
specific case.  If any library or application that you build with CMake has
symbols in it that are resolved by an external library, then your best
approach is to use the find_library command (in your top-level
CMakeLists.txt file or a module included from that file) to find the
complete path to that external library.  Then specify that complete path to
TARGET_LINK_LIBRARIES only for those targets where it is required (i.e.,
only for targets which specifically have symbols that need to be resolved by
an external library), and CMake will do the rest for you following the
linking rules for your platform of choice.

For example, PLplot has a core library which in turn depends on external
libraries.  Those external libraries only have to be mentioned for the core
library, and not for all our other applications/libraries which depend on
our core library.  For such hierarchical linking, cmake figures everything
out for you, if you follow the rule I have specified (i.e., mention the
external library only for those targets which have specific symbols that
need to be resolved by that external library).

BTW, to test that the resulting CMake linking is correct for all targets in
the build tree or install tree, I find the ldd command (especially with the
-r option) and nm commands are extremely useful for the Linux case.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the Yorick front-end to PLplot (yplot.sf.net); the
Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
__________________________

Linux-powered Science
__________________________