[CMake] Explicit <NAME>_LIBRARIES and <NAME>_INCLUDE_DIRS

[Alexander Neundorf]

On Friday 22 March 2013, Mateusz Loskot wrote:
> On 22 March 2013 18:01, Sergei Nikulov <sergey.nikulov at gmail.com> wrote:
> > 2013/3/22 Mateusz Loskot <mateusz at loskot.net>
> > 
> >> I'm trying to build software which uses libE57 library which has
> >> Xerces as dependency.
> >> I build Xerces too as part of my project and I deploy it in custom
> >> locations
> >> and Xerces library has custom name.
> >> 
> >> libE57 provides FindXerces.cmake [1] and I've been trying to figure
> >> out how I can
> >> make this module find Xerces I provide, I tried to explicitly the two
> >> variables:
> >> Xerces_INCLUDE_DIR
> >> Xerces_LIBRARY
> >> on invocation of cmake, but obviously this FindXerces.cmake is still
> >> nagging me
> >> about XERCES_ROOT
> >> 
> >> This is first time when I have to deal with CMake-based software and
> >> custom
> >> names and locations of libraries, so I'm not sure either I'm missing
> >> some important tricks here or this FindXerces.cmake is just poorly
> >> written module
> >> and it does not check if user passes <NAME>_INCLUDE or <NAME>_LIBRARY
> >> directly.
> >> 
> >> I know I can also use CMAKE_INCLUDE_PATH and CMAKE_LIBRARY_PATH,
> >> but how to deal with custom library names, when this module expects
> >> two options only [2].
> >> 
> >> Could anyone advise about workaround?
> >> 
> >> Is this an issue in the FindXerces.cmake and would you say it's worth
> >> to submit bug report to libE57?
> >> 
> >> [1]
> >> http://sourceforge.net/p/e57-3d-imgfmt/code/331/tree/trunk/cmake/Modules
> >> /FindXerces.cmake [2]
> >> http://sourceforge.net/p/e57-3d-imgfmt/code/331/tree/trunk/cmake/Modules
> >> /FindXerces.cmake#l44
> > 
> > Hi Mateusz,
> > 
> > FindXerces is not part of officially supported modules, so you're on your
> > own here :-)
> > As workaround - try provide for script you're pointed with two more
> > parameters _LIBRARY_DEBUG & _LIBRARY_RELEASE.
> > AFAIR you need all vars be set to avoid error message from
> > "find_package_handle_standard_args".
> > Custom name add to NAMES.
> 
> Sergei,
> 
> I tried that, I specified location of my build of .lib of Xerces using
> all the three
> variables:
> 
> Xerces_LIBRARY_DEBUG
> Xerces_LIBRARY_RELEASE
> Xerces_LIBRARY

This should work.
You don't have to set Xerces_LIBRARY, since this is set in the find-module:
set (Xerces_LIBRARY debug ${Xerces_LIBRARY_DEBUG} optimized 
${Xerces_LIBRARY_RELEASE})


To find out what's going on, either insert some debug output (message(STATUS 
"...") )
or run cmake --trace , which prints every line which is executed.

Alex