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

[Mateusz Loskot]

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

and it's ignored.

I'm confused, because as I have been taught by Ryan here
http://www.cmake.org/pipermail/cmake/2010-March/035597.html

"find_whatever won't run if the variable it's given already has a valid value"

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net