[CMake] Ada and CMake

[Bill Hoffman]

Alan W. Irwin wrote:
> On 2007-02-25 22:36-0000 Filipe Sousa wrote:
>
>> In Modules directory there is a file with instructions on how to add 
>> a new language to cmake.
>>
>> http://public.kitware.com/cgi-bin/viewcvs.cgi/Modules/CMakeAddNewLanguage.txt?rev=1.1.2.1&root=CMake&view=markup 
>>
>
> Thanks to that tip from Filipe, I now have add_library working for Ada on
> the two platforms accessible to me (Debian stable and Ubuntu Dapper), 
> and I
> think it should also work on most other platforms where the GNAT 
> extension
> to the gcc compiler has been installed.  The 4 Ada language support files
> for CMake are named as follows: CMakeAdaCompiler.cmake.in,
> CMakeAdaInformation.cmake, CMakeDetermineAdaCompiler.cmake, and
> CMakeTestAdaCompiler.cmake.  Those files are based on the equivalent 
> Fortran
> files distributed with CMake, and most changes can be described by the
> following sed command:
>
> sed -e 's?FC?ADA?g' -e 's?_Fortran?_Ada?g' -e 's? Fortran ? Ada ?g'
> <inputFortranfile >outputAdafile
>
> although some additional changes had to be made as well.
>
> The Ada language support files can be found at
> http://plplot.cvs.sourceforge.net/plplot/plplot/cmake/modules/, and I
> encourage everyone interested in Ada support in CMake to try those out.
>
> One current limitation of the Ada language support for CMake is that in
> CMakeAdaInformation.cmake, I must use
>
> SET(CMAKE_Ada_LINK_EXECUTABLE  "")
>
> because when CMake uses the pattern in CMAKE_Ada_LINK_EXECUTABLE to 
> link the
> executable it does not have access to <SOURCE>, and I therefore cannot 
> use
> the proper gnatmake command (which requires access to the source code to
> prepare an executable).
>
> The result is add_executable merely compiles Ada code and does not 
> actually
> link it into a viable executable.
>
> A question for the CMake developers: how difficult would it be to add
> support for <SOURCE> when interpreting CMAKE_(LANG)_LINK_EXECUTABLE?
>
> As explained above without this core change to CMake it is impossible to
> implement a useful ADD_EXECUTABLE for Ada, and I am forced to use a 
> rather
> complicated custom rule instead (see
> http://plplot.cvs.sourceforge.net/plplot/plplot/examples/ada/CMakeLists.txt 
>
> for an example of such a rule.)
>
> The current status is that Ada now has an interface to PLplot (and 
> also one
> test example written in Ada that uses PLplot) that can be built with the
> CMake build system for PLplot.  Aside from the problem mentioned above 
> with
> ADD_EXECUTABLE which forces using custom commands to build 
> executables, it
> is looking pretty good. The next step is to write our ~25 standard 
> examples
> (currently implemented for all our mature language interfaces) in Ada to
> greatly improve the level of testing of this Ada interface to PLplot.
What would <SOURCE> be expanded out to be?  

-Bill