Re: [Plplot-devel] Question about Ada support

[Tom K. <tom...@ve...>]

I figured it out.  One need only set CMAKE_Ada_COMPILER_INIT to a list of
fully qualified paths to the gcc/gnatgcc one wants.

On Wed, May 20, 2015 at 1:17 PM, Tom Kacvinsky <tom...@ve...
> wrote:

>
>
> On Tue, May 19, 2015 at 7:22 PM, Alan W. Irwin <ir...@be...>
> wrote:
>
>> On 2015-05-19 13:20-0400 Tom Kacvinsky wrote:
>>
>>  Alan,
>>>
>>> This is not in regards to plplot proper, but rather the cmake Ada support
>>> bundled with plplot.
>>>
>>> How is add_executable supposed to work?  Does it invoke gcc for each
>>> adb/ads file, then call the rest of the GNAT tool chain utilities to
>>> generate an executable, or does it just invoke gnatmake?  the reason I
>>> ask
>>> is that we aren't listing all of the Ada files necessary to build the
>>> executable, but all of the necessary files end up getting compiled.  But
>>> upon a subsequent build, not all Ada files get recompiled, even if
>>> they've
>>> changed.  I am thinking if gnatmake is used, this change would be
>>> detected
>>> and the right thing would happen.
>>>
>>> So, should I be listing all of the necessary Ada files in the
>>> add_executable(<target> <files>) invocation so that no matter what is
>>> used
>>> under the hood, recompiles happen when necessary.
>>>
>>
>> Hi Tom:
>>
>> From memory I am pretty sure that gnatmake is used under the hood for
>> the add_executable case.  But the thing to do is to run
>>
>> make VERBOSE=1
>>
>> (or verbose equivalent if you are building with a non-make generator) to
>> see exactly what commands are being used for the Ada executable build.
>>
>> And to answer your last question, I am virtually positive you should
>> mention all necessary Ada source files in the add_executable(<target>
>> <files>) invocation because that is the way add_excutable is supposed
>> to work in general.  But to figure it out for sure try with and
>> without mentioning all Ada source files for VERBOSE=1 to see the
>> exact difference that makes to the build.
>>
>> Sorry that I am being a little vague here, but our own use of Ada
>> language support only uses single files in the add_executable command
>> so I don't know exactly what would happen for multiple files.
>> Furthermore, it has been a very long while since I worked on our Ada
>> language support, and when I implemented that I had very little
>> understanding of CMake language support (and that is still the case).
>> So I converted existing language support for C over to Ada language
>> support using trial and error methods using tests like I suggested
>> above to evaluate whether the results were good enough for our needs.
>> And stopped when that was finally the case.
>>
>
> Hi again Alan,
>
> I made the changes to add_executable and it appears gnatmake is not
> invoked to build the executable, at least not that I can tell with "make
> VERBOSE=1".  gcc is getting invoked to make object files from the Ada
> source, but the problem I am now running into is that cmake is now using
> the system gcc to compile the files, where we want a different gcc to be
> used.  IS there a way of telling the cmake Ada support to use a different
> gcc (like there is for C, C++ and FORTRAN compilers)?  I am talking about
> tricks with cmake variables, not the PATH setting (as then the gcc that we
> want for Ada would be used for C/C++, and for those compiles, we want a
> different gcc).
>
> Thanks,
>
> Tom
>