Re: Specifying an `--RTS` option in a GPR file, for a runtime library

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Sun, 14 Apr 2013 21:54:20 +0200, Yannick Duchêne (Hibou57)  
<yannick_duchene@yahoo.fr> a écrit:

> If in the test project file I specify an absolute path like with
>
>      Switches :=
>        ("-s",
>         "--RTS=/<dir>/runtime");
>
> I get this message from `gprbuild`: “warning: RTS for language ada is  
> discarded (full path)”. Well, it compiles the test project, but `ldd`  
> shows it does not use the expected runtime.

The runtime was wrong, and was discarded fro this reason, but GPRBuild did  
not say it clearly, and instead, made a misleading reference to a full  
path, although using a full path was not the reason.

> If in the test project file I specify a relative path like with
>
>      Switches :=
>        ("-s",
>         "--RTS=runtime");
>
> I get this message from `gprbuild`: “warning: no compiler specified for  
> language "Ada", ignoring all its sources” then below “"test" is not a  
> source of project "test" gprbuild: problems with main sources”, and the  
> compilation fails.

That was because I messed up somethings: the target for this runtime  
source was not the same as the target of the compiler used, and GPRBuild  
did not found a compiler for the target, thus the “no compiler specified  
for language Ada”.

> I can't understand what's wrong, according to
> http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gnat_ugn_unw/Switches-for-gnatmake.html
> it should works as follow:
>
> (documentations says)
>> --RTS=rts-path
>> Specifies the default location of the runtime library.GNAT looks for  
>> the runtime in the following directories,and stops as soon as a valid  
>> runtime is found (adaincludeor ada_source_path, and adalib or  
>> ada_object_path present):
>>
>>        <current directory>/$rts_path
>>        <default-search-dir>/$rts_path
>>        <default-search-dir>/rts-$rts_path
>

The path is either absolute or relative to the build directory. The  
erroneously named “current directory” is not the one from which GPRBuild  
is invoked nor the directory containing the project file, that's the one  
to which GPRBuild switches, which is the build directory specified in the  
project file (the documentation is not very clear with this).

Last but not least, the `--RTS=…` option, has to be given in the Binder  
package, not the Builder package.


-- 
“Syntactic sugar causes cancer of the semi-colons.” [1]
“Structured Programming supports the law of the excluded muddle.” [1]
[1]: Epigrams on Programming — Alan J. — P. Yale University