Re: Interfacing Ada with C

[Simon Wright <simon@pushface.org>]

Ada novice <posts@gmx.us> writes:

> On Jul 30, 9:41 pm, "John B. Matthews" <nos...@nospam.invalid> wrote:
>
>>
>> I think you may be looking at [raw] [diff] (difference) files.
>
> Thanks. I have been able to locate the correct set of files.

Great!

>                                                              Opening
> test_extensions.gpr in GPS gives me the following error messages:
>
> [2010-07-30 22:54:16] E:\\ada\numerics\simon\jul29\test_extensions.gpr:
> 15:06: unknown project file: "../src/ada_math_build"
> [2010-07-30 22:54:16] Error while loading project 'E:\ada\numerics
> \simon\jul29\test_extensions.gpr'. Loading the default project.

Maybe - for Windows - you'll need to change

   with "../src/ada_math_build";

to

   with "..\src\ada_math_build";

(I thought gnatmake was slash-direction-agnostic, certainly it's OK for
paths inside a GPR ...)


Oh! that probably wasn't it: you seem to have the structure set up
differently from what the GPR expects, which is:

   ./src:
      ada-numerics-generic_complex_arrays-extensions.adb
      ada-numerics-generic_complex_arrays-extensions.ads
      ada_math_build.gpr

   ./test:
      test_extensions.adb
      test_extensions.gpr

If you go to the 'test' directory in a command window (or whatever it's
called in Windows now) and say

   E:\...> gnatmake -p -P test_extensions

it should go OK. The '-p' says 'create any necessary directories'. I'm
pretty sure it'll do this in GPS too (it may ask for permission).


> I've tried to compile the source ads file
> (Ada.Numerics.Generic_Complex_Arrays.Extensions.ads) in AdaGIDE and I
> get the warning:
>
> 22. package Ada.Numerics.Generic_Complex_Arrays.Extensions is
>                                                    |
>         >>> warning: file name does not match unit name, should be "a-
> ngcaex.ads"

From back in the day when GNAT had to run on DOS filesystems, the names
of units had to be 'krunched' to fit the 8.3 format, and for some reason
the standard library is still supplied this way. However, the code as
supplied builds OK with GCC 4.5.0 and GNAT GPL 2010 provided it's
compiled with ada_math_build.gpr.

I don't know whether AdaGIDE can manage GPRs, if not you're going to
have trouble using it for this...


> and I get an error message with
> Ada.Numerics.Generic_Complex_Arrays.Extensions.adb on compiling:
>
> 25.
>     26. package body Ada.Numerics.Generic_Complex_Arrays.Extensions is
>         |
>         >>> descendents of package Ada may not be compiled

You need special compilation options (-gnatpg) to allow compiling units
like these which (look as if they) are part of the standard
library. These options mean too that compilations have to be
warning-free.

src/ada_math_build.gpr supplies the necessary options.


> Note: for the source files adb and ads the name is ada-numerics-
> generic_complex_arrays-extensions. Should it be ada-numerics-
> generic_complex_arrays.extensions (with a dot between "arrays" and
> "extensions" instead)?

No, the dash is right:

ada-numerics-generic_complex_arrays-extensions
Ada.Numerics.Generic_Complex_Arrays.Extensions