Re: STM32F4 GNAT Run Time System - roadmap

[Simon Wright <simon@pushface.org>]

jan.de.kruyf@gmail.com writes:

> on the matter of bug 66205:
> -------
>         if not Suppress_Standard_Library_On_Target then
>             WBI ("   Is_Elaborated : Boolean := False;");
>          end if;
> -------
> This ties with the behaviour I get on 4.7.4 
> When Standard_Library is not suppressed it wants to load some Handler
> and initialize a handful of variables. So for mixed language mode with
> minimal runtime and a foreign linker I have to suppress the standard
> library, so 'adainit' purely does the elaboration of the stuff I wrote
> (be it program or runtime) As I said: with it, adainit does a few
> things more.

These bugs were about including finalization in the RTS.

I guess there's some work to be done on exiting a kernel module; whether
that's something that relates to Ada.Finalization is a different matter!

And I'm not clear what Suppress_Standard_Library_On_Target means .. oh,
it's about standard exception data. I had to include it in my RTS
because some packages needed it, but it's only needed if the user code
calls the features involved (e.g. streams, containers).

I think the writeup in [1] is slightly misleading:

 Suppress_Standard_Library : Boolean;

 --  If this flag is True, then the standard library is not included by
 --  default in the executable (see unit System.Standard_Library in file
 --  s-stalib.ads for details of what this includes). This is for example
 --  set True for the Zero Footprint case, where these files should not
 --  be included by default.
 --
 --  This flag has some other related effects:
 --
 --    The generation of global variables in the bind file is suppressed,
 --    with the exception of the priority of the environment task, which
 --    is needed by the Ravenscar run-time.
 --
 --    The generation of exception tables is suppressed for front end
 --    ZCX exception handling (since we assume no exception handling).
 --
 --    The calls to __gnat_initialize and __gnat_finalize are omitted
 --
 --    All finalization and initialization (controlled types) is omitted
 --
 --    The routine __gnat_handler_installed is not imported

At least the part about "All finalization and initialization (controlled
types) is omitted" iw wrong; it just doesn't work!

[1] http://docs.adacore.com/gnathie_ug-docs/html/gnathie_ug/gnathie_ug/the_gnat_configurable_run_time_facility.html