[PATCH][Ada][PING] Add option to gnatlink to fix gnat.dg on some platforms

[Laurent GUERBY]

Ping.

Laurent

On Wed, 2009-06-03 at 13:02 +0200, Laurent GUERBY wrote:
> Ping.
> 
> Laurent
> 
> On Thu, 2009-05-28 at 14:28 +0200, Laurent GUERBY wrote:
> > For reference the patch worked fine:
> > 
> > http://gcc.gnu.org/ml/gcc-testresults/2009-05/msg02440.html
> > 
> > I checked manually that in the context of gnat.dg gnatlink is calling
> > xgcc with the right multilib for both compiling the binder file and
> > linking.
> > 
> > So waiting for approval or another suggestion :).
> > 
> > Thanks in advance,
> > 
> > Laurent
> > 
> > On Wed, 2009-05-27 at 10:12 +0200, Laurent GUERBY wrote:
> > > On Thu, 2009-05-07 at 16:30 +0200, Arnaud Charlet wrote:
> > > > Adding also Vincent in the loop, since he implement (in 2001!) this switch,
> > > > after lots of discussion at AdaCore (under 9510-006...) and refined it
> > > > later on, see below:
> > > > 
> > > > > On Thu, 2009-05-07 at 14:17 +0200, Laurent GUERBY wrote:
> > > > > > On Thu, 2009-05-07 at 14:10 +0200, Arnaud Charlet wrote:
> > > > > > > Actually that's not what we want: what we want is to have --GCC be
> > > > > > > smarter and recognize that the compiler specified is "gcc" or "another
> > > > > > > non GCC compiler", which would also solve this issue.
> > > > > > 
> > > > > > Ok if this was the idea behind the --GCC behaviour I believe it's easy
> > > > > > to extend the current gnatlink --GCC check to accept "xgcc" as well
> > > > > > as what it accepts now:
> > > > > > 
> > > > > > gcc/ada/gnatlink.adb:
> > > > > > 
> > > > > >                      if Program_Args.all (1).all /= Gcc.all then
> > > > > >                         Gcc := new String'(Program_Args.all (1).all);
> > > > > >                         Standard_Gcc := False;
> > > > > >                      end if;
> > > > > > 
> > > > > > I will submit a new patch shortly, thanks for your help on this issue.
> > > > > 
> > > > > Here it is. 
> > > > > 
> > > > > I've not changed the documentation because in the light about what you
> > > > > said about the intended semantics I think it covers xgcc as well
> > > > > since it's gcc too :).
> > > > 
> > > > Right. Actually what was initially intended was to pass switches from the
> > > > main ALI file if no --GCC is specified, or if --GCC specifies additional
> > > > switches (so not just --GCC=<some-gcc>), and not as I misremembered to
> > > > differenciate between "some gcc" and "non gcc compilers".
> > > > 
> > > > Now, that's NOT what Vincent implemented: originally he implemented a simple
> > > > "if --GCC is passed, then do not read switches from ALI". Then later
> > > > he modified to the current behavior by comparing between --GCC=xxx and the
> > > > default gcc used by gnatlink (under our internal ticket H423-001), and
> > > > documented this behavior at the same tim.
> > > > 
> > > > I'm not sure why though, and believe that the original suggestion is
> > > > the right one.
> > > > 
> > > > So if we go back to the original intent (no additional switches specified in
> > > > --GCC), that would solve this specific issue as far as I can see, but maybe
> > > > there was a good reason why Vincent did things differently?
> > > > 
> > > > If not, then a possible patch would be something like:
> > > > 
> > > >    if Program_Args'Length > 1 then
> > > >       Standard_Gcc := False;
> > > >    end if;
> > > > 
> > > > instead of
> > > > 
> > > >    if Program_Args.all (1).all /= Gcc.all then
> > > >       Gcc := new String'(Program_Args.all (1).all);
> > > >       Standard_Gcc := False;
> > > >    end if;
> > > 
> > > Did you mean the following?
> > > 
> > > We still need to update Gcc.all otherwise gnatlink won't call xgcc
> > > unless I'm reading the code wrong.
> > > 
> > > Laurent
> > > 
> > > Index: gcc/ada/gnatlink.adb
> > > ===================================================================
> > > --- gcc/ada/gnatlink.adb	(revision 147903)
> > > +++ gcc/ada/gnatlink.adb	(working copy)
> > > @@ -523,7 +523,10 @@
> > >                    begin
> > >                       if Program_Args.all (1).all /= Gcc.all then
> > >                          Gcc := new String'(Program_Args.all (1).all);
> > > -                        Standard_Gcc := False;
> > > +
> > > +                        if Program_Args.all'Length > 1 then
> > > +                           Standard_Gcc := False;
> > > +                        end if;
> > >                       end if;
> > >  
> > >                       --  Set appropriate flags for switches passed
> > >