Bus error with new gpc snapshot

[Adriaan van Os]

Russell Whitaker wrote:
>>> I suppose this is a back-end bug, reproducible on other platforms.
>>>
>>
>> I can not reproduce this on Amd64 Linux (tried verious option incuding
>> -fPIC).  I will try i386 Linux, but it looks that the program uses 
>> features
>> that Apple decided to implement in its own way.
>>
> On linux i686, compiles & runs ok.

Thanks for trying this out on other platforms. Looking into this further, the cause seems to be a 
curious miscalculation of record sizes.

program prog;

type
   pv1 = record
     x, y: Extended;
     v: array[1..2] of Boolean;
   end;
   pv2 = packed record
     x, y: Extended;
     v: array[1..2] of Boolean;
   end;
   pv3 = record
     x, y: Extended;
   end;
   pv4 = packed record
     x, y: Extended;
   end;
   pv5 = record
     v: array[1..2] of Boolean;
   end;
   pv6 = packed record
     v: array[1..2] of Boolean;
   end;

procedure dcp;
   var
     sp: pv1;
     z: Boolean;

   procedure d(p: pv1);
     begin
       writeln('access z before');
       if z then
         writeln('z is true');
     end;

   begin { dcp }
     z := True;
     d(sp);
   end;

begin
writeln( 'sizeof(pv1) = ', sizeof( pv1));
writeln( 'sizeof(pv2) = ', sizeof( pv2));
writeln( 'sizeof(pv3) = ', sizeof( pv3));
writeln( 'sizeof(pv4) = ', sizeof( pv4));
writeln( 'sizeof(pv5) = ', sizeof( pv5));
writeln( 'sizeof(pv6) = ', sizeof( pv6));
dcp;
end.

[p17:~/gpc/testgpc/adriaan] adriaan% gpc schorn2.pas -Os
[p17:~/gpc/testgpc/adriaan] adriaan% ./a.out
sizeof(pv1) = 48
sizeof(pv2) = 34
sizeof(pv3) = 32
sizeof(pv4) = 32
sizeof(pv5) = 2
sizeof(pv6) = 2
access z before
Bus error

Any hint where about to look in the back-end sources ?

Regards,

Adriaan van Os