Re: Addressing in Object Ada v/s GNAT (2013) showing Vast Differences

[Anh Vo <anhvofrcaus@gmail.com>]

On Tuesday, September 8, 2015 at 12:30:57 AM UTC-7, Lucas Redding wrote:
> On Monday, September 7, 2015 at 5:28:39 PM UTC+1, Anh Vo wrote:
> > On Monday, September 7, 2015 at 9:02:48 AM UTC-7, Lucas Redding wrote:
> > > On Monday, September 7, 2015 at 3:04:43 PM UTC+1, G.B. wrote:
> > > > On 07.09.15 13:54, Lucas Redding wrote:
> > > 
> > > Yes I have included alignment of types and objects. I have not explicitly specified the padding gaps. In object Ada, this is not necessary provided the type specifications are explicitly size constrained and the object fits in between its address and the next objects address. In other words if there is a gap between the end of one object and the beginning of the next object, the data is read correctly (if the size of the type is explicitly constrained). 
> > > 
> > > Many thanks for that pointerto the -gnatR option. Being a novice to the compiler there are so many options to get to grips with. I am also using GPS, and toggling all the tick boxes did not produce this switch.
> >  
> > When compiled with GNAT, did GNAT spit out any Warnings at all? I would suspect misaligned address value during run time should have warned during compilation.
> > 
> > Anh Vo
> 
> Indeed Anh Vo
> 
> That would have been very useful. Unfortunately warnings are not being issued during the compilation stages.
> 
> I shall check the level of warnings in the compiler options just in case I have missed something. Any pointers greatly appreciated.

I would suggest to look at difference address alignment between the two where OA may patch it by default while GNAT does not. The worst case is that you need to post part of the codes. So, we can test it if needed.

AV