Re: Ada to Ada Translator ?

[Optikos <optikos@verizon.net>]

On Sunday, May 19, 2019 at 12:08:33 PM UTC-5, Simon Wright wrote:
> "G.B." <bauhaus@notmyhomepage.invalid> writes:
> 
> > At face value, the license exception applies to that very compiler's
> > sources, unchanged.
> 
> Actually the compiler sources are plain GPL; the RTS sources have the
> exception.
> 
> > It does not extend to derivative works which you seem to have in mind
> > when mentioning to fork.
> 
> Agreed that this is a potentially contentious area: the Exception says
> that it 'applies to a given file (the "Runtime Library") that bears a
> notice placed by the copyright holder of the file stating that the file
> is governed by GPLv3 along with this Exception' - are you entitled to
> maintain the Exception in a derivative work? if you do, does it count?
> (you not being the sole copyright holder).

If a legitimate copyright holder places the Runtime Library Exception in a file, then anyone may create derivative works of that file with the Runtime Library Exception still in effect as long as all the restrictions regarding Target Code and Compilation Process being an Eligible Compilation Process are obeyed (e.g., no intermediate code was emitted then processed by a nonGPL-compliant Compilation Process).  Whether the source code (e.g., incremental maintenance; drastic departure) is the derivative work or whether the object code then executable is the derivative work makes no difference to copyright law; they are all derivative works under the GPL.  If Simon's worry applies to source-code derivative works, then it applies to object-code & executable derivative works as well.

BIGGER ISSUE:
The vastly more germane dicey question legally is whether Patrick's proposed generated Ada-to-Ada source code qualifies as Target Code (and thus gets to enjoy the Runtime Library Exception's generous nonGPL-license permissions for Target Code emitted from an Eligible Compilation Process) or whether it would be deemed the onerous intermediate representation that then decisively revokes the permissions of the Runtime Library Exception for any programmer using the ineligible Compilation Process.

[I am not a lawyer.  This posting is merely a remembrance of my understanding for my own usage.  Please consult a copyright-law & contract-law lawyer if these matters affect you.]

> I've carefully avoided this issue in my Cortex GNAT RTS by assigning the
> copyright to the FSF :-)