[fpc-devel] Dangerous optimization in CASE..OF

[Martok]

Good morning!

Am 02.07.2017 um 22:02 schrieb Florian Klämpfl:
> Am 02.07.2017 um 21:40 schrieb Martok:
>> Honestly, I still don't understand why we're even having this discussion.
> 
> Because it is a fundamental question: if there is any defined behavior possible if a variable
> contains an invalid value. _I consider a value outside of the declared range as invalid_,
(emphasis mine)
And this is where you disagree with Borland's explicit documentation, Borland's
implicit extensions via consistent compiler behaviour, and with at least ISO
7185:1990 (that revision has no concept of range checks, and explicitly allows
all operations other than constant assignment to exceed a subrange type).
If this is what you always had in mind for the FPC dialect, fair enough. It is
your project, after all :-) I shall submit appropriate change requests for the
documentation, as well as for several other simplifications for all other
conditionals except CASE..OF that then become possible. I will also submit
another set of change requests to *not* do that in modes TP, DELPHI and ISO for
code compatibility reasons. Probably a 'modeswitch strictenums' or something
like that.

To remind you: CASE..OF is currently the only statement that casts this concept
into code (grep -R getrange compiler/*). Everything else is consistent and
compatible.


Regards,

Martok

PS: starting a mail with "good morning" looks rather stupid if one then spends
two hours writing it. Hm.