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pat-rogers / Ada-202x-WG9-Informal-Review

This is the place for WG 9 members to submit informal comments on the 202x source document. (This is not the formal ballot that WG 9 will hold later in the process.)
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4.1.4 - Attributes #133

Open pat-rogers opened 3 years ago

pat-rogers commented 3 years ago

We say "An implementation may extend the definition of a language-defined attribute ... in the following cases:", but 13.12.1 does not talk about how this interacts with the No_Implementation_Attributes restriction. Was this intended?

SteveB

sttaft commented 3 years ago

Good question, but not something we can resolve now. Deferred to next time! ;-)

ARG-Editor commented 3 years ago

Certainly no one considered that. Given the very strict restrictions on extending language-defined attributes, I would argue that there is no problem - these attributes are not considered impl-def (especially since they are based either on previous or likely future standards). The wording of 13.12.1(2/2) is rather ambiguous, though, one could read it to mean "attributes with implementation-defined results". That would knock out many language-defined attributes (even Size and Alignment), so it doesn't seem likely that was intended.

So I don't think there is a problem here, but I'm OK with deferring the issue so that it can be considered more carefully (and perhaps the 13.12.1 wording should be cleaned up).