> On 17 Jun 2025, at 06:02, Jason Merrill <ja...@redhat.com> wrote:
>
> On 6/16/25 4:00 PM, Iain Sandoe wrote:
>> Hi Jason
>>> On 11 Jun 2025, at 23:50, Jason Merrill <ja...@redhat.com> wrote:
>>>
>>> On 6/9/25 4:12 PM, Iain Sandoe wrote:
>>>> There was some discussion of this in the PR116775 comments. In the
>>>> end I have matched what clang does in this circumstance, since that
>>>> seems reasonable - and we may ignore the attributes as needed.
>>>> + warning_at (loc_n, OPT_Wattributes,"assumption ignored"
>>>> + " because it contains possible side-effects");
>>>> + *stmt = build_empty_stmt (loc_n);
>>>> + }
>>>> + }
>>>
>>> Why is this in coroutines.cc?
>> Because, at the moment I am not sure where else it can be handled ( although
>> I have now a semi-propsal, below ).
>> await expressions, when [normally] lowered, depend on and effect the state
>> of the function (that is, they are lowered to something that alters the code
>> of the function - which cannot work in the intent of an assumption).
>> we are permitted to ignore these attributes, and therefore punting on them
>> when they contain await expressions seemed a reasonable initial stance.
>
> I agree, but your patch doesn't check for await expressions, it just checks
> TREE_SIDE_EFFECTS.
>
> Ah, I guess we don't get into analyze_expression_awaits unless we've already
> found an await?
yes, that’s the case
> So I guess this approach is fine, but the warning should mention awaits
> rather than the general "possible side-effects". OK with that tweak.
I did that, thanks
Iain
