On 3/12/25 10:57 AM, Nathaniel Shead wrote:
On Mon, Mar 10, 2025 at 02:52:07PM -0400, Jason Merrill wrote:
On 3/10/25 9:52 AM, Nathaniel Shead wrote:
Bootstrapped and regtested on x86_64-pc-linux-gnu, OK for trunk?
Or should this wait for GCC16?
-- >8 --
While looking at PR c++/119154 I noticed some more properties that we
don't stream or check properly. This patch adds the ones we were
missing, and adds checks that the values don't clash with existing
decls.
These seem to me like properties that should be recomputed rather than
streamed; aren't we already streaming the section attribute?
Hm, right; we're streaming the attributes but in general we don't
reapply any of the effects they have that aren't streamed regardless.
We should probably do that somehow; it looks like using decl_attributes
directly for this might do too much so I suppose we would need another
interface for this.
I'd probably go ahead trying to use decl_attributes and deal with any
problems.
This is probably the way to go to fix PR108080, too; rather than messing
around with trying to work out how to stream OPTIMIZATION_NODEs etc. we
can just reapply the attribute, which also would probably have the
expected behaviour in the case of mismatching optimisation flags between
exporter and consumer.
This comment also applies to the existing streaming of tls_model.
I assume we can just use 'decl_default_tls_model' in the no-attribute
case? Is there anything we should worry about wrt to it potentially
providing different results in different modules (due to different
choices of -ftls-model)?
I think then you get what you get, just as with headers. If it breaks,
you shouldn't build your project with inconsistent ABI flags.
Also, while reworking my other patch I'm now semi-convinced that there's
no need to stream comdat group, it should be recalculated correctly
anyway in all cases that I could find. But I definitely might have
missed something; either way it hasn't bitten us yet.
Nathaniel
