by using an opaque type obligation to bubble up comparisons between opaque types and other types
Also uses proper obligation causes so that the body id works, because out of some reason nll uses body ids for logic instead of just diagnostics.
Continue work on associated const equality
This actually implements some more complex logic for assigning associated consts to values.
Inside of projection candidates, it now defers to a separate function for either consts or
types. To reduce amount of code, projections are now generic over T, where T is either a Type or
a Const. I can add some comments back later, but this was the fastest way to implement it.
It also now finds the correct type of consts in type_of.
---
The current main TODO is finding the const of the def id for the LeafDef.
Right now it works if the function isn't called, but once you use the trait impl with the bound it fails inside projection.
I was hoping to get some help in getting the `&'tcx ty::Const<'tcx>`, in addition to a bunch of other `todo!()`s which I think may not be hit.
r? `@oli-obk`
Updates #92827
Add note suggesting that predicate may be satisfied, but is not `const`
Not sure if we should be printing this in addition to, or perhaps _instead_ of the help message:
```
help: the trait `~const Add` is not implemented for `NonConstAdd`
```
Also added `ParamEnv::is_const` and `PolyTraitPredicate::is_const_if_const` and, in a separate commit, used those in other places instead of `== hir::Constness::Const`, etc.
r? ````@fee1-dead````
Only traverse attrs once while checking for coherence override attributes
In coherence, while checking for negative impls override attributes: only traverse the `DefId`s' attributes once.
This PR is an easy way to get back some of the small perf loss in #93175
Store a `Symbol` instead of an `Ident` in `AssocItem`
This is the same idea as #92533, but for `AssocItem` instead
of `VariantDef`/`FieldDef`.
With this change, we no longer have any uses of
`#[stable_hasher(project(...))]`
Properly track `DepNode`s in trait evaluation provisional cache
Fixes#92987
During evaluation of an auto trait predicate, we may encounter a cycle.
This causes us to store the evaluation result in a special 'provisional
cache;. If we later end up determining that the type can legitimately
implement the auto trait despite the cycle, we remove the entry from
the provisional cache, and insert it into the evaluation cache.
Additionally, trait evaluation creates a special anonymous `DepNode`.
All queries invoked during the predicate evaluation are added as
outoging dependency edges from the `DepNode`. This `DepNode` is then
store in the evaluation cache - if a different query ends up reading
from the cache entry, it will also perform a read of the stored
`DepNode`. As a result, the cached evaluation will still end up
(transitively) incurring all of the same dependencies that it would
if it actually performed the uncached evaluation (e.g. a call to
`type_of` to determine constituent types).
Previously, we did not correctly handle the interaction between the
provisional cache and the created `DepNode`. Storing an evaluation
result in the provisional cache would cause us to lose the `DepNode`
created during the evaluation. If we later moved the entry from the
provisional cache to the evaluation cache, we would use the `DepNode`
associated with the evaluation that caused us to 'complete' the cycle,
not the evaluatoon where we first discovered the cycle. As a result,
future reads from the evaluation cache would miss some incremental
compilation dependencies that would have otherwise been added if the
evaluation was *not* cached.
Under the right circumstances, this could lead to us trying to force
a query with a no-longer-existing `DefPathHash`, since we were missing
the (red) dependency edge that would have caused us to bail out before
attempting forcing.
This commit makes the provisional cache store the `DepNode` create
during the provisional evaluation. When we move an entry from the
provisional cache to the evaluation cache, we create a *new* `DepNode`
that has dependencies going to *both* of the evaluation `DepNodes` we
have available. This ensures that cached reads will incur all of
the necessary dependency edges.
Check `const Drop` impls considering `~const` Bounds
This PR adds logic to trait selection to account for `~const` bounds in custom `impl const Drop` for types, elaborates the `const Drop` check in `rustc_const_eval` to check those bounds, and steals some drop linting fixes from #92922, thanks `@DrMeepster.`
r? `@fee1-dead` `@oli-obk` <sup>(edit: guess I can't request review from two people, lol)</sup>
since each of you wrote and reviewed #88558, respectively.
Since the logic here is more complicated than what existed, it's possible that this is a perf regression. But it works correctly with tests, and that makes me happy.
Fixes#92881
- Also rename a trivial_const_drop to match style of other functions in
the util module.
- Also add a test for `const Drop` that doesn't depend on a `~const`
bound.
- Also comment a bit why we remove the const bound during dropck impl
check.
This is the same idea as #92533, but for `AssocItem` instead
of `VariantDef`/`FieldDef`.
With this change, we no longer have any uses of
`#[stable_hasher(project(...))]`
Fixes#92987
During evaluation of an auto trait predicate, we may encounter a cycle.
This causes us to store the evaluation result in a special 'provisional
cache;. If we later end up determining that the type can legitimately
implement the auto trait despite the cycle, we remove the entry from
the provisional cache, and insert it into the evaluation cache.
Additionally, trait evaluation creates a special anonymous `DepNode`.
All queries invoked during the predicate evaluation are added as
outoging dependency edges from the `DepNode`. This `DepNode` is then
store in the evaluation cache - if a different query ends up reading
from the cache entry, it will also perform a read of the stored
`DepNode`. As a result, the cached evaluation will still end up
(transitively) incurring all of the same dependencies that it would
if it actually performed the uncached evaluation (e.g. a call to
`type_of` to determine constituent types).
Previously, we did not correctly handle the interaction between the
provisional cache and the created `DepNode`. Storing an evaluation
result in the provisional cache would cause us to lose the `DepNode`
created during the evaluation. If we later moved the entry from the
provisional cache to the evaluation cache, we would use the `DepNode`
associated with the evaluation that caused us to 'complete' the cycle,
not the evaluatoon where we first discovered the cycle. As a result,
future reads from the evaluation cache would miss some incremental
compilation dependencies that would have otherwise been added if the
evaluation was *not* cached.
Under the right circumstances, this could lead to us trying to force
a query with a no-longer-existing `DefPathHash`, since we were missing
the (red) dependency edge that would have caused us to bail out before
attempting forcing.
This commit makes the provisional cache store the `DepNode` create
during the provisional evaluation. When we move an entry from the
provisional cache to the evaluation cache, we create a *new* `DepNode`
that has dependencies going to *both* of the evaluation `DepNodes` we
have available. This ensures that cached reads will incur all of
the necessary dependency edges.
