Speed up `opt_normalize_projection_type`
`opt_normalize_projection_type` is hot in the serde and futures benchmarks in rustc-perf. These two patches speed up the execution of most runs for them by 2--4%.
This patch changes `opt_normalize_project_type` so it appends
obligations to a given obligations vector, instead of returning a new
obligations vector.
This change avoids lots of allocations. In the most extreme case, for a
clean "Check" build of serde it reduces the total number of allocations
by 20%.
This leads to a lot of simplifications, as most code doesn't actually need to know about the specific lifetime/type data; rather, it's concerned with properties like name, index and def_id.
This is meant to address rust-lang/rust#49918.
Review feedback: put back comment justifying skipping interior traversal.
Review feedback: dropck generators like trait objects: all their upvars must
outlive the generator itself, so just create a DtorckConstraint saying so.
Create a canonical trait query for `evaluate_obligation`
This builds on the canonical query machinery introduced in #48411 to introduce a new canonical trait query for `evaluate_obligation` in the trait selector. Also ports most callers of the original `evaluate_obligation` to the new system (except in coherence, which requires support for intercrate mode). Closes#48537.
r? @nikomatsakis
This computes the transitive closure of traits that appear in the
environment and then appends their clauses. It needs some work, but
it's in the right direction.
Chalk wants to be able to pass these constraints around. Also, the
form we were using in our existing queries was not as general as we
are going to need.
traits: Implement interning for Goal and Clause
r? @nikomatsakis
Close#49054
Contains some refactoring for the interning mechanism, mainly aimed at reducing pain when changing types of interning map.
This should be mostly good, although I'm not sure with the naming of `Goal::from_poly_domain_goal`.
chalkify: Implement lowering rule Implied-Bound-From-Trait
For #49177.
TODO:
- [x] Implement where clauses besides trait and projection predicates
- [x] Is the output of the `lower_trait_higher_rank` test correct?
- [ ] Remove `Self::Trait` from the query `tcx.predicates_of(<trait_id>).predicates`
- [ ] Consider moving tests to compile-fail to make them more manageable
