This now uses `node_to_string` for both missing and seen Ids, which includes
the snippet of code for which the Id was allocated.
Also removes the duplicated printing of `HirId`, as `node_to_string` includes that already.
Similarly, changes all other users of `node_to_string` that do so, and changes the output of `node_to_string`, which is now "$hirid ($what `$span` in $path)".
Track bound types like bound regions
When we instantiate bound types into placeholder types, we throw away the names for some reason. These names are particularly useful for error reporting once we have `for<T>` binders.
r? types
small refactor to new projection code
extract `eq_term_and_make_canonical_response` into a helper function which also is another guarantee that the expected term does not influence candidate selection for projections.
also change `evaluate_all(vec![single_goal])` to use `evaluate_goal`.
the second commit now also adds a `debug_assert!` to `evaluate_goal`.
Modify primary span label for E0308
Looking at the reactions to https://hachyderm.io/`@ekuber/109622160673605438,` a lot of people seem to have trouble understanding the current output, where the primary span label on type errors talks about the specific types that diverged, but these can be deeply nested type parameters. Because of that we could see "expected i32, found u32" in the label while the note said "expected Vec<i32>, found Vec<u32>". This understandably confuses people. I believe that once people learn to read these errors it starts to make more sense, but this PR changes the output to be more in line with what people might expect, without sacrificing terseness.
Fix#68220.
Use `ObligationCtxt::new_in_snapshot` in `satisfied_from_param_env`
We can evaluate nested `ConstEvaluatable` obligations in an evaluation probe, which will ICE if we use `ObligationCtxt::new`.
Fixes#107474Fixes#106666
r? `@BoxyUwU` but feel free to reassign
cc `@JulianKnodt` who i think added this assertion code
Not sure if the rustdoc test is needed, but can't hurt. They're the same root cause, though.
Skip possible where_clause_object_safety lints when checking `multiple_supertrait_upcastable`
Fix#106247
To achieve this, I lifted the `WhereClauseReferencesSelf` out from `object_safety_violations` and move it into `is_object_safe` (which is changed to a new query).
cc `@dtolnay`
r? `@compiler-errors`
Remove HirId -> LocalDefId map from HIR.
Having this map in HIR prevents the creating of new definitions after HIR has been built.
Thankfully, we do not need it.
Based on https://github.com/rust-lang/rust/pull/103902
Remove `ControlFlow::{BREAK, CONTINUE}`
Libs-API decided to remove these in #102697.
Follow-up to #107023, which removed them from `compiler/`, but a couple new ones showed up since that was merged.
r? libs
Minor tweaks in the new solver
1. `InferCtxt::probe` is not needed in `compute_subtype_goal` and `compute_well_formed_goal`.
2. Add a handful of comments.
3. Add a micro-optimization in `consider_assumption` where we check the def-ids of the assumption and goal match before instantiating any binders.
r? ``@lcnr``
Correct suggestions for closure arguments that need a borrow
Fixes#107301 by dealing with binders correctly
Fixes another issue where we were suggesting adding just `&` when we expected `&mut _` in a closure arg
Use new solver in `evaluate_obligation` query (when new solver is enabled)
(only when `-Ztrait-solver=next`, of course)
... Does this make sense? It seems to me like it should be reasonable, but maybe there's some reason why this is a bad idea.
r? ``@lcnr``
Needs a perf run because I guess this `solver == TraitSolver::Next` check is on a hot path.
Libs-API decided to remove these in #102697.
Follow-up to #107023, which removed them from `compiler/`, but a couple new ones showed up since that was merged.
Compute generator saved locals on MIR
Generators are currently type-checked by introducing a `witness` type variable, which is unified with a `GeneratorWitness(captured types)` whose purpose is to ensure that the auto traits correctly migrate from the captured types to the `witness` type. This requires computing the captured types on HIR during type-checking, only to re-do it on MIR later.
This PR proposes to drop the HIR-based computation, and only keep the MIR one. This is done in 3 steps.
1. During type-checking, the `witness` type variable is never unified. This allows to stall all the obligations that depend on it until the end of type-checking. Then, the stalled obligations are marked as successful, and saved into the typeck results for later verification.
2. At type-checking writeback, `witness` is replaced by `GeneratorWitnessMIR(def_id, substs)`. From this point on, all trait selection involving `GeneratorWitnessMIR` will fetch the MIR-computed locals, similar to what opaque types do. There is no lifetime to be preserved here: we consider all the lifetimes appearing in this witness type to be higher-ranked.
3. After borrowck, the stashed obligations are verified against the actually computed types, in the `check_generator_obligations` query. If any obligation was wrongly marked as fulfilled in step 1, it should be reported here.
There are still many issues:
- ~I am not too happy having to filter out some locals from the checked bounds, I think this is MIR building that introduces raw pointers polluting the analysis;~ solved by a check specific to static variables.
- the diagnostics for captured types don't show where they are used/dropped;
- I do not attempt to support chalk.
cc `@eholk` `@jyn514` for the drop-tracking work
r? `@oli-obk` as you warned me of potential unsoundness
solver comments + remove `TyCtxt::evaluate_goal`
from the `RustcContributor::explore` session yesterday.
This also removes `TyCtxt::evaluate_goal` because to canonicalize you have to use an `InferCtxt` anyways at which point we should just always get people to use `evaluate_root_goal`.
r? ``@spastorino``
