Neither require nor imply lifetime bounds on opaque type for well formedness
The actual hidden type can live arbitrarily longer than any individual lifetime and arbitrarily shorter than all but one of the lifetimes.
fixes#86218fixes#84305
This is a **breaking change** but it is a necessary soundness fix
implied_bounds: deal with inference vars
fixes#101951
while computing implied bounds for `<<T as ConstructionFirm>::Builder as BuilderFn<'_>>::Output` normalization replaces a projection with an inference var (adding a `Projection` obligation). Until we prove that obligation, this inference var remains unknown, which caused us to miss an implied bound necessary to prove that the unnormalized projection from the trait method signature is wf.
r? types
fix a ui test
use `into`
fix clippy ui test
fix a run-make-fulldeps test
implement `IntoQueryParam<DefId>` for `OwnerId`
use `OwnerId` for more queries
change the type of `ParentOwnerIterator::Item` to `(OwnerId, OwnerNode)`
Introduce mir::Unevaluated
Previously the distinction between unevaluated constants in the type-system and in mir was not explicit and a little confusing. Probably better to introduce its own type for that.
r? `@lcnr`
Rollup of 8 pull requests
Successful merges:
- #100734 (Split out async_fn_in_trait into a separate feature)
- #101664 (Note if mismatched types have a similar name)
- #101815 (Migrated the rustc_passes annotation without effect diagnostic infrastructure)
- #102042 (Distribute rust-docs-json via rustup.)
- #102066 (rustdoc: remove unnecessary `max-width` on headers)
- #102095 (Deduplicate two functions that would soon have been three)
- #102104 (Set 'exec-env:RUST_BACKTRACE=0' in const-eval-select tests)
- #102112 (Allow full relro on powerpc64-unknown-linux-gnu)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Note if mismatched types have a similar name
If users get a type error between similarly named types, it will point out that these are actually different types, and where they were defined.
Const unification is already infallible, remove the error handling logic
r? `@lcnr`
is this expected to be used in the future? Right now it is dead code.
Rollup of 8 pull requests
Successful merges:
- #101598 (Update rustc's information on Android's sanitizers)
- #102036 (Remove use of `io::ErrorKind::Other` in std)
- #102037 (Make cycle errors recoverable)
- #102069 (Skip `Equate` relation in `handle_opaque_type`)
- #102076 (rustc_transmute: fix big-endian discriminants)
- #102107 (Add missing space between notable trait tooltip and where clause)
- #102119 (Fix a typo “pararmeter” in error message)
- #102131 (Added which number is computed in compute_float.)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Make cycle errors recoverable
In particular, this allows rustdoc to recover from cycle errors when normalizing associated types for documentation.
In the past, ```@jackh726``` has said we need to be careful about overflow errors: https://github.com/rust-lang/rust/pull/91430#issuecomment-983997013
> Off the top of my head, we definitely should be careful about treating overflow errors the same as
"not implemented for some reason" errors. Otherwise, you could end up with behavior that is
different depending on recursion depth. But, that might be context-dependent.
But cycle errors should be safe to unconditionally report; they don't depend on the recursion depth, they will always be an error whenever they're encountered.
Helps with https://github.com/rust-lang/rust/issues/81091.
r? ```@lcnr``` cc ```@matthewjasper```
Normalize opaques w/ bound vars
First, we reenable normalization of opaque types with escaping late bound regions to fix rust-lang/miri#2433. This essentially reverts #89285.
Second, we mitigate the perf regression found in #88862 by simplifying the way that we relate (sub and eq) GeneratorWitness types.
This relies on the fact that we construct these GeneratorWitness types somewhat particularly (with all free regions found in the witness types replaced with late bound regions) -- but those bound regions really should be treated as existential regions, not universal ones. Those two facts leads me to believe that we do not need to use the full `higher_ranked_sub` machinery to relate two generator witnesses. I'm pretty confident that this is correct, but I'm glad to discuss this further.
Move and rename `SessionDiagnostic` & `SessionSubdiagnostic` traits and macros
After PR #101434, we want to:
- [x] Move `SessionDiagnostic` to `rustc_errors`.
- [x] Add `emit_` methods that accept `impl SessionDiagnostic` to `Handler`.
- [x] _(optional)_ Rename trait `SessionDiagnostic` to `DiagnosticHandler`.
- [x] _(optional)_ Rename macro `SessionDiagnostic` to `DiagnosticHandler`.
- [x] Update Rustc Dev Guide and Docs to reflect these changes. https://github.com/rust-lang/rustc-dev-guide/pull/1460
Now I am having build issues getting the compiler to build when trying to rename the macro.
<details>
<summary>See diagnostics errors and context when building.</summary>
```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
--> compiler/rustc_attr/src/session_diagnostics.rs:13:10
|
13 | #[derive(DiagnosticHandler)]
| ^^^^^^^^^^^^^^^^^ in this derive macro expansion
|
::: /Users/jhonny/.cargo/registry/src/github.com-1ecc6299db9ec823/synstructure-0.12.6/src/macros.rs:94:9
|
94 | / pub fn $derives(
95 | | i: $crate::macros::TokenStream
96 | | ) -> $crate::macros::TokenStream {
| |________________________________________- in this expansion of `#[derive(DiagnosticHandler)]`
|
note: the lint level is defined here
--> compiler/rustc_attr/src/lib.rs:10:9
|
10 | #![deny(rustc::diagnostic_outside_of_impl)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
```
And also this one:
```
error: diagnostics should only be created in `SessionDiagnostic`/`AddSubdiagnostic` impls
--> compiler/rustc_attr/src/session_diagnostics.rs:213:32
|
213 | let mut diag = handler.struct_span_err_with_code(
| ^^^^^^^^^^^^^^^^^^^^^^^^^
```
> **Note**
> Can't find where this message is coming from, because you can see in [this experimental branch](https://github.com/JhonnyBillM/rust/tree/experimental/trying-to-rename-session-diagnostic-macro) that I updated all errors and diags to say:
> error: diagnostics should only be created in **`DiagnosticHandler`**/`AddSubdiagnostic` impls
> and not:
> error: diagnostics should only be created in **`SessionDiagnostic`**/`AddSubdiagnostic` impls
</details>
I tried building the compiler in different ways (playing with the stages etc), but nothing worked.
## Question
**Do we need to build or do something different when renaming a macro and identifiers?**
For context, see experimental commit f2193a98b4 where the macro and symbols are renamed, but it doesn't compile.
FIX - ambiguous Diagnostic link in docs
UPDATE - rename diagnostic_items to IntoDiagnostic and AddToDiagnostic
[Gardening] FIX - formatting via `x fmt`
FIX - rebase conflicts. NOTE: Confirm wheather or not we want to handle TargetDataLayoutErrorsWrapper this way
DELETE - unneeded allow attributes in Handler method
FIX - broken test
FIX - Rebase conflict
UPDATE - rename residual _SessionDiagnostic and fix LintDiag link
In particular, this allows rustdoc to recover from cycle errors when normalizing associated types for documentation.
In the past, `@jackh726` has said we need to be careful about overflow errors:
> Off the top of my head, we definitely should be careful about treating overflow errors the same as
"not implemented for some reason" errors. Otherwise, you could end up with behavior that is
different depending on recursion depth. But, that might be context-dependent.
But cycle errors should be safe to unconditionally report; they don't depend on the recursion depth, they will always be an error whenever they're encountered.
On later stages, the feature is already stable.
Result of running:
rg -l "feature.let_else" compiler/ src/librustdoc/ library/ | xargs sed -s -i "s#\\[feature.let_else#\\[cfg_attr\\(bootstrap, feature\\(let_else\\)#"
Initial implementation of dyn*
This PR adds extremely basic and incomplete support for [dyn*](https://smallcultfollowing.com/babysteps//blog/2022/03/29/dyn-can-we-make-dyn-sized/). The goal is to get something in tree behind a flag to make collaboration easier, and also to make sure the implementation so far is not unreasonable. This PR does quite a few things:
* Introduce `dyn_star` feature flag
* Adds parsing for `dyn* Trait` types
* Defines `dyn* Trait` as a sized type
* Adds support for explicit casts, like `42usize as dyn* Debug`
* Including const evaluation of such casts
* Adds codegen for drop glue so things are cleaned up properly when a `dyn* Trait` object goes out of scope
* Adds codegen for method calls, at least for methods that take `&self`
Quite a bit is still missing, but this gives us a starting point. Note that this is never intended to become stable surface syntax for Rust, but rather `dyn*` is planned to be used as an implementation detail for async functions in dyn traits.
Joint work with `@nikomatsakis` and `@compiler-errors.`
r? `@bjorn3`
Emit a note that static bounds from HRTBs are a bug
This note isn't perfect, but opening this to either 1) land as is or 2) get some feedback on how to improve it
Let r? `@compiler-errors` and cc. `@nikomatsakis`
Make `compare_predicate_entailment` no longer a query
Make `compare_predicate_entailment` so it's no longer a query (again), and splits out the new logic (that equates the return types to infer RPITITs) into its own query. This means that this new query (now called `collect_trait_impl_trait_tys`) is no longer executed for non-RPITIT cases.
This should improve perf (https://github.com/rust-lang/rust/pull/101224#issuecomment-1241682203), though in practice we see that these some crates remain from the primary regressions list on the original report... They are all <= 0.43% regression and seemingly only on the incr-full scenario for all of them.
I am at a loss for what might be causing this regression other than what I fixed here, since we don't introduce much new non-RPITIT logic except for some `def_kind` query calls in some places, for example, like projection. Maybe that's it?
----
Originally this PR was opened to test enabling `cache_on_disk` (62164aaaa11) but that didn't turn out to be very useful (https://github.com/rust-lang/rust/pull/101615#issuecomment-1242403205), so that led me to just split the query (and rename the PR).
const_generics: correctly deal with bound variables
removes the hack in `resolve` which was needed because we evaluated constants without caring about their bound variables.
Each commit should be fairly self-contained, even if they build on each other
r? `@jackh726`
Migrate another part of rustc_infer to session diagnostic
Probably will migrate another file before marking this one as ready-to-merge.
`@rustbot` label +A-translation
r? rust-lang/diagnostics
cc https://github.com/rust-lang/rust/issues/100717
Update `SessionDiagnostic::into_diagnostic` to take `Handler` instead of `ParseSess`
Suggested by the team in [this Zulip Topic](https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20SessionDiagnostic.20on.20Handler).
`Handler` already has almost all the capabilities of `ParseSess` when it comes to diagnostic emission, in this migration we only needed to add the ability to access `source_map` from the emitter in order to get a `Snippet` and the `start_point`. Not sure if adding these two methods [`span_to_snippet_from_emitter` and `span_start_point_from_emitter`] is the best way to address this gap.
P.S. If this goes in the right direction, then we probably may want to move `SessionDiagnostic` to `rustc_errors` and rename it to `DiagnosticHandler` or something similar.
r? `@davidtwco`
r? `@compiler-errors`
Suggested by the team in this Zulip Topic https://rust-lang.zulipchat.com/#narrow/stream/336883-i18n/topic/.23100717.20SessionDiagnostic.20on.20Handler
Handler already has almost all the capabilities of ParseSess when it comes to diagnostic emission, in this migration we only needed to add the ability to access source_map from the emitter in order to get a Snippet and the start_point. Not sure if this is the best way to address this gap
This PR will fix some typos detected by [typos].
I only picked the ones I was sure were spelling errors to fix, mostly in
the comments.
[typos]: https://github.com/crate-ci/typos
Attempt to normalize `FnDef` signature in `InferCtxt::cmp`
Stashes a normalization callback in `InferCtxt` so that the signature we get from `tcx.fn_sig(..).subst(..)` in `InferCtxt::cmp` can be properly normalized, since we cannot expect for it to have normalized types since it comes straight from astconv.
This is kind of a hack, but I will say that `@jyn514` found the fact that we present unnormalized types to be very confusing in real life code, and I agree with that feeling. Though altogether I am still a bit unsure about whether this PR is worth the effort, so I'm open to alternatives and/or just closing it outright.
On the other hand, this isn't a ridiculously heavy implementation anyways -- it's less than a hundred lines of changes, and half of that is just miscellaneous cleanup.
This is stacked onto #100471 which is basically unrelated, and it can be rebased off of that when that lands or if needed.
---
The code:
```rust
trait Foo { type Bar; }
impl<T> Foo for T {
type Bar = i32;
}
fn foo<T>(_: <T as Foo>::Bar) {}
fn needs_i32_ref_fn(f: fn(&'static i32)) {}
fn main() {
needs_i32_ref_fn(foo::<()>);
}
```
Before:
```
= note: expected fn pointer `fn(&'static i32)`
found fn item `fn(<() as Foo>::Bar) {foo::<()>}`
```
After:
```
= note: expected fn pointer `fn(&'static i32)`
found fn item `fn(i32) {foo::<()>}`
```
Do not leak type variables from opaque type relation
The "root cause" is that we call `InferCtxt::resolve_vars_if_possible` (3d9dd681f5) on the types we get back in `TypeError::Sorts` since I added a call to it in `InferCtxt::same_type_modulo_infer`. However if this `TypeError` comes from a `InferCtxt::commit_if_ok`, then it may reference type variables that do not exist anymore, which is problematic.
We avoid this by substituting the `TypeError` with the types we had before being generalized while handling opaques.
This is kinda gross, and I feel like we can get the same issue from other places where we generalize type/const inference variables. Maybe not? I don't know.
Fixes#99914Fixes#99970Fixes#100463
Rollup of 9 pull requests
Successful merges:
- #95376 (Add `vec::Drain{,Filter}::keep_rest`)
- #100092 (Fall back when relating two opaques by substs in MIR typeck)
- #101019 (Suggest returning closure as `impl Fn`)
- #101022 (Erase late bound regions before comparing types in `suggest_dereferences`)
- #101101 (interpret: make read-pointer-as-bytes a CTFE-only error with extra information)
- #101123 (Remove `register_attr` feature)
- #101175 (Don't --bless in pre-push hook)
- #101176 (rustdoc: remove unused CSS selectors for `.table-display`)
- #101180 (Add another MaybeUninit array test with const)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fall back when relating two opaques by substs in MIR typeck
This is certainly _one_ way to fix#100075. Not really confident it's the _best_ way to do it, though.
The root cause of this issue is that during MIR type-check, we end up trying to equate an opaque against the same opaque def-id but with different substs. Because of the way that we replace RPITs during (HIR) typeck with an inference variable, we don't end up emitting a type-checking error, so the delayed MIR bug causes an ICE.
See the `src/test/ui/impl-trait/issue-100075-2.rs` test below to make that clear -- in that example, we try to equate `{impl Sized} substs=[T]` and `{impl Sized} substs=[Option<T>]`, which causes an ICE. This new logic will instead cause us to infer `{impl Sized} substs=[Option<T>]` as the hidden type for `{impl Sized} substs=[T]`, which causes a proper error to be emitted later on when we check that an opaque isn't recursive.
I'm open to closing this in favor of something else. Ideally we'd fix this in typeck, but the thing we do to ensure backwards compatibility with weird RPIT cases makes that difficult. Also open to discussing this further.
Revert let_chains stabilization
This is the revert against master, the beta revert was already done in #100538.
Bumps the stage0 compiler which already has it reverted.
Rollup of 7 pull requests
Successful merges:
- #100898 (Do not report too many expr field candidates)
- #101056 (Add the syntax of references to their documentation summary.)
- #101106 (Rustdoc-Json: Retain Stripped Modules when they are imported, not when they have items)
- #101131 (CTFE: exposing pointers and calling extern fn is just impossible)
- #101141 (Simplify `get_trait_ref` fn used for `virtual_function_elimination`)
- #101146 (Various changes to logging of borrowck-related code)
- #101156 (Remove `Sync` requirement from lint pass objects)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove separate indexing of early-bound regions
~Based on https://github.com/rust-lang/rust/pull/99728.~
This PR copies some modifications from https://github.com/rust-lang/rust/pull/97839 around object lifetime defaults.
These modifications allow to stop counting generic parameters during lifetime resolution, and rely on the indexing given by `rustc_typeck::collect`.
InferCtxt tainted_by_errors_flag should be Option<ErrorGuaranteed>
Fixes#100321.
Use Cell<Option<ErrorGuaranteed>> to guarantee that we emit an error when that flag is set.
Make `same_type_modulo_infer` a proper `TypeRelation`
Specifically, this fixes#100690 because we no longer consider a `ReLateBound` and a `ReVar` to be equal. `ReVar` can only be equal to free regions or static.
Revert "Rollup merge of #97346 - JohnTitor:remove-back-compat-hacks, …
…r=oli-obk"
This reverts commit c703d11dcc, reversing
changes made to 64eb9ab869.
it didn't apply cleanly, so now it works the same for RPIT and for TAIT instead of just working for RPIT, but we should keep those in sync anyway. It also exposed a TAIT bug (see the feature gated test that now ICEs).
r? `@pnkfelix`
fixes#99536
remove `commit_unconditionally`
`commit_unconditionally` is a noop unless we somehow inspect the current state of our snapshot. The only thing which does that is the leak check which was only used in one place where `commit_if_ok` is probably at least as, or even more, correct.
r? rust-lang/types
make `PlaceholderConst` not store the type of the const
Currently the `Placeholder` variant on `ConstKind` is 28 bytes when with this PR its 8 bytes, i am not sure this is really useful at all rn since `Unevaluated` and `Value` variants are huge still but eventually it should be possible to get both down to 16 bytes 🤔. Mostly opening this to see if this change has any perf impact when done before it can make `ConstKind`/`ConstS` smaller
`codegen_fulfill_obligation` expect erased regions
it's a query, so by erasing regions before calling it, we get better caching.
This doesn't actually change anything as its already the status quo.
use `check_region_obligations_and_report_errors` to avoid ICEs
If we don't call `process_registered_region_obligations` before `resolve_regions_and_report_errors` then we'll ICE if we have any region obligations, and `check_region_obligations_and_report_errors` just does both of these for us in a nice convenient function.
Fixes#53475
r? types
Previously, `infcx.instantiate_canonical_*` maps the root universe in `canonical` into `ty::UniverseIndex::Root`, I think because it assumes it works with a fresh `infcx` but this is not true for the use cases in mir typeck. Now the root universe is mapped into `infcx.universe()`.
I catched this accidentally while reviewing the code. I'm not sure if this is the right fix or if it is really a bug!
Check that RPITs constrained by a recursive call in a closure are compatible
Fixes#99073
Adapts a similar visitor pattern to `find_opaque_ty_constraints` (that we use to check TAITs), but with some changes:
0. Only walk the "OnlyBody" children, instead of all items in the RPIT's defining scope
1. Only walk through the body's children if we found a constraining usage
2. Don't actually do any inference, just do a comparison and error if they're mismatched
----
r? `@oli-obk` -- you know all this impl-trait stuff best... is this the right approach? I can explain the underlying issue better if you'd like, in case that might reveal a better solution. Not sure if it's possible to gather up the closure's defining usages of the RPIT while borrowck'ing the outer function, that might be a better place to put this check...
Use full type name instead of just saying `impl Trait` in "captures lifetime" error
I think this is very useful, especially when there's >1 `impl Trait`, and it just means passing around a bit more info that we already have access to.
handle consts with param/infer in `const_eval_resolve` better
This PR addresses [this thread here](https://github.com/rust-lang/rust/pull/99449#discussion_r924141230). Was this the change you were looking for ``@lcnr?``
Interestingly, one test has begun to pass. Was that expected?
r? ``@lcnr``
Improve suggestions for returning binding
Fixes#99525
Also reworks the cause codes for match and if a bit, I think cleaning them up in a positive way.
We no longer need to call `could_remove_semicolon` in successful code, which might save a few cycles?
Remove the unused StableSet and StableMap types from rustc_data_structures.
The current implementation is not "stable" in the same sense that `HashStable` and `StableHasher` are stable, i.e. across compilation sessions. So, in my opinion, it's better to remove those types (which are basically unused anyway) than to give the wrong impression that these are safe for incr. comp.
I plan to provide new "stable" collection types soon that can be used to replace `FxHashMap` and `FxHashSet` in query results (see [draft](69d03ac7a7)). It's unsound that `HashMap` and `HashSet` implement `HashStable` (see https://github.com/rust-lang/rust/issues/98890 for a recent P-critical bug caused by this) -- so we should make some progress there.
