Rename `IndexVec::last` → `last_index`
As I've been trying to replace a `Vec` with an `IndexVec`, having `last` exist on both but returning very different types makes the transition a bit awkward -- the errors are later, where you get things like "there's no `ty` method on `mir::Field`" rather than a more localized error like "hey, there's no `last` on `IndexVec`".
So I propose renaming `last` to `last_index` to help distinguish `Vec::last`, which returns an element, and `IndexVec::last_index`, which returns an index.
(Similarly, `Iterator::last` also returns an element, not an index.)
Check for overflow in `assemble_candidates_after_normalizing_self_ty`
Prevents a stack overflow (⚠️❗) in the new solver when we have param-env candidates that look like: `T: Trait<Assoc = <T as Trait>::Assoc>`
The current error message looks bad, but that's because we don't distinguish overflow and other ambiguity errors. I'll break that out into a separate PR since the fix may be controversial.
r? `@lcnr`
Use span of placeholders in format_args!() expansion.
`format_args!("{}", x)` expands to something that contains `Argument::new_display(&x)`. That entire expression was generated with the span of `x`.
After this PR, `&x` uses the span of `x`, but the `new_display` call uses the span of the `{}` placeholder within the format string. If an implicitly captured argument was used like in `format_args!("{x}")`, both use the span of the `{x}` placeholder.
This fixes https://github.com/rust-lang/rust/issues/109576, and also allows for more improvements to similar diagnostics in the future, since the usage of `x` can now be traced to the exact `{}` placeholder that required it to be `Display` (or `Debug` etc.)
As I've been trying to replace a `Vec` with an `IndexVec`, having `last` exist on both but returning very different types makes the transition a bit awkward -- the errors are later, where you get things like "there's no `ty` method on `mir::Field`" rather than a more localized error like "hey, there's no `last` on `IndexVec`".
So I propose renaming `last` to `last_index` to help distinguish `Vec::last`, which returns an element, and `IndexVec::last_index`, which returns an index.
(Similarly, `Iterator::last` also returns an element, not an index.)
Rollup of 6 pull requests
Successful merges:
- #109149 (Improve error message when writer is forgotten in write and writeln macro)
- #109367 (Streamline fast rejection)
- #109548 (AnnotationColumn struct to fix hard tab column numbers in errors)
- #109694 (do not panic on failure to acquire jobserver token)
- #109705 (new solver: check for intercrate mode when accessing the cache)
- #109708 (Specialization involving RPITITs is broken so ignore the diagnostic differences)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
do not panic on failure to acquire jobserver token
Purpose: remove `panic`.
Rust fails to acquire token if an error in build system occurs - environment variable contains incorrect `jobserver-auth`. It isn't ice so compiler shouldn't panic on such error.
Related issue: #46981
Improve error message when writer is forgotten in write and writeln macro
Modified write! macro error message when writer is forgotten as in issue #108713Fixes#108713
r? ``@WaffleLapkin``
Thanks to the combination of #108246 and #108442 it could already remove identity transmutes.
With this PR, it can also simplify them to `IntToInt` casts, `Discriminant` reads, or `Field` projections.
Rollup of 8 pull requests
Successful merges:
- #91793 (socket ancillary data implementation for FreeBSD (from 13 and above).)
- #92284 (Change advance(_back)_by to return the remainder instead of the number of processed elements)
- #102472 (stop special-casing `'static` in evaluation)
- #108480 (Use Rayon's TLV directly)
- #109321 (Erase impl regions when checking for impossible to eagerly monomorphize items)
- #109470 (Correctly substitute GAT's type used in `normalize_param_env` in `check_type_bounds`)
- #109562 (Update ar_archive_writer to 0.1.3)
- #109629 (remove obsolete `givens` from regionck)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add a builtin `FnPtr` trait that is implemented for all function pointers
r? `@ghost`
Rebased version of https://github.com/rust-lang/rust/pull/99531 (plus adjustments mentioned in the PR).
If perf is happy with this version, I would like to land it, even if the diagnostics fix in 9df8e1befb5031a5bf9d8dfe25170620642d3c59 only works for `FnPtr` specifically, and does not generally improve blanket impls.
Update ar_archive_writer to 0.1.3
This updates object to 0.30 and fixes a bug where the symbol table would be omitted for archives where there are object files yet none that export any symbol. This bug could lead to linker errors for crates like rustc_std_workspace_core which don't contain any code of their own but exist solely for their dependencies. This is likely the cause of the linker issues I was experiencing on Webassembly. It has been shown to cause issues on other platforms too.
cc rust-lang/ar_archive_writer#5
Correctly substitute GAT's type used in `normalize_param_env` in `check_type_bounds`
Given:
```rust
trait Foo {
type Assoc<T>: PartialEq<Self::Assoc<i32>>;
}
impl Foo for () {
type Assoc<T> = Wrapper<T>;
}
struct Wrapper<T>(T);
impl<T> PartialEq<Wrapper<i32>> for Wrapper<T> { }
```
We add an additional predicate in the `normalize_param_env` in `check_type_bounds` that is used to normalize the GAT's bounds to check them in the impl. Problematically, though, that predicate is constructed to be `for<^0> <() as Foo>::Assoc<^0> => Wrapper<T>`, instead of `for<^0> <() as Foo>::Assoc<^0> => Wrapper<^0>`.
That means `Self::Assoc<i32>` in the bounds that we're checking normalizes to `Wrapper<T>`, instead of `Wrapper<i32>`, and so the bound `Self::Assoc<T>: PartialEq<Self::Assoc<i32>>` normalizes to `Wrapper<T>: PartialEq<Wrapper<T>>`, which does not hold.
Fixes this by properly substituting the RHS of that normalizes predicate that we add to the `normalize_param_env`. That means the bound is properly normalized to `Wrapper<T>: PartialEq<Wrapper<i32>>`, which *does* hold.
---
The second commit in this PR just cleans up some substs stuff and some naming.
r? `@jackh726` cc #87900
Erase impl regions when checking for impossible to eagerly monomorphize items
We were inserting `ReErased` for method substs, but not for impl substs, leading to the call for `subst_and_check_impossible_predicates` being a bit weaker than it should be (since it ignores predicates that need substitution -- incl early-bound regions).
Fixes#109297
Use Rayon's TLV directly
This accesses Rayon's `TLV` thread local directly avoiding wrapper functions. This makes rustc work with https://github.com/rust-lang/rustc-rayon/pull/10.
r? `@cuviper`
stop special-casing `'static` in evaluation
fixes#102360
I have no idea whether this actually removed all places where `'static` matters. Without canonicalization it's very easy to accidentally rely on `'static` again. Blocked on changing the `order_dependent_trait_objects` future-compat lint to a hard error
r? `@nikomatsakis`
Move const trait bounds checks to MIR constck
Fixes#109543. When checking paths in HIR typeck, we don't want to check for const predicates since all we want might just be a function pointer. Therefore we move this to MIR constck and check that bounds are met during MIR constck.
r? `@oli-obk`
Fixes#109543. When checking paths in HIR typeck, we don't want to check
for const predicates since all we want might just be a function pointer.
Therefore we move this to MIR constck and check that bounds are met
during MIR constck.
Make doc comment a little bit more accurate
It queries not LLVM in particular but the codegen backend *in general*. While cranelift does not provide target features, other codegen backends do.
Found while looking for [this answer](https://github.com/rust-lang/rust/issues/108680#issuecomment-1484324690).
Don't shadow the `dep_node` var in `incremental_verify_ich_failed`
It's better to debug print `DepNode` instead of `ErrorGuaranteed` one line below :^)
fixes#109676
Clarify the 'use a constant in a pattern' error message
```rs
use std::borrow::Cow;
const ERROR_CODE: Cow<'_, str> = Cow::Borrowed("23505");
fn main() {
let x = Cow::from("23505");
match x {
ERROR_CODE => {}
}
}
```
```
error: to use a constant of type `Cow` in a pattern, `Cow` must be annotated with `#[derive(PartialEq, Eq)]`
--> src/main.rs:9:9
|
9 | ERROR_CODE => {}
| ^^^^^^^^^^
error: could not compile `playground` due to previous error
```
It seems helpful to link to StructuralEq in this message. I was a little confused, because `Cow<'_, str>` implements PartialEq and Eq, but they're not derived, which I learned is necessary for structural equality and using constants in patterns (thanks to the Rust community Discord server)
For tests, should I update every occurrence of this message? I see tests where this is still a warning and I'm not sure if I should update those.
Don't skip all directories when tidy-checking
This fixes a regression from https://github.com/rust-lang/rust/pull/108772 which basically made it that tidy style checks only `README.md` and `COMPILER_TESTS.md`.
Remove the `NodeId` of `ast::ExprKind::Async`
This is a followup to https://github.com/rust-lang/rust/pull/104833#pullrequestreview-1314537416.
In my original attempt, I was using `LoweringContext::expr`, which was not correct as it creates a fresh `DefId`.
It now uses the correct `DefId` for the wrapping `Expr`, and also makes forwarding `#[track_caller]` attributes more explicit.
Refactor: Separate `LocalRef` variant for not-evaluated-yet operands
As I was reading through this, I noticed that almost every place that was using this needed to distinguish between Some vs None in the match arm anyway, so thought that separating the cases at the variant level might be clearer instead.
I like how it ended up; let me know what you think!
