Given the code
```rust
pub fn main() {
const y: i32 = 4;
let y: i32 = 3;
}
```
`y` in the let binding is actually interpreted as a constant pattern
and is not a new variable, causing confusing diagnostics about
refutable patterns in local binding.
This commit extends the note for type ascription as a constant pattern
to `AscribeUserType` patterns as well.
only suppress coercion error if type is definitely unsized
we previously suppressed coercion errors when the return type was `dyn Trait` because we expect a far more descriptive `Sized` trait error to be emitted instead, however the code that does this suppression does not consider where-clause predicates since it just looked at the HIR. let's do that instead by creating an obligation and checking if it may hold.
fixes#110683fixes#112208
suggest `Option::as_deref(_mut)` on type mismatch in option combinator if it passes typeck
Fixes#106342.
This adds a suggestion to call `.as_deref()` (or `.as_deref_mut()` resp.) if typeck fails due to a type mismatch in the function passed to an `Option` combinator such as `.map()` or `.and_then()`.
For example:
```rs
fn foo(_: &str) {}
Some(String::new()).map(foo);
```
The `.map()` method requires its argument to satisfy `F: FnOnce(String)`, but it received `fn(&str)`, which won't pass. However, placing a `.as_deref()` before the `.map()` call fixes this since `&str == &<String as Deref>::Target`
Don't use `can_eq` in `derive(..)` suggestion for missing method
Unsatisfied predicates returned from method probe may reference inference vars from that probe, so drop this extra check I added in #110877 for more accurate derive suggestions...
Fixes#111500
Require that const param tys implement `ConstParamTy`
1. Require that const param tys implement `ConstParamTy` instead of using `search_for_adt_const_param_violation`
2. Add `StructuralPartialEq` as a supertrait for `ConstParamTy`, since we need to make sure that we derive *both* `PartialEq` and `Eq`
3. Implement `ConstParamTy` for tuples up to 12 (or whatever the default for tuples is)
4. Add some custom diagnostics to `ConstParamTy` errors, to avoid regressions from (1.). It's still not as great as it could be -- will point out inline in comments.
r? `@BoxyUwU`
Use translatable diagnostics in `rustc_const_eval`
This PR:
* adds a `no_span` parameter to `note` / `help` attributes when using `Subdiagnostic` to allow adding notes/helps without using a span
* has minor tweaks and changes to error messages
Preserve substs in opaques recorded in typeck results
This means that we now prepopulate MIR with opaques with the right substs.
The first commit is a hack that I think we discussed, having to do with `DefiningAnchor::Bubble` basically being equivalent to `DefiningAnchor::Error` in the new solver, so having to use `DefiningAnchor::Bind` instead, lol.
r? `@lcnr`
Replace const eval limit by a lint and add an exponential backoff warning
The lint triggers at the first power of 2 that comes after 1 million function calls or traversed back-edges (takes less than a second on usual programs). After the first emission, an unsilenceable warning is repeated at every following power of 2 terminators, causing it to get reported less and less the longer the evaluation runs.
cc `@rust-lang/wg-const-eval`
fixes#93481closes#67217
Uplift `clippy::cast_ref_to_mut` lint
This PR aims at uplifting the `clippy::cast_ref_to_mut` lint into rustc.
## `cast_ref_to_mut`
(deny-by-default)
The `cast_ref_to_mut` lint checks for casts of `&T` to `&mut T` without using interior mutability.
### Example
```rust,compile_fail
fn x(r: &i32) {
unsafe {
*(r as *const i32 as *mut i32) += 1;
}
}
```
### Explanation
Casting `&T` to `&mut T` without interior mutability is undefined behavior, as it's a violation of Rust reference aliasing requirements.
-----
Mostly followed the instructions for uplifting a clippy lint described here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
`@rustbot` label: +I-lang-nominated
r? compiler
-----
For Clippy:
changelog: Moves: Uplifted `clippy::cast_ref_to_mut` into rustc
linker: Report linker flavors incompatible with the current target
The linker flavor is checked for target compatibility even if linker is never used (e.g. we are producing a rlib).
If it causes trouble, we can move the check to `link.rs` so it will run if the linker (flavor) is actually used.
And also feature gate explicitly specifying linker flavors for tier 3 targets.
The next step is supporting all the internal linker flavors in user-visible interfaces (command line and json).
Only rewrite valtree-constants to patterns and keep other constants opaque
Now that we can reliably fall back to comparing constants with `PartialEq::eq` to the match scrutinee, we can
1. eagerly try to convert constants to valtrees
2. then deeply convert the valtree to a pattern
3. if the to-valtree conversion failed, create an "opaque constant" pattern.
This PR specifically avoids any behavioral changes or major cleanups. What we can now do as follow ups is
* move the two remaining call sites to `destructure_mir_constant` off that query
* make valtree to pattern conversion infallible
* this needs to be done after careful analysis of the effects. There may be user visible changes from that.
based on https://github.com/rust-lang/rust/pull/111768
Rollup of 5 pull requests
Successful merges:
- #111772 (Fix linkage for large binaries on mips64 platforms)
- #111975 (Stop normalizing so many different prefixes)
- #111979 (Respect CARGOFLAGS in bootstrap.py)
- #112089 (Add `--warnings warn` flag to `x.py`)
- #112103 (Bootstrap update to 1.71 beta)
r? `@ghost`
`@rustbot` modify labels: rollup
Stop normalizing so many different prefixes
Previously, we would normalize *all* of
- the absolute path to the repository checkout
- the /rustc/$sha for stage1 (if `remap-debuginfo` was enabled)
- the /rustc/$sha for download-rustc
- the sysroot for download-rustc
Now, we consistently only normalize /rustc/FAKE_PREFIX. Not only is this much simpler, but it also avoids ongoing maintenance for download-rustc and makes it much less likely that tests break by accident.
- Change `tests/ui/track-diagnostics/track6.rs` to use a relative path instead of an absolute one. I am not actually sure why `track_caller` works here, but it does seem to work 🤷
- Pass `-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX` to all suites, not just UI. In particular, mir-opt tests emit /rustc/ paths in their output.
r? ```@cjgillot``` since you reviewed https://github.com/rust-lang/rust/pull/110699 - this is the test that it doesn't regress :)
move `super_relate_consts` hack to `normalize_param_env_or_error`
`super_relate_consts` has as hack in it to work around the fact that `normalize_param_env_or_error` is broken. When relating two constants we attempt to evaluate them (aka normalize them). This is not an issue in any way specific to const generics, type aliases also have the same issue as demonstrated in [this code](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=84b6d3956a2c852a04b60782476b56c9).
Since the hack in `super_relate_consts` only exists to make `normalize_param_env_or_error` emit less errors move it to `normalize_param_env_or_error`. This makes `super_relate_consts` act more like the normal plain structural equality its supposed to and should help ensure that the hack doesnt accidentally affect other situations.
r? `@compiler-errors`
offset_of: don't require type to be `Sized`
Fixes#112051
~~The RFC [explicitly forbids](https://rust-lang.github.io/rfcs/3308-offset_of.html#limitations) non-`Sized` types, but it looks like only the fields being recursed into were checked. The sized check also seemed to have been completely missing for tuples~~
change `BorrowKind::Unique` to be a mutating `PlaceContext`
fixes#112056
I believe that `BorrowKind::Unique` is a footgun in general, so I added a FIXME and opened https://github.com/rust-lang/rust/issues/112072. This is a bit too involved for this PR though.
refactor and cleanup the leak check, add it to new solver
ended up being a bit more involved than I wanted but is hopefully still easy enough to review as a single PR, can split it into separate ones otherwise.
this can be reviewed commit by commit:
a473d55cdb9284aa2b01282d1b529a2a4d26547b 31a686646534ca006d906ec757ece4e771d6f973 949039c107852a5e36361c08b62821a0613656f5 242917bf5170d9a723c6c8e23e9d9d0c2fa8dc9d ed2b25a7aa28be3184be9e3022c2796a30eaad87 are all pretty straightforward.
03dd83b4c3f4ff27558f5c8ab859bd9f83db1d04 makes it easier to refactor coherence in a later commit, see the commit description, cc `@oli-obk`
4fe311d807a77b6270f384e41689bf5d58f46aec I don't quite remember what we wanted to test here, this definitely doesn't test that the occurs check doesn't cause incorrect errors in coherence, also cc `@oli-obk` here. I may end up writing a new test for this myself later.
5c200d88a91b75bd0875b973150655bd581ef97a is the main refactor of the leak check, changing it to take the `outer_universe` instead of getting it from a snapshot. Using a snapshot requires us to be in a probe which we aren't in the new solver, it also just feels dirty as snapshots don't really have anything to do with universes.
with all of this cfc230d54188d9c7ed867a9a0d1f51be77b485f9 is now kind of trivial.
r? `@nikomatsakis`
Don't typecheck recovered method call from suggestion
Only make the use-dot-operator-to-call-method suggestion, but do not double down and use the recovered type to perform method call typechecking as it will produce confusing diagnostics relevant for the *fixed* code.
### Code Sample
```rust
struct Client;
impl Client {
fn post<T: std::ops::Add>(&self, _: T, _: T) {}
}
fn f() {
let c = Client;
post(c, ());
}
```
### Before This PR
```
error[[E0277]](https://doc.rust-lang.org/stable/error_codes/E0277.html): cannot add `()` to `()`
--> src/lib.rs:9:5
|
9 | post(c, ());
| ^^^^^^^^^^^ no implementation for `() + ()`
|
= help: the trait `Add` is not implemented for `()`
note: required by a bound in `Client::post`
--> src/lib.rs:4:16
|
4 | fn post<T: std::ops::Add>(&self, _: T, _: T) {}
| ^^^^^^^^^^^^^ required by this bound in `Client::post`
error[[E0061]](https://doc.rust-lang.org/stable/error_codes/E0061.html): this function takes 2 arguments but 1 argument was supplied
--> src/lib.rs:9:5
|
9 | post(c, ());
| ^^^^ an argument of type `()` is missing
|
note: method defined here
--> src/lib.rs:4:8
|
4 | fn post<T: std::ops::Add>(&self, _: T, _: T) {}
| ^^^^ ----- ---- ----
help: provide the argument
|
9 | post((), ())(c, ());
| ++++++++
error[[E0425]](https://doc.rust-lang.org/stable/error_codes/E0425.html): cannot find function `post` in this scope
--> src/lib.rs:9:5
|
9 | post(c, ());
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `post` on `&Client`
|
9 - post(c, ());
9 + c.post(());
|
Some errors have detailed explanations: E0061, E0277, E0425.
For more information about an error, try `rustc --explain E0061`.
```
### After This PR
```
error[E0425]: cannot find function `post` in this scope
--> tests/ui/typeck/issue-106929.rs:9:5
|
9 | post(c, ());
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `post` on `&Client`
|
9 - post(c, ());
9 + c.post(());
|
error: aborting due to previous error
For more information about this error, try `rustc --explain E0425`.
```
Fixes#106929.
fix: dedup `static_candidates` before report
Fixes https://github.com/rust-lang/rust/issues/103646
`record_static_candidate` had been executed twice, resulting in the presence of two identical `CandidateSource::Trait(Cat)` in static_candidates. This PR aims to deduplication the `static_candidates` list, allowing it to execute `suggest_associated_call_syntax` properly.
