Commit graph

16041 commits

Author SHA1 Message Date
Matthias Krüger
961bf7ffa6
Rollup merge of #136434 - RalfJung:rustc_allowed_through_unstable_modules-deprecation-required, r=compiler-errors
rustc_allowed_through_unstable_modules: require deprecation message

This changes the `#[rustc_allowed_through_unstable_modules]` attribute so that a deprecation message (ideally directing people towards the stable path) is required.
2025-02-02 18:05:25 +01:00
Matthias Krüger
7e3d872bc0
Rollup merge of #136415 - estebank:highlight-clarification, r=compiler-errors
Highlight clarifying information in "expected/found" error

When the expected and found types have the same textual representation, we add clarifying in parentheses. We now visually highlight it in the output.

Detect a corner case where the clarifying information would be the same for both types and skip it, as it doesn't add anything useful.

![Screenshot of the rustc highlighted output on the terminal](https://github.com/user-attachments/assets/aa4b9433-5332-4941-b2c2-1a43e5cadff7)
2025-02-02 18:05:24 +01:00
Matthias Krüger
e066208255
Rollup merge of #136402 - notriddle:notriddle/let-expr-detector, r=compiler-errors
diagnostics: fix borrowck suggestions for if/while let conditionals

This code detects the case where one of the borrows is inside the let init expr while the other end is not. If that happens, we don't want to suggest adding a semicolon, because it won't work.

Fixes #133941
2025-02-02 18:05:23 +01:00
Matthias Krüger
48aede0773
Rollup merge of #134272 - RalfJung:destabilize-rustc_encodable_decodable, r=oli-obk
Remove rustc_encodable_decodable feature

This has been shown in future-compat reports since Rust 1.79 (https://github.com/rust-lang/rust/pull/116016), released June 2024. Let's see if crater still finds any issues.

Part of https://github.com/rust-lang/rust/issues/134301.

Cc ``@rust-lang/libs-api``
2025-02-02 18:05:22 +01:00
Ralf Jung
3320e91575 rustc_allowed_through_unstable_modules: require deprecation message 2025-02-02 12:36:12 +01:00
Matthias Krüger
44def58274
Rollup merge of #136412 - estebank:fn-ptr-cast-suggestion, r=jieyouxu
Tweak fn pointer suggestion span

Use a more targeted span when suggesting casting an `fn` item to an `fn` pointer.

```
error[E0308]: cannot coerce functions which must be inlined to function pointers
  --> $DIR/cast.rs:10:33
   |
LL |     let _: fn(isize) -> usize = callee;
   |            ------------------   ^^^^^^ cannot coerce functions which must be inlined to function pointers
   |            |
   |            expected due to this
   |
   = note: expected fn pointer `fn(_) -> _`
                 found fn item `fn(_) -> _ {callee}`
   = note: fn items are distinct from fn pointers
help: consider casting to a fn pointer
   |
LL |     let _: fn(isize) -> usize = callee as fn(isize) -> usize;
   |                                        +++++++++++++++++++++
```
```
error[E0308]: mismatched types
  --> $DIR/fn-pointer-mismatch.rs:42:30
   |
LL |     let d: &fn(u32) -> u32 = foo;
   |            ---------------   ^^^ expected `&fn(u32) -> u32`, found fn item
   |            |
   |            expected due to this
   |
   = note: expected reference `&fn(_) -> _`
                found fn item `fn(_) -> _ {foo}`
help: consider using a reference
   |
LL |     let d: &fn(u32) -> u32 = &foo;
   |                              +
```
Previously we'd point at the whole expression for replacement, instead of marking what was being added.

We could also modify the suggestions for `&(name as fn())`, but for that we require storing more accurate spans than we have now.
2025-02-02 12:31:58 +01:00
Matthias Krüger
ce5db2f9f1
Rollup merge of #136358 - clubby789:opt-none-noinline, r=saethlin
`#[optimize(none)]` implies `#[inline(never)]`

Fixes #136329
2025-02-02 12:31:57 +01:00
Matthias Krüger
39efaa09d6
Rollup merge of #136328 - estebank:long-ty-path, r=jieyouxu,lqd
Rework "long type names" printing logic

Make it so more type-system types can be printed in a shortened version (like `Predicate`s).

Centralize printing the information about the "full type name path".

Make the "long type path" for the file where long types are written part of `Diag`, so that it becomes easier to keep track of it, and ensure it will always will be printed out last in the diagnostic by making its addition to the output implicit.

Tweak the shortening of types in "expected/found" labels.

Remove dead file `note.rs`.
2025-02-02 12:31:56 +01:00
Esteban Küber
c75e601543 Highlight clarifying information in "expected/found" error
When the expected and found types have the same textual representation, we add clarifying in parentheses. We now visually highlight it in the output.

Detect a corner case where the clarifying information would be the same for both types and skip it, as it doesn't add anything useful.
2025-02-02 02:39:43 +00:00
Esteban Küber
028a920c53 Tweak fn pointer suggestion span
Use a more targeted span when suggesting casting an `fn` item to an `fn` pointer.

```
error[E0308]: cannot coerce functions which must be inlined to function pointers
  --> $DIR/cast.rs:10:33
   |
LL |     let _: fn(isize) -> usize = callee;
   |            ------------------   ^^^^^^ cannot coerce functions which must be inlined to function pointers
   |            |
   |            expected due to this
   |
   = note: expected fn pointer `fn(_) -> _`
                 found fn item `fn(_) -> _ {callee}`
   = note: fn items are distinct from fn pointers
help: consider casting to a fn pointer
   |
LL |     let _: fn(isize) -> usize = callee as fn(isize) -> usize;
   |                                        +++++++++++++++++++++
```
```
error[E0308]: mismatched types
  --> $DIR/fn-pointer-mismatch.rs:42:30
   |
LL |     let d: &fn(u32) -> u32 = foo;
   |            ---------------   ^^^ expected `&fn(u32) -> u32`, found fn item
   |            |
   |            expected due to this
   |
   = note: expected reference `&fn(_) -> _`
                found fn item `fn(_) -> _ {foo}`
help: consider using a reference
   |
LL |     let d: &fn(u32) -> u32 = &foo;
   |                              +
```
Previously we'd point at the whole expression for replacement, instead of marking what was being added.

We could also modify the suggestions for `&(name as fn())`, but for that we require storing more accurate spans than we have now.
2025-02-02 00:46:02 +00:00
Michael Howell
ecb2d5c43d diagnostics: fix borrowck suggestions for if/while let conditionals
This code detects the case where one of the borrows is inside the
let init expr while the other end is not. If that happens, we don't
want to suggest adding a semicolon, because it won't work.
2025-02-01 14:39:43 -07:00
Matthias Krüger
2fd3007cbc
Rollup merge of #130514 - compiler-errors:unsafe-binders, r=oli-obk
Implement MIR lowering for unsafe binders

This is the final bit of the unsafe binders puzzle. It implements MIR, CTFE, and codegen for unsafe binders, and enforces that (for now) they are `Copy`. Later on, I'll introduce a new trait that relaxes this requirement to being "is `Copy` or `ManuallyDrop<T>`" which more closely models how we treat union fields.

Namely, wrapping unsafe binders is now `Rvalue::WrapUnsafeBinder`, which acts much like an `Rvalue::Aggregate`. Unwrapping unsafe binders are implemented as a MIR projection `ProjectionElem::UnwrapUnsafeBinder`, which acts much like `ProjectionElem::Field`.

Tracking:
- https://github.com/rust-lang/rust/issues/130516
2025-02-01 16:41:03 +01:00
bors
9e48dfe5e0 Auto merge of #136371 - matthiaskrgr:rollup-0b880v3, r=matthiaskrgr
Rollup of 7 pull requests

Successful merges:

 - #135840 (omit unused args warnings for intrinsics without body)
 - #135900 (Manually walk into WF obligations in `BestObligation` proof tree visitor)
 - #136163 (Fix off-by-one error causing slice::sort to abort the program)
 - #136266 (fix broken release notes id)
 - #136314 (Use proper type when applying deref adjustment in const)
 - #136348 (miri: make float min/max non-deterministic)
 - #136351 (Add documentation for derive(CoercePointee))

r? `@ghost`
`@rustbot` modify labels: rollup
2025-02-01 03:08:52 +00:00
bors
9709af7901 Auto merge of #135768 - jieyouxu:migrate-symbol-mangling-hashed, r=Noratrieb
tests: Port `symbol-mangling-hashed` to rmake.rs

Part of #121876.

This PR supersedes #128567 and is co-authored with `@lolbinarycat.`

### Summary

This PR ports `tests/run-make/symbol-mangling-hashed` to rmake.rs. Notable differences when compared to the Makefile version includes:

- It's no longer limited to linux + x86_64 only. In particular, this now is exercised on darwin and windows (esp. msvc) too.
- The test uses `object` crate to be more precise in the filtering, and avoids relying on parsing the human-readable `nm` output for *some* `nm` in the given environment (which isn't really a thing on msvc anyway, and `llvm-nm` doesn't handle msvc dylibs AFAICT).
- Dump the symbols satisfying various criteria on test failure to make it hopefully less of a pain to debug if it ever fails in CI.

### Review advice

- Best reviewed commit-by-commit.
- I'm not *super* sure about the msvc logic, would benefit from a MSVC (PE/COFF) expert taking a look.

---

try-job: x86_64-msvc-1
try-job: i686-msvc-1
try-job: i686-mingw
try-job: x86_64-mingw-1
try-job: x86_64-apple-1
try-job: aarch64-apple
try-job: test-various
2025-02-01 00:19:28 +00:00
Matthias Krüger
47e6684e53
Rollup merge of #136314 - compiler-errors:const-deref-adj, r=fee1-dead
Use proper type when applying deref adjustment in const

When applying a deref adjustment to some type `Wrap<T>` which derefs to `T`, we were checking that `T: ~const Deref`, not `Wrap<T>: ~const Deref` like we should have been.

r? project-const-traits

Fixes #136273
Fixes #135210 -- I just deleted the test since the regression test is uninteresting
2025-02-01 01:19:21 +01:00
Matthias Krüger
f90c321eb2
Rollup merge of #136163 - uellenberg:driftsort-off-by-one, r=Mark-Simulacrum
Fix off-by-one error causing slice::sort to abort the program

Fixes #136103.
Based on the analysis by ``@jonathan-gruber-jg`` and ``@orlp.``
2025-02-01 01:19:20 +01:00
Matthias Krüger
3c4b9122ec
Rollup merge of #135900 - compiler-errors:derive-wf, r=lcnr
Manually walk into WF obligations in `BestObligation` proof tree visitor

When we encounter a `WellFormed` obligation in the `BestObligation` proof tree visitor, ignore the proof tree and call `wf::unnormalized_obligations` to derive well-formed obligations with the correct cause codes. This is to avoid having to replicate the somewhat delicate logic that `wf.rs` does to set up its obligation causes... Don't see a better way to do this.

vibes?? r? lcnr
2025-02-01 01:19:19 +01:00
Matthias Krüger
2460b280db
Rollup merge of #135840 - vayunbiyani:omit_intrinsic_unused_param_warning, r=oli-obk
omit unused args warnings for intrinsics without body

potential fix for https://github.com/rust-lang/rust/issues/135598
2025-02-01 01:19:19 +01:00
Esteban Küber
0751e9036a Rework "long type names" printing logic
Make it so more type-system types can be printed in a shortened version (like `Predicate`s).

Centralize printing the information about the "full type name path".

Make the "long type path" for the file where long types are written part of `Diag`, so that it becomes easier to keep track of it, and ensure it will always will be printed out last in the diagnostic by making its addition to the output implicit.

Tweak the shortening of types in "expected/found" labels.

Remove dead file `note.rs`.
2025-01-31 20:39:01 +00:00
bors
854f22563c Auto merge of #136350 - matthiaskrgr:rollup-6eqfyvh, r=matthiaskrgr
Rollup of 9 pull requests

Successful merges:

 - #134531 ([rustdoc] Add `--extract-doctests` command-line flag)
 - #135860 (Compiler: Finalize dyn compatibility renaming)
 - #135992 (Improve documentation when adding a new target)
 - #136194 (Support clobber_abi in BPF inline assembly)
 - #136325 (Delay a bug when indexing unsized slices)
 - #136326 (Replace our `LLVMRustDIBuilderRef` with LLVM-C's `LLVMDIBuilderRef`)
 - #136330 (Remove unnecessary hooks)
 - #136336 (Overhaul `rustc_middle::util`)
 - #136341 (Remove myself from vacation)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-31 20:16:46 +00:00
Michael Goulet
304b3cfcb2 Manually walk into WF obligations in BestObligation proof tree visitor 2025-01-31 18:21:58 +00:00
clubby789
2c35bd0499 #[optimize(none)] implies #[inline(never)] 2025-01-31 17:51:49 +00:00
Michael Goulet
b63341e892 Enforce unsafe binders must be Copy (for now) 2025-01-31 17:40:28 +00:00
Michael Goulet
fc1a9186dc Implement MIR, CTFE, and codegen for unsafe binders 2025-01-31 17:19:53 +00:00
bors
aa4cfd0809 Auto merge of #134424 - 1c3t3a:null-checks, r=saethlin
Insert null checks for pointer dereferences when debug assertions are enabled

Similar to how the alignment is already checked, this adds a check
for null pointer dereferences in debug mode. It is implemented similarly
to the alignment check as a `MirPass`.

This inserts checks in the same places as the `CheckAlignment` pass and additionally
also inserts checks for `Borrows`, so code like
```rust
let ptr: *const u32 = std::ptr::null();
let val: &u32 = unsafe { &*ptr };
```
will have a check inserted on dereference. This is done because null references
are UB. The alignment check doesn't cover these places, because in `&(*ptr).field`,
the exact requirement is that the final reference must be aligned. This is something to
consider further enhancements of the alignment check.

For now this is implemented as a separate `MirPass`, to make it easy to disable
this check if necessary.

This is related to a 2025H1 project goal for better UB checks in debug
mode: https://github.com/rust-lang/rust-project-goals/pull/177.

r? `@saethlin`
2025-01-31 15:56:53 +00:00
Matthias Krüger
f1daf9e2c4
Rollup merge of #136325 - compiler-errors:indirectly, r=RalfJung
Delay a bug when indexing unsized slices

Fixes #136298

r? RalfJung or reassign
2025-01-31 12:28:18 +01:00
Matthias Krüger
12a7f06e3c
Rollup merge of #136194 - taiki-e:bpf-clobber-abi, r=amanieu
Support clobber_abi in BPF inline assembly

This supports [`clobber_abi`](https://doc.rust-lang.org/nightly/reference/inline-assembly.html#abi-clobbers) which is one of the requirements of stabilization mentioned in the tracking Issue for `asm_experimental_arch` (#93335).

Refs: [Section 1.1 "Registers and calling convention" in BPF ABI Recommended Conventions and Guidelines v1.0](https://github.com/torvalds/linux/blob/v6.13/Documentation/bpf/standardization/abi.rst#11registers-and-calling-convention)
> R0 - R5 are scratch registers and BPF programs needs to spill/fill them if necessary across calls.

cc `@alessandrod` `@dave-tucker` `@tamird` `@vadorovsky` (target maintainers mentioned in platform support document which will be added by https://github.com/rust-lang/rust/pull/135107)

r? `@Amanieu`

`@rustbot` label +O-eBPF +A-inline-assembly
2025-01-31 12:28:17 +01:00
Matthias Krüger
308ea7120b
Rollup merge of #135860 - fmease:compiler-mv-obj-save-dyn-compat-ii, r=jieyouxu
Compiler: Finalize dyn compatibility renaming

Update the Reference link to use the new URL fragment from https://github.com/rust-lang/reference/pull/1666 (this change has finally hit stable). Fixes a FIXME.

Follow-up to #130826.
Part of #130852.

~~Blocking it on #133372.~~ (merged)

r? ghost
2025-01-31 12:28:15 +01:00
Matthias Krüger
86595e4c88
Rollup merge of #134531 - GuillaumeGomez:extract-doctests, r=notriddle,aDotInTheVoid
[rustdoc] Add `--extract-doctests` command-line flag

Part of https://github.com/rust-lang/rust/issues/134529.

It was discussed with the Rust-for-Linux project recently that they needed a way to extract doctests so they can modify them and then run them more easily (look for "a way to extract doctests" [here](https://github.com/Rust-for-Linux/linux/issues/2)).

For now, I output most of `ScrapedDoctest` fields in JSON format with `serde_json`. So it outputs the following information:

 * filename
 * line
 * langstr
 * text

cc `@ojeda`
r? `@notriddle`
2025-01-31 12:28:15 +01:00
Bastian Kersting
b151b513ba Insert null checks for pointer dereferences when debug assertions are enabled
Similar to how the alignment is already checked, this adds a check
for null pointer dereferences in debug mode. It is implemented similarly
to the alignment check as a MirPass.

This is related to a 2025H1 project goal for better UB checks in debug
mode: https://github.com/rust-lang/rust-project-goals/pull/177.
2025-01-31 11:13:34 +00:00
bors
7f36543a48 Auto merge of #136332 - jhpratt:rollup-aa69d0e, r=jhpratt
Rollup of 9 pull requests

Successful merges:

 - #132156 (When encountering unexpected closure return type, point at return type/expression)
 - #133429 (Autodiff Upstreaming - rustc_codegen_ssa, rustc_middle)
 - #136281 (`rustc_hir_analysis` cleanups)
 - #136297 (Fix a typo in profile-guided-optimization.md)
 - #136300 (atomic: extend compare_and_swap migration docs)
 - #136310 (normalize `*.long-type.txt` paths for compare-mode tests)
 - #136312 (Disable `overflow_delimited_expr` in edition 2024)
 - #136313 (Filter out RPITITs when suggesting unconstrained assoc type on too many generics)
 - #136323 (Fix a typo in conventions.md)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-31 09:42:28 +00:00
bors
25a16572a3 Auto merge of #136331 - jhpratt:rollup-curo1f4, r=jhpratt
Rollup of 8 pull requests

Successful merges:

 - #135414 (Stabilize `const_black_box`)
 - #136150 (ci: use windows 2025 for i686-mingw)
 - #136258 (rustdoc: rename `issue-\d+.rs` tests to have meaningful names (part 11))
 - #136270 (Remove `NamedVarMap`.)
 - #136278 (add constraint graph to polonius MIR dump)
 - #136287 (LLVM changed the nocapture attribute to captures(none))
 - #136291 (some test suite cleanups)
 - #136296 (float::min/max: mention the non-determinism around signed 0)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-31 06:55:04 +00:00
Jacob Pratt
e6285b8ff1
Rollup merge of #136313 - compiler-errors:too-many-args, r=lqd
Filter out RPITITs when suggesting unconstrained assoc type on too many generics

Fixes #136233
2025-01-31 00:26:34 -05:00
Jacob Pratt
4e64180917
Rollup merge of #136310 - lqd:long-types, r=compiler-errors
normalize `*.long-type.txt` paths for compare-mode tests

When using a compare mode, the name of the test + compare-mode is embedded in some of rustc's output, like the location where a long type `bla.long-type(-some-hash)?.txt` is written to. That generally makes these tests fail under all compare-modes.

This PR fixes this by normalizing the compare-mode suffix away in the stderr output. We can also see some remnants of the long-removed `nll` compare mode being normalized away ^^.

I did this to fix some failures with `--compare-mode next-solver` (but it also fixes them with e.g. `--compare-mode polonius` of course):
- it makes 9 new tests pass with the new solver
- however, 3 tests I changed here still don't pass with the new solver (IIRC there were 2 ICEs, and some duplicate errors for the 3rd one)

(There was also one that triggered slowness in the new solver while triggering the long type failure, I'll mention this on zulip. )
2025-01-31 00:26:33 -05:00
Jacob Pratt
ae9dbf169f
Rollup merge of #132156 - estebank:closure-return, r=Nadrieril,compiler-errors
When encountering unexpected closure return type, point at return type/expression

```
error[E0271]: expected `{closure@fallback-closure-wrap.rs:18:40}` to be a closure that returns `()`, but it returns `!`
  --> $DIR/fallback-closure-wrap.rs:19:9
   |
LL |     let error = Closure::wrap(Box::new(move || {
   |                                        -------
LL |         panic!("Can't connect to server.");
   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found `!`
   |
   = note: expected unit type `()`
                   found type `!`
   = note: required for the cast from `Box<{closure@$DIR/fallback-closure-wrap.rs:18:40: 18:47}>` to `Box<dyn FnMut()>`
```

```
error[E0271]: expected `{closure@dont-ice-for-type-mismatch-in-closure-in-async.rs:6:10}` to be a closure that returns `bool`, but it returns `Option<()>`
  --> $DIR/dont-ice-for-type-mismatch-in-closure-in-async.rs:6:16
   |
LL |     call(|| -> Option<()> {
   |     ---- ------^^^^^^^^^^
   |     |          |
   |     |          expected `bool`, found `Option<()>`
   |     required by a bound introduced by this call
   |
   = note: expected type `bool`
              found enum `Option<()>`
note: required by a bound in `call`
  --> $DIR/dont-ice-for-type-mismatch-in-closure-in-async.rs:3:25
   |
LL | fn call(_: impl Fn() -> bool) {}
   |                         ^^^^ required by this bound in `call`
```

```
error[E0271]: expected `{closure@f670.rs:28:13}` to be a closure that returns `Result<(), _>`, but it returns `!`
    --> f670.rs:28:20
     |
28   |     let c = |e| -> ! {
     |             -------^
     |                    |
     |                    expected `Result<(), _>`, found `!`
...
32   |     f().or_else(c);
     |         ------- required by a bound introduced by this call
-Ztrack-diagnostics: created at compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs:1433:28
     |
     = note: expected enum `Result<(), _>`
                found type `!`
note: required by a bound in `Result::<T, E>::or_else`
    --> /home/gh-estebank/rust/library/core/src/result.rs:1406:39
     |
1406 |     pub fn or_else<F, O: FnOnce(E) -> Result<T, F>>(self, op: O) -> Result<T, F> {
     |                                       ^^^^^^^^^^^^ required by this bound in `Result::<T, E>::or_else`
```

CC #111539.
2025-01-31 00:26:29 -05:00
Jacob Pratt
55512db4aa
Rollup merge of #136291 - lcnr:compare-mode, r=oli-obk
some test suite cleanups

found while checking `compare-mode next-solver`

r? `@oli-obk`

<sub> [lcnr](https://github.com/rust-lang/rust/commits?author=lcnr) authored and JJ_EMPTY_STRING committed </sub>
2025-01-31 00:25:38 -05:00
Jacob Pratt
b87df231c5
Rollup merge of #136287 - zmodem:nocapture, r=nikic
LLVM changed the nocapture attribute to captures(none)

This updates RustWrapper.cpp and tests after
https://github.com/llvm/llvm-project/pull/123181
2025-01-31 00:25:37 -05:00
Jacob Pratt
1a5ebc9e52
Rollup merge of #136258 - notriddle:notriddle/issue-d, r=fmease
rustdoc: rename `issue-\d+.rs` tests to have meaningful names (part 11)

Follow up

* https://github.com/rust-lang/rust/pull/134053
* https://github.com/rust-lang/rust/pull/130287

et al

As always, it's easier to review the commits one at a time. Don't use the Files Changed tab. It's confusing.
2025-01-31 00:25:35 -05:00
许杰友 Jieyou Xu (Joe)
9734ebb9be tests: port symbol-mangling-hashed to rmake.rs
- Use `object` based test logic instead of processing `nm`
  human-readable textual output.
- Try to expand test coverage to not be limited to only linux + x86_64.

Co-authored-by: binarycat <binarycat@envs.net>
2025-01-31 04:30:51 +00:00
bors
c37fbd873a Auto merge of #135318 - compiler-errors:vtable-fixes, r=lcnr
Fix deduplication mismatches in vtables leading to upcasting unsoundness

We currently have two cases where subtleties in supertraits can trigger disagreements in the vtable layout, e.g. leading to a different vtable layout being accessed at a callsite compared to what was prepared during unsizing. Namely:

### #135315

In this example, we were not normalizing supertraits when preparing vtables. In the example,

```
trait Supertrait<T> {
    fn _print_numbers(&self, mem: &[usize; 100]) {
        println!("{mem:?}");
    }
}
impl<T> Supertrait<T> for () {}

trait Identity {
    type Selff;
}
impl<Selff> Identity for Selff {
    type Selff = Selff;
}

trait Middle<T>: Supertrait<()> + Supertrait<T> {
    fn say_hello(&self, _: &usize) {
        println!("Hello!");
    }
}
impl<T> Middle<T> for () {}

trait Trait: Middle<<() as Identity>::Selff> {}
impl Trait for () {}

fn main() {
    (&() as &dyn Trait as &dyn Middle<()>).say_hello(&0);
}
```

When we prepare `dyn Trait`, we see a supertrait of `Middle<<() as Identity>::Selff>`, which itself has two supertraits `Supertrait<()>` and `Supertrait<<() as Identity>::Selff>`. These two supertraits are identical, but they are not duplicated because we were using structural equality and *not* considering normalization. This leads to a vtable layout with two trait pointers.

When we upcast to `dyn Middle<()>`, those two supertraits are now the same, leading to a vtable layout with only one trait pointer. This leads to an offset error, and we call the wrong method.

### #135316

This one is a bit more interesting, and is the bulk of the changes in this PR. It's a bit similar, except it uses binder equality instead of normalization to make the compiler get confused about two vtable layouts. In the example,

```
trait Supertrait<T> {
    fn _print_numbers(&self, mem: &[usize; 100]) {
        println!("{mem:?}");
    }
}
impl<T> Supertrait<T> for () {}

trait Trait<T, U>: Supertrait<T> + Supertrait<U> {
    fn say_hello(&self, _: &usize) {
        println!("Hello!");
    }
}
impl<T, U> Trait<T, U> for () {}

fn main() {
    (&() as &'static dyn for<'a> Trait<&'static (), &'a ()>
        as &'static dyn Trait<&'static (), &'static ()>)
        .say_hello(&0);
}
```

When we prepare the vtable for `dyn for<'a> Trait<&'static (), &'a ()>`, we currently consider the PolyTraitRef of the vtable as the key for a supertrait. This leads two two supertraits -- `Supertrait<&'static ()>` and `for<'a> Supertrait<&'a ()>`.

However, we can upcast[^up] without offsetting the vtable from `dyn for<'a> Trait<&'static (), &'a ()>` to `dyn Trait<&'static (), &'static ()>`. This is just instantiating the principal trait ref for a specific `'a = 'static`. However, when considering those supertraits, we now have only one distinct supertrait -- `Supertrait<&'static ()>` (which is deduplicated since there are two supertraits with the same substitutions). This leads to similar offsetting issues, leading to the wrong method being called.

[^up]: I say upcast but this is a cast that is allowed on stable, since it's not changing the vtable at all, just instantiating the binder of the principal trait ref for some lifetime.

The solution here is to recognize that a vtable isn't really meaningfully higher ranked, and to just treat a vtable as corresponding to a `TraitRef` so we can do this deduplication more faithfully. That is to say, the vtable for `dyn for<'a> Tr<'a>` and `dyn Tr<'x>` are always identical, since they both would correspond to a set of free regions on an impl... Do note that `Tr<for<'a> fn(&'a ())>` and `Tr<fn(&'static ())>` are still distinct.

----

There's a bit more that can be cleaned up. In codegen, we can stop using `PolyExistentialTraitRef` basically everywhere. We can also fix SMIR to stop storing `PolyExistentialTraitRef` in its vtable allocations.

As for testing, it's difficult to actually turn this into something that can be tested with `rustc_dump_vtable`, since having multiple supertraits that are identical is a recipe for ambiguity errors. Maybe someone else is more creative with getting that attr to work, since the tests I added being run-pass tests is a bit unsatisfying. Miri also doesn't help here, since it doesn't really generate vtables that are offset by an index in the same way as codegen.

r? `@lcnr` for the vibe check? Or reassign, idk. Maybe let's talk about whether this makes sense.

<sup>(I guess an alternative would also be to not do any deduplication of vtable supertraits (or only a really conservative subset) rather than trying to normalize and deduplicate more faithfully here. Not sure if that works and is sufficient tho.)</sup>

cc `@steffahn` -- ty for the minimizations
cc `@WaffleLapkin` -- since you're overseeing the feature stabilization :3

Fixes #135315
Fixes #135316
2025-01-31 04:09:11 +00:00
Michael Goulet
d6e8c7f7a0 Delay a bug when indexing unsized slices 2025-01-31 00:12:09 +00:00
bors
6c1d960d88 Auto merge of #136318 - matthiaskrgr:rollup-a159mzo, r=matthiaskrgr
Rollup of 9 pull requests

Successful merges:

 - #135026 (Cast global variables to default address space)
 - #135475 (uefi: Implement path)
 - #135852 (Add `AsyncFn*` to `core` prelude)
 - #136004 (tests: Skip const OOM tests on aarch64-unknown-linux-gnu)
 - #136157 (override build profile for bootstrap tests)
 - #136180 (Introduce a wrapper for "typed valtrees" and properly check the type before extracting the value)
 - #136256 (Add release notes for 1.84.1)
 - #136271 (Remove minor future footgun in `impl Debug for MaybeUninit`)
 - #136288 (Improve documentation for file locking)

r? `@ghost`
`@rustbot` modify labels: rollup
2025-01-30 23:11:38 +00:00
bors
a730edcd67 Auto merge of #135030 - Flakebi:require-cpu, r=workingjubilee
Target option to require explicit cpu

Some targets have many different CPUs and no generic CPU that can be used as a default. For these targets, the user needs to explicitly specify a CPU through `-C target-cpu=`.

Add an option for targets and an error message if no CPU is set.

This affects the proposed amdgpu and avr targets.

amdgpu tracking issue: #135024
AVR MCP: https://github.com/rust-lang/compiler-team/issues/800
2025-01-30 20:21:50 +00:00
Matthias Krüger
6a66a270b0
Rollup merge of #136180 - lukas-code:typed-valtree, r=oli-obk
Introduce a wrapper for "typed valtrees" and properly check the type before extracting the value

This PR adds a new wrapper type `ty::Value` to replace the tuple `(Ty, ty::ValTree)` and become the new canonical representation of type-level constant values.

The value extraction methods `try_to_bits`/`try_to_bool`/`try_to_target_usize` are moved to this new type. For `try_to_bits` in particular, this avoids some redundant matches on `ty::ConstKind::Value`. Furthermore, these methods and will now properly check the type before extracting the value, which fixes some ICEs.

The name `ty::Value` was chosen to be consistent with `ty::Expr`.

Commit 1 should be non-functional and commit 2 adds the type check.

---

fixes https://github.com/rust-lang/rust/issues/131102
supercedes https://github.com/rust-lang/rust/pull/136130

r? `@oli-obk`
cc `@FedericoBruzzone` `@BoxyUwU`
2025-01-30 20:47:07 +01:00
Matthias Krüger
47ee068a88
Rollup merge of #136004 - mrkajetanp:aarch64-skip-large-const-alloc-tests, r=Kobzol
tests: Skip const OOM tests on aarch64-unknown-linux-gnu

Skip const OOM tests on AArch64 Linux through explicit annotations instead of inside opt-dist.
Intended to avoid confusion in cases like #135952.

Prerequisite for https://github.com/rust-lang/rust/pull/135960.

 r? `@Kobzol`
cc `@workingjubilee`

try-job: dist-aarch64-linux
2025-01-30 20:47:06 +01:00
Michael Howell
c17d5689da
Direct link 108459 to issues -> pull redirect 2025-01-30 12:09:33 -07:00
Michael Howell
a1a55a2e0a Give 104145, 103463, and 31948 more descriptive names 2025-01-30 12:05:31 -07:00
Michael Goulet
88d7ea36e9 Filter out RPITITs when suggesting unconstrained assoc type on too many generics 2025-01-30 18:51:49 +00:00
Michael Goulet
c64038a51f Use proper type when applying deref adjustment in const 2025-01-30 18:44:12 +00:00
Esteban Küber
87d323c81e Add closure labels 2025-01-30 18:38:42 +00:00