Less unsafe in `dangling`/`without_provenance`
This PR was inspired by the new `NonNull::without_provenance` (cc https://github.com/rust-lang/rust/issues/135243#issuecomment-2583913562) since it made me realize that we could write `NonNull::dangling` in completely-safe code using other existing things.
Then doing that led me to a few more places that could be simplified, like now that GVN will optimize Transmute-then-PtrToPtr, we can just implement `ptr::without_provenance` by calling `ptr::without_provenance_mut` since the shipped rlib of `core` ends up with the same single statement as the implementation (thanks to GVN merging the steps) and thus there's no need to duplicate the `transmute` -- and more importantly, no need to repeat a long safety comment.
There did end up being a couple of other changes needed to avoid exploding certain bits of MIR, though -- like `<Box<[i32]>>::default()`'s MIR originally got way worse as certain things didn't inline, or had a bunch of extraneous UbChecks -- so there's a couple of other changes to solve that.
tests: Port `extern-fn-reachable` to rmake.rs
Part of #121876.
## Summary
This PR ports `tests/run-make/extern-fn-reachable` to use `rmake.rs`. Notable changes:
- We now use the `object` crate and look at the exported symbols specifically.
- This test's coverage regressed against windows-msvc back in [replace dynamic library module with libloading #90716](https://github.com/rust-lang/rust/pull/90716), but since we use `object` now, we're able to claw the test coverage back.
- The checks are now stricter:
1. It no longer looks for substring symbol matches in `nm` textual outputs, it inspects the symbol names precisely.
2. We now also explicitly check for the presence of leading underscore in exported symbol names on apple vs non-apple targets.
- Added another case of `#[no_mangle] fn fun6() {}` (note the lack of `pub`) to check that Rust nameres visibility is orthogonal to symbol visibility in dylib.
## History
- Test was initially introduced as a run-pass[^run-pass] test as part of [Don't mark reachable extern fns as internal #10539](https://github.com/rust-lang/rust/pull/10539).
- Test re-introduced as a run-make test in https://github.com/rust-lang/rust/pull/13741.
- Later, the test coverage regressed in https://github.com/rust-lang/rust/pull/90716.
[^run-pass]: no longer a thing nowadays
Supersedes #128314.
Co-authored with `@lolbinarycat.`
try-job: x86_64-msvc
try-job: i686-msvc
try-job: i686-mingw
try-job: x86_64-mingw-1
try-job: x86_64-apple-1
try-job: aarch64-apple
try-job: test-various
```
error[E0308]: `if` and `else` have incompatible types
--> $DIR/if-else-chain-missing-else.rs:12:12
|
LL | let x = if let Ok(x) = res {
| ______________-
LL | | x
| | - expected because of this
LL | | } else if let Err(e) = res {
| | ____________^
LL | || return Err(e);
LL | || };
| || ^
| ||_____|
| |_____`if` and `else` have incompatible types
| expected `i32`, found `()`
|
= note: `if` expressions without `else` evaluate to `()`
= note: consider adding an `else` block that evaluates to the expected type
```
We probably want a longer explanation and fewer spans on this case.
Partially address #133316.
The amdgpu-kernel calling convention was reverted in commit
f6b21e90d1 due to inactivity in the amdgpu
target.
Introduce a `gpu-kernel` calling convention that translates to
`ptx_kernel` or `amdgpu_kernel`, depending on the target that rust
compiles for.
The amdgpu-kernel calling convention was reverted in commit
f6b21e90d1 due to inactivity in the amdgpu
target.
Introduce a `gpu-kernel` calling convention that translates to
`ptx_kernel` or `amdgpu_kernel`, depending on the target that rust
compiles for.
Rollup of 5 pull requests
Successful merges:
- #135497 (fix typo in typenames of pin documentation)
- #135522 (add incremental test for issue 135514)
- #135523 (const traits: remove some known-bug that do not seem to make sense)
- #135535 (Add GUI test for #135499)
- #135541 (Methods of const traits are const)
r? `@ghost`
`@rustbot` modify labels: rollup
const traits: remove some known-bug that do not seem to make sense
These tests were made to point to #103507 in https://github.com/rust-lang/rust/pull/114134; I think that was a mistake: that issue is about a rather specific problem, and most tests marked as known-bug in that PR are pointing at https://github.com/rust-lang/rust/issues/110395 which makes more sense.
Of the 4 tests that still point to #103507:
- One is [the original test](2088260852/tests/ui/impl-trait/normalize-tait-in-const.rs). It still fails to compile, though currently for unrelated reasons (`~const Fn` is not valid as that is not a const trait). I made it point at #110395 like all the other tests that were disabled when the previous const trait impl was removed.
- One is being fixed in https://github.com/rust-lang/rust/pull/135423
- The other two are fixed in this PR
The errors we are getting here are not great but they do look correct?
FWIW there are still a whole lot of tests mentioning #110395 despite that issue being closed... I hope someone is tracking that.^^
r? `@compiler-errors`
add incremental test for issue 135514
r? `@compiler-errors` as requested in https://github.com/rust-lang/rust/issues/135514#issuecomment-2591614811
This adds parts of `@steffahn's` repro as an incremental test for #135514. I had initially added the actual exploitation of the issue into the safe transmute, but removed it because it's not exactly needed for such a test. I can add it back if you'd like.
I've verified that the test fails with https://github.com/rust-lang/rust/pull/133828 reverted.
fix typo in typenames of pin documentation
I noticed this whilst reading the documentation for pin.
Basically there was just one to many closing angle brackets on the type parameters in the documentation where instead of being `Pin<&mut T>` it was `Pin<&mut T>>`
