try_question_mark_nop: update test for LLVM 20
llvm/llvm-project@dd116369f6 changes the IR of this test in a way that I don't think is bad, but needs adjusting.
r? `@nikic`
`@rustbot` label: +llvm-main
pointee_info_at: fix logic for recursing into enums
Fixes https://github.com/rust-lang/rust/issues/131834
The logic in `pointee_info_at` was likely written at a time when the null pointer optimization was the *only* enum layout optimization -- and as `Variant::Multiple` kept getting expanded, nobody noticed that the logic is now unsound.
The job of this function is to figure out whether there is a dereferenceable-or-null and aligned pointer at a given offset inside a type. So when we recurse into a multi-variant enum, we better make sure that all the other enum variants must be null! This is the part that was forgotten, and this PR adds it.
The reason this didn't explode in many ways so far is that our references only have 1 niche value (null), so it's not possible on stable to have a multi-variant enum with a dereferenceable pointer and other enum variants that are not null. But with `rustc_layout_scalar_valid_range` attributes one can force such a layout, and if `@the8472's` work on alignment niches ever lands, that will make this possible on stable.
Trim and tidy includes in `rustc_llvm`
These includes tend to accumulate over time, and are usually only removed when something breaks in a new LLVM version, so it's nice to clean them up manually once in a while.
General strategy used for this PR:
- Remove all includes from `LLVMWrapper.h` that aren't needed by the header itself, transplanting them to individual source files as necessary.
- For each source file, temporarily remove each include if doing so doesn't cause a compile error.
- If a “required” include looks like it shouldn't be needed, try replacing it with its sub-includes, then trim that list.
- After doing all of the above, go back and re-add any removed include if the file does actually use things defined in that header, even if the header happens to also be included by something else.
use verbose for path separator suggestion
A single `-` of suggestion underlining that is adjacent to a much more significant `^^^` underlying of the LHS path component is hard to distinguish. IMO this presents much more cleanly when it's verbose, especially because it's a *replacment* suggestion.
r? estebank
Don't suggest `.into_iter()` on iterators
This makes the the suggestion to call `.into_iter()` only consider unsatisfied `Iterator` bounds for the receiver type itself. That way, it ignores predicates generated by trying to auto-ref the receiver (the result of which usually won't implement `Iterator`).
Fixes#127511
Unfortunately, the error in that case is still confusing: it labels `Iterator` as an unsatisfied bound because `&impl Iterator: Iterator` can't be satisfied, despite that not being required or helpful. I'd like to handle that in a separate PR. ~~I'm hoping fixing #124802 will fix it too.~~ It doesn't look connected to that issue. Still, I think it'd be clearest to visually distinguish unsatisfied predicates from different attempts at `pick_method`; I'll make a PR for that soon.
Get rid of `check_opaque_type_well_formed`
Instead, replicate it by improving the span of the opaque in `check_opaque_meets_bounds`.
This has two consequences:
1. We now prefer "concrete type differs" errors, since we'll hit those first before we check the opaque is WF.
2. Spans have gotten slightly worse.
Specifically, (2.) could be improved by adding a new obligation cause that explains that the definition's environment has stronger assumptions than the declaration.
r? lcnr
Make `RustString` an extern type to avoid `improper_ctypes` warnings
Currently, any FFI function that uses `&RustString` needs to also add `#[ignore(improper_ctypes)]` to silence a warning.
The warning is not _completely_ bogus, because `RustString` contains `Vec<u8>` and therefore does not have a guaranteed layout. But we have no way of telling the lint that this doesn't matter, because the C++ code only uses that pointer opaquely and never relies on its underlying layout.
Ideally there would be some way to silence `improper_ctypes` at the type-definition site. But because there isn't, casting to and from a separate extern type is better than having to annotate every single use site.
On arm64, Cranelift used to produce object files that don't work with
lld. This has since been fixed. The GCC backend should always produce
object files that work with lld unless lld for whatever reason drops GCC
support. Most of the other more niche backends don't use cg_ssa's linker
code at all. If they do and don't work with lld, they can always disable
lld usage using a cli argument.
Without this commit using cg_clif is by default in a non-trivial amount
of cases a perf regression on Linux due to ld.bfd being a fair bit
slower than lld. It is possible to explicitly enable it without this
commit, but most users are unlikely to do this.
"whenever possible" means applying it if `download-rustc` isn't explicitly set and
the source is Git-managed.
Signed-off-by: onur-ozkan <work@onurozkan.dev>
remove support for rustc_safe_intrinsic attribute; use rustc_intrinsic functions instead
This brings us one step closer towards removing support for `extern "rust-intrinsic"` blocks, in favor of `#[rustc_intrinsic]` functions.
Also move `#[rustc_intrinsic]` under the `intrinsics` feature gate, to match the `extern "rust-intrinsic"` style.
Functions currently can't have mappings in multiple files, and if that ever
changes (e.g. to properly support expansion regions), this code will need to be
completely overhauled anyway.
We already had a dedicated `LocalFileId` index type, but previously we used a
raw `u32` for global file IDs, because index types were harder to pass through
FFI.
