Miri/CTFE: properly treat overflow in (signed) division/rem as UB
To my surprise, it looks like LLVM treats overflow of signed div/rem as UB. From what I can tell, MIR `Div`/`Rem` directly lowers to the corresponding LLVM operation, so to make that correct we also have to consider these overflows UB in the CTFE/Miri interpreter engine.
r? `@oli-obk`
Remove out-of-context line at end of E0284 message
Removed the last line of E0284 message because it was out of context (probably kept by accident when changing whole error message).
Restore the local filter on mono item sorting
In `CodegenUnit::items_in_deterministic_order`, there's a comment that
only local HirIds should be taken into account, but #90408 removed the
`as_local` call that sets others to None. Restoring that check fixes the
s390x hangs seen in [RHBZ 2058803].
[RHBZ 2058803]: https://bugzilla.redhat.com/show_bug.cgi?id=2058803
Improve allowness of the unexpected_cfgs lint
This pull-request improve the allowness (`#[allow(...)]`) of the `unexpected_cfgs` lint.
Before this PR only crate level `#![allow(unexpected_cfgs)]` worked, now with this PR it also work when put around `cfg!` or if it is in a upper level. Making it work ~for the attributes `cfg`, `cfg_attr`, ...~ for the same level is awkward as the current code is design to give "Some parent node that is close to this macro call" (cf. https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/base/struct.ExpansionData.html) meaning that allow on the same line as an attribute won't work. I'm note even sure if this would be possible.
Found while working on https://github.com/rust-lang/rust/pull/94298.
r? ````````@petrochenkov````````
Adt copy suggestions
Previously we've only suggested adding `Copy` bounds when the type being moved/copied is a type parameter (generic). With this PR we also suggest adding bounds when a type
- Can be copy
- All predicates that need to be satisfied for that are based on type params
i.e. we will suggest `T: Copy` for `Option<T>`, but won't suggest anything for `Option<String>`.
An example:
```rust
fn duplicate<T>(t: Option<T>) -> (Option<T>, Option<T>) {
(t, t)
}
```
New error (current compiler doesn't provide `help`:):
```text
error[E0382]: use of moved value: `t`
--> t.rs:2:9
|
1 | fn duplicate<T>(t: Option<T>) -> (Option<T>, Option<T>) {
| - move occurs because `t` has type `Option<T>`, which does not implement the `Copy` trait
2 | (t, t)
| - ^ value used here after move
| |
| value moved here
|
help: consider restricting type parameter `T`
|
1 | fn duplicate<T: Copy>(t: Option<T>) -> (Option<T>, Option<T>) {
| ++++++
```
Fixes#93623
r? ``````````@estebank``````````
``````````@rustbot`````````` label +A-diagnostics +A-suggestion-diagnostics +C-enhancement
----
I'm not at all sure if this is the right implementation for this kind of suggestion, but it seems to work :')
Remove LLVM attribute removal
This was necessary before, because `declare_raw_fn` would always apply
the default optimization attributes to every declared function.
Then `attributes::from_fn_attrs` would have to remove the default
attributes in the case of, e.g. `#[optimize(speed)]` in a `-Os` build.
(see [`src/test/codegen/optimize-attr-1.rs`](03a8cc7df1/src/test/codegen/optimize-attr-1.rs (L33)))
However, every relevant callsite of `declare_raw_fn` (i.e. where we
actually generate code for the function, and not e.g. a call to an
intrinsic, where optimization attributes don't [?] matter)
calls `from_fn_attrs`, so we can remove the attribute setting
from `declare_raw_fn`, and rely on `from_fn_attrs` to apply the correct
attributes all at once.
r? `@ghost` (blocked on #94221)
`@rustbot` label S-blocked
Rollup of 9 pull requests
Successful merges:
- #94464 (Suggest adding a new lifetime parameter when two elided lifetimes should match up for traits and impls.)
- #94476 (7 - Make more use of `let_chains`)
- #94478 (Fix panic when handling intra doc links generated from macro)
- #94482 (compiler: fix some typos)
- #94490 (Update books)
- #94496 (tests: accept llvm intrinsic in align-checking test)
- #94498 (9 - Make more use of `let_chains`)
- #94503 (Provide C FFI types via core::ffi, not just in std)
- #94513 (update Miri)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Suggest adding a new lifetime parameter when two elided lifetimes should match up for traits and impls.
Suggest adding a new lifetime parameter when two elided lifetimes should match up for functions in traits and impls.
Issue #94462
Direct users towards using Rust target feature names in CLI
This PR consists of a couple of changes on how we handle target features.
In particular there is a bug-fix wherein we avoid passing through features that aren't prefixed by `+` or `-` to LLVM. These appear to be causing LLVM to assert, which is pretty poor a behaviour (and also makes it pretty clear we expect feature names to be prefixed).
The other commit, I anticipate to be somewhat more controversial is outputting a warning when users specify a LLVM-specific, or otherwise unknown, feature name on the CLI. In those situations we request users to either replace it with a known Rust feature name (e.g. `bmi` -> `bmi1`) or file a feature request. I've a couple motivations for this: first of all, if users are specifying these features on the command line, I'm pretty confident there is also a need for these features to be usable via `#[cfg(target_feature)]` machinery. And second, we're growing a fair number of backends recently and having ability to provide some sort of unified-ish interface in this place seems pretty useful to me.
Sponsored by: standard.ai
In `CodegenUnit::items_in_deterministic_order`, there's a comment that
only local HirIds should be taken into account, but #90408 removed the
`as_local` call that sets others to None. Restoring that check fixes the
s390x hangs seen in [RHBZ 2058803].
[RHBZ 2058803]: https://bugzilla.redhat.com/show_bug.cgi?id=2058803
Previously we've only suggested adding `Copy` bounds when the type being
moved/copied is a type parameter (generic). With this commit we also
suggest adding bounds when a type
- Can be copy
- All predicates that need to be satisfied for that are based on type
params
i.e. we will suggest `T: Copy` for `Option<T>`, but won't suggest
anything for `Option<String>`.
Future work: it would be nice to also suggest adding `.clone()` calls
Rollup of 3 pull requests
Successful merges:
- #94359 (Fix inconsistent symbol mangling of integers constants with -Zverbose)
- #94465 (6 - Make more use of `let_chains`)
- #94470 (⬆️ rust-analyzer)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix inconsistent symbol mangling of integers constants with -Zverbose
The `PrettyPrinter` changes formatting of array size and integer
constants based on `-Zverbose`, so its implementation cannot be used in
legacy symbol mangling.
Example symbol demangling before changes:
```console
$ cat a.rs
pub struct A<T>(T);
impl A<[u8; 128]> { pub fn f() {} }
$ rustc --crate-type=lib a.rs -Zverbose=n && nm -C ./liba.rlib
00000000 T a::A<[u8; 128]>::f
$ rustc --crate-type=lib a.rs -Zverbose=y && nm -C ./liba.rlib
00000000 T a::A<[u8; Const { ty. usize, val. Value(Scalar(0x0000000000000080)) }]>::f
```
Add `rustc_middle::ty::suggest_constraining_type_params` that suggests
adding multiple constraints.
`suggest_constraining_type_param` now just forwards params to this new
function.
Check method input expressions once
If the user mistakenly forgets to wrap their method args in a tuple, then the compiler tries to check that types within the tuple match the expression args. This means we call `check_expr` once within this diagnostic code, so when we check the expr once again in `demand_compatible`, we attempt to apply expr adjustments twice, leading to ICEs.
This PR attempts to fix this by skipping the expression type check in `demand_compatible` if we have detected an method arg mismatch at all.
This does lead to a single UI test regressing slightly, due to a diagnostic disappearing, though I don't know if it is generally meaningful to even raise an type error after noting that the argument count is incorrect in a function call, since the user might be providing (in-context) meaningless expressions to the wrong method.
I can adjust this to be a bit more targeted (to just skip checking exprs in `demand_compatible` in the tuple case) if this UI test regression is a problem.
fixes#94334
cc #94291
Also drive-by fixup of `.node_type(expr.hir_id)` to `.expr_ty(expr)`, since that method exists.
Lint against more useless `#[must_use]` attributes
This expands the existing `#[must_use]` check in `unused_attributes` to lint against pretty much everything `#[must_use]` doesn't support.
Fixes#93906.
Generalize "remove `&`" and "add `*`" suggestions to more than one deref
Suggest removing more than one `&` and `&mut`, along with suggesting adding more than one `*` (or a combination of the two).
r? `@estebank`
(since you're experienced with these types of suggestions, feel free to reassign)
If they are trying to use features rustc doesn't yet know about,
request a feature request.
Additionally, also warn against using feature names without leading `+`
or `-` signs.
Caching the stable hash of Ty within itself
Instead of computing stable hashes on types as needed, we compute it during interning.
This way we can, when a hash is requested, just hash that hash, which is significantly faster than traversing the type itself.
We only do this for incremental for now, as incremental is the only frequent user of stable hashing.
As a next step we can try out
* moving the hash and TypeFlags to Interner, so projections and regions get the same benefit (tho regions are not nested, so maybe that's not a good idea? Would be nice for dedup tho)
* start comparing types via their stable hash instead of their address?
The `PrettyPrinter` changes formatting of array size and integer
constants based on `-Zverbose`, so its implementation cannot be used in
legacy symbol mangling.
