Rename `assert_uninit_valid` intrinsic
It's not about "uninit" anymore but about "filling with 0x01 bytes" so the name should at least try to reflect that.
This is actually not fully correct though, as it does still panic for all uninit with `-Zstrict-init-checks`. I'm not sure what the best way is to deal with that not causing confusion. I guess we could just remove the flag? I don't think having it makes a lot of sense anymore with the direction that we have chose to go. It could be relevant again if #100423 lands so removing it may be a bit over eager.
r? `@RalfJung`
Improve syntax of `newtype_index`
This makes it more like proper Rust and also makes the implementation a lot simpler.
Mostly just turns weird flags in the body into proper attributes.
It should probably also be converted to an attribute macro instead of function-like, but that can be done in a future PR.
Add `IMPLIED_BOUNDS_ENTAILMENT` lint
Implements a lint (#105572) version of the hard-error introduced in #105483. Context is in that PR.
r? `@lcnr`
cc `@oli-obk` who had asked for this to be a lint first
Not sure if this needs to be an FCP, since it's a lint for now.
Remove the `..` from the body, only a few invocations used it and it's
inconsistent with rust syntax.
Use `;` instead of `,` between consts. As the Rust syntax gods inteded.
always use `anonymize_bound_vars`
Unless this is perf-sensitive, it's probably best to always use one anonymize function that does the right thing for all bound vars.
r? types
Ensure async trait impls are async (or otherwise return an opaque type)
As a workaround for the full `#[refine]` semantics not being implemented
yet, forbit returning a concrete future type like `Box<dyn Future>` or a
manually implemented Future.
`-> impl Future` is still permitted; while that can also cause
accidental refinement, that's behind a different feature gate
(`return_position_impl_trait_in_trait`) and that problem exists
regardless of whether the trait method is async, so will have to be
solved more generally.
Fixes https://github.com/rust-lang/rust/issues/102745
As a workaround for the full `#[refine]` semantics not being implemented
yet, forbit returning a concrete future type like `Box<dyn Future>` or a
manually implemented Future.
`-> impl Future` is still permitted; while that can also cause
accidental refinement, that's behind a different feature gate
(`return_position_impl_trait_in_trait`) and that problem exists
regardless of whether the trait method is async, so will have to be
solved more generally.
Fixes#102745
Combine `ty::Projection` and `ty::Opaque` into `ty::Alias`
Implements https://github.com/rust-lang/types-team/issues/79.
This PR consolidates `ty::Projection` and `ty::Opaque` into a single `ty::Alias`, with an `AliasKind` and `AliasTy` type (renamed from `ty::ProjectionTy`, which is the inner data of `ty::Projection`) defined as so:
```
enum AliasKind {
Projection,
Opaque,
}
struct AliasTy<'tcx> {
def_id: DefId,
substs: SubstsRef<'tcx>,
}
```
Since we don't have access to `TyCtxt` in type flags computation, and because repeatedly calling `DefKind` on the def-id is expensive, these two types are distinguished with `ty::AliasKind`, conveniently glob-imported into `ty::{Projection, Opaque}`. For example:
```diff
match ty.kind() {
- ty::Opaque(..) =>
+ ty::Alias(ty::Opaque, ..) => {}
_ => {}
}
```
This PR also consolidates match arms that treated `ty::Opaque` and `ty::Projection` identically.
r? `@ghost`
compiler: remove unnecessary imports and qualified paths
Some of these imports were necessary before Edition 2021, others were already in the prelude.
I hope it's fine that this PR is so spread-out across files :/
Add LLVM KCFI support to the Rust compiler
This PR adds LLVM Kernel Control Flow Integrity (KCFI) support to the Rust compiler. It initially provides forward-edge control flow protection for operating systems kernels for Rust-compiled code only by aggregating function pointers in groups identified by their return and parameter types. (See llvm/llvm-project@cff5bef.)
Forward-edge control flow protection for C or C++ and Rust -compiled code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code share the same virtual address space) will be provided in later work as part of this project by identifying C char and integer type uses at the time types are encoded (see Type metadata in the design document in the tracking issue #89653).
LLVM KCFI can be enabled with -Zsanitizer=kcfi.
Thank you again, `@bjorn3,` `@eddyb,` `@nagisa,` and `@ojeda,` for all the help!
This commit adds LLVM Kernel Control Flow Integrity (KCFI) support to
the Rust compiler. It initially provides forward-edge control flow
protection for operating systems kernels for Rust-compiled code only by
aggregating function pointers in groups identified by their return and
parameter types. (See llvm/llvm-project@cff5bef.)
Forward-edge control flow protection for C or C++ and Rust -compiled
code "mixed binaries" (i.e., for when C or C++ and Rust -compiled code
share the same virtual address space) will be provided in later work as
part of this project by identifying C char and integer type uses at the
time types are encoded (see Type metadata in the design document in the
tracking issue #89653).
LLVM KCFI can be enabled with -Zsanitizer=kcfi.
Co-authored-by: bjorn3 <17426603+bjorn3@users.noreply.github.com>
This ensures that the error is printed even for unused variables,
as well as unifying the handling between the LLVM and GCC backends.
This also fixes unusual behavior around exported Rust-defined variables
with linkage attributes. With the previous behavior, it appears to be
impossible to define such a variable such that it can actually be imported
and used by another crate. This is because on the importing side, the
variable is required to be a pointer, but on the exporting side, the
type checker rejects static variables of pointer type because they do
not implement `Sync`. Even if it were possible to import such a type, it
appears that code generation on the importing side would add an unexpected
additional level of pointer indirection, which would break type safety.
This highlighted that the semantics of linkage on Rust-defined variables
is different to linkage on foreign items. As such, we now model the
difference with two different codegen attributes: linkage for Rust-defined
variables, and import_linkage for foreign items.
This change gives semantics to the test
src/test/ui/linkage-attr/auxiliary/def_illtyped_external.rs which was
previously expected to fail to compile. Therefore, convert it into a
test that is expected to successfully compile.
The update to the GCC backend is speculative and untested.
Avoid some `InferCtxt::build` calls
Either because we're inside of an `InferCtxt` already, or because we're not in a place where we'd ever see inference vars.
r? types
Rollup of 6 pull requests
Successful merges:
- #101975 (Suggest to use . instead of :: when accessing a method of an object)
- #105141 (Fix ICE on invalid variable declarations in macro calls)
- #105224 (Properly substitute inherent associated types.)
- #105236 (Add regression test for #47814)
- #105247 (Use parent function WfCheckingContext to check RPITIT.)
- #105253 (Update a couple of rustbuild deps)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove drop order twist of && and || and make them associative
Previously a short circuiting binop chain (chain of && or ||s) would drop the temporaries created by the first element after all the other elements, and otherwise follow evaluation order. So `f(1).g() && f(2).g() && f(3).g() && f(4).g()` would drop the temporaries in the order `2,3,4,1`. This made `&&` and `||` non-associative regarding drop order. In other words, adding ()'s to the expression would change drop order: `f(1).g() && (f(2).g() && f(3).g()) && f(4).g()` for example would drop in the order `3,2,4,1`.
As, except for the bool result, there is no data returned by the sub-expressions of the short circuiting binops, we can safely discard of any temporaries created by the sub-expr. Previously, code was already putting the rhs's into terminating scopes, but missed it for the lhs's.
This commit addresses this "twist". We now also put the lhs into a terminating scope. The drop order of the above expressions becomes `1,2,3,4`.
There might be code relying on the current order, and therefore I'd recommend doing a crater run to gauge the impact. I'd argue that such code is already quite wonky as it is one `foo() &&` addition away from breaking. ~~For the impact, I don't expect any *build* failures, as the compiler gets strictly more tolerant: shortening the lifetime of temporaries only expands the list of programs the compiler accepts as valid. There might be *runtime* failures caused by this change however.~~ Edit: both build and runtime failures are possible, e.g. see the example provided by dtolnay [below](https://github.com/rust-lang/rust/pull/103293#issuecomment-1285341113). Edit2: the crater run has finished and [results](https://github.com/rust-lang/rust/pull/103293#issuecomment-1292275203) are that there is only one build failure which is easy to fix with a +/- 1 line diff.
I've included a testcase that now compiles thanks to this patch.
The breakage is also limited to drop order relative to conditionals in the && chain: that is, in code like this:
```Rust
let hello = foo().hi() && bar().world();
println!("hi");
```
we already drop the temporaries of `foo().hi()` before we reach "hi".
I'd ideally have this PR merged before let chains are stabilized. If this PR is taking too long, I'd love to have a more restricted version of this change limited to `&&`'s in let chains: the `&&`'s of such chains are quite special anyways as they accept `let` bindings, in there the `&&` is therefore more a part of the "if let chain" construct than a construct of its own.
Fixes#103107
Status: waiting on [this accepted FCP](https://github.com/rust-lang/rust/pull/103293#issuecomment-1293411354) finishing.
This avoids creation of a terminating scope in
chains that contain both && and ||, because
also there we know that a terminating scope is
not neccessary: all the chain members are already
in such terminating scopes.
Also add a mixed && / || test.
Previously a short circuiting && chain would drop the
first element after all the other elements, and otherwise
follow evaluation order, so code like:
f(1).g() && f(2).g() && f(3).g() && f(4).g()
would drop the temporaries in the order 2,3,4,1. This made
&& and || non-associative regarding drop order, so
adding ()'s to the expression would change drop order:
f(1).g() && (f(2).g() && f(3).g()) && f(4).g()
for example would drop in the order 3,2,4,1.
As, except for the bool result, there is no data returned
by the sub-expressions of the short circuiting binops,
we can safely discard of any temporaries created by the
sub-expr. Previously, code was already putting the rhs's
into terminating scopes, but missed it for the lhs's.
This commit addresses this "twist". In the expression,
we now also put the lhs into a terminating scope.
The drop order for the above expressions is 1,2,3,4
now.
Check lifetime param count in `collect_trait_impl_trait_tys`
We checked the type and const generics count, but not the lifetimes, which were handled in a different function.
Fixes#105154
Some initial normalization method changes
1. Rename `AtExt::normalize` to `QueryNormalizeExt::query_normalize` (using the `QueryNormalizer`)
2. Introduce `NormalizeExt::normalize` to replace `partially_normalize_associated_types_in` (using the `AssocTypeNormalizer`)
3. Rename `FnCtxt::normalize_associated_types_in` to `FnCtxt::normalize`
4. Remove some unused other normalization fns in `Inherited` and `FnCtxt`
Also includes one drive-by where we're no longer creating a `FnCtxt` inside of `check_fn`, but passing it in. This means we don't need such weird `FnCtxt` construction logic.
Stacked on top of #104835 for convenience.
r? types
Prefer doc comments over `//`-comments in compiler
Doc comments are generally nicer: they show up in the documentation, they are shown in IDEs when you hover other mentions of items, etc. Thus it makes sense to use them instead of `//`-comments.
Separate lifetime ident from lifetime resolution in HIR
Drive-by: change how suggested generic args are computed.
Fixes https://github.com/rust-lang/rust/issues/103815
I recommend reviewing commit-by-commit.
Use `as_deref` in compiler (but only where it makes sense)
This simplifies some code :3
(there are some changes that are not exacly `as_deref`, but more like "clever `Option`/`Result` method use")
Use `tcx.require_lang_item` instead of unwrapping lang items
I clearly remember esteban telling me that there is `require_lang_item` but he was from a phone atm and I couldn't find it, so I didn't use it. Stumbled on it today, so here we are :)
Remove a lifetime resolution hack from `compare_predicate_entailment`
This is not needed anymore, probably due to #102334 equating the function signatures fully in `collect_trait_impl_trait_tys`. Also, the assertion in in #102903 makes sure that this is actually fixed, so I'm pretty confident this isn't needed.
Rollup of 9 pull requests
Successful merges:
- #104420 (Fix doc example for `wrapping_abs`)
- #104499 (rustdoc JSON: Use `Function` everywhere and remove `Method`)
- #104500 (`rustc_ast`: remove `ref` patterns)
- #104511 (Mark functions created for `raw-dylib` on x86 with DllImport storage class)
- #104595 (Add `PolyExistentialPredicate` type alias)
- #104605 (deduplicate constant evaluation in cranelift backend)
- #104628 (Revert "Update CI to use Android NDK r25b")
- #104662 (Streamline deriving on packed structs.)
- #104667 (Revert formatting changes of a test)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Add `PolyExistentialPredicate` type alias
Wrapping `ExistentialPredicate`s in a binder is very common, and this alias already exists for the `PolyExistential{TraitRef,Projection}` types.
Support using `Self` or projections inside an RPIT/async fn
I reuse the same idea as https://github.com/rust-lang/rust/pull/103449 to use variances to encode whether a lifetime parameter is captured by impl-trait.
The current implementation of async and RPIT replace all lifetimes from the parent generics by `'static`. This PR changes the scheme
```rust
impl<'a> Foo<'a> {
fn foo<'b, T>() -> impl Into<Self> + 'b { ... }
}
opaque Foo::<'_a>::foo::<'_b, T>::opaque<'b>: Into<Foo<'_a>> + 'b;
impl<'a> Foo<'a> {
// OLD
fn foo<'b, T>() -> Foo::<'static>::foo::<'static, T>::opaque::<'b> { ... }
^^^^^^^ the `Self` becomes `Foo<'static>`
// NEW
fn foo<'b, T>() -> Foo::<'a>::foo::<'b, T>::opaque::<'b> { ... }
^^ the `Self` stays `Foo<'a>`
}
```
There is the same issue with projections. In the example, substitute `Self` by `<T as Trait<'b>>::Assoc` in the sugared version, and `Foo<'_a>` by `<T as Trait<'_b>>::Assoc` in the desugared one.
This allows to support `Self` in impl-trait, since we do not replace lifetimes by `'static` any more. The same trick allows to use projections like `T::Assoc` where `Self` is allowed. The feature is gated behind a `impl_trait_projections` feature gate.
The implementation relies on 2 tweaking rules for opaques in 2 places:
- we only relate substs that correspond to captured lifetimes during TypeRelation;
- we only list captured lifetimes in choice region computation.
For simplicity, I encoded the "capturedness" of lifetimes as a variance, `Bivariant` vs `Invariant` for unused vs captured lifetimes. The `variances_of` query used to ICE for opaques.
Impl-trait that do not reference `Self` or projections will have their variances as:
- `o` (invariant) for each parent type or const;
- `*` (bivariant) for each parent lifetime --> will not participate in borrowck;
- `o` (invariant) for each own lifetime.
Impl-trait that does reference `Self` and/or projections will have some parent lifetimes marked as `o` (as the example above), and participate in type relation and borrowck. In the example above, `variances_of(opaque) = ['_a: o, '_b: *, T: o, 'b: o]`.
r? types
cc `@compiler-errors` , as you asked about the issue with `Self` and projections.
Fix substraction with overflow in `wrong_number_of_generic_args.rs`
Fixes#104287
This issue happens in the `suggest_moving_args_from_assoc_fn_to_trait_for_qualified_path` function, which seems to run before the error checking facilities can catch an invalid use of generic arguments. Thus we get a subtraction with overflow because the code implicitly assumes that the source program makes sense (or is this assumption not true even if the program is correct?).
Rarranging the substration and equality check into an addition and an equality
check is sufficient.
Algebra is cool, isn't it?
Co-authored-by: Michael Goulet <michael@errs.io>
Improve spans for RPITIT object-safety errors
No reason why we can't point at the `impl Trait` that causes the object-safety violation.
Also [drive-by: Add is_async fn to hir::IsAsync](c4165f3a96), which touches clippy too.
Use `ErrorGuaranteed::unchecked_claim_error_was_emitted` less
there are only like 3 or 4 call sites left after this but it wasnt obvious to me how to remove them
nll: correctly deal with bivariance
fixes#104409
when in a bivariant context, relating stuff should always trivially succeed. Also changes the mir validator to correctly deal with higher ranked regions.
r? types cc ``@RalfJung``
Convert predicates into Predicate in the Obligation constructor
instead of having almost all callers do that.
This reduces a bit of boilerplate, and also paves the way for my work towards https://github.com/rust-lang/compiler-team/issues/531 (as it makes it easier to accept both goals and clauses where right now it only accepts predicates).
Don't remap early-bound regions for return-position `impl Trait` in trait originating from `impl`
long title 😓
We don't want to remap early-bound regions that originate from the `impl`s themselves, since they have no corresponding region in the trait. Not sure if there's a better condition than checking if the EBR's def-id's parent is the impl -- maybe we should be checking if the region comes from the method or RPITIT... 🤷
r? types
Fixes#103850
Record `LocalDefId` in HIR nodes instead of a side table
This is part of an attempt to remove the `HirId -> LocalDefId` table from HIR.
This attempt is a prerequisite to creation of `LocalDefId` after HIR lowering (https://github.com/rust-lang/rust/pull/96840), by controlling how `def_id` information is accessed.
This first part adds the information to HIR nodes themselves instead of a table.
The second part is https://github.com/rust-lang/rust/pull/103902
The third part will be to make `hir::Visitor::visit_fn` take a `LocalDefId` as last parameter.
The fourth part will be to completely remove the side table.
Respect visibility & stability of inherent associated types
As discussed in #103621, this probably won't be the final location of the code that resolves inherent associated types. Still, I think it's valuable to push correctness fixes for this feature (in regards to visibility and stability).
Let me know if I should write a translatable diagnostic instead and if I should move the tests to `privacy/` and `stability-attribute/` respectively.
Fixes#104243.
````@rustbot```` label A-visibility F-inherent_associated_types
r? ````@cjgillot```` (since you reviewed #103621, feel free to reroll though)
interpret: support for per-byte provenance
Also factors the provenance map into its own module.
The third commit does the same for the init mask. I can move it in a separate PR if you prefer.
Fixes https://github.com/rust-lang/miri/issues/2181
r? `@oli-obk`
Add `rustc_deny_explicit_impl`
Also adjust `E0322` error message to be more general, since it's used for `DiscriminantKind` and `Pointee` as well.
Also add `rustc_deny_explicit_impl` on the `Tuple` and `Destruct` marker traits.
