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.
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.
This removes the `custom` format functionality as its only user was
trivially migrated to using a normal format.
If a new use case for a custom formatting impl pops up, you can add it
back.
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>
Cleanup macro-expanded code in `rustc_type_ir`
We could of course just leave this as-is, but every time I go-to-def to this file it's painful to see all this `(&A(ref __self_1_0),)` stuff.
Replaces using `ResumeTy` / `get_context` in favor of using `&'static mut Context<'_>`.
Usage of the `'static` lifetime here is technically "cheating", and replaces
the raw pointer in `ResumeTy` and the `get_context` fn that pulls the
correct lifetimes out of thin air.
Remove useless borrows and derefs
They are nothing more than noise.
<sub>These are not all of them, but my clippy started crashing (stack overflow), so rip :(</sub>
Add `type_ascribe!` macro as placeholder syntax for type ascription
This makes it still possible to test the internal semantics of type ascription even once the `:`-syntax is removed from the parser. The macro now gets used in a bunch of UI tests that test the semantics and not syntax of type ascription.
I might have forgotten a few tests but this should hopefully be most of them. The remaining ones will certainly be found once type ascription is removed from the parser altogether.
Part of #101728
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.
Remove redundant `all` in cfg
This appears to have been accidentally left in after removing the other branches 45bf1ed1a1
(hat tip to kangalioo for the git archaeology)
Previously, async constructs would be lowered to "normal" generators,
with an additional `from_generator` / `GenFuture` shim in between to
convert from `Generator` to `Future`.
The compiler will now special-case these generators internally so that
async constructs will *directly* implement `Future` without the need
to go through the `from_generator` / `GenFuture` shim.
The primary motivation for this change was hiding this implementation
detail in stack traces and debuginfo, but it can in theory also help
the optimizer as there is less abstractions to see through.
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")
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.
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.
Remove unused symbols and diagnostic items
As the title suggests, this removes unused symbols from `sym::` and `#[rustc_diagnostic_item]` annotations that weren't mentioned anywhere.
Originally I tried to use grep, to find symbols and item names that are never mentioned via `sym::name`, however this produced a lot of false positives (?), for example clippy matching on `Symbol::as_str` or macros "implicitly" adding `sym::`. I ended up fixing all these false positives (?) by hand, but tbh I'm not sure if it was worth it...
Add the `#[derive_const]` attribute
Closes#102371. This is a minimal patchset for the attribute to work. There are no restrictions on what traits this attribute applies to.
r? `````@oli-obk`````
Add support for custom mir
This implements rust-lang/compiler-team#564 . Details about the design, motivation, etc. can be found in there.
r? ```@oli-obk```
Avoid possible infinite loop when next_point reaching the end of file
Fixes#103451
If we return a span with `lo` = `hi`, `span_to_snippet` will always get `Ok("")`, which may introduce infinite loop if we don't care.
This PR make `find_width_of_character_at_span` return `width` with 1, so that `span_to_snippet` will get an `Err`.
Enable varargs support for calling conventions other than C or cdecl
This patch makes it possible to use varargs for calling conventions,
which are either based on C (efiapi) or C is based on them (sysv64 and win64).
Also pinging ``@phlopsi,`` because he noticed first this oversight when writing a library for UEFI.
Allow `impl Fn() -> impl Trait` in return position
_This was originally proposed as part of #93082 which was [closed](https://github.com/rust-lang/rust/pull/93082#issuecomment-1027225715) due to allowing `impl Fn() -> impl Trait` in argument position._
This allows writing the following function signatures:
```rust
fn f0() -> impl Fn() -> impl Trait;
fn f3() -> &'static dyn Fn() -> impl Trait;
```
These signatures were already allowed for common traits and associated types, there is no reason why `Fn*` traits should be special in this regard.
`impl Trait` in both `f0` and `f3` means "new existential type", just like with `-> impl Iterator<Item = impl Trait>` and such.
Arrow in `impl Fn() ->` is right-associative and binds from right to left, it's tested by [this test](a819fecb8d/src/test/ui/impl-trait/impl_fn_associativity.rs).
There even is a test that `f0` compiles:
2f004d2d40/src/test/ui/impl-trait/nested_impl_trait.rs (L25-L28)
But it was changed in [PR 48084 (lines)](https://github.com/rust-lang/rust/pull/48084/files#diff-ccecca938872d65ffe8cd1c3ef1956e309fac83bcda547d8b16b89257e53a437R37) to test the opposite, probably unintentionally given [PR 48084 (lines)](https://github.com/rust-lang/rust/pull/48084/files#diff-5a02f1ed43debed1fd24f7aad72490064f795b9420f15d847bac822aa4621a1cR476-R477).
r? `@nikomatsakis`
----
This limitation is especially annoying with async code, since it forces one to write this:
```rust
trait AsyncFn3<A, B, C>: Fn(A, B, C) -> <Self as AsyncFn3<A, B, C>>::Future {
type Future: Future<Output = Self::Out>;
type Out;
}
impl<A, B, C, Fut, F> AsyncFn3<A, B, C> for F
where
F: Fn(A, B, C) -> Fut,
Fut: Future,
{
type Future = Fut;
type Out = Fut::Output;
}
fn async_closure() -> impl AsyncFn3<i32, i32, i32, Out = u32> {
|a, b, c| async move { (a + b + c) as u32 }
}
```
Instead of:
```rust
fn async_closure() -> impl Fn(i32, i32, i32) -> impl Future<Output = u32> {
|a, b, c| async move { (a + b + c) as u32 }
}
```
Fix line numbers for MIR inlined code
`should_collapse_debuginfo` detects if the specified span is part of a
macro expansion however it does this by checking if the span is anything
other than a normal (non-expanded) kind, then the span sequence is
walked backwards to the root span.
This doesn't work when the MIR inliner inlines code as it creates spans
with expansion information set to `ExprKind::Inlined` and results in the
line number being attributed to the inline callsite rather than the
normal line number of the inlined code.
Fixes#103068
Shorten the `lookup_line` code slightly
The `match` looks like it's exactly the same as `checked_sub(1)`, so we might as well see if perf says we can just do that to save a couple lines.
This patch makes it possible to use varargs for calling conventions,
which are either based on C (like efiapi) or C is based
on them (for example sysv64 and win64).
Fix the bug of next_point in source_map
There is a bug in `next_point`, the new span won't move to next position when be called in the first time.
For this reason, our current code is working like this:
1. When we really want to move to the next position, we called two times of `next_point`
2. Some code which use `next_point` actually done the same thing with `shrink_to_hi`
This fix make sure when `next_point` is called, span will move with the width at least 1, and also work correctly in the scenario of multiple bytes.
Ref: https://github.com/rust-lang/rust/pull/103140#discussion_r997710998
r? `@davidtwco`
`should_collapse_debuginfo` detects if the specified span is part of a
macro expansion however it does this by checking if the span is anything
other than a normal (non-expanded) kind, then the span sequence is
walked backwards to the root span.
This doesn't work when the MIR inliner inlines code as it creates spans
with expansion information set to `ExprKind::Inlined` and results in the
line number being attributed to the inline callsite rather than the
normal line number of the inlined code.
Add missing documentation for FileNameDisplayPreference variants
Took me a while to find the information when I needed it so hopefully it should save some time for the next ones.
r? ``@thomcc``
Manually order `DefId` on 64-bit big-endian
`DefId` uses different field orders on 64-bit big-endian vs. others, in
order to optimize its `Hash` implementation. However, that also made it
derive different lexical ordering for `PartialOrd` and `Ord`. That
caused spurious differences wherever `DefId`s are sorted, like the
candidate sources list in `report_method_error`.
Now we manually implement `PartialOrd` and `Ord` on 64-bit big-endian to
match the same lexical ordering as other targets, fixing at least one
test, `src/test/ui/methods/method-ambig-two-traits-cross-crate.rs`.
Add `#[rustc_safe_intrinsic]`
This PR adds the `#[rustc_safe_intrinsic]` attribute as mentionned on Zulip. The goal of this attribute is to avoid keeping a list of symbols as the source for stable intrinsics, and instead rely on an attribute. This is similar to `#[rustc_const_stable]` and `#[rustc_const_unstable]`, which among other things, are used to mark the constness of intrinsic functions.
Rollup of 8 pull requests
Successful merges:
- #100747 (Add long description and test for E0311)
- #102232 (Stabilize bench_black_box)
- #102288 (Suggest unwrapping `???<T>` if a method cannot be found on it but is present on `T`.)
- #102338 (Deny associated type bindings within associated type bindings)
- #102347 (Unescaping cleanups)
- #102348 (Tweak `FulfillProcessor`.)
- #102378 (Use already resolved `self_ty` in `confirm_fn_pointer_candidate`)
- #102380 (rustdoc: remove redundant mobile `.source > .sidebar` CSS)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
`DefId` uses different field orders on 64-bit big-endian vs. others, in
order to optimize its `Hash` implementation. However, that also made it
derive different lexical ordering for `PartialOrd` and `Ord`. That
caused spurious differences wherever `DefId`s are sorted, like the
candidate sources list in `report_method_error`.
Now we manually implement `PartialOrd` and `Ord` on 64-bit big-endian to
match the same lexical ordering as other targets, fixing at least one
test, `src/test/ui/methods/method-ambig-two-traits-cross-crate.rs`.
Split out async_fn_in_trait into a separate feature
PR #101224 added support for async fn in trait desuraging behind the `return_position_impl_trait_in_trait` feature.
Split this out so that it's behind its own feature gate, since async fn in trait doesn't need to follow the same stabilization schedule.
Inline SyntaxContext in both encoded span representation.
The current interned representation for spans does not use the `ctxt_or_zero: u16` field. This PR proposes to use this field to store the `SyntaxContext` of the interned span instead. When `ctxt_or_zero` and the interned span's `ctxt` don't match, the inlined one takes precedence.
This allows to implement `Span::ctxt` and `Span::with_ctxt` with much less probability to access the interner. Those functions are used a lot for hygiene, so this may be worth it.
use partition_point instead of binary_search when looking up source lines
In local benchmarks this results in 0.4% fewer cycles in a critical sequential section when compiling libcore.
