Move format_args!() into AST (and expand it during AST lowering)
Implements https://github.com/rust-lang/compiler-team/issues/541
This moves FormatArgs from rustc_builtin_macros to rustc_ast_lowering. For now, the end result is the same. But this allows for future changes to do smarter things with format_args!(). It also allows Clippy to directly access the ast::FormatArgs, making things a lot easier.
This change turns the format args types into lang items. The builtin macro used to refer to them by their path. After this change, the path is no longer relevant, making it easier to make changes in `core`.
This updates clippy to use the new language items, but this doesn't yet make clippy use the ast::FormatArgs structure that's now available. That should be done after this is merged.
Transform async `ResumeTy` in generator transform
- Eliminates all the `get_context` calls that async lowering created.
- Replace all `Local` `ResumeTy` types with `&mut Context<'_>`.
The `Local`s that have their types replaced are:
- The `resume` argument itself.
- The argument to `get_context`.
- The yielded value of a `yield`.
The `ResumeTy` hides a `&mut Context<'_>` behind an unsafe raw pointer, and the `get_context` function is being used to convert that back to a `&mut Context<'_>`.
Ideally the async lowering would not use the `ResumeTy`/`get_context` indirection, but rather directly use `&mut Context<'_>`, however that would currently lead to higher-kinded lifetime errors.
See <https://github.com/rust-lang/rust/issues/105501>.
The async lowering step and the type / lifetime inference / checking are still using the `ResumeTy` indirection for the time being, and that indirection is removed here. After this transform, the generator body only knows about `&mut Context<'_>`.
---
Fixes https://github.com/bjorn3/rustc_codegen_cranelift/issues/1330 CC `@bjorn3`
r? `@compiler-errors`
- Eliminates all the `get_context` calls that async lowering created.
- Replace all `Local` `ResumeTy` types with `&mut Context<'_>`.
The `Local`s that have their types replaced are:
- The `resume` argument itself.
- The argument to `get_context`.
- The yielded value of a `yield`.
The `ResumeTy` hides a `&mut Context<'_>` behind an unsafe raw pointer, and the
`get_context` function is being used to convert that back to a `&mut Context<'_>`.
Ideally the async lowering would not use the `ResumeTy`/`get_context` indirection,
but rather directly use `&mut Context<'_>`, however that would currently
lead to higher-kinded lifetime errors.
See <https://github.com/rust-lang/rust/issues/105501>.
The async lowering step and the type / lifetime inference / checking are
still using the `ResumeTy` indirection for the time being, and that indirection
is removed here. After this transform, the generator body only knows about `&mut Context<'_>`.
Various cleanups around pre-TyCtxt queries and functions
part of #105462
based on https://github.com/rust-lang/rust/pull/106776 (everything starting at [0e2b39f](0e2b39fd1f) is new in this PR)
r? `@petrochenkov`
I think this should be most of the uncontroversial part of #105462.
Remove duplicate sha-1 dependency
[`sha-1`](https://crates.io/crates/sha-1) is more or less a duplicate of [`sha1`](https://crates.io/crates/sha1). The `sha-1` is deprecated and no longer updated. This updates the dependencies to use the new name.
Some other dependencies that got updated as a consequence:
* The updated pest dependencies are currently only used by mdbook, and shouldn't have any issues.
* ucd-trie 0.1.3 to 0.1.5: No changelog, but looks like some tables were updated for new unicode versions: https://github.com/BurntSushi/ucd-generate/commits/master/ucd-trie. This is only used by pest (and thus mdbook).
* thiserror 1.33 to 1.38: Nothing significant in the notes at https://github.com/dtolnay/thiserror/releases.
Convert all the crates that have had their diagnostic migration
completed (except save_analysis because that will be deleted soon and
apfloat because of the licensing problem).
Encode spans relative to the enclosing item -- enable on nightly
Follow-up to #84373 with the flag `-Zincremental-relative-spans` set by default.
This PR seeks to remove one of the main shortcomings of incremental: the handling of spans.
Changing the contents of a function may require redoing part of the compilation process for another function in another file because of span information is changed.
Within one file: all the spans in HIR change, so typechecking had to be re-done.
Between files: spans of associated types/consts/functions change, so type-based resolution needs to be re-done (hygiene information is stored in the span).
The flag `-Zincremental-relative-spans` encodes local spans relative to the span of an item, stored inside the `source_span` query.
Trap: stashed diagnostics are referenced by the "raw" span, so stealing them requires to remove the span's parent.
In order to avoid too much traffic in the span interner, span encoding uses the `ctxt_or_tag` field to encode:
- the parent when the `SyntaxContext` is 0;
- the `SyntaxContext` when the parent is `None`.
Even with this, the PR creates a lot of traffic to the Span interner, when a Span has both a LocalDefId parent and a non-root SyntaxContext. They appear in lowering, when we add a parent to all spans, including those which come from macros, and during inlining when we mark inlined spans.
The last commit changes how queries of `LocalDefId` manage their cache. I can put this in a separate PR if required.
Possible future directions:
- validate that all spans are marked in HIR validation;
- mark macro-expanded spans relative to the def-site and not the use-site.
Revert "Implement allow-by-default `multiple_supertrait_upcastable` lint"
This is a clean revert of #105484.
I confirmed that reverting that PR fixes the regression reported in #106247. ~~I can't say I understand what this code is doing, but maybe it can be re-landed with a different implementation.~~ **Edit:** https://github.com/rust-lang/rust/issues/106247#issuecomment-1367174384 has an explanation of why #105484 ends up surfacing spurious `where_clause_object_safety` errors. The implementation of `where_clause_object_safety` assumes we only check whether a trait is object safe when somebody actually uses that trait with `dyn`. However the implementation of `multiple_supertrait_upcastable` added in the problematic PR involves checking *every* trait for whether it is object-safe.
FYI `@nbdd0121` `@compiler-errors`
Improve heuristics whether `format_args` string is a source literal
Previously, it only checked whether there was _a_ literal at the span of the first argument, not whether the literal actually matched up. This caused issues when a proc macro was generating a different literal with the same span.
This requires an annoying special case for literals ending in `\n` because otherwise `println` wouldn't give detailed diagnostics anymore which would be bad.
Fixes#106191
Implement allow-by-default `multiple_supertrait_upcastable` lint
The lint detects when an object-safe trait has multiple supertraits.
Enabled in libcore and liballoc as they are low-level enough that many embedded programs will use them.
r? `@nikomatsakis`
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
