Rollup of 10 pull requests
Successful merges:
- #96557 (Allow inline consts to reference generic params)
- #96590 (rustdoc: when running a function-signature search, tweak the tab bar)
- #96650 (Collect function instance used in `global_asm!` sym operand)
- #96733 (turn `append_place_to_string` from recursion into iteration)
- #96748 (Fixes reexports in search)
- #96752 (Put the incompatible_closure_captures lint messages in alphabetical order)
- #96754 (rustdoc: ensure HTML/JS side implementors don't have dups)
- #96772 (Suggest fully qualified path with appropriate params)
- #96776 (Fix two minor issues in hir.rs)
- #96782 (a small `mirror_expr` cleanup)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Fix two minor issues in hir.rs
I found these two places in hir.rs which could use a bit of improvements while going through the code.
No functional change.
Put the incompatible_closure_captures lint messages in alphabetical order
Looks like they were in hash order before, which was causing me trouble in #94598, so this PR sorts the errors by trait name.
turn `append_place_to_string` from recursion into iteration
This PR fixes the FIXME in the impl of `append_place_to_string` which turns `append_place_to_string` from recursion into iteration, meanwhile simplifying the code relatively.
Collect function instance used in `global_asm!` sym operand
The constants used in SymFn operands have FnDef type,
so the type of the constant identifies the function.
Fixes#96623.
Allow inline consts to reference generic params
Tracking issue: #76001
The RFC says that inline consts cannot reference to generic parameters (for now), same as array length expressions. And expresses that it's desirable for it to reference in-scope generics, when array length expressions gain that feature as well.
However it is possible to implement this for inline consts before doing this for all anon consts, because inline consts are only used as values and they won't be used in the type system. So we can have:
```rust
fn foo<T>() {
let x = [4i32; std::mem::size_of::<T>()]; // NOT ALLOWED (for now)
let x = const { std::mem::size_of::<T>() }; // ALLOWED with this PR!
let x = [4i32; const { std::mem::size_of::<T>() }]; // NOT ALLOWED (for now)
}
```
This would make inline consts super useful for compile-time checks and assertions:
```rust
fn assert_zst<T>() {
const { assert!(std::mem::size_of::<T>() == 0) };
}
```
This would create an error during monomorphization when `assert_zst` is instantiated with non-ZST `T`s. A error during mono might sound scary, but this is exactly what a "desugared" inline const would do:
```rust
fn assert_zst<T>() {
struct F<T>(T);
impl<T> F<T> {
const V: () = assert!(std::mem::size_of::<T>() == 0);
}
let _ = F::<T>::V;
}
```
It should also be noted that the current inline const implementation can already reference the type params via type inference, so this resolver-level restriction is not any useful either:
```rust
fn foo<T>() -> usize {
let (_, size): (PhantomData<T>, usize) = const {
const fn my_size_of<T>() -> (PhantomData<T>, usize) {
(PhantomData, std::mem::size_of::<T>())
}
my_size_of()
};
size
}
```
```@rustbot``` label: F-inline_const
Fixing #95444 by only displaying passes that take more than 5 millise…
As discussed in #95444, I have added the code to test and only display prints that are greater than 5 milliseconds.
r? `@jyn514`
Remove mutable_borrow_reservation_conflict lint and allow the code pattern
This was the only breaking issue with the NLL stabilization PR. Lang team decided to go ahead and allow this.
r? `@nikomatsakis`
Closes#59159Closes#56254
Add a dedicated length-prefixing method to `Hasher`
This accomplishes two main goals:
- Make it clear who is responsible for prefix-freedom, including how they should do it
- Make it feasible for a `Hasher` that *doesn't* care about Hash-DoS resistance to get better performance by not hashing lengths
This does not change rustc-hash, since that's in an external crate, but that could potentially use it in future.
Fixes#94026
r? rust-lang/libs
---
The core of this change is the following two new methods on `Hasher`:
```rust
pub trait Hasher {
/// Writes a length prefix into this hasher, as part of being prefix-free.
///
/// If you're implementing [`Hash`] for a custom collection, call this before
/// writing its contents to this `Hasher`. That way
/// `(collection![1, 2, 3], collection![4, 5])` and
/// `(collection![1, 2], collection![3, 4, 5])` will provide different
/// sequences of values to the `Hasher`
///
/// The `impl<T> Hash for [T]` includes a call to this method, so if you're
/// hashing a slice (or array or vector) via its `Hash::hash` method,
/// you should **not** call this yourself.
///
/// This method is only for providing domain separation. If you want to
/// hash a `usize` that represents part of the *data*, then it's important
/// that you pass it to [`Hasher::write_usize`] instead of to this method.
///
/// # Examples
///
/// ```
/// #![feature(hasher_prefixfree_extras)]
/// # // Stubs to make the `impl` below pass the compiler
/// # struct MyCollection<T>(Option<T>);
/// # impl<T> MyCollection<T> {
/// # fn len(&self) -> usize { todo!() }
/// # }
/// # impl<'a, T> IntoIterator for &'a MyCollection<T> {
/// # type Item = T;
/// # type IntoIter = std::iter::Empty<T>;
/// # fn into_iter(self) -> Self::IntoIter { todo!() }
/// # }
///
/// use std:#️⃣:{Hash, Hasher};
/// impl<T: Hash> Hash for MyCollection<T> {
/// fn hash<H: Hasher>(&self, state: &mut H) {
/// state.write_length_prefix(self.len());
/// for elt in self {
/// elt.hash(state);
/// }
/// }
/// }
/// ```
///
/// # Note to Implementers
///
/// If you've decided that your `Hasher` is willing to be susceptible to
/// Hash-DoS attacks, then you might consider skipping hashing some or all
/// of the `len` provided in the name of increased performance.
#[inline]
#[unstable(feature = "hasher_prefixfree_extras", issue = "88888888")]
fn write_length_prefix(&mut self, len: usize) {
self.write_usize(len);
}
/// Writes a single `str` into this hasher.
///
/// If you're implementing [`Hash`], you generally do not need to call this,
/// as the `impl Hash for str` does, so you can just use that.
///
/// This includes the domain separator for prefix-freedom, so you should
/// **not** call `Self::write_length_prefix` before calling this.
///
/// # Note to Implementers
///
/// The default implementation of this method includes a call to
/// [`Self::write_length_prefix`], so if your implementation of `Hasher`
/// doesn't care about prefix-freedom and you've thus overridden
/// that method to do nothing, there's no need to override this one.
///
/// This method is available to be overridden separately from the others
/// as `str` being UTF-8 means that it never contains `0xFF` bytes, which
/// can be used to provide prefix-freedom cheaper than hashing a length.
///
/// For example, if your `Hasher` works byte-by-byte (perhaps by accumulating
/// them into a buffer), then you can hash the bytes of the `str` followed
/// by a single `0xFF` byte.
///
/// If your `Hasher` works in chunks, you can also do this by being careful
/// about how you pad partial chunks. If the chunks are padded with `0x00`
/// bytes then just hashing an extra `0xFF` byte doesn't necessarily
/// provide prefix-freedom, as `"ab"` and `"ab\u{0}"` would likely hash
/// the same sequence of chunks. But if you pad with `0xFF` bytes instead,
/// ensuring at least one padding byte, then it can often provide
/// prefix-freedom cheaper than hashing the length would.
#[inline]
#[unstable(feature = "hasher_prefixfree_extras", issue = "88888888")]
fn write_str(&mut self, s: &str) {
self.write_length_prefix(s.len());
self.write(s.as_bytes());
}
}
```
With updates to the `Hash` implementations for slices and containers to call `write_length_prefix` instead of `write_usize`.
`write_str` defaults to using `write_length_prefix` since, as was pointed out in the issue, the `write_u8(0xFF)` approach is insufficient for hashers that work in chunks, as those would hash `"a\u{0}"` and `"a"` to the same thing. But since `SipHash` works byte-wise (there's an internal buffer to accumulate bytes until a full chunk is available) it overrides `write_str` to continue to use the add-non-UTF-8-byte approach.
---
Compatibility:
Because the default implementation of `write_length_prefix` calls `write_usize`, the changed hash implementation for slices will do the same thing the old one did on existing `Hasher`s.
This accomplishes two main goals:
- Make it clear who is responsible for prefix-freedom, including how they should do it
- Make it feasible for a `Hasher` that *doesn't* care about Hash-DoS resistance to get better performance by not hashing lengths
This does not change rustc-hash, since that's in an external crate, but that could potentially use it in future.
95444: Adding passes that include memory increase
Fix95444: Change the substraction with the abs_diff() method
Fix95444: Change the substraction with abs_diff() method
Fixes#96319
The logic around handling co-inductive cycles in the evaluation cache
is confusing and error prone. Fortunately, a perf run showed that it
doesn't actually appear to improve performance, so we can simplify
this code (and eliminate a source of ICEs) by just skipping caching
the evaluation results for co-inductive cycle participants.
This commit makes no changes to any of the other logic around
co-inductive cycle handling. Thus, while this commit could
potentially expose latent bugs that were being hidden by
caching, it should not introduce any new bugs.
interpret/validity: debug-check ScalarPair layout information
This would have caught https://github.com/rust-lang/rust/issues/96158.
I ran the Miri test suite and it still passes.
r? `@oli-obk`
Report that opaque types are not allowed in impls even in the presence of other errors
fixes #96569
before this PR those useful errors were hidden because either `unused parameter` or `only traits defined in the current crate can be implemented for arbitrary types` got emitted first.
Add a new Rust attribute to support embedding debugger visualizers
Implemented [this RFC](https://github.com/rust-lang/rfcs/pull/3191) to add support for embedding debugger visualizers into a PDB.
Added a new attribute `#[debugger_visualizer]` and updated the `CrateMetadata` to store debugger visualizers for crate dependencies.
RFC: https://github.com/rust-lang/rfcs/pull/3191
do not suggest when trait_ref is some
Update compiler/rustc_resolve/src/late/diagnostics.rs
Co-authored-by: lcnr <rust@lcnr.de>
use helper struct
add a test for functions with some params
refactor debug log
Enable tracing for all queries
This allows you to log everything within a specific query, e.g.
```
env RUSTC_LOG=[mir_borrowck]
```
dumping all borrowck queries may be a bit verbose, so you can also restrict it to just an item of your choice:
```
env RUSTC_LOG=[mir_borrowck{key=\.\*name_of_item\.\*}]
```
the regex `.*` in the key name are because the key is a debug printed DefId, so you'd get all kinds of things like hashes in there. The tracing logs will show you the key, so you can restrict it further if you want.
Revert "Prefer projection candidates instead of param_env candidates for Sized predicates"
Fixes#93262Reopens#89352
This was a hack that seemed to have no negative side-effects at the time. Given that the latter has a workaround and likely less common than the former, it makes sense to revert this change.
r? `@compiler-errors`
Overhaul `MacArgs`
Motivation:
- Clarify some code that I found hard to understand.
- Eliminate one use of three places where `TokenKind::Interpolated` values are created.
r? `@petrochenkov`
The value in `MacArgs::Eq` is currently represented as a `Token`.
Because of `TokenKind::Interpolated`, `Token` can be either a token or
an arbitrary AST fragment. In practice, a `MacArgs::Eq` starts out as a
literal or macro call AST fragment, and then is later lowered to a
literal token. But this is very non-obvious. `Token` is a much more
general type than what is needed.
This commit restricts things, by introducing a new type `MacArgsEqKind`
that is either an AST expression (pre-lowering) or an AST literal
(post-lowering). The downside is that the code is a bit more verbose in
a few places. The benefit is that makes it much clearer what the
possibilities are (though also shorter in some other places). Also, it
removes one use of `TokenKind::Interpolated`, taking us a step closer to
removing that variant, which will let us make `Token` impl `Copy` and
remove many "handle Interpolated" code paths in the parser.
Things to note:
- Error messages have improved. Messages like this:
```
unexpected token: `"bug" + "found"`
```
now say "unexpected expression", which makes more sense. Although
arbitrary expressions can exist within tokens thanks to
`TokenKind::Interpolated`, that's not obvious to anyone who doesn't
know compiler internals.
- In `parse_mac_args_common`, we no longer need to collect tokens for
the value expression.
