This makes `Obligation` two words bigger, but avoids allocating a lot of
the time.
I previously tried this in #73983 and it didn't help much, but local
timings look more promising now.
Remove `in_band_lifetimes` from `rustc_middle`
See #91867
This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.
Remove `SymbolStr`
This was originally proposed in https://github.com/rust-lang/rust/pull/74554#discussion_r466203544. As well as removing the icky `SymbolStr` type, it allows the removal of a lot of `&` and `*` occurrences.
Best reviewed one commit at a time.
r? `@oli-obk`
Add user seed to `-Z randomize-layout`
Allows users of -`Z randomize-layout` to provide `-Z layout-seed=<seed>` in order to further randomizing type layout randomization. Extension of [compiler-team/#457](https://github.com/rust-lang/compiler-team/issues/457), allows users to change struct layouts without changing code and hoping that item path hashes change, aiding in detecting layout errors
hir: Do not introduce dummy type names for `extern` blocks in def paths
Use a separate nameless `DefPathData` variant instead.
Extracted from https://github.com/rust-lang/rust/pull/91795.
Implement normalize_erasing_regions queries in terms of 'try' version
Attempt to lessen performance regression caused by https://github.com/rust-lang/rust/pull/91255
r? `@jackh726`
See #91867
This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.
extend `simplify_type`
might cause a slight perf inprovement and imo more accurately represents what types there are.
considering that I was going to use this in #85048 it seems like we might need this in the future anyways 🤷
Make `TyS::is_suggestable` check for non-suggestable types structually
Not sure if I went overboard checking substs in dyn types, etc. Let me know if I should simplify this function.
Fixes#91832
By changing `as_str()` to take `&self` instead of `self`, we can just
return `&str`. We're still lying about lifetimes, but it's a smaller lie
than before, where `SymbolStr` contained a (fake) `&'static str`!
Stabilize `iter::zip`
Hello all!
As the tracking issue (#83574) for `iter::zip` completed the final commenting period without any concerns being raised, I hereby submit this stabilization PR on the issue.
As the pull request that introduced the feature (#82917) states, the `iter::zip` function is a shorter way to zip two iterators. As it's generally a quality-of-life/ergonomic improvement, it has been integrated into the codebase without any trouble, and has been
used in many places across the rust compiler and standard library since March without any issues.
For more details, I would refer to `@cuviper's` original PR, or the [function's documentation](https://doc.rust-lang.org/std/iter/fn.zip.html).
Tweak errors coming from `for`-loop, `?` and `.await` desugaring
* Suggest removal of `.await` on non-`Future` expression
* Keep track of obligations introduced by desugaring
* Remove span pointing at method for obligation errors coming from desugaring
* Point at called local sync `fn` and suggest making it `async`
```
error[E0277]: `()` is not a future
--> $DIR/unnecessary-await.rs:9:10
|
LL | boo().await;
| -----^^^^^^ `()` is not a future
| |
| this call returns `()`
|
= help: the trait `Future` is not implemented for `()`
help: do not `.await` the expression
|
LL - boo().await;
LL + boo();
|
help: alternatively, consider making `fn boo` asynchronous
|
LL | async fn boo () {}
| +++++
```
Fix#66731.
Stabilise `feature(const_generics_defaults)`
`feature(const_generics_defaults)` is complete implementation wise and has a pretty extensive test suite so I think is ready for stabilisation.
needs stabilisation report and maybe an RFC 😅
r? `@lcnr`
cc `@rust-lang/project-const-generics`
Tweak assoc type obligation spans
* Point at RHS of associated type in obligation span
* Point at `impl` assoc type on projection error
* Reduce verbosity of recursive obligations
* Point at source of binding lifetime obligation
* Tweak "required bound" note
* Tweak "expected... found opaque (return) type" labels
* Point at set type in impl assoc type WF errors
r? `@oli-obk`
This is a(n uncontroversial) subset of #85799.
Point at capture points for non-`'static` reference crossing a `yield` point
```
error[E0759]: `self` has an anonymous lifetime `'_` but it needs to satisfy a `'static` lifetime requirement
--> $DIR/issue-72312.rs:10:24
|
LL | pub async fn start(&self) {
| ^^^^^ this data with an anonymous lifetime `'_`...
...
LL | require_static(async move {
| -------------- ...is required to live as long as `'static` here...
LL | &self;
| ----- ...and is captured here
|
note: `'static` lifetime requirement introduced by this trait bound
--> $DIR/issue-72312.rs:2:22
|
LL | fn require_static<T: 'static>(val: T) -> T {
| ^^^^^^^
error: aborting due to previous error
For more information about this error, try `rustc --explain E0759`.
```
Fix#72312.
Suggest using a temporary variable to fix borrowck errors
Fixes#77834.
In Rust, nesting method calls with both require `&mut` access to `self`
produces a borrow-check error:
error[E0499]: cannot borrow `*self` as mutable more than once at a time
--> src/lib.rs:7:14
|
7 | self.foo(self.bar());
| ---------^^^^^^^^^^-
| | | |
| | | second mutable borrow occurs here
| | first borrow later used by call
| first mutable borrow occurs here
That's because Rust has a left-to-right evaluation order, and the method
receiver is passed first. Thus, the argument to the method cannot then
mutate `self`.
There's an easy solution to this error: just extract a local variable
for the inner argument:
let tmp = self.bar();
self.foo(tmp);
However, the error doesn't give any suggestion of how to solve the
problem. As a result, new users may assume that it's impossible to
express their code correctly and get stuck.
This commit adds a (non-structured) suggestion to extract a local
variable for the inner argument to solve the error. The suggestion uses
heuristics that eliminate most false positives, though there are a few
false negatives (cases where the suggestion should be emitted but is
not). Those other cases can be implemented in a future change.
Improve the readability of `List<T>`.
This commit does the following.
- Expands on some of the things already mentioned in comments.
- Describes the uniqueness assumption, which is critical but wasn't
mentioned at all.
- Rewrites `empty()` into a clearer form, as provided by Daniel
Henry-Mantilla on Zulip.
- Reorders things slightly so that more important things
are higher up, and incidental things are lower down, which makes
reading the code easier.
r? ````@lcnr````
