arbitrary_self_types: add support for raw pointer `self` types
This adds support for raw pointer `self` types, under the `arbitrary_self_types` feature flag. Types like `self: *const Self`, `self: *const Rc<Self>`, `self: Rc<*const Self` are all supported. Object safety checks are updated to allow`self: *const Self` and `self: *mut Self`.
This PR does not add support for `*const self` and `*mut self` syntax. That can be added in a later PR once this code is reviewed and merged.
#44874
r? @arielb1
Fix the wrong subtraction in align_offset intrinsic.
Given how the stage0 implementation in #43903 is written, as well as that in the RFC, I suppose the current implementation has a typo.
cc #44488, cc @oli-obk.
rustc: ensure optimized enums have a properly aligned size.
Fixes#46769 by padding the optimized enums wrapping packed data as necessary.
Note that this is not the only way to solve this - on nightly, #46436 makes it easier to fix without adding new padding because of the replacement of `packed` flags with a non-redundant scheme.
But because it can't be backported, the optimal fix will be in a separate nightly-only PR (#46809).
fix broken assertion in type_param
Nested generics (aka method generics) in trait methods don't have an
*additional* Self parameter in their own type parameter list (they have
a Self parameter in the parent generics), so don't try to check we're
correctly adjusting for it.
Fixes#46568.
r? @eddyb
This simple patch resolves#46756 (which was specifically about the case of
casts, but it would be poor form indeed to fix a reported issue without at
least a cursory attempt at answering the immortal question, "How does this bug
generalize?").
Point at var in short lived borrows instead of drop location
For RLS' sake, point at the borrow location as primary span for short lived borrows, instead of the borrow drop location.
Fix#39268.
rustc_trans: approximate ABI alignment for padding/union fillers.
Before #45225 and after this PR, unions and enums are filled with integers of size and alignment matching their alignment (e.g. `Option<u32>` becomes `[u32; 2]`) instead of mere bytes.
Also, the alignment padding between struct fields gets this treatment after this PR.
Partially helps with some reduced testcases in #46449, although it doesn't solve the bug itself.
Lifetime Resolution for Generic Associated Types
Tracking Issue: https://github.com/rust-lang/rust/issues/44265
r? @nikomatsakis
This PR implements lifetime resolution for generic associated types. 🎉
## Remaining Work Before Merge
I'm going to go do these things in the next day or so. Please let me know if you spot anything in my changes until then.
- [x] If I'm not mistaken, at least some tests should pass now. I need to go through the tests and re-enable the ones that should work by removing the appropriate `~ ERROR` comments
[MIR-borrowck] Two phase borrows
This adds limited support for two-phase borrows as described in
http://smallcultfollowing.com/babysteps/blog/2017/03/01/nested-method-calls-via-two-phase-borrowing/
The support is off by default; you opt into it via the flag `-Z two-phase-borrows`
I have written "*limited* support" above because there are simple variants of the simple `v.push(v.len())` example that one would think should work but currently do not, such as the one documented in the test compile-fail/borrowck/two-phase-reservation-sharing-interference-2.rs
(To be clear, that test is not describing something that is unsound. It is just providing an explicit example of a limitation in the implementation given in this PR. I have ideas on how to fix, but I want to land the work that is in this PR first, so that I can stop repeatedly rebasing this branch.)
In reality the currently generated MIR has at least one of the activations
in a copy that occurs before the merge. But still, good to have a test,
in anticipation of that potentially changing...
trait alias infrastructure
This will be an implementation of trait aliases (RFC 1733, #41517).
Progress so far:
- [x] Feature gate
- [x] Add to parser
- [x] `where` clauses
- [x] prohibit LHS type parameter bounds via AST validation https://github.com/rust-lang/rust/pull/45047#discussion_r143575575
- [x] Add to AST and HIR
- [x] make a separate PathSource for trait alias contexts https://github.com/rust-lang/rust/pull/45047#discussion_r143353932
- [x] Stub out enough of typeck and resolve to just barely not ICE
Postponed:
- [ ] Actually implement the alias part
- [ ] #21903
- [ ] #24010
I need some pointers on where to start with that last one. The test currently does this:
```
error[E0283]: type annotations required: cannot resolve `_: CD`
--> src/test/run-pass/trait-alias.rs:34:16
|
34 | let both = foo();
| ^^^
|
= note: required by `foo`
```
