implied bounds: explicitly state which types are assumed to be wf
Adds a new query which maps each definition to the types which that definition assumes to be well formed. The intent is to make it easier to reason about implied bounds.
This change should not influence the user-facing behavior of rustc. Notably, `borrowck` still only assumes that the function signature of associated functions is well formed while `wfcheck` assumes that the both the function signature and the impl trait ref is well formed. Not sure if that by itself can trigger UB or whether it's just annoying.
As a next step, we can add `WellFormed` predicates to `predicates_of` of these items and can stop adding the wf bounds at each place which uses them. I also intend to move the computation from `assumed_wf_types` to `implied_bounds` into the `param_env` computation. This requires me to take a deeper look at `compare_predicate_entailment` which is currently somewhat weird wrt implied bounds so I am not touching this here.
r? `@nikomatsakis`
Use `AttrVec` more
In some places we use `Vec<Attribute>` and some places we use
`ThinVec<Attribute>` (a.k.a. `AttrVec`). This results in various points
where we have to convert between `Vec` and `ThinVec`.
This commit changes the places that use `Vec<Attribute>` to use
`AttrVec`. A lot of this is mechanical and boring, but there are
some interesting parts:
- It adds a few new methods to `ThinVec`.
- It implements `MapInPlace` for `ThinVec`, and introduces a macro to
avoid the repetition of this trait for `Vec`, `SmallVec`, and
`ThinVec`.
Overall, it makes the code a little nicer, and has little effect on
performance. But it is a precursor to removing
`rustc_data_structures::ThinVec` and replacing it with
`thin_vec::ThinVec`, which is implemented more efficiently.
r? `@spastorino`
Rework "point at arg" suggestions to be more accurate
Fixes#100560
Introduce a new set of `ObligationCauseCode`s which have additional bookeeping for what expression caused the obligation, and which predicate caused the obligation. This allows us to look at the _unsubstituted_ signature to find out which parameter or generic type argument caused an obligaton to fail.
This means that (in most cases) we significantly improve the likelihood of pointing out the right argument that causes a fulfillment error. Also, since this logic isn't happening in just the `select_where_possible_and_mutate_fulfillment()` calls in the argument checking code, but instead during all trait selection in `FnCtxt`, we are also able to point out the correct argument even if inference means that we don't know whether an obligation has failed until well after a call expression has been checked.
r? `@ghost`
In some places we use `Vec<Attribute>` and some places we use
`ThinVec<Attribute>` (a.k.a. `AttrVec`). This results in various points
where we have to convert between `Vec` and `ThinVec`.
This commit changes the places that use `Vec<Attribute>` to use
`AttrVec`. A lot of this is mechanical and boring, but there are
some interesting parts:
- It adds a few new methods to `ThinVec`.
- It implements `MapInPlace` for `ThinVec`, and introduces a macro to
avoid the repetition of this trait for `Vec`, `SmallVec`, and
`ThinVec`.
Overall, it makes the code a little nicer, and has little effect on
performance. But it is a precursor to removing
`rustc_data_structures::thin_vec::ThinVec` and replacing it with
`thin_vec::ThinVec`, which is implemented more efficiently.
Rollup of 11 pull requests
Successful merges:
- #100556 (Clamp Function for f32 and f64)
- #100663 (Make slice::reverse const)
- #100697 ( Minor syntax and formatting update to doc comment on `find_vtable_types_for_unsizing`)
- #100760 (update test for LLVM change)
- #100761 (some general mir typeck cleanup)
- #100775 (rustdoc: Merge source code pages HTML elements together v2)
- #100813 (Add `/build-rust-analyzer/` to .gitignore)
- #100821 (Make some docs nicer wrt pointer offsets)
- #100822 (Replace most uses of `pointer::offset` with `add` and `sub`)
- #100839 (Make doc for stdin field of process consistent)
- #100842 (Add diagnostics lints to `rustc_transmute` module (zero diags))
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
rustdoc: strategic boxing to reduce the size of ItemKind and Type
The `Type` change redesigns `QPath` to box the entire data structure instead of boxing `self_type` and the `trait_`.
This reduces the size of several `ItemKind` variants, leaving `Impl` as the biggest variant. The `ItemKind` change boxes that variant's payload.
Replace most uses of `pointer::offset` with `add` and `sub`
As PR title says, it replaces `pointer::offset` in compiler and standard library with `pointer::add` and `pointer::sub`. This generally makes code cleaner, easier to grasp and removes (or, well, hides) integer casts.
This is generally trivially correct, `.offset(-constant)` is just `.sub(constant)`, `.offset(usized as isize)` is just `.add(usized)`, etc. However in some cases we need to be careful with signs of things.
r? ````@scottmcm````
_split off from #100746_
Make some docs nicer wrt pointer offsets
This PR replaces `pointer::offset` with `pointer::add` and similarly `.cast().wrapping_add().cast()` with `.wrapping_byte_add()` **in docs**.
r? ``````@scottmcm``````
_split off from #100746_
rustdoc: Merge source code pages HTML elements together v2
This is the follow-up of https://github.com/rust-lang/rust/pull/100429.
I strongly recommend to review it one commit at a time because otherwise it's a lot at once.
For these ones, on each page, I run this JS: `document.getElementsByTagName('*').length`. The goal is to count the number of DOM elements. I took some pages that seemed big, but don't hesitate to check some others. I also added the "starting point" because it's quite nice to see how much the page was reduced thanks to these two PRs.
| file name | before #100429 | before this PR | with this PR | diff |
|-|-|-|-|-|
| std/lib.rs.html (source link on std crate page) | 3455 | 2332 | 1772 | 24% |
| alloc/vec/mod.rs.html (source on Vec type page) | 11012 | 5982 | 5833 | 2.5% |
| alloc/string.rs.html (source on String type page) | 10800 | 6010 | 5822 | 3.2% |
| std/sync/mutex.rs.html (source on Mutex type page) | 2953 | 2041 | 2038 | 0.1% |
So unsurprisingly, the more attributes you have, the bigger the difference.
You can test it [here](https://rustdoc.crud.net/imperio/reduce-span-v2/src/std/lib.rs.html).
cc ``````@jsha``````
r? ``````@notriddle``````
some general mir typeck cleanup
this pr contains the parts of #95763 which already work correctly.
the remaining commits of that PR have some issues which are more complex to fix.
r? types
Minor syntax and formatting update to doc comment on `find_vtable_types_for_unsizing`
I noticed the code examples on this function weren't formatted as code, and also the that the syntax for trait objects was out of date (or just incorrect). This should bring it up to date.
Clamp Function for f32 and f64
I thought the clamp function could use a little improvement for readability purposes. The function now returns early in order to skip the extra bound checks.
If there was a reason for binding `self` to `x` or if this code is incorrect, please correct me :)
Deriving SessionDiagnostic on a type no longer forces that diagnostic to
be one of warning, error, or fatal. The level is instead decided when
the struct is passed to the respective Handler::emit_*() method.
