This commit makes `AdtDef` use `Interned`. Much the commit is tedious
changes to introduce getter functions. The interesting changes are in
`compiler/rustc_middle/src/ty/adt.rs`.
`Layout` is another type that is sometimes interned, sometimes not, and
we always use references to refer to it so we can't take any advantage
of the uniqueness properties for hashing or equality checks.
This commit renames `Layout` as `LayoutS`, and then introduces a new
`Layout` that is a newtype around an `Interned<LayoutS>`. It also
interns more layouts than before. Previously layouts within layouts
(via the `variants` field) were never interned, but now they are. Hence
the lifetime on the new `Layout` type.
Unlike other interned types, these ones are in `rustc_target` instead of
`rustc_middle`. This reflects the existing structure of the code, which
does layout-specific stuff in `rustc_target` while `TyAndLayout` is
generic over the `Ty`, allowing the type-specific stuff to occur in
`rustc_middle`.
The commit also adds a `HashStable` impl for `Interned`, which was
needed. It hashes the contents, unlike the `Hash` impl which hashes the
pointer.
There's still open discussion if this lint is ready to be enabled by
default. We want to give us more time to figure this out and prevent
this lint from getting to stable as an enabled-by-default lint.
Transmute_undefined_repr to nursery again
This PR reinstates #8418, which was reverted in #8425 (incorrectly I think).
I don't want to start a revert war over this but I feel very strongly that this lint is not in a state that would be a net benefit to users of clippy. In its current form, making this an enabled-by-default `correctness` lint with authoritative-sounding proclamations of undefined behavior does more harm than the benefit of the true positive cases.
I can file a bunch more examples of false positives but I don't want to give the author of this lint the impression that it is ready to graduate from `nursery` as soon as I've exhausted the amount of time I am willing to spend revising this lint.
Instead I would recommend that the author of the lint try running it on some reputable codebases containing transmutes. Everywhere that the lint triggers please consider critically whether it should be triggering. For cases that you think are true positives, please raise a few of them with the crate authors (in a PR or issue) to better understand their perspective if they think the transmute is correct.
---
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: Re-remove [`transmute_undefined_repr`] from default set of enabled lints
Move transmute_undefined_repr back to nursery
There's still open discussion if this lint is ready to be enabled by
default. We want to give us more time to figure this out and prevent
this lint from getting to stable as an enabled-by-default lint.
cc https://github.com/rust-lang/rust-clippy/pull/8432
r? `@Manishearth` `@dtolnay`
I think this is the way to go here. We can re-enable this lint with the next sync, if we should decide to do so. But I would hold of for this release.
We have until Friday (beta branching) to decide if we want to merge this.
There's still open discussion if this lint is ready to be enabled by
default. We want to give us more time to figure this out and prevent
this lint from getting to stable as an enabled-by-default lint.
Specifically, change `Ty` from this:
```
pub type Ty<'tcx> = &'tcx TyS<'tcx>;
```
to this
```
pub struct Ty<'tcx>(Interned<'tcx, TyS<'tcx>>);
```
There are two benefits to this.
- It's now a first class type, so we can define methods on it. This
means we can move a lot of methods away from `TyS`, leaving `TyS` as a
barely-used type, which is appropriate given that it's not meant to
be used directly.
- The uniqueness requirement is now explicit, via the `Interned` type.
E.g. the pointer-based `Eq` and `Hash` comes from `Interned`, rather
than via `TyS`, which wasn't obvious at all.
Much of this commit is boring churn. The interesting changes are in
these files:
- compiler/rustc_middle/src/arena.rs
- compiler/rustc_middle/src/mir/visit.rs
- compiler/rustc_middle/src/ty/context.rs
- compiler/rustc_middle/src/ty/mod.rs
Specifically:
- Most mentions of `TyS` are removed. It's very much a dumb struct now;
`Ty` has all the smarts.
- `TyS` now has `crate` visibility instead of `pub`.
- `TyS::make_for_test` is removed in favour of the static `BOOL_TY`,
which just works better with the new structure.
- The `Eq`/`Ord`/`Hash` impls are removed from `TyS`. `Interned`s impls
of `Eq`/`Hash` now suffice. `Ord` is now partly on `Interned`
(pointer-based, for the `Equal` case) and partly on `TyS`
(contents-based, for the other cases).
- There are many tedious sigil adjustments, i.e. adding or removing `*`
or `&`. They seem to be unavoidable.
Factor out several utils, add `path_def_id`
changelog: none
This is generally an effort to reduce the total number of utils. `path_def_id` is added which I believe is more "cross-cutting" and also complements `path_to_local`. Best reviewed one commit at a time.
Added:
* `path_def_id`
* `path_res`
Removed:
* `is_qpath_def_path`
* `match_any_diagnostic_items`
* `expr_path_res`
* `single_segment_path`
* `differing_macro_contexts`
* `is_ty_param_lang_item`
* `is_ty_param_diagnostic_item`
* `get_qpath_generics`
Renamed:
* `path_to_res` to `def_path_res`
* `get_qpath_generic_tys` to `qpath_generic_tys`
CC `@Jarcho` since this relates to some of your work and you may have input.
So, some context for this, well, more a story. I'm not used to scripting, I've never really scripted anything, even if it's a valuable skill. I just never really needed it. Now, `@flip1995` correctly suggested using a script for this in `rust-clippy#7813`...
And I decided to write a script using nushell because why not? This was a mistake... I spend way more time on this than I would like to admit. It has definitely been more than 4 hours. It shouldn't take that long, but me being new to scripting and nushell just wasn't a good mixture... Anyway, here is the script that creates another script which adds the versions. Fun...
Just execute this on the `gh-pages` branch and the resulting `replacer.sh` in `clippy_lints` and it should all work.
```nu
mv v0.0.212 rust-1.00.0;
mv beta rust-1.57.0;
mv master rust-1.58.0;
let paths = (open ./rust-1.58.0/lints.json | select id id_span | flatten | select id path);
let versions = (
ls | where name =~ "rust-" | select name | format {name}/lints.json |
each { open $it | select id | insert version $it | str substring "5,11" version} |
group-by id | rotate counter-clockwise id version |
update version {get version | first 1} | flatten | select id version);
$paths | each { |row|
let version = ($versions | where id == ($row.id) | format {version})
let idu = ($row.id | str upcase)
$"sed -i '0,/($idu),/{s/pub ($idu),/#[clippy::version = "($version)"]\n pub ($idu),/}' ($row.path)"
} | str collect ";" | str find-replace --all '1.00.0' 'pre 1.29.0' | save "replacer.sh";
```
And this still has some problems, but at this point I just want to be done -.-
