2021-03-25 13:29:11 -05:00
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use clippy_utils::diagnostics::span_lint;
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2021-03-12 08:30:50 -06:00
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use if_chain::if_chain;
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use rustc_hir as hir;
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use rustc_lint::LateContext;
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use rustc_middle::ty;
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use super::ZST_OFFSET;
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2021-04-08 10:50:13 -05:00
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pub(super) fn check(cx: &LateContext<'_>, expr: &hir::Expr<'_>, recv: &hir::Expr<'_>) {
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2021-03-12 08:30:50 -06:00
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if_chain! {
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2021-04-08 10:50:13 -05:00
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if let ty::RawPtr(ty::TypeAndMut { ty, .. }) = cx.typeck_results().expr_ty(recv).kind();
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Overhaul `TyS` and `Ty`.
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.
2022-01-24 21:13:38 -06:00
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if let Ok(layout) = cx.tcx.layout_of(cx.param_env.and(*ty));
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2021-03-12 08:30:50 -06:00
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if layout.is_zst();
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then {
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span_lint(cx, ZST_OFFSET, expr.span, "offset calculation on zero-sized value");
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}
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}
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}
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