Replace rustc_data_structures::thin_vec::ThinVec with thin_vec::ThinVec.

`rustc_data_structures::thin_vec::ThinVec` looks like this:
```
pub struct ThinVec<T>(Option<Box<Vec<T>>>);
```
It's just a zero word if the vector is empty, but requires two
allocations if it is non-empty. So it's only usable in cases where the
vector is empty most of the time.

This commit removes it in favour of `thin_vec::ThinVec`, which is also
word-sized, but stores the length and capacity in the same allocation as
the elements. It's good in a wider variety of situation, e.g. in enum
variants where the vector is usually/always non-empty.

The commit also:
- Sorts some `Cargo.toml` dependency lists, to make additions easier.
- Sorts some `use` item lists, to make additions easier.
- Changes `clean_trait_ref_with_bindings` to take a
  `ThinVec<TypeBinding>` rather than a `&[TypeBinding]`, because this
  avoid some unnecessary allocations.
This commit is contained in:
Nicholas Nethercote 2022-08-17 14:22:30 +10:00
parent 223d16ebbd
commit b38106b6d8
42 changed files with 174 additions and 366 deletions

View file

@ -4,6 +4,9 @@
use crate::keys::Key;
use crate::{on_disk_cache, Queries};
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::sync::Lock;
use rustc_errors::{Diagnostic, Handler};
use rustc_middle::dep_graph::{self, DepKind, DepNodeIndex, SerializedDepNodeIndex};
use rustc_middle::ty::tls::{self, ImplicitCtxt};
use rustc_middle::ty::{self, TyCtxt};
@ -12,14 +15,9 @@ use rustc_query_system::ich::StableHashingContext;
use rustc_query_system::query::{
QueryContext, QueryJobId, QueryMap, QuerySideEffects, QueryStackFrame,
};
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::sync::Lock;
use rustc_data_structures::thin_vec::ThinVec;
use rustc_errors::{Diagnostic, Handler};
use std::any::Any;
use std::num::NonZeroU64;
use thin_vec::ThinVec;
#[derive(Copy, Clone)]
pub struct QueryCtxt<'tcx> {