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| author | pierwill <pierwill@users.noreply.github.com> | 2021-12-30 11:01:30 -0600 |
|---|---|---|
| committer | pierwill <pierwill@users.noreply.github.com> | 2021-12-30 11:45:20 -0600 |
| commit | 0bac713569a56089c3b5435f49d7e8d900535d30 (patch) | |
| tree | e40aa10f904414ed928c978765def603f7051092 /compiler/rustc_span/src | |
| parent | f8d4ee7c7adcea52dfc62328309f5ef7df000266 (diff) | |
| download | rust-0bac713569a56089c3b5435f49d7e8d900535d30.tar.gz rust-0bac713569a56089c3b5435f49d7e8d900535d30.zip | |
Add negative `impl` for `Ord`, `PartialOrd` on `LocalDefId`
Add comment about why `LocalDefId` should not be `Ord` Also fix some formatting in the doc comment.
Diffstat (limited to 'compiler/rustc_span/src')
| -rw-r--r-- | compiler/rustc_span/src/def_id.rs | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/compiler/rustc_span/src/def_id.rs b/compiler/rustc_span/src/def_id.rs index d15befbf287..f6b0785a07c 100644 --- a/compiler/rustc_span/src/def_id.rs +++ b/compiler/rustc_span/src/def_id.rs @@ -316,17 +316,23 @@ impl fmt::Debug for DefId { rustc_data_structures::define_id_collections!(DefIdMap, DefIdSet, DefId); -/// A LocalDefId is equivalent to a DefId with `krate == LOCAL_CRATE`. Since +/// A `LocalDefId` is equivalent to a `DefId` with `krate == LOCAL_CRATE`. Since /// we encode this information in the type, we can ensure at compile time that -/// no DefIds from upstream crates get thrown into the mix. There are quite a -/// few cases where we know that only DefIds from the local crate are expected -/// and a DefId from a different crate would signify a bug somewhere. This -/// is when LocalDefId comes in handy. +/// no `DefId`s from upstream crates get thrown into the mix. There are quite a +/// few cases where we know that only `DefId`s from the local crate are expected; +/// a `DefId` from a different crate would signify a bug somewhere. This +/// is when `LocalDefId` comes in handy. #[derive(Clone, Copy, PartialEq, Eq, Hash)] pub struct LocalDefId { pub local_def_index: DefIndex, } +// To ensure correctness of incremental compilation, +// `LocalDefId` must not implement `Ord` or `PartialOrd`. +// See https://github.com/rust-lang/rust/issues/90317. +impl !Ord for LocalDefId {} +impl !PartialOrd for LocalDefId {} + pub const CRATE_DEF_ID: LocalDefId = LocalDefId { local_def_index: CRATE_DEF_INDEX }; impl Idx for LocalDefId { |