diff options
Diffstat (limited to 'compiler/rustc_middle/src')
| -rw-r--r-- | compiler/rustc_middle/src/traits/mod.rs | 3 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/ty/context.rs | 12 |
2 files changed, 15 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs index 0a903a76974..bf3872e81d4 100644 --- a/compiler/rustc_middle/src/traits/mod.rs +++ b/compiler/rustc_middle/src/traits/mod.rs @@ -445,6 +445,9 @@ pub enum ObligationCauseCode<'tcx> { /// Obligations to prove that a `std::ops::Drop` impl is not stronger than /// the ADT it's being implemented for. DropImpl, + + /// Requirement for a `const N: Ty` to implement `Ty: ConstParamTy` + ConstParam(Ty<'tcx>), } /// The 'location' at which we try to perform HIR-based wf checking. diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs index b05e791211d..673d09cddf4 100644 --- a/compiler/rustc_middle/src/ty/context.rs +++ b/compiler/rustc_middle/src/ty/context.rs @@ -478,6 +478,17 @@ impl<'tcx> TyCtxtFeed<'tcx, LocalDefId> { /// [rustc dev guide] for more details. /// /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/ty.html +/// +/// An implementation detail: `TyCtxt` is a wrapper type for [GlobalCtxt], +/// which is the struct that actually holds all the data. `TyCtxt` derefs to +/// `GlobalCtxt`, and in practice `TyCtxt` is passed around everywhere, and all +/// operations are done via `TyCtxt`. A `TyCtxt` is obtained for a `GlobalCtxt` +/// by calling `enter` with a closure `f`. That function creates both the +/// `TyCtxt`, and an `ImplicitCtxt` around it that is put into TLS. Within `f`: +/// - The `ImplicitCtxt` is available implicitly via TLS. +/// - The `TyCtxt` is available explicitly via the `tcx` parameter, and also +/// implicitly within the `ImplicitCtxt`. Explicit access is preferred when +/// possible. #[derive(Copy, Clone)] #[rustc_diagnostic_item = "TyCtxt"] #[rustc_pass_by_value] @@ -493,6 +504,7 @@ impl<'tcx> Deref for TyCtxt<'tcx> { } } +/// See [TyCtxt] for details about this type. pub struct GlobalCtxt<'tcx> { pub arena: &'tcx WorkerLocal<Arena<'tcx>>, pub hir_arena: &'tcx WorkerLocal<hir::Arena<'tcx>>, |