Remove hook calling via `TyCtxtAt`.

All hooks receive a `TyCtxtAt` argument.

Currently hooks can be called through `TyCtxtAt` or `TyCtxt`. In the
latter case, a `TyCtxtAt` is constructed with a dummy span and passed to
the hook.

However, in practice hooks are never called through `TyCtxtAt`, and
always receive a dummy span. (I confirmed this via code inspection, and
double-checked it by temporarily making the `TyCtxtAt` code path panic
and running all the tests.)

This commit removes all the `TyCtxtAt` machinery for hooks. All hooks
now receive `TyCtxt` instead of `TyCtxtAt`. There are two existing hooks
that use `TyCtxtAt::span`: `const_caller_location_provider` and
`try_destructure_mir_constant_for_user_output`. For both hooks the span
is always a dummy span, probably unintentionally. This dummy span use is
now explicit. If a non-dummy span is needed for these two hooks it would
be easy to add it as an extra argument because hooks are less
constrained than queries.

1 files changed, 1 insertions, 3 deletions

diff --git a/compiler/rustc_mir_transform/src/coverage/query.rs b/compiler/rustc_mir_transform/src/coverage/query.rs
index 5e7b46182dc..a849ed4c3e2 100644
--- a/compiler/rustc_mir_transform/src/coverage/query.rs
+++ b/compiler/rustc_mir_transform/src/coverage/query.rs
@@ -6,7 +6,6 @@ use rustc_middle::mir::coverage::{
     FunctionCoverageInfo, MappingKind, Op,
 };
 use rustc_middle::mir::{Body, Statement, StatementKind};
-use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_middle::util::Providers;
 use rustc_span::def_id::LocalDefId;
@@ -15,8 +14,7 @@ use tracing::trace;
 
 /// Registers query/hook implementations related to coverage.
 pub(crate) fn provide(providers: &mut Providers) {
-    providers.hooks.is_eligible_for_coverage =
-        |TyCtxtAt { tcx, .. }, def_id| is_eligible_for_coverage(tcx, def_id);
+    providers.hooks.is_eligible_for_coverage = is_eligible_for_coverage;
     providers.queries.coverage_attr_on = coverage_attr_on;
     providers.queries.coverage_ids_info = coverage_ids_info;
 }