Rollup merge of #136464 - nnethercote:rm-TyCtxtAt-for-hooks, r=oli-obk

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.

r? `@oli-obk`

1 files changed, 3 insertions, 17 deletions

diff --git a/compiler/rustc_middle/src/hooks/mod.rs b/compiler/rustc_middle/src/hooks/mod.rs
index 2be242364c1..276a02b4e0f 100644
--- a/compiler/rustc_middle/src/hooks/mod.rs
+++ b/compiler/rustc_middle/src/hooks/mod.rs
@@ -6,11 +6,9 @@
 use rustc_hir::def_id::{DefId, DefPathHash};
 use rustc_session::StableCrateId;
 use rustc_span::def_id::{CrateNum, LocalDefId};
-use rustc_span::{DUMMY_SP, ExpnHash, ExpnId};
-use tracing::instrument;
+use rustc_span::{ExpnHash, ExpnId};
 
 use crate::mir;
-use crate::query::TyCtxtAt;
 use crate::ty::{Ty, TyCtxt};
 
 macro_rules! declare_hooks {
@@ -22,26 +20,14 @@ macro_rules! declare_hooks {
             #[inline(always)]
             pub fn $name(self, $($arg: $K,)*) -> $V
             {
-                self.at(DUMMY_SP).$name($($arg,)*)
-            }
-            )*
-        }
-
-        impl<'tcx> TyCtxtAt<'tcx> {
-            $(
-            $(#[$attr])*
-            #[inline(always)]
-            #[instrument(level = "debug", skip(self), ret)]
-            pub fn $name(self, $($arg: $K,)*) -> $V
-            {
-                (self.tcx.hooks.$name)(self, $($arg,)*)
+                (self.hooks.$name)(self, $($arg,)*)
             }
             )*
         }
 
         pub struct Providers {
             $(pub $name: for<'tcx> fn(
-                TyCtxtAt<'tcx>,
+                TyCtxt<'tcx>,
                 $($arg: $K,)*
             ) -> $V,)*
         }