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, 3 deletions

diff --git a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
index 5fcb9c85035..028ff56155f 100644
--- a/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
+++ b/compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs
@@ -689,7 +689,7 @@ fn provide_cstore_hooks(providers: &mut Providers) {
     providers.hooks.def_path_hash_to_def_id_extern = |tcx, hash, stable_crate_id| {
         // If this is a DefPathHash from an upstream crate, let the CrateStore map
         // it to a DefId.
-        let cstore = CStore::from_tcx(tcx.tcx);
+        let cstore = CStore::from_tcx(tcx);
         let cnum = *tcx
             .untracked()
             .stable_crate_ids
@@ -702,11 +702,11 @@ fn provide_cstore_hooks(providers: &mut Providers) {
     };
 
     providers.hooks.expn_hash_to_expn_id = |tcx, cnum, index_guess, hash| {
-        let cstore = CStore::from_tcx(tcx.tcx);
+        let cstore = CStore::from_tcx(tcx);
         cstore.get_crate_data(cnum).expn_hash_to_expn_id(tcx.sess, index_guess, hash)
     };
     providers.hooks.import_source_files = |tcx, cnum| {
-        let cstore = CStore::from_tcx(tcx.tcx);
+        let cstore = CStore::from_tcx(tcx);
         let cdata = cstore.get_crate_data(cnum);
         for file_index in 0..cdata.root.source_map.size() {
             cdata.imported_source_file(file_index as u32, tcx.sess);