Remove with_related_context.

There is only one GlobalCtxt ever.

Author: cjgillot

compiler/rustc_middle/src/ty/context/tls.rs

@@ -6,8 +6,6 @@ use rustc_data_structures::sync::{self, Lock};
 use rustc_errors::Diagnostic;
 #[cfg(not(parallel_compiler))]
 use std::cell::Cell;
-use std::mem;
-use std::ptr;
 use thin_vec::ThinVec;
 
 /// This is the implicit state of rustc. It contains the current
@@ -111,29 +109,6 @@ where
     with_context_opt(|opt_context| f(opt_context.expect("no ImplicitCtxt stored in tls")))
 }
 
-/// Allows access to the current `ImplicitCtxt` whose tcx field is the same as the tcx argument
-/// passed in. This means the closure is given an `ImplicitCtxt` with the same `'tcx` lifetime
-/// as the `TyCtxt` passed in.
-/// This will panic if you pass it a `TyCtxt` which is different from the current
-/// `ImplicitCtxt`'s `tcx` field.
-#[inline]
-pub fn with_related_context<'tcx, F, R>(tcx: TyCtxt<'tcx>, f: F) -> R
-where
-    F: FnOnce(&ImplicitCtxt<'_, 'tcx>) -> R,
-{
-    with_context(|context| {
-        // The two gcx have different invariant lifetimes, so we need to erase them for the comparison.
-        assert!(ptr::eq(
-            context.tcx.gcx as *const _ as *const (),
-            tcx.gcx as *const _ as *const ()
-        ));
-
-        let context: &ImplicitCtxt<'_, '_> = unsafe { mem::transmute(context) };
-
-        f(context)
-    })
-}
-
 /// Allows access to the `TyCtxt` in the current `ImplicitCtxt`.
 /// Panics if there is no `ImplicitCtxt` available.
 #[inline]

compiler/rustc_query_impl/src/plumbing.rs

@@ -77,7 +77,7 @@ impl QueryContext for QueryCtxt<'_> {
 
     #[inline]
     fn current_query_job(self) -> Option<QueryJobId> {
-        tls::with_related_context(self.tcx, |icx| icx.query)
+        tls::with_context(|icx| icx.query)
     }
 
     fn collect_active_jobs(self) -> QueryMap {
@@ -131,9 +131,9 @@ impl QueryContext for QueryCtxt<'_> {
         compute: impl FnOnce() -> R,
     ) -> R {
         // The `TyCtxt` stored in TLS has the same global interner lifetime
-        // as `self`, so we use `with_related_context` to relate the 'tcx lifetimes
+        // as `self`, so we use `with_context` to relate the 'tcx lifetimes
         // when accessing the `ImplicitCtxt`.
-        tls::with_related_context(self.tcx, move |current_icx| {
+        tls::with_context(move |current_icx| {
             if depth_limit && !self.recursion_limit().value_within_limit(current_icx.query_depth) {
                 self.depth_limit_error(token);
             }