Move outlives env computation into methods

compiler/rustc_trait_selection/src/regions.rs

@@ -9,6 +9,46 @@ use rustc_middle::ty::{self, Ty};
 use crate::traits::ScrubbedTraitError;
 use crate::traits::outlives_bounds::InferCtxtExt;
 
+#[extension(pub trait OutlivesEnvironmentBuildExt<'tcx>)]
+impl<'tcx> OutlivesEnvironment<'tcx> {
+    fn new(
+        infcx: &InferCtxt<'tcx>,
+        body_id: LocalDefId,
+        param_env: ty::ParamEnv<'tcx>,
+        assumed_wf_tys: impl IntoIterator<Item = Ty<'tcx>>,
+    ) -> Self {
+        Self::new_with_implied_bounds_compat(
+            infcx,
+            body_id,
+            param_env,
+            assumed_wf_tys,
+            !infcx.tcx.sess.opts.unstable_opts.no_implied_bounds_compat,
+        )
+    }
+
+    fn new_with_implied_bounds_compat(
+        infcx: &InferCtxt<'tcx>,
+        body_id: LocalDefId,
+        param_env: ty::ParamEnv<'tcx>,
+        assumed_wf_tys: impl IntoIterator<Item = Ty<'tcx>>,
+        implied_bounds_compat: bool,
+    ) -> Self {
+        // FIXME: This needs to be modified so that we normalize the known type
+        // outlives obligations then elaborate them into their region/type components.
+        // Otherwise, `<W<'a> as Mirror>::Assoc: 'b` will not imply `'a: 'b` even
+        // if we can normalize `'a`.
+        OutlivesEnvironment::with_bounds(
+            param_env,
+            infcx.implied_bounds_tys_with_compat(
+                body_id,
+                param_env,
+                assumed_wf_tys,
+                implied_bounds_compat,
+            ),
+        )
+    }
+}
+
 #[extension(pub trait InferCtxtRegionExt<'tcx>)]
 impl<'tcx> InferCtxt<'tcx> {
     /// Resolve regions, using the deep normalizer to normalize any type-outlives
@@ -23,9 +63,11 @@ impl<'tcx> InferCtxt<'tcx> {
         param_env: ty::ParamEnv<'tcx>,
         assumed_wf_tys: impl IntoIterator<Item = Ty<'tcx>>,
     ) -> Vec<RegionResolutionError<'tcx>> {
-        self.resolve_regions_with_outlives_env(&OutlivesEnvironment::with_bounds(
+        self.resolve_regions_with_outlives_env(&OutlivesEnvironment::new(
+            self,
+            body_id,
             param_env,
-            self.implied_bounds_tys(body_id, param_env, assumed_wf_tys),
+            assumed_wf_tys,
         ))
     }
 

compiler/rustc_trait_selection/src/traits/auto_trait.rs

@@ -6,6 +6,7 @@ use std::iter;
 
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet, IndexEntry};
 use rustc_data_structures::unord::UnordSet;
+use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_infer::infer::DefineOpaqueTypes;
 use rustc_middle::ty::{Region, RegionVid};
 use tracing::debug;
@@ -13,6 +14,7 @@ use tracing::debug;
 use super::*;
 use crate::errors::UnableToConstructConstantValue;
 use crate::infer::region_constraints::{Constraint, RegionConstraintData};
+use crate::regions::OutlivesEnvironmentBuildExt;
 use crate::traits::project::ProjectAndUnifyResult;
 
 // FIXME(twk): this is obviously not nice to duplicate like that
@@ -158,7 +160,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
             panic!("Unable to fulfill trait {trait_did:?} for '{ty:?}': {errors:?}");
         }
 
-        let outlives_env = OutlivesEnvironment::new(full_env);
+        let outlives_env = OutlivesEnvironment::new(&infcx, CRATE_DEF_ID, full_env, []);
         let _ = infcx.process_registered_region_obligations(&outlives_env, |ty, _| Ok(ty));
 
         let region_data = infcx.inner.borrow_mut().unwrap_region_constraints().data().clone();

compiler/rustc_trait_selection/src/traits/outlives_bounds.rs

@@ -108,8 +108,9 @@ fn implied_outlives_bounds<'a, 'tcx>(
 
 #[extension(pub trait InferCtxtExt<'tcx>)]
 impl<'tcx> InferCtxt<'tcx> {
-    /// Do *NOT* call this directly.
-    fn implied_bounds_tys_compat<Tys: IntoIterator<Item = Ty<'tcx>>>(
+    /// Do *NOT* call this directly. You probably want to construct a `OutlivesEnvironment`
+    /// instead if you're interested in the implied bounds for a given signature.
+    fn implied_bounds_tys_with_compat<Tys: IntoIterator<Item = Ty<'tcx>>>(
         &self,
         body_id: LocalDefId,
         param_env: ParamEnv<'tcx>,
@@ -119,20 +120,4 @@ impl<'tcx> InferCtxt<'tcx> {
         tys.into_iter()
             .flat_map(move |ty| implied_outlives_bounds(self, param_env, body_id, ty, compat))
     }
-
-    /// If `-Z no-implied-bounds-compat` is set, calls `implied_bounds_tys_compat`
-    /// with `compat` set to `true`, otherwise `false`.
-    fn implied_bounds_tys(
-        &self,
-        body_id: LocalDefId,
-        param_env: ParamEnv<'tcx>,
-        tys: impl IntoIterator<Item = Ty<'tcx>>,
-    ) -> impl Iterator<Item = OutlivesBound<'tcx>> {
-        self.implied_bounds_tys_compat(
-            body_id,
-            param_env,
-            tys,
-            !self.tcx.sess.opts.unstable_opts.no_implied_bounds_compat,
-        )
-    }
 }