Move outlives env computation into methods

8 files changed, 71 insertions, 49 deletions

diff --git a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
index 1e7451a16af..5440d451ec8 100644
--- a/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
+++ b/compiler/rustc_borrowck/src/region_infer/opaque_types.rs
@@ -1,6 +1,8 @@
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::ErrorGuaranteed;
+use rustc_hir::OpaqueTyOrigin;
 use rustc_hir::def_id::LocalDefId;
+use rustc_infer::infer::outlives::env::OutlivesEnvironment;
 use rustc_infer::infer::{InferCtxt, NllRegionVariableOrigin, TyCtxtInferExt as _};
 use rustc_macros::extension;
 use rustc_middle::ty::fold::fold_regions;
@@ -10,6 +12,7 @@ use rustc_middle::ty::{
     TypingMode,
 };
 use rustc_span::Span;
+use rustc_trait_selection::regions::OutlivesEnvironmentBuildExt;
 use rustc_trait_selection::traits::ObligationCtxt;
 use tracing::{debug, instrument};
 
@@ -406,10 +409,6 @@ impl<'tcx> LazyOpaqueTyEnv<'tcx> {
     }
 
     fn get_canonical_args(&self) -> ty::GenericArgsRef<'tcx> {
-        use rustc_hir as hir;
-        use rustc_infer::infer::outlives::env::OutlivesEnvironment;
-        use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _;
-
         if let Some(&canonical_args) = self.canonical_args.get() {
             return canonical_args;
         }
@@ -417,9 +416,9 @@ impl<'tcx> LazyOpaqueTyEnv<'tcx> {
         let &Self { tcx, def_id, .. } = self;
         let origin = tcx.local_opaque_ty_origin(def_id);
         let parent = match origin {
-            hir::OpaqueTyOrigin::FnReturn { parent, .. }
-            | hir::OpaqueTyOrigin::AsyncFn { parent, .. }
-            | hir::OpaqueTyOrigin::TyAlias { parent, .. } => parent,
+            OpaqueTyOrigin::FnReturn { parent, .. }
+            | OpaqueTyOrigin::AsyncFn { parent, .. }
+            | OpaqueTyOrigin::TyAlias { parent, .. } => parent,
         };
         let param_env = tcx.param_env(parent);
         let args = GenericArgs::identity_for_item(tcx, parent).extend_to(
@@ -439,8 +438,7 @@ impl<'tcx> LazyOpaqueTyEnv<'tcx> {
             tcx.dcx().span_delayed_bug(tcx.def_span(def_id), "error getting implied bounds");
             Default::default()
         });
-        let implied_bounds = infcx.implied_bounds_tys(parent, param_env, wf_tys);
-        let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
+        let outlives_env = OutlivesEnvironment::new(&infcx, parent, param_env, wf_tys);
 
         let mut seen = vec![tcx.lifetimes.re_static];
         let canonical_args = fold_regions(tcx, args, |r1, _| {
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 5023a09e2f3..83bb8c0dfaf 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -25,11 +25,10 @@ use rustc_middle::{bug, span_bug};
 use rustc_session::parse::feature_err;
 use rustc_span::{DUMMY_SP, Ident, Span, sym};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
-use rustc_trait_selection::regions::InferCtxtRegionExt;
+use rustc_trait_selection::regions::{InferCtxtRegionExt, OutlivesEnvironmentBuildExt};
 use rustc_trait_selection::traits::misc::{
     ConstParamTyImplementationError, type_allowed_to_implement_const_param_ty,
 };
-use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _;
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_trait_selection::traits::{
     self, FulfillmentError, Obligation, ObligationCause, ObligationCauseCode, ObligationCtxt,
@@ -128,13 +127,13 @@ where
     let infcx_compat = infcx.fork();
 
     // We specifically want to call the non-compat version of `implied_bounds_tys`; we do this always.
-    let implied_bounds = infcx.implied_bounds_tys_compat(
+    let outlives_env = OutlivesEnvironment::new_with_implied_bounds_compat(
+        &infcx,
         body_def_id,
         param_env,
         assumed_wf_types.iter().copied(),
         false,
     );
-    let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
 
     lint_redundant_lifetimes(tcx, body_def_id, &outlives_env);
 
@@ -176,9 +175,13 @@ where
     // but that does result in slightly more work when this option is set and
     // just obscures what we mean here anyways. Let's just be explicit.
     if is_bevy && !infcx.tcx.sess.opts.unstable_opts.no_implied_bounds_compat {
-        let implied_bounds =
-            infcx_compat.implied_bounds_tys_compat(body_def_id, param_env, assumed_wf_types, true);
-        let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
+        let outlives_env = OutlivesEnvironment::new_with_implied_bounds_compat(
+            &infcx,
+            body_def_id,
+            param_env,
+            assumed_wf_types,
+            true,
+        );
         let errors_compat = infcx_compat.resolve_regions_with_outlives_env(&outlives_env);
         if errors_compat.is_empty() {
             Ok(())
diff --git a/compiler/rustc_infer/src/infer/outlives/env.rs b/compiler/rustc_infer/src/infer/outlives/env.rs
index 9300fc574dc..f8ab0b53a00 100644
--- a/compiler/rustc_infer/src/infer/outlives/env.rs
+++ b/compiler/rustc_infer/src/infer/outlives/env.rs
@@ -59,12 +59,6 @@ pub struct OutlivesEnvironment<'tcx> {
 pub type RegionBoundPairs<'tcx> = FxIndexSet<ty::OutlivesPredicate<'tcx, GenericKind<'tcx>>>;
 
 impl<'tcx> OutlivesEnvironment<'tcx> {
-    /// Create a new `OutlivesEnvironment` without extra outlives bounds.
-    #[inline]
-    pub fn new(param_env: ty::ParamEnv<'tcx>) -> Self {
-        Self::with_bounds(param_env, vec![])
-    }
-
     /// Create a new `OutlivesEnvironment` with extra outlives bounds.
     pub fn with_bounds(
         param_env: ty::ParamEnv<'tcx>,
diff --git a/compiler/rustc_lint/src/impl_trait_overcaptures.rs b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
index d6546066d86..d251b4b7459 100644
--- a/compiler/rustc_lint/src/impl_trait_overcaptures.rs
+++ b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
@@ -25,8 +25,8 @@ use rustc_span::{Span, Symbol};
 use rustc_trait_selection::errors::{
     AddPreciseCapturingForOvercapture, impl_trait_overcapture_suggestion,
 };
+use rustc_trait_selection::regions::OutlivesEnvironmentBuildExt;
 use rustc_trait_selection::traits::ObligationCtxt;
-use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt;
 
 use crate::{LateContext, LateLintPass, fluent_generated as fluent};
 
@@ -190,9 +190,7 @@ fn check_fn(tcx: TyCtxt<'_>, parent_def_id: LocalDefId) {
             let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
             let ocx = ObligationCtxt::new(&infcx);
             let assumed_wf_tys = ocx.assumed_wf_types(param_env, parent_def_id).unwrap_or_default();
-            let implied_bounds =
-                infcx.implied_bounds_tys_compat(parent_def_id, param_env, assumed_wf_tys, false);
-            OutlivesEnvironment::with_bounds(param_env, implied_bounds)
+            OutlivesEnvironment::new(&infcx, parent_def_id, param_env, assumed_wf_tys)
         }),
     });
 }
diff --git a/compiler/rustc_trait_selection/src/regions.rs b/compiler/rustc_trait_selection/src/regions.rs
index 1bae6c80cfa..fc9fa44b4c6 100644
--- a/compiler/rustc_trait_selection/src/regions.rs
+++ b/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,
         ))
     }
 
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index 9a53e8a5d51..1fca2f4da7e 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/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();
diff --git a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
index eecc499f384..18932695807 100644
--- a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs
+++ b/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,
-        )
-    }
 }
diff --git a/src/doc/rustc-dev-guide/src/traits/implied-bounds.md b/src/doc/rustc-dev-guide/src/traits/implied-bounds.md
index 63b09a43f47..05693dcd5a1 100644
--- a/src/doc/rustc-dev-guide/src/traits/implied-bounds.md
+++ b/src/doc/rustc-dev-guide/src/traits/implied-bounds.md
@@ -40,7 +40,7 @@ requirements of impls and functions as explicit predicates.
 ### using implicit implied bounds as assumptions
 
 These bounds are not added to the `ParamEnv` of the affected item itself. For lexical
-region resolution they are added using [`fn OutlivesEnvironment::with_bounds`].
+region resolution they are added using [`fn OutlivesEnvironment::new`].
 Similarly, during MIR borrowck we add them using
 [`fn UniversalRegionRelationsBuilder::add_implied_bounds`].
 
@@ -55,7 +55,7 @@ The assumed outlives constraints for implicit bounds are computed using the
 MIR borrowck adds the outlives constraints for both the normalized and unnormalized types,
 lexical region resolution [only uses the unnormalized types][notnorm].
 
-[`fn OutlivesEnvironment::with_bounds`]: https://github.com/rust-lang/rust/blob/5b8bc568d28b2e922290c9a966b3231d0ce9398b/compiler/rustc_infer/src/infer/outlives/env.rs#L90-L97
+[`fn OutlivesEnvironment::new`]: TODO
 [`fn UniversalRegionRelationsBuilder::add_implied_bounds`]: https://github.com/rust-lang/rust/blob/5b8bc568d28b2e922290c9a966b3231d0ce9398b/compiler/rustc_borrowck/src/type_check/free_region_relations.rs#L316
 [mir]: https://github.com/rust-lang/rust/blob/91cae1dcdcf1a31bd8a92e4a63793d65cfe289bb/compiler/rustc_borrowck/src/type_check/free_region_relations.rs#L258-L332
 [`fn assumed_wf_types`]: https://github.com/rust-lang/rust/blob/5b8bc568d28b2e922290c9a966b3231d0ce9398b/compiler/rustc_ty_utils/src/implied_bounds.rs#L21