Add -Zno-implied-bounds-compat option and use it

5 files changed, 18 insertions, 13 deletions

diff --git a/compiler/rustc_hir_analysis/src/check/check.rs b/compiler/rustc_hir_analysis/src/check/check.rs
index d7b1447d980..03e2b0e0022 100644
--- a/compiler/rustc_hir_analysis/src/check/check.rs
+++ b/compiler/rustc_hir_analysis/src/check/check.rs
@@ -368,7 +368,7 @@ fn check_opaque_meets_bounds<'tcx>(
         // Can have different predicates to their defining use
         hir::OpaqueTyOrigin::TyAlias { .. } => {
             let wf_tys = ocx.assumed_wf_types_and_report_errors(param_env, def_id)?;
-            let implied_bounds = infcx.implied_bounds_tys_compat(param_env, def_id, &wf_tys);
+            let implied_bounds = infcx.implied_bounds_tys(param_env, def_id, &wf_tys);
             let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
             ocx.resolve_regions_and_report_errors(defining_use_anchor, &outlives_env)?;
         }
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index e2cdeb5b204..5b264f6f034 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -378,7 +378,7 @@ fn compare_method_predicate_entailment<'tcx>(
     // lifetime parameters.
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
-        infcx.implied_bounds_tys_compat(param_env, impl_m_def_id, &wf_tys),
+        infcx.implied_bounds_tys(param_env, impl_m_def_id, &wf_tys),
     );
     let errors = infcx.resolve_regions(&outlives_env);
     if !errors.is_empty() {
@@ -702,7 +702,7 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
     // lifetime parameters.
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
-        infcx.implied_bounds_tys_compat(param_env, impl_m_def_id, &wf_tys),
+        infcx.implied_bounds_tys(param_env, impl_m_def_id, &wf_tys),
     );
     ocx.resolve_regions_and_report_errors(impl_m_def_id, &outlives_env)?;
 
@@ -2070,8 +2070,7 @@ pub(super) fn check_type_bounds<'tcx>(
 
     // Finally, resolve all regions. This catches wily misuses of
     // lifetime parameters.
-    let implied_bounds =
-        infcx.implied_bounds_tys_compat(param_env, impl_ty_def_id, &assumed_wf_types);
+    let implied_bounds = infcx.implied_bounds_tys(param_env, impl_ty_def_id, &assumed_wf_types);
     let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
     ocx.resolve_regions_and_report_errors(impl_ty_def_id, &outlives_env)
 }
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item/refine.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item/refine.rs
index 3509a39fec9..0d8de0cabd1 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item/refine.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item/refine.rs
@@ -158,7 +158,7 @@ pub(super) fn check_refining_return_position_impl_trait_in_trait<'tcx>(
     }
     let outlives_env = OutlivesEnvironment::with_bounds(
         param_env,
-        infcx.implied_bounds_tys_compat(param_env, impl_m.def_id.expect_local(), &implied_wf_types),
+        infcx.implied_bounds_tys(param_env, impl_m.def_id.expect_local(), &implied_wf_types),
     );
     let errors = infcx.resolve_regions(&outlives_env);
     if !errors.is_empty() {
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 1af6282070e..58046173fb1 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -127,10 +127,13 @@ where
         }
     }
 
+    debug!(?assumed_wf_types);
+
     let infcx_compat = infcx.fork();
 
-    debug!(?assumed_wf_types);
-    let implied_bounds = infcx.implied_bounds_tys(param_env, body_def_id, &assumed_wf_types);
+    // 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(param_env, body_def_id, &assumed_wf_types, false);
     let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
 
     let errors = infcx.resolve_regions(&outlives_env);
@@ -166,9 +169,13 @@ where
         false
     };
 
-    if is_bevy {
+    // If we have set `no_implied_bounds_compat`, then do not attempt compatibility.
+    // We could also just always enter if `is_bevy`, and call `implied_bounds_tys`,
+    // 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(param_env, body_def_id, &assumed_wf_types);
+            infcx_compat.implied_bounds_tys_compat(param_env, body_def_id, &assumed_wf_types, true);
         let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
         let errors_compat = infcx_compat.resolve_regions(&outlives_env);
         if errors_compat.is_empty() {
@@ -770,7 +777,7 @@ fn resolve_regions_with_wf_tys<'tcx>(
     let infcx = tcx.infer_ctxt().build();
     let outlives_environment = OutlivesEnvironment::with_bounds(
         param_env,
-        infcx.implied_bounds_tys_compat(param_env, id, wf_tys),
+        infcx.implied_bounds_tys(param_env, id, wf_tys),
     );
     let region_bound_pairs = outlives_environment.region_bound_pairs();
 
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index a922209deb8..6964446f9c7 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -202,8 +202,7 @@ fn get_impl_args(
         return Err(guar);
     }
 
-    let implied_bounds =
-        infcx.implied_bounds_tys_compat(param_env, impl1_def_id, &assumed_wf_types);
+    let implied_bounds = infcx.implied_bounds_tys(param_env, impl1_def_id, &assumed_wf_types);
     let outlives_env = OutlivesEnvironment::with_bounds(param_env, implied_bounds);
     let _ = ocx.resolve_regions_and_report_errors(impl1_def_id, &outlives_env);
     let Ok(impl2_args) = infcx.fully_resolve(impl2_args) else {