use ty::Unevaluated instead of def substs pair

compiler/rustc_trait_selection/src/traits/const_evaluatable.rs

@@ -19,7 +19,7 @@ use rustc_middle::mir::{self, Rvalue, StatementKind, TerminatorKind};
 use rustc_middle::ty::subst::{Subst, SubstsRef};
 use rustc_middle::ty::{self, TyCtxt, TypeFoldable};
 use rustc_session::lint;
-use rustc_span::def_id::{DefId, LocalDefId};
+use rustc_span::def_id::LocalDefId;
 use rustc_span::Span;
 
 use std::cmp;
@@ -29,26 +29,20 @@ use std::ops::ControlFlow;
 /// Check if a given constant can be evaluated.
 pub fn is_const_evaluatable<'cx, 'tcx>(
     infcx: &InferCtxt<'cx, 'tcx>,
-    def: ty::WithOptConstParam<DefId>,
-    substs: SubstsRef<'tcx>,
+    uv: ty::Unevaluated<'tcx>,
     param_env: ty::ParamEnv<'tcx>,
     span: Span,
 ) -> Result<(), NotConstEvaluatable> {
-    debug!("is_const_evaluatable({:?}, {:?})", def, substs);
+    debug!("is_const_evaluatable({:?})", uv);
     if infcx.tcx.features().const_evaluatable_checked {
         let tcx = infcx.tcx;
-        match AbstractConst::new(tcx, def, substs)? {
+        match AbstractConst::new(tcx, uv)? {
             // We are looking at a generic abstract constant.
             Some(ct) => {
                 for pred in param_env.caller_bounds() {
                     match pred.kind().skip_binder() {
-                        ty::PredicateKind::ConstEvaluatable(b_def, b_substs) => {
-                            if b_def == def && b_substs == substs {
-                                debug!("is_const_evaluatable: caller_bound ~~> ok");
-                                return Ok(());
-                            }
-
-                            if let Some(b_ct) = AbstractConst::new(tcx, b_def, b_substs)? {
+                        ty::PredicateKind::ConstEvaluatable(uv) => {
+                            if let Some(b_ct) = AbstractConst::new(tcx, uv)? {
                                 // Try to unify with each subtree in the AbstractConst to allow for
                                 // `N + 1` being const evaluatable even if theres only a `ConstEvaluatable`
                                 // predicate for `(N + 1) * 2`
@@ -134,7 +128,7 @@ pub fn is_const_evaluatable<'cx, 'tcx>(
     }
 
     let future_compat_lint = || {
-        if let Some(local_def_id) = def.did.as_local() {
+        if let Some(local_def_id) = uv.def.did.as_local() {
             infcx.tcx.struct_span_lint_hir(
                 lint::builtin::CONST_EVALUATABLE_UNCHECKED,
                 infcx.tcx.hir().local_def_id_to_hir_id(local_def_id),
@@ -155,13 +149,12 @@ pub fn is_const_evaluatable<'cx, 'tcx>(
     // and hopefully soon change this to an error.
     //
     // See #74595 for more details about this.
-    let concrete =
-        infcx.const_eval_resolve(param_env, ty::Unevaluated::new(def, substs), Some(span));
+    let concrete = infcx.const_eval_resolve(param_env, uv, Some(span));
 
-    if concrete.is_ok() && substs.has_param_types_or_consts(infcx.tcx) {
-        match infcx.tcx.def_kind(def.did) {
+    if concrete.is_ok() && uv.substs(infcx.tcx).has_param_types_or_consts(infcx.tcx) {
+        match infcx.tcx.def_kind(uv.def.did) {
             DefKind::AnonConst => {
-                let mir_body = infcx.tcx.mir_for_ctfe_opt_const_arg(def);
+                let mir_body = infcx.tcx.mir_for_ctfe_opt_const_arg(uv.def);
 
                 if mir_body.is_polymorphic {
                     future_compat_lint();
@@ -173,7 +166,7 @@ pub fn is_const_evaluatable<'cx, 'tcx>(
 
     debug!(?concrete, "is_const_evaluatable");
     match concrete {
-        Err(ErrorHandled::TooGeneric) => Err(match substs.has_infer_types_or_consts() {
+        Err(ErrorHandled::TooGeneric) => Err(match uv.has_infer_types_or_consts() {
             true => NotConstEvaluatable::MentionsInfer,
             false => NotConstEvaluatable::MentionsParam,
         }),
@@ -198,15 +191,14 @@ pub struct AbstractConst<'tcx> {
     pub substs: SubstsRef<'tcx>,
 }
 
-impl AbstractConst<'tcx> {
+impl<'tcx> AbstractConst<'tcx> {
     pub fn new(
         tcx: TyCtxt<'tcx>,
-        def: ty::WithOptConstParam<DefId>,
-        substs: SubstsRef<'tcx>,
+        uv: ty::Unevaluated<'tcx>,
     ) -> Result<Option<AbstractConst<'tcx>>, ErrorReported> {
-        let inner = tcx.mir_abstract_const_opt_const_arg(def)?;
-        debug!("AbstractConst::new({:?}) = {:?}", def, inner);
-        Ok(inner.map(|inner| AbstractConst { inner, substs }))
+        let inner = tcx.mir_abstract_const_opt_const_arg(uv.def)?;
+        debug!("AbstractConst::new({:?}) = {:?}", uv, inner);
+        Ok(inner.map(|inner| AbstractConst { inner, substs: uv.substs(tcx) }))
     }
 
     pub fn from_const(
@@ -214,7 +206,7 @@ impl AbstractConst<'tcx> {
         ct: &ty::Const<'tcx>,
     ) -> Result<Option<AbstractConst<'tcx>>, ErrorReported> {
         match ct.val {
-            ty::ConstKind::Unevaluated(uv) => AbstractConst::new(tcx, uv.def, uv.substs(tcx)),
+            ty::ConstKind::Unevaluated(uv) => AbstractConst::new(tcx, uv),
             ty::ConstKind::Error(_) => Err(ErrorReported),
             _ => Ok(None),
         }
@@ -564,14 +556,11 @@ pub(super) fn mir_abstract_const<'tcx>(
 
 pub(super) fn try_unify_abstract_consts<'tcx>(
     tcx: TyCtxt<'tcx>,
-    ((a, a_substs), (b, b_substs)): (
-        (ty::WithOptConstParam<DefId>, SubstsRef<'tcx>),
-        (ty::WithOptConstParam<DefId>, SubstsRef<'tcx>),
-    ),
+    (a, b): (ty::Unevaluated<'tcx>, ty::Unevaluated<'tcx>),
 ) -> bool {
     (|| {
-        if let Some(a) = AbstractConst::new(tcx, a, a_substs)? {
-            if let Some(b) = AbstractConst::new(tcx, b, b_substs)? {
+        if let Some(a) = AbstractConst::new(tcx, a)? {
+            if let Some(b) = AbstractConst::new(tcx, b)? {
                 return Ok(try_unify(tcx, a, b));
             }
         }