pattern lowering, yeet TypingEnv::from_param_env

Author: lcnr

compiler/rustc_mir_build/src/thir/cx/mod.rs

@@ -123,7 +123,7 @@ impl<'tcx> Cx<'tcx> {
 
     #[instrument(level = "debug", skip(self))]
     fn pattern_from_hir(&mut self, p: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> {
-        pat_from_hir(self.tcx, self.param_env, self.typeck_results(), p)
+        pat_from_hir(self.tcx, self.typing_env(), self.typeck_results(), p)
     }
 
     fn closure_env_param(&self, owner_def: LocalDefId, expr_id: HirId) -> Option<Param<'tcx>> {

compiler/rustc_mir_build/src/thir/pattern/const_to_pat.rs

@@ -2,11 +2,11 @@ use rustc_abi::{FieldIdx, VariantIdx};
 use rustc_apfloat::Float;
 use rustc_hir as hir;
 use rustc_index::Idx;
-use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
+use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::traits::Obligation;
 use rustc_middle::mir::interpret::ErrorHandled;
 use rustc_middle::thir::{FieldPat, Pat, PatKind};
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, TypingMode, ValTree};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitableExt, ValTree};
 use rustc_middle::{mir, span_bug};
 use rustc_span::Span;
 use rustc_trait_selection::traits::ObligationCause;
@@ -35,10 +35,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         id: hir::HirId,
         span: Span,
     ) -> Box<Pat<'tcx>> {
-        // FIXME(#132279): We likely want to be able to reveal the hidden types
-        // of opaques defined in this function here.
-        let infcx = self.tcx.infer_ctxt().build(TypingMode::non_body_analysis());
-        let mut convert = ConstToPat::new(self, id, span, infcx);
+        let mut convert = ConstToPat::new(self, id, span);
 
         match c.kind() {
             ty::ConstKind::Unevaluated(uv) => convert.unevaluated_to_pat(uv, ty),
@@ -49,44 +46,29 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
 }
 
 struct ConstToPat<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     span: Span,
 
-    // inference context used for checking `T: Structural` bounds.
-    infcx: InferCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
-
     treat_byte_string_as_slice: bool,
 }
 
 impl<'tcx> ConstToPat<'tcx> {
-    fn new(
-        pat_ctxt: &PatCtxt<'_, 'tcx>,
-        id: hir::HirId,
-        span: Span,
-        infcx: InferCtxt<'tcx>,
-    ) -> Self {
+    fn new(pat_ctxt: &PatCtxt<'_, 'tcx>, id: hir::HirId, span: Span) -> Self {
         trace!(?pat_ctxt.typeck_results.hir_owner);
         ConstToPat {
+            tcx: pat_ctxt.tcx,
+            typing_env: pat_ctxt.typing_env,
             span,
-            infcx,
-            param_env: pat_ctxt.param_env,
             treat_byte_string_as_slice: pat_ctxt
                 .typeck_results
                 .treat_byte_string_as_slice
                 .contains(&id.local_id),
         }
     }
 
-    fn tcx(&self) -> TyCtxt<'tcx> {
-        self.infcx.tcx
-    }
-
-    fn typing_env(&self) -> ty::TypingEnv<'tcx> {
-        self.infcx.typing_env(self.param_env)
-    }
-
     fn type_marked_structural(&self, ty: Ty<'tcx>) -> bool {
-        ty.is_structural_eq_shallow(self.infcx.tcx)
+        ty.is_structural_eq_shallow(self.tcx)
     }
 
     fn unevaluated_to_pat(
@@ -105,22 +87,21 @@ impl<'tcx> ConstToPat<'tcx> {
         // FIXME: `const_eval_resolve_for_typeck` should probably just set the env to `Reveal::All`
         // instead of having this logic here
         let typing_env =
-            self.tcx().erase_regions(self.typing_env()).with_reveal_all_normalized(self.tcx());
-        let uv = self.tcx().erase_regions(uv);
+            self.tcx.erase_regions(self.typing_env).with_reveal_all_normalized(self.tcx);
+        let uv = self.tcx.erase_regions(uv);
 
         // try to resolve e.g. associated constants to their definition on an impl, and then
         // evaluate the const.
-        let valtree = match self.infcx.tcx.const_eval_resolve_for_typeck(typing_env, uv, self.span)
-        {
+        let valtree = match self.tcx.const_eval_resolve_for_typeck(typing_env, uv, self.span) {
             Ok(Ok(c)) => c,
             Err(ErrorHandled::Reported(_, _)) => {
                 // Let's tell the use where this failing const occurs.
-                let e = self.tcx().dcx().emit_err(CouldNotEvalConstPattern { span: self.span });
+                let e = self.tcx.dcx().emit_err(CouldNotEvalConstPattern { span: self.span });
                 return pat_from_kind(PatKind::Error(e));
             }
             Err(ErrorHandled::TooGeneric(_)) => {
                 let e = self
-                    .tcx()
+                    .tcx
                     .dcx()
                     .emit_err(ConstPatternDependsOnGenericParameter { span: self.span });
                 return pat_from_kind(PatKind::Error(e));
@@ -130,13 +111,13 @@ impl<'tcx> ConstToPat<'tcx> {
                 let e = match bad_ty.kind() {
                     ty::Adt(def, ..) => {
                         assert!(def.is_union());
-                        self.tcx().dcx().emit_err(UnionPattern { span: self.span })
+                        self.tcx.dcx().emit_err(UnionPattern { span: self.span })
                     }
                     ty::FnPtr(..) | ty::RawPtr(..) => {
-                        self.tcx().dcx().emit_err(PointerPattern { span: self.span })
+                        self.tcx.dcx().emit_err(PointerPattern { span: self.span })
                     }
                     _ => self
-                        .tcx()
+                        .tcx
                         .dcx()
                         .emit_err(InvalidPattern { span: self.span, non_sm_ty: bad_ty }),
                 };
@@ -151,7 +132,7 @@ impl<'tcx> ConstToPat<'tcx> {
             // Always check for `PartialEq` if we had no other errors yet.
             if !self.type_has_partial_eq_impl(ty) {
                 let err = TypeNotPartialEq { span: self.span, non_peq_ty: ty };
-                let e = self.tcx().dcx().emit_err(err);
+                let e = self.tcx.dcx().emit_err(err);
                 return pat_from_kind(PatKind::Error(e));
             }
         }
@@ -161,18 +142,19 @@ impl<'tcx> ConstToPat<'tcx> {
 
     #[instrument(level = "trace", skip(self), ret)]
     fn type_has_partial_eq_impl(&self, ty: Ty<'tcx>) -> bool {
-        let tcx = self.tcx();
+        let (infcx, param_env) = self.tcx.infer_ctxt().build_with_typing_env(self.typing_env);
         // double-check there even *is* a semantic `PartialEq` to dispatch to.
         //
         // (If there isn't, then we can safely issue a hard
         // error, because that's never worked, due to compiler
         // using `PartialEq::eq` in this scenario in the past.)
-        let partial_eq_trait_id = tcx.require_lang_item(hir::LangItem::PartialEq, Some(self.span));
+        let partial_eq_trait_id =
+            self.tcx.require_lang_item(hir::LangItem::PartialEq, Some(self.span));
         let partial_eq_obligation = Obligation::new(
-            tcx,
+            self.tcx,
             ObligationCause::dummy(),
-            self.param_env,
-            ty::TraitRef::new(tcx, partial_eq_trait_id, [ty, ty]),
+            param_env,
+            ty::TraitRef::new(self.tcx, partial_eq_trait_id, [ty, ty]),
         );
 
         // This *could* accept a type that isn't actually `PartialEq`, because region bounds get
@@ -181,7 +163,7 @@ impl<'tcx> ConstToPat<'tcx> {
         // `PartialEq` for some lifetime but *not* for `'static`? If this ever becomes a problem
         // we'll need to leave some sort of trace of this requirement in the MIR so that borrowck
         // can ensure that the type really implements `PartialEq`.
-        self.infcx.predicate_must_hold_modulo_regions(&partial_eq_obligation)
+        infcx.predicate_must_hold_modulo_regions(&partial_eq_obligation)
     }
 
     fn field_pats(
@@ -192,7 +174,7 @@ impl<'tcx> ConstToPat<'tcx> {
             .map(|(idx, (val, ty))| {
                 let field = FieldIdx::new(idx);
                 // Patterns can only use monomorphic types.
-                let ty = self.tcx().normalize_erasing_regions(self.typing_env(), ty);
+                let ty = self.tcx.normalize_erasing_regions(self.typing_env, ty);
                 FieldPat { field, pattern: self.valtree_to_pat(val, ty) }
             })
             .collect()
@@ -202,12 +184,12 @@ impl<'tcx> ConstToPat<'tcx> {
     #[instrument(skip(self), level = "debug")]
     fn valtree_to_pat(&self, cv: ValTree<'tcx>, ty: Ty<'tcx>) -> Box<Pat<'tcx>> {
         let span = self.span;
-        let tcx = self.tcx();
+        let tcx = self.tcx;
         let kind = match ty.kind() {
             ty::Adt(adt_def, _) if !self.type_marked_structural(ty) => {
                 // Extremely important check for all ADTs! Make sure they opted-in to be used in
                 // patterns.
-                debug!("adt_def {:?} has !type_marked_structural for cv.ty: {:?}", adt_def, ty,);
+                debug!("adt_def {:?} has !type_marked_structural for cv.ty: {:?}", adt_def, ty);
                 let err = TypeNotStructural { span, non_sm_ty: ty };
                 let e = tcx.dcx().emit_err(err);
                 // We errored. Signal that in the pattern, so that follow up errors can be silenced.
@@ -225,22 +207,17 @@ impl<'tcx> ConstToPat<'tcx> {
                             adt_def.variants()[variant_index]
                                 .fields
                                 .iter()
-                                .map(|field| field.ty(self.tcx(), args)),
+                                .map(|field| field.ty(self.tcx, args)),
                         ),
                     ),
                 }
             }
             ty::Adt(def, args) => {
                 assert!(!def.is_union()); // Valtree construction would never succeed for unions.
                 PatKind::Leaf {
-                    subpatterns: self.field_pats(
-                        cv.unwrap_branch().iter().copied().zip(
-                            def.non_enum_variant()
-                                .fields
-                                .iter()
-                                .map(|field| field.ty(self.tcx(), args)),
-                        ),
-                    ),
+                    subpatterns: self.field_pats(cv.unwrap_branch().iter().copied().zip(
+                        def.non_enum_variant().fields.iter().map(|field| field.ty(self.tcx, args)),
+                    )),
                 }
             }
             ty::Tuple(fields) => PatKind::Leaf {
@@ -274,9 +251,7 @@ impl<'tcx> ConstToPat<'tcx> {
                 // convert the dereferenced constant to a pattern that is the sub-pattern of the
                 // deref pattern.
                 _ => {
-                    if !pointee_ty.is_sized(tcx, self.infcx.typing_env(self.param_env))
-                        && !pointee_ty.is_slice()
-                    {
+                    if !pointee_ty.is_sized(tcx, self.typing_env) && !pointee_ty.is_slice() {
                         let err = UnsizedPattern { span, non_sm_ty: *pointee_ty };
                         let e = tcx.dcx().emit_err(err);
                         // We errored. Signal that in the pattern, so that follow up errors can be silenced.

compiler/rustc_mir_build/src/thir/pattern/mod.rs

@@ -30,7 +30,7 @@ use crate::thir::util::UserAnnotatedTyHelpers;
 
 struct PatCtxt<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     typeck_results: &'a ty::TypeckResults<'tcx>,
 
     /// Used by the Rust 2024 migration lint.
@@ -39,13 +39,13 @@ struct PatCtxt<'a, 'tcx> {
 
 pub(super) fn pat_from_hir<'a, 'tcx>(
     tcx: TyCtxt<'tcx>,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     typeck_results: &'a ty::TypeckResults<'tcx>,
     pat: &'tcx hir::Pat<'tcx>,
 ) -> Box<Pat<'tcx>> {
     let mut pcx = PatCtxt {
         tcx,
-        param_env,
+        typing_env,
         typeck_results,
         rust_2024_migration_suggestion: typeck_results
             .rust_2024_migration_desugared_pats()
@@ -242,7 +242,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         let lo = lo.unwrap_or(PatRangeBoundary::NegInfinity);
         let hi = hi.unwrap_or(PatRangeBoundary::PosInfinity);
 
-        let cmp = lo.compare_with(hi, ty, self.tcx, ty::TypingEnv::from_param_env(self.param_env));
+        let cmp = lo.compare_with(hi, ty, self.tcx, self.typing_env);
         let mut kind = PatKind::Range(Box::new(PatRange { lo, hi, end, ty }));
         match (end, cmp) {
             // `x..y` where `x < y`.