use `TypingEnv` when no `infcx` is available

the behavior of the type system not only depends on the current
assumptions, but also the currentnphase of the compiler. This is
mostly necessary as we need to decide whether and how to reveal
opaque types. We track this via the `TypingMode`.

1 files changed, 24 insertions, 12 deletions

diff --git a/compiler/rustc_pattern_analysis/src/rustc.rs b/compiler/rustc_pattern_analysis/src/rustc.rs
index 9ea5023064c..936e5235c55 100644
--- a/compiler/rustc_pattern_analysis/src/rustc.rs
+++ b/compiler/rustc_pattern_analysis/src/rustc.rs
@@ -9,6 +9,7 @@ use rustc_index::{Idx, IndexVec};
 use rustc_middle::middle::stability::EvalResult;
 use rustc_middle::mir::{self, Const};
 use rustc_middle::thir::{self, Pat, PatKind, PatRange, PatRangeBoundary};
+use rustc_middle::traits::Reveal;
 use rustc_middle::ty::layout::IntegerExt;
 use rustc_middle::ty::{
     self, FieldDef, OpaqueTypeKey, ScalarInt, Ty, TyCtxt, TypeVisitableExt, VariantDef,
@@ -108,6 +109,17 @@ impl<'p, 'tcx: 'p> fmt::Debug for RustcPatCtxt<'p, 'tcx> {
 }
 
 impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
+    pub fn typing_mode(&self) -> ty::TypingMode<'tcx> {
+        debug_assert_eq!(self.param_env.reveal(), Reveal::UserFacing);
+        // FIXME(#132279): This is inside of a body. If we need to use the `param_env`
+        // and `typing_mode` we should reveal opaques defined by that body.
+        ty::TypingMode::non_body_analysis()
+    }
+
+    pub fn typing_env(&self) -> ty::TypingEnv<'tcx> {
+        ty::TypingEnv { typing_mode: self.typing_mode(), param_env: self.param_env }
+    }
+
     /// Type inference occasionally gives us opaque types in places where corresponding patterns
     /// have more specific types. To avoid inconsistencies as well as detect opaque uninhabited
     /// types, we use the corresponding concrete type if possible.
@@ -139,7 +151,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
     pub fn is_uninhabited(&self, ty: Ty<'tcx>) -> bool {
         !ty.inhabited_predicate(self.tcx).apply_revealing_opaque(
             self.tcx,
-            self.param_env,
+            self.typing_env(),
             self.module,
             &|key| self.reveal_opaque_key(key),
         )
@@ -179,7 +191,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
         variant.fields.iter().map(move |field| {
             let ty = field.ty(self.tcx, args);
             // `field.ty()` doesn't normalize after instantiating.
-            let ty = self.tcx.normalize_erasing_regions(self.param_env, ty);
+            let ty = self.tcx.normalize_erasing_regions(self.typing_env(), ty);
             let ty = self.reveal_opaque_ty(ty);
             (field, ty)
         })
@@ -369,7 +381,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                         let is_inhabited = v
                             .inhabited_predicate(cx.tcx, *def)
                             .instantiate(cx.tcx, args)
-                            .apply_revealing_opaque(cx.tcx, cx.param_env, cx.module, &|key| {
+                            .apply_revealing_opaque(cx.tcx, cx.typing_env(), cx.module, &|key| {
                                 cx.reveal_opaque_key(key)
                             });
                         // Variants that depend on a disabled unstable feature.
@@ -430,7 +442,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
         match bdy {
             PatRangeBoundary::NegInfinity => MaybeInfiniteInt::NegInfinity,
             PatRangeBoundary::Finite(value) => {
-                let bits = value.eval_bits(self.tcx, self.param_env);
+                let bits = value.eval_bits(self.tcx, self.typing_env());
                 match *ty.kind() {
                     ty::Int(ity) => {
                         let size = Integer::from_int_ty(&self.tcx, ity).size().bits();
@@ -539,7 +551,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
             PatKind::Constant { value } => {
                 match ty.kind() {
                     ty::Bool => {
-                        ctor = match value.try_eval_bool(cx.tcx, cx.param_env) {
+                        ctor = match value.try_eval_bool(cx.tcx, cx.typing_env()) {
                             Some(b) => Bool(b),
                             None => Opaque(OpaqueId::new()),
                         };
@@ -547,7 +559,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                         arity = 0;
                     }
                     ty::Char | ty::Int(_) | ty::Uint(_) => {
-                        ctor = match value.try_eval_bits(cx.tcx, cx.param_env) {
+                        ctor = match value.try_eval_bits(cx.tcx, cx.typing_env()) {
                             Some(bits) => {
                                 let x = match *ty.kind() {
                                     ty::Int(ity) => {
@@ -564,7 +576,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                         arity = 0;
                     }
                     ty::Float(ty::FloatTy::F16) => {
-                        ctor = match value.try_eval_bits(cx.tcx, cx.param_env) {
+                        ctor = match value.try_eval_bits(cx.tcx, cx.typing_env()) {
                             Some(bits) => {
                                 use rustc_apfloat::Float;
                                 let value = rustc_apfloat::ieee::Half::from_bits(bits);
@@ -576,7 +588,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                         arity = 0;
                     }
                     ty::Float(ty::FloatTy::F32) => {
-                        ctor = match value.try_eval_bits(cx.tcx, cx.param_env) {
+                        ctor = match value.try_eval_bits(cx.tcx, cx.typing_env()) {
                             Some(bits) => {
                                 use rustc_apfloat::Float;
                                 let value = rustc_apfloat::ieee::Single::from_bits(bits);
@@ -588,7 +600,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                         arity = 0;
                     }
                     ty::Float(ty::FloatTy::F64) => {
-                        ctor = match value.try_eval_bits(cx.tcx, cx.param_env) {
+                        ctor = match value.try_eval_bits(cx.tcx, cx.typing_env()) {
                             Some(bits) => {
                                 use rustc_apfloat::Float;
                                 let value = rustc_apfloat::ieee::Double::from_bits(bits);
@@ -600,7 +612,7 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                         arity = 0;
                     }
                     ty::Float(ty::FloatTy::F128) => {
-                        ctor = match value.try_eval_bits(cx.tcx, cx.param_env) {
+                        ctor = match value.try_eval_bits(cx.tcx, cx.typing_env()) {
                             Some(bits) => {
                                 use rustc_apfloat::Float;
                                 let value = rustc_apfloat::ieee::Quad::from_bits(bits);
@@ -649,8 +661,8 @@ impl<'p, 'tcx: 'p> RustcPatCtxt<'p, 'tcx> {
                     }
                     ty::Float(fty) => {
                         use rustc_apfloat::Float;
-                        let lo = lo.as_finite().map(|c| c.eval_bits(cx.tcx, cx.param_env));
-                        let hi = hi.as_finite().map(|c| c.eval_bits(cx.tcx, cx.param_env));
+                        let lo = lo.as_finite().map(|c| c.eval_bits(cx.tcx, cx.typing_env()));
+                        let hi = hi.as_finite().map(|c| c.eval_bits(cx.tcx, cx.typing_env()));
                         match fty {
                             ty::FloatTy::F16 => {
                                 use rustc_apfloat::ieee::Half;