Auto merge of #132460 - lcnr:questionable-uwu, r=compiler-errors

Use `TypingMode` throughout the compiler instead of `ParamEnv`

Hopefully the biggest single PR as part of https://github.com/rust-lang/types-team/issues/128.

## `infcx.typing_env` while defining opaque types

I don't know how'll be able to correctly handle opaque types when using something taking a `TypingEnv` while defining opaque types. To correctly handle the opaques we need to be able to pass in the current `opaque_type_storage` and return constraints, i.e. we need to use a proper canonical query. We should migrate all the queries used during HIR typeck and borrowck where this matters to proper canonical queries. This is

## `layout_of` and `Reveal::All`

We convert the `ParamEnv` to `Reveal::All` right at the start of the `layout_of` query, so I've changed callers of `layout_of` to already use a post analysis `TypingEnv` when encountering it.

https://github.com/rust-lang/rust/blob/ca87b535a05097df6abbe2a031b057de2cefac5b/compiler/rustc_ty_utils/src/layout.rs#L51

## `Ty::is_[unpin|sized|whatever]`

I haven't migrated `fn is_item_raw` to use `TypingEnv`, will do so in a followup PR, this should significantly reduce the amount of `typing_env.param_env`. At some point there will probably be zero such uses as using the type system while ignoring the `typing_mode` is incorrect.

## `MirPhase` and phase-transitions

When inside of a MIR-body, we can mostly use its `MirPhase` to figure out the right `typing_mode`. This does not work during phase transitions, most notably when transitioning from `Analysis` to `Runtime`:

https://github.com/rust-lang/rust/blob/dae7ac133b9eda152784c075facb31a6688c92b1/compiler/rustc_mir_transform/src/lib.rs#L606-L625

All these passes still run with `MirPhase::Analysis`, but we should only use `Reveal::All` once we're run the `RevealAll` pass. This required me to manually construct the right `TypingEnv` in all these passes. Given that it feels somewhat easy to accidentally miss this going forward, I would maybe like to change `Body::phase` to an `Option` and replace it at the start of phase transitions. This then makes it clear that the MIR is currently in a weird state.

r? `@ghost`

3 files changed, 12 insertions, 11 deletions

diff --git a/compiler/rustc_traits/src/codegen.rs b/compiler/rustc_traits/src/codegen.rs
index d8c1c50d79a..57225df0819 100644
--- a/compiler/rustc_traits/src/codegen.rs
+++ b/compiler/rustc_traits/src/codegen.rs
@@ -6,7 +6,7 @@
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::bug;
 use rustc_middle::traits::CodegenObligationError;
-use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt, TypingMode};
+use rustc_middle::ty::{self, PseudoCanonicalInput, TyCtxt, TypeVisitableExt};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::traits::{
     ImplSource, Obligation, ObligationCause, ObligationCtxt, ScrubbedTraitError, SelectionContext,
@@ -23,14 +23,15 @@ use tracing::debug;
 /// This also expects that `trait_ref` is fully normalized.
 pub(crate) fn codegen_select_candidate<'tcx>(
     tcx: TyCtxt<'tcx>,
-    (param_env, trait_ref): (ty::ParamEnv<'tcx>, ty::TraitRef<'tcx>),
+    key: PseudoCanonicalInput<'tcx, ty::TraitRef<'tcx>>,
 ) -> Result<&'tcx ImplSource<'tcx, ()>, CodegenObligationError> {
+    let PseudoCanonicalInput { typing_env, value: trait_ref } = key;
     // We expect the input to be fully normalized.
-    debug_assert_eq!(trait_ref, tcx.normalize_erasing_regions(param_env, trait_ref));
+    debug_assert_eq!(trait_ref, tcx.normalize_erasing_regions(typing_env, trait_ref));
 
     // Do the initial selection for the obligation. This yields the
     // shallow result we are looking for -- that is, what specific impl.
-    let infcx = tcx.infer_ctxt().ignoring_regions().build(TypingMode::from_param_env(param_env));
+    let (infcx, param_env) = tcx.infer_ctxt().ignoring_regions().build_with_typing_env(typing_env);
     let mut selcx = SelectionContext::new(&infcx);
 
     let obligation_cause = ObligationCause::dummy();
diff --git a/compiler/rustc_traits/src/dropck_outlives.rs b/compiler/rustc_traits/src/dropck_outlives.rs
index 4e5309eea28..51e4dbe81b3 100644
--- a/compiler/rustc_traits/src/dropck_outlives.rs
+++ b/compiler/rustc_traits/src/dropck_outlives.rs
@@ -5,7 +5,7 @@ use rustc_infer::infer::canonical::{Canonical, QueryResponse};
 use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::traits::query::{DropckConstraint, DropckOutlivesResult};
-use rustc_middle::ty::{GenericArgs, TyCtxt};
+use rustc_middle::ty::{self, GenericArgs, TyCtxt};
 use rustc_trait_selection::infer::InferCtxtBuilderExt;
 use rustc_trait_selection::traits::query::dropck_outlives::{
     compute_dropck_outlives_inner, dtorck_constraint_for_ty_inner,
@@ -35,7 +35,7 @@ pub(crate) fn adt_dtorck_constraint(
 ) -> Result<&DropckConstraint<'_>, NoSolution> {
     let def = tcx.adt_def(def_id);
     let span = tcx.def_span(def_id);
-    let param_env = tcx.param_env(def_id);
+    let typing_env = ty::TypingEnv::non_body_analysis(tcx, def_id);
     debug!("dtorck_constraint: {:?}", def);
 
     if def.is_manually_drop() {
@@ -57,7 +57,7 @@ pub(crate) fn adt_dtorck_constraint(
     let mut result = DropckConstraint::empty();
     for field in def.all_fields() {
         let fty = tcx.type_of(field.did).instantiate_identity();
-        dtorck_constraint_for_ty_inner(tcx, param_env, span, 0, fty, &mut result)?;
+        dtorck_constraint_for_ty_inner(tcx, typing_env, span, 0, fty, &mut result)?;
     }
     result.outlives.extend(tcx.destructor_constraints(def));
     dedup_dtorck_constraint(&mut result);
diff --git a/compiler/rustc_traits/src/normalize_erasing_regions.rs b/compiler/rustc_traits/src/normalize_erasing_regions.rs
index d79059a39a1..68ff66bbce7 100644
--- a/compiler/rustc_traits/src/normalize_erasing_regions.rs
+++ b/compiler/rustc_traits/src/normalize_erasing_regions.rs
@@ -1,7 +1,7 @@
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::query::Providers;
 use rustc_middle::traits::query::NoSolution;
-use rustc_middle::ty::{self, ParamEnvAnd, TyCtxt, TypeFoldable, TypeVisitableExt, TypingMode};
+use rustc_middle::ty::{self, PseudoCanonicalInput, TyCtxt, TypeFoldable, TypeVisitableExt};
 use rustc_trait_selection::traits::query::normalize::QueryNormalizeExt;
 use rustc_trait_selection::traits::{Normalized, ObligationCause};
 use tracing::debug;
@@ -19,10 +19,10 @@ pub(crate) fn provide(p: &mut Providers) {
 
 fn try_normalize_after_erasing_regions<'tcx, T: TypeFoldable<TyCtxt<'tcx>> + PartialEq + Copy>(
     tcx: TyCtxt<'tcx>,
-    goal: ParamEnvAnd<'tcx, T>,
+    goal: PseudoCanonicalInput<'tcx, T>,
 ) -> Result<T, NoSolution> {
-    let ParamEnvAnd { param_env, value } = goal;
-    let infcx = tcx.infer_ctxt().build(TypingMode::from_param_env(param_env));
+    let PseudoCanonicalInput { typing_env, value } = goal;
+    let (infcx, param_env) = tcx.infer_ctxt().build_with_typing_env(typing_env);
     let cause = ObligationCause::dummy();
     match infcx.at(&cause, param_env).query_normalize(value) {
         Ok(Normalized { value: normalized_value, obligations: normalized_obligations }) => {