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`

5 files changed, 22 insertions, 10 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index 9e11360cab4..f0787d286fd 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1819,8 +1819,8 @@ pub(crate) fn clean_ty<'tcx>(ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> T
                     {
                         // Only anon consts can implicitly capture params.
                         // FIXME: is this correct behavior?
-                        let param_env = cx.tcx.param_env(*def_id);
-                        cx.tcx.normalize_erasing_regions(param_env, ct)
+                        let typing_env = ty::TypingEnv::from_param_env(cx.tcx.param_env(*def_id));
+                        cx.tcx.normalize_erasing_regions(typing_env, ct)
                     } else {
                         ct
                     };
@@ -2039,7 +2039,7 @@ pub(crate) fn clean_middle_ty<'tcx>(
             format!("{pat:?}").into_boxed_str(),
         ),
         ty::Array(ty, n) => {
-            let n = cx.tcx.normalize_erasing_regions(cx.param_env, n);
+            let n = cx.tcx.normalize_erasing_regions(cx.typing_env(), n);
             let n = print_const(cx, n);
             Array(Box::new(clean_middle_ty(bound_ty.rebind(ty), cx, None, None)), n.into())
         }
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index e3a0dbe1a7f..a10a6a92bf5 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -772,8 +772,10 @@ impl Item {
                         .find(|field| {
                             let ty =
                                 field.ty(tcx, ty::GenericArgs::identity_for_item(tcx, field.did));
-                            tcx.layout_of(tcx.param_env(field.did).and(ty))
-                                .is_ok_and(|layout| !layout.is_1zst())
+                            tcx.layout_of(
+                                ty::TypingEnv::post_analysis(tcx, field.did).as_query_input(ty),
+                            )
+                            .is_ok_and(|layout| !layout.is_1zst())
                         })
                         .map_or_else(
                             || adt.all_fields().any(|field| field.vis.is_public()),
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
index e551e0170c6..d59b4e4081c 100644
--- a/src/librustdoc/clean/utils.rs
+++ b/src/librustdoc/clean/utils.rs
@@ -419,7 +419,10 @@ fn print_const_with_custom_print_scalar<'tcx>(
         }
         (mir::Const::Val(mir::ConstValue::Scalar(int), _), ty::Int(i)) => {
             let ty = ct.ty();
-            let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
+            let size = tcx
+                .layout_of(ty::TypingEnv::fully_monomorphized().as_query_input(ty))
+                .unwrap()
+                .size;
             let sign_extended_data = int.assert_scalar_int().to_int(size);
             let mut output = if with_underscores {
                 format_integer_with_underscore_sep(&sign_extended_data.to_string())
diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index d5f6bfe415d..a562a9eee71 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -19,7 +19,7 @@ use rustc_hir::{HirId, Path};
 use rustc_interface::interface;
 use rustc_lint::{MissingDoc, late_lint_mod};
 use rustc_middle::hir::nested_filter;
-use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
 use rustc_session::config::{self, CrateType, ErrorOutputType, Input, ResolveDocLinks};
 pub(crate) use rustc_session::config::{Options, UnstableOptions};
 use rustc_session::{Session, lint};
@@ -88,6 +88,13 @@ impl<'tcx> DocContext<'tcx> {
         ret
     }
 
+    pub(crate) fn typing_env(&self) -> ty::TypingEnv<'tcx> {
+        ty::TypingEnv {
+            typing_mode: ty::TypingMode::non_body_analysis(),
+            param_env: self.param_env,
+        }
+    }
+
     /// Call the closure with the given parameters set as
     /// the generic parameters for a type alias' RHS.
     pub(crate) fn enter_alias<F, R>(
diff --git a/src/librustdoc/html/render/type_layout.rs b/src/librustdoc/html/render/type_layout.rs
index d85ba3a2b14..9317844956d 100644
--- a/src/librustdoc/html/render/type_layout.rs
+++ b/src/librustdoc/html/render/type_layout.rs
@@ -37,9 +37,9 @@ pub(crate) fn document_type_layout<'a, 'cx: 'a>(
         }
 
         let tcx = cx.tcx();
-        let param_env = tcx.param_env(ty_def_id);
+        let typing_env = ty::TypingEnv::post_analysis(tcx, ty_def_id);
         let ty = tcx.type_of(ty_def_id).instantiate_identity();
-        let type_layout = tcx.layout_of(param_env.and(ty));
+        let type_layout = tcx.layout_of(typing_env.as_query_input(ty));
 
         let variants = if let Ok(type_layout) = type_layout
             && let Variants::Multiple { variants, tag, tag_encoding, .. } =
@@ -71,7 +71,7 @@ pub(crate) fn document_type_layout<'a, 'cx: 'a>(
             Vec::new()
         };
 
-        let type_layout_size = tcx.layout_of(param_env.and(ty)).map(|layout| {
+        let type_layout_size = tcx.layout_of(typing_env.as_query_input(ty)).map(|layout| {
             let is_unsized = layout.is_unsized();
             let is_uninhabited = layout.is_uninhabited();
             let size = layout.size.bytes();