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`

1 files changed, 9 insertions, 7 deletions

diff --git a/compiler/rustc_codegen_gcc/src/context.rs b/compiler/rustc_codegen_gcc/src/context.rs
index 707b35967a6..3846d025537 100644
--- a/compiler/rustc_codegen_gcc/src/context.rs
+++ b/compiler/rustc_codegen_gcc/src/context.rs
@@ -11,10 +11,10 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_middle::mir::mono::CodegenUnit;
 use rustc_middle::span_bug;
 use rustc_middle::ty::layout::{
-    FnAbiError, FnAbiOf, FnAbiOfHelpers, FnAbiRequest, HasParamEnv, HasTyCtxt, LayoutError,
+    FnAbiError, FnAbiOf, FnAbiOfHelpers, FnAbiRequest, HasTyCtxt, HasTypingEnv, LayoutError,
     LayoutOfHelpers,
 };
-use rustc_middle::ty::{self, Instance, ParamEnv, PolyExistentialTraitRef, Ty, TyCtxt};
+use rustc_middle::ty::{self, Instance, PolyExistentialTraitRef, Ty, TyCtxt};
 use rustc_session::Session;
 use rustc_span::source_map::respan;
 use rustc_span::{DUMMY_SP, Span};
@@ -144,7 +144,9 @@ impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
         supports_f128_type: bool,
     ) -> Self {
         let create_type = |ctype, rust_type| {
-            let layout = tcx.layout_of(ParamEnv::reveal_all().and(rust_type)).unwrap();
+            let layout = tcx
+                .layout_of(ty::TypingEnv::fully_monomorphized().as_query_input(rust_type))
+                .unwrap();
             let align = layout.align.abi.bytes();
             #[cfg(feature = "master")]
             {
@@ -459,7 +461,7 @@ impl<'gcc, 'tcx> MiscCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
             Some(def_id) if !wants_msvc_seh(self.sess()) => {
                 let instance = ty::Instance::expect_resolve(
                     tcx,
-                    ty::ParamEnv::reveal_all(),
+                    self.typing_env(),
                     def_id,
                     ty::List::empty(),
                     DUMMY_SP,
@@ -583,9 +585,9 @@ impl<'gcc, 'tcx> FnAbiOfHelpers<'tcx> for CodegenCx<'gcc, 'tcx> {
     }
 }
 
-impl<'tcx, 'gcc> HasParamEnv<'tcx> for CodegenCx<'gcc, 'tcx> {
-    fn param_env(&self) -> ParamEnv<'tcx> {
-        ParamEnv::reveal_all()
+impl<'tcx, 'gcc> HasTypingEnv<'tcx> for CodegenCx<'gcc, 'tcx> {
+    fn typing_env(&self) -> ty::TypingEnv<'tcx> {
+        ty::TypingEnv::fully_monomorphized()
     }
 }