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`.

compiler/rustc_const_eval/src/util/alignment.rs

@@ -9,7 +9,7 @@ use tracing::debug;
 pub fn is_disaligned<'tcx, L>(
     tcx: TyCtxt<'tcx>,
     local_decls: &L,
-    param_env: ty::ParamEnv<'tcx>,
+    typing_env: ty::TypingEnv<'tcx>,
     place: Place<'tcx>,
 ) -> bool
 where
@@ -22,8 +22,8 @@ where
     };
 
     let ty = place.ty(local_decls, tcx).ty;
-    let unsized_tail = || tcx.struct_tail_for_codegen(ty, param_env);
-    match tcx.layout_of(param_env.and(ty)) {
+    let unsized_tail = || tcx.struct_tail_for_codegen(ty, typing_env);
+    match tcx.layout_of(typing_env.as_query_input(ty)) {
         Ok(layout)
             if layout.align.abi <= pack
                 && (layout.is_sized()

compiler/rustc_const_eval/src/util/check_validity_requirement.rs

@@ -3,7 +3,7 @@ use rustc_middle::bug;
 use rustc_middle::ty::layout::{
     HasTyCtxt, LayoutCx, LayoutError, LayoutOf, TyAndLayout, ValidityRequirement,
 };
-use rustc_middle::ty::{ParamEnvAnd, Ty, TyCtxt};
+use rustc_middle::ty::{PseudoCanonicalInput, Ty, TyCtxt};
 
 use crate::const_eval::{CanAccessMutGlobal, CheckAlignment, CompileTimeMachine};
 use crate::interpret::{InterpCx, MemoryKind};
@@ -23,16 +23,16 @@ use crate::interpret::{InterpCx, MemoryKind};
 pub fn check_validity_requirement<'tcx>(
     tcx: TyCtxt<'tcx>,
     kind: ValidityRequirement,
-    param_env_and_ty: ParamEnvAnd<'tcx, Ty<'tcx>>,
+    input: PseudoCanonicalInput<'tcx, Ty<'tcx>>,
 ) -> Result<bool, &'tcx LayoutError<'tcx>> {
-    let layout = tcx.layout_of(param_env_and_ty)?;
+    let layout = tcx.layout_of(input)?;
 
     // There is nothing strict or lax about inhabitedness.
     if kind == ValidityRequirement::Inhabited {
         return Ok(!layout.is_uninhabited());
     }
 
-    let layout_cx = LayoutCx::new(tcx, param_env_and_ty.param_env);
+    let layout_cx = LayoutCx::new(tcx, input.typing_env);
     if kind == ValidityRequirement::Uninit || tcx.sess.opts.unstable_opts.strict_init_checks {
         check_validity_requirement_strict(layout, &layout_cx, kind)
     } else {
@@ -49,7 +49,7 @@ fn check_validity_requirement_strict<'tcx>(
 ) -> Result<bool, &'tcx LayoutError<'tcx>> {
     let machine = CompileTimeMachine::new(CanAccessMutGlobal::No, CheckAlignment::Error);
 
-    let mut cx = InterpCx::new(cx.tcx(), rustc_span::DUMMY_SP, cx.param_env, machine);
+    let mut cx = InterpCx::new(cx.tcx(), rustc_span::DUMMY_SP, cx.typing_env.param_env, machine);
 
     let allocated = cx
         .allocate(ty, MemoryKind::Machine(crate::const_eval::MemoryKind::Heap))

compiler/rustc_const_eval/src/util/compare_types.rs

@@ -5,18 +5,17 @@
 
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::traits::ObligationCause;
-use rustc_middle::ty::{ParamEnv, Ty, TyCtxt, TypingMode, Variance};
+use rustc_middle::ty::{Ty, TyCtxt, TypingEnv, Variance};
 use rustc_trait_selection::traits::ObligationCtxt;
 
 /// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
 pub fn sub_types<'tcx>(
     tcx: TyCtxt<'tcx>,
-    typing_mode: TypingMode<'tcx>,
-    param_env: ParamEnv<'tcx>,
+    typing_env: TypingEnv<'tcx>,
     src: Ty<'tcx>,
     dest: Ty<'tcx>,
 ) -> bool {
-    relate_types(tcx, typing_mode, param_env, Variance::Covariant, src, dest)
+    relate_types(tcx, typing_env, Variance::Covariant, src, dest)
 }
 
 /// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
@@ -26,8 +25,7 @@ pub fn sub_types<'tcx>(
 /// because we want to check for type equality.
 pub fn relate_types<'tcx>(
     tcx: TyCtxt<'tcx>,
-    typing_mode: TypingMode<'tcx>,
-    param_env: ParamEnv<'tcx>,
+    typing_env: TypingEnv<'tcx>,
     variance: Variance,
     src: Ty<'tcx>,
     dest: Ty<'tcx>,
@@ -36,8 +34,7 @@ pub fn relate_types<'tcx>(
         return true;
     }
 
-    let mut builder = tcx.infer_ctxt().ignoring_regions();
-    let infcx = builder.build(typing_mode);
+    let (infcx, param_env) = tcx.infer_ctxt().ignoring_regions().build_with_typing_env(typing_env);
     let ocx = ObligationCtxt::new(&infcx);
     let cause = ObligationCause::dummy();
     let src = ocx.normalize(&cause, param_env, src);