util::compare_types, no more ParamEnv::reveal

Author: lcnr

compiler/rustc_const_eval/src/interpret/eval_context.rs

@@ -4,6 +4,7 @@ use rustc_hir::def_id::DefId;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_infer::infer::at::ToTrace;
 use rustc_infer::traits::ObligationCause;
+use rustc_middle::mir::MirPhase;
 use rustc_middle::mir::interpret::{ErrorHandled, InvalidMetaKind, ReportedErrorInfo};
 use rustc_middle::query::TyCtxtAt;
 use rustc_middle::ty::layout::{
@@ -116,6 +117,7 @@ impl<'tcx, M: Machine<'tcx>> FnAbiOfHelpers<'tcx> for InterpCx<'tcx, M> {
 /// This test should be symmetric, as it is primarily about layout compatibility.
 pub(super) fn mir_assign_valid_types<'tcx>(
     tcx: TyCtxt<'tcx>,
+    mir_phase: MirPhase,
     param_env: ParamEnv<'tcx>,
     src: TyAndLayout<'tcx>,
     dest: TyAndLayout<'tcx>,
@@ -124,7 +126,7 @@ pub(super) fn mir_assign_valid_types<'tcx>(
     // all normal lifetimes are erased, higher-ranked types with their
     // late-bound lifetimes are still around and can lead to type
     // differences.
-    if util::relate_types(tcx, param_env, Variance::Covariant, src.ty, dest.ty) {
+    if util::relate_types(tcx, mir_phase, param_env, Variance::Covariant, src.ty, dest.ty) {
         // Make sure the layout is equal, too -- just to be safe. Miri really
         // needs layout equality. For performance reason we skip this check when
         // the types are equal. Equal types *can* have different layouts when
@@ -144,6 +146,7 @@ pub(super) fn mir_assign_valid_types<'tcx>(
 #[cfg_attr(not(debug_assertions), inline(always))]
 pub(super) fn from_known_layout<'tcx>(
     tcx: TyCtxtAt<'tcx>,
+    mir_phase: MirPhase,
     param_env: ParamEnv<'tcx>,
     known_layout: Option<TyAndLayout<'tcx>>,
     compute: impl FnOnce() -> InterpResult<'tcx, TyAndLayout<'tcx>>,
@@ -153,7 +156,13 @@ pub(super) fn from_known_layout<'tcx>(
         Some(known_layout) => {
             if cfg!(debug_assertions) {
                 let check_layout = compute()?;
-                if !mir_assign_valid_types(tcx.tcx, param_env, check_layout, known_layout) {
+                if !mir_assign_valid_types(
+                    tcx.tcx,
+                    mir_phase,
+                    param_env,
+                    check_layout,
+                    known_layout,
+                ) {
                     span_bug!(
                         tcx.span,
                         "expected type differs from actual type.\nexpected: {}\nactual: {}",

compiler/rustc_const_eval/src/interpret/operand.rs

@@ -773,6 +773,7 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 )?;
             if !mir_assign_valid_types(
                 *self.tcx,
+                self.body().phase,
                 self.param_env,
                 self.layout_of(normalized_place_ty)?,
                 op.layout,
@@ -832,7 +833,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             })
         };
         let layout =
-            from_known_layout(self.tcx, self.param_env, layout, || self.layout_of(ty).into())?;
+            from_known_layout(self.tcx, self.body().phase, self.param_env, layout, || {
+                self.layout_of(ty).into()
+            })?;
         let imm = match val_val {
             mir::ConstValue::Indirect { alloc_id, offset } => {
                 // This is const data, no mutation allowed.

compiler/rustc_const_eval/src/interpret/place.rs

@@ -540,6 +540,7 @@ where
                 )?;
             if !mir_assign_valid_types(
                 *self.tcx,
+                self.body().phase,
                 self.param_env,
                 self.layout_of(normalized_place_ty)?,
                 place.layout,
@@ -870,8 +871,13 @@ where
     ) -> InterpResult<'tcx> {
         // We do NOT compare the types for equality, because well-typed code can
         // actually "transmute" `&mut T` to `&T` in an assignment without a cast.
-        let layout_compat =
-            mir_assign_valid_types(*self.tcx, self.param_env, src.layout(), dest.layout());
+        let layout_compat = mir_assign_valid_types(
+            *self.tcx,
+            self.body().phase,
+            self.param_env,
+            src.layout(),
+            dest.layout(),
+        );
         if !allow_transmute && !layout_compat {
             span_bug!(
                 self.cur_span(),

compiler/rustc_const_eval/src/interpret/stack.rs

@@ -596,12 +596,13 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
             return interp_ok(layout);
         }
 
-        let layout = from_known_layout(self.tcx, self.param_env, layout, || {
-            let local_ty = frame.body.local_decls[local].ty;
-            let local_ty =
-                self.instantiate_from_frame_and_normalize_erasing_regions(frame, local_ty)?;
-            self.layout_of(local_ty).into()
-        })?;
+        let layout =
+            from_known_layout(self.tcx, self.body().phase, self.param_env, layout, || {
+                let local_ty = frame.body.local_decls[local].ty;
+                let local_ty =
+                    self.instantiate_from_frame_and_normalize_erasing_regions(frame, local_ty)?;
+                self.layout_of(local_ty).into()
+            })?;
 
         // Layouts of locals are requested a lot, so we cache them.
         state.layout.set(Some(layout));

compiler/rustc_const_eval/src/util/compare_types.rs

@@ -4,28 +4,20 @@
 //! other areas of the compiler as well.
 
 use rustc_infer::infer::TyCtxtInferExt;
+use rustc_middle::mir::MirPhase;
 use rustc_middle::traits::ObligationCause;
-use rustc_middle::ty::{ParamEnv, Ty, TyCtxt, TypingMode, Variance};
+use rustc_middle::ty::{ParamEnv, Ty, TyCtxt, Variance};
 use rustc_trait_selection::traits::ObligationCtxt;
 
-/// Returns whether the two types are equal up to subtyping.
-///
-/// This is used in case we don't know the expected subtyping direction
-/// and still want to check whether anything is broken.
-pub fn is_equal_up_to_subtyping<'tcx>(
+/// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
+pub fn sub_types<'tcx>(
     tcx: TyCtxt<'tcx>,
+    mir_phase: MirPhase,
     param_env: ParamEnv<'tcx>,
     src: Ty<'tcx>,
     dest: Ty<'tcx>,
 ) -> bool {
-    // Fast path.
-    if src == dest {
-        return true;
-    }
-
-    // Check for subtyping in either direction.
-    relate_types(tcx, param_env, Variance::Covariant, src, dest)
-        || relate_types(tcx, param_env, Variance::Covariant, dest, src)
+    relate_types(tcx, mir_phase, param_env, Variance::Covariant, src, dest)
 }
 
 /// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`.
@@ -35,6 +27,7 @@ pub fn is_equal_up_to_subtyping<'tcx>(
 /// because we want to check for type equality.
 pub fn relate_types<'tcx>(
     tcx: TyCtxt<'tcx>,
+    mir_phase: MirPhase,
     param_env: ParamEnv<'tcx>,
     variance: Variance,
     src: Ty<'tcx>,
@@ -45,8 +38,7 @@ pub fn relate_types<'tcx>(
     }
 
     let mut builder = tcx.infer_ctxt().ignoring_regions();
-    // FIXME(#132279): This should eventually use the already defined hidden types.
-    let infcx = builder.build(TypingMode::from_param_env(param_env));
+    let infcx = builder.build(mir_phase.typing_mode());
     let ocx = ObligationCtxt::new(&infcx);
     let cause = ObligationCause::dummy();
     let src = ocx.normalize(&cause, param_env, src);

compiler/rustc_const_eval/src/util/mod.rs

@@ -8,7 +8,7 @@ mod type_name;
 
 pub use self::alignment::{is_disaligned, is_within_packed};
 pub use self::check_validity_requirement::check_validity_requirement;
-pub use self::compare_types::{is_equal_up_to_subtyping, relate_types};
+pub use self::compare_types::{relate_types, sub_types};
 pub use self::type_name::type_name;
 
 /// Classify whether an operator is "left-homogeneous", i.e., the LHS has the

compiler/rustc_mir_transform/src/inline.rs

@@ -244,8 +244,13 @@ impl<'tcx> Inliner<'tcx> {
         // Normally, this shouldn't be required, but trait normalization failure can create a
         // validation ICE.
         let output_type = callee_body.return_ty();
-        if !util::relate_types(self.tcx, self.param_env, ty::Covariant, output_type, destination_ty)
-        {
+        if !util::sub_types(
+            self.tcx,
+            caller_body.phase,
+            self.param_env,
+            output_type,
+            destination_ty,
+        ) {
             trace!(?output_type, ?destination_ty);
             return Err("failed to normalize return type");
         }
@@ -275,7 +280,7 @@ impl<'tcx> Inliner<'tcx> {
                 self_arg_ty.into_iter().chain(arg_tuple_tys).zip(callee_body.args_iter())
             {
                 let input_type = callee_body.local_decls[input].ty;
-                if !util::relate_types(self.tcx, self.param_env, ty::Covariant, input_type, arg_ty)
+                if !util::sub_types(self.tcx, caller_body.phase, self.param_env, input_type, arg_ty)
                 {
                     trace!(?arg_ty, ?input_type);
                     return Err("failed to normalize tuple argument type");
@@ -285,7 +290,7 @@ impl<'tcx> Inliner<'tcx> {
             for (arg, input) in args.iter().zip(callee_body.args_iter()) {
                 let input_type = callee_body.local_decls[input].ty;
                 let arg_ty = arg.node.ty(&caller_body.local_decls, self.tcx);
-                if !util::relate_types(self.tcx, self.param_env, ty::Covariant, input_type, arg_ty)
+                if !util::sub_types(self.tcx, caller_body.phase, self.param_env, input_type, arg_ty)
                 {
                     trace!(?arg_ty, ?input_type);
                     return Err("failed to normalize argument type");

compiler/rustc_mir_transform/src/validate.rs

@@ -20,7 +20,7 @@ use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::traits::ObligationCtxt;
 use rustc_type_ir::Upcast;
 
-use crate::util::{is_within_packed, relate_types};
+use crate::util::{self, is_within_packed};
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 enum EdgeKind {
@@ -583,7 +583,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
             Variance::Covariant
         };
 
-        crate::util::relate_types(self.tcx, self.param_env, variance, src, dest)
+        crate::util::relate_types(self.tcx, self.body.phase, self.param_env, variance, src, dest)
     }
 
     /// Check that the given predicate definitely holds in the param-env of this MIR body.
@@ -794,10 +794,10 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                 }
             }
             ProjectionElem::Subtype(ty) => {
-                if !relate_types(
+                if !util::sub_types(
                     self.tcx,
+                    self.body.phase,
                     self.param_env,
-                    Variance::Covariant,
                     ty,
                     place_ref.ty(&self.body.local_decls, self.tcx).ty,
                 ) {