Remove StatementKind::Deinit.

compiler/rustc_borrowck/src/dataflow.rs

@@ -577,7 +577,6 @@ impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
 
             mir::StatementKind::FakeRead(..)
             | mir::StatementKind::SetDiscriminant { .. }
-            | mir::StatementKind::Deinit(..)
             | mir::StatementKind::StorageLive(..)
             | mir::StatementKind::Retag { .. }
             | mir::StatementKind::PlaceMention(..)

compiler/rustc_borrowck/src/def_use.rs

@@ -80,7 +80,7 @@ pub(crate) fn categorize(context: PlaceContext) -> Option<DefUse> {
         // Backwards incompatible drop hint is not a use, just a marker for linting.
         PlaceContext::NonUse(NonUseContext::BackwardIncompatibleDropHint) => None,
 
-        PlaceContext::MutatingUse(MutatingUseContext::Deinit | MutatingUseContext::SetDiscriminant) => {
+        PlaceContext::MutatingUse(MutatingUseContext::SetDiscriminant) => {
             bug!("These statements are not allowed in this MIR phase")
         }
     }

compiler/rustc_borrowck/src/lib.rs

@@ -857,7 +857,6 @@ impl<'a, 'tcx> ResultsVisitor<'tcx, Borrowck<'a, 'tcx>> for MirBorrowckCtxt<'a,
             }
             StatementKind::Nop
             | StatementKind::Retag { .. }
-            | StatementKind::Deinit(..)
             | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")
             }

compiler/rustc_borrowck/src/polonius/legacy/loan_invalidations.rs

@@ -84,7 +84,6 @@ impl<'a, 'tcx> Visitor<'tcx> for LoanInvalidationsGenerator<'a, 'tcx> {
             StatementKind::ConstEvalCounter
             | StatementKind::Nop
             | StatementKind::Retag { .. }
-            | StatementKind::Deinit(..)
             | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -748,7 +748,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
             | StatementKind::BackwardIncompatibleDropHint { .. }
             | StatementKind::Nop => {}
             StatementKind::Intrinsic(box NonDivergingIntrinsic::CopyNonOverlapping(..))
-            | StatementKind::Deinit(..)
             | StatementKind::SetDiscriminant { .. } => {
                 bug!("Statement not allowed in this MIR phase")
             }

compiler/rustc_codegen_cranelift/src/base.rs

@@ -932,7 +932,6 @@ fn codegen_stmt<'tcx>(fx: &mut FunctionCx<'_, '_, 'tcx>, cur_block: Block, stmt:
         }
         StatementKind::StorageLive(_)
         | StatementKind::StorageDead(_)
-        | StatementKind::Deinit(_)
         | StatementKind::ConstEvalCounter
         | StatementKind::Nop
         | StatementKind::FakeRead(..)

compiler/rustc_codegen_cranelift/src/constant.rs

@@ -597,7 +597,6 @@ pub(crate) fn mir_operand_get_const_val<'tcx>(
                         StatementKind::Assign(_)
                         | StatementKind::FakeRead(_)
                         | StatementKind::SetDiscriminant { .. }
-                        | StatementKind::Deinit(_)
                         | StatementKind::StorageLive(_)
                         | StatementKind::StorageDead(_)
                         | StatementKind::Retag(_, _)

compiler/rustc_codegen_ssa/src/mir/analyze.rs

@@ -229,7 +229,6 @@ impl<'a, 'b, 'tcx, Bx: BuilderMethods<'b, 'tcx>> Visitor<'tcx> for LocalAnalyzer
 
             PlaceContext::MutatingUse(
                 MutatingUseContext::Store
-                | MutatingUseContext::Deinit
                 | MutatingUseContext::SetDiscriminant
                 | MutatingUseContext::AsmOutput
                 | MutatingUseContext::Borrow

compiler/rustc_codegen_ssa/src/mir/statement.rs

@@ -50,11 +50,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             mir::StatementKind::SetDiscriminant { box ref place, variant_index } => {
                 self.codegen_place(bx, place.as_ref()).codegen_set_discr(bx, variant_index);
             }
-            mir::StatementKind::Deinit(..) => {
-                // For now, don't codegen this to anything. In the future it may be worth
-                // experimenting with what kind of information we can emit to LLVM without hurting
-                // perf here
-            }
             mir::StatementKind::StorageLive(local) => {
                 if let LocalRef::Place(cg_place) = self.locals[local] {
                     cg_place.storage_live(bx);

compiler/rustc_const_eval/src/check_consts/check.rs

@@ -732,7 +732,6 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
         match statement.kind {
             StatementKind::Assign(..)
             | StatementKind::SetDiscriminant { .. }
-            | StatementKind::Deinit(..)
             | StatementKind::FakeRead(..)
             | StatementKind::StorageLive(_)
             | StatementKind::StorageDead(_)

compiler/rustc_const_eval/src/interpret/step.rs

@@ -98,11 +98,6 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
                 self.write_discriminant(*variant_index, &dest)?;
             }
 
-            Deinit(place) => {
-                let dest = self.eval_place(**place)?;
-                self.write_uninit(&dest)?;
-            }
-
             // Mark locals as alive
             StorageLive(local) => {
                 self.storage_live(*local)?;

compiler/rustc_middle/src/mir/pretty.rs

@@ -818,7 +818,6 @@ impl Debug for Statement<'_> {
             SetDiscriminant { ref place, variant_index } => {
                 write!(fmt, "discriminant({place:?}) = {variant_index:?}")
             }
-            Deinit(ref place) => write!(fmt, "Deinit({place:?})"),
             PlaceMention(ref place) => {
                 write!(fmt, "PlaceMention({place:?})")
             }

compiler/rustc_middle/src/mir/statement.rs

@@ -50,7 +50,6 @@ impl<'tcx> StatementKind<'tcx> {
             StatementKind::Assign(..) => "Assign",
             StatementKind::FakeRead(..) => "FakeRead",
             StatementKind::SetDiscriminant { .. } => "SetDiscriminant",
-            StatementKind::Deinit(..) => "Deinit",
             StatementKind::StorageLive(..) => "StorageLive",
             StatementKind::StorageDead(..) => "StorageDead",
             StatementKind::Retag(..) => "Retag",

compiler/rustc_middle/src/mir/syntax.rs

@@ -135,7 +135,6 @@ pub enum RuntimePhase {
     /// And the following variants are allowed:
     /// * [`StatementKind::Retag`]
     /// * [`StatementKind::SetDiscriminant`]
-    /// * [`StatementKind::Deinit`]
     ///
     /// Furthermore, `Copy` operands are allowed for non-`Copy` types.
     Initial = 0,
@@ -362,11 +361,6 @@ pub enum StatementKind<'tcx> {
     /// the type.
     SetDiscriminant { place: Box<Place<'tcx>>, variant_index: VariantIdx },
 
-    /// Deinitializes the place.
-    ///
-    /// This writes `uninit` bytes to the entire place.
-    Deinit(Box<Place<'tcx>>),
-
     /// `StorageLive` and `StorageDead` statements mark the live range of a local.
     ///
     /// At any point during the execution of a function, each local is either allocated or

compiler/rustc_middle/src/mir/visit.rs

@@ -445,13 +445,6 @@ macro_rules! make_mir_visitor {
                             location
                         );
                     }
-                    StatementKind::Deinit(place) => {
-                        self.visit_place(
-                            place,
-                            PlaceContext::MutatingUse(MutatingUseContext::Deinit),
-                            location
-                        )
-                    }
                     StatementKind::StorageLive(local) => {
                         self.visit_local(
                             $(& $mutability)? *local,
@@ -1372,8 +1365,6 @@ pub enum MutatingUseContext {
     Store,
     /// Appears on `SetDiscriminant`
     SetDiscriminant,
-    /// Appears on `Deinit`
-    Deinit,
     /// Output operand of an inline assembly block.
     AsmOutput,
     /// Destination of a call.

compiler/rustc_mir_build/src/builder/custom/parse/instruction.rs

@@ -24,9 +24,6 @@ impl<'a, 'tcx> ParseCtxt<'a, 'tcx> {
                 let op = self.parse_operand(args[0])?;
                 Ok(StatementKind::Intrinsic(Box::new(NonDivergingIntrinsic::Assume(op))))
             },
-            @call(mir_deinit, args) => {
-                Ok(StatementKind::Deinit(Box::new(self.parse_place(args[0])?)))
-            },
             @call(mir_retag, args) => {
                 Ok(StatementKind::Retag(RetagKind::Default, Box::new(self.parse_place(args[0])?)))
             },

compiler/rustc_mir_dataflow/src/impls/liveness.rs

@@ -159,8 +159,7 @@ impl DefUse {
                 MutatingUseContext::Call
                 | MutatingUseContext::Yield
                 | MutatingUseContext::AsmOutput
-                | MutatingUseContext::Store
-                | MutatingUseContext::Deinit,
+                | MutatingUseContext::Store,
             ) => {
                 // Treat derefs as a use of the base local. `*p = 4` is not a def of `p` but a use.
                 if place.is_indirect() {
@@ -238,7 +237,7 @@ impl<'a> MaybeTransitiveLiveLocals<'a> {
                 && (!debuginfo_locals.contains(place.local)
                     || (place.as_local().is_some() && stmt_kind.as_debuginfo().is_some())))
             .then_some(*place),
-            StatementKind::SetDiscriminant { place, .. } | StatementKind::Deinit(place) => {
+            StatementKind::SetDiscriminant { place, .. } => {
                 (!debuginfo_locals.contains(place.local)).then_some(**place)
             }
             StatementKind::FakeRead(_)

compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs

@@ -156,8 +156,7 @@ impl<'tcx> Analysis<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
 
             // If a place is assigned to in a statement, it needs storage for that statement.
             StatementKind::Assign(box (place, _))
-            | StatementKind::SetDiscriminant { box place, .. }
-            | StatementKind::Deinit(box place) => {
+            | StatementKind::SetDiscriminant { box place, .. } => {
                 state.gen_(place.local);
             }
 

compiler/rustc_mir_dataflow/src/move_paths/builder.rs

@@ -371,7 +371,7 @@ impl<'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> MoveDataBuilder<'a, 'tcx, F> {
                     self.gather_move(Place::from(*local));
                 }
             }
-            StatementKind::SetDiscriminant { .. } | StatementKind::Deinit(..) => {
+            StatementKind::SetDiscriminant { .. } => {
                 span_bug!(
                     stmt.source_info.span,
                     "SetDiscriminant/Deinit should not exist during borrowck"

compiler/rustc_mir_transform/src/coroutine.rs

@@ -1723,7 +1723,6 @@ impl<'tcx> Visitor<'tcx> for EnsureCoroutineFieldAssignmentsNeverAlias<'_> {
 
             StatementKind::FakeRead(..)
             | StatementKind::SetDiscriminant { .. }
-            | StatementKind::Deinit(..)
             | StatementKind::StorageLive(_)
             | StatementKind::StorageDead(_)
             | StatementKind::Retag(..)

compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs

@@ -91,7 +91,6 @@ fn filtered_statement_span(statement: &Statement<'_>) -> Option<Span> {
         )
         | StatementKind::Assign(_)
         | StatementKind::SetDiscriminant { .. }
-        | StatementKind::Deinit(..)
         | StatementKind::Retag(_, _)
         | StatementKind::PlaceMention(..)
         | StatementKind::AscribeUserType(_, _) => Some(statement.source_info.span),

compiler/rustc_mir_transform/src/cross_crate_inline.rs

@@ -115,10 +115,7 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> {
     fn visit_statement(&mut self, statement: &Statement<'tcx>, _: Location) {
         // Don't count StorageLive/StorageDead in the inlining cost.
         match statement.kind {
-            StatementKind::StorageLive(_)
-            | StatementKind::StorageDead(_)
-            | StatementKind::Deinit(_)
-            | StatementKind::Nop => {}
+            StatementKind::StorageLive(_) | StatementKind::StorageDead(_) | StatementKind::Nop => {}
             _ => self.statements += 1,
         }
     }

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -178,10 +178,6 @@ impl<'a, 'tcx> ConstAnalysis<'a, 'tcx> {
                     FlatSet::<Scalar>::BOTTOM,
                 );
             }
-            StatementKind::Deinit(box place) => {
-                // Deinit makes the place uninitialized.
-                state.flood_with(place.as_ref(), &self.map, FlatSet::<Scalar>::BOTTOM);
-            }
             StatementKind::Retag(..) => {
                 // We don't track references.
             }

compiler/rustc_mir_transform/src/jump_threading.rs

@@ -332,8 +332,7 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {
         stmt: &Statement<'tcx>,
     ) -> Option<(Place<'tcx>, Option<TrackElem>)> {
         match stmt.kind {
-            StatementKind::Assign(box (place, _))
-            | StatementKind::Deinit(box place) => Some((place, None)),
+            StatementKind::Assign(box (place, _)) => Some((place, None)),
             StatementKind::SetDiscriminant { box place, variant_index: _ } => {
                 Some((place, Some(TrackElem::Discriminant)))
             }

compiler/rustc_mir_transform/src/known_panics_lint.rs

@@ -926,7 +926,6 @@ impl<'tcx> Visitor<'tcx> for CanConstProp {
             // mutations of the same local via `Store`
             | MutatingUse(MutatingUseContext::Call)
             | MutatingUse(MutatingUseContext::AsmOutput)
-            | MutatingUse(MutatingUseContext::Deinit)
             // Actual store that can possibly even propagate a value
             | MutatingUse(MutatingUseContext::Store)
             | MutatingUse(MutatingUseContext::SetDiscriminant) => {

compiler/rustc_mir_transform/src/large_enums.rs

@@ -126,8 +126,6 @@ impl<'tcx> crate::MirPass<'tcx> for EnumSizeOpt {
                     Rvalue::Cast(CastKind::PtrToPtr, Operand::Copy(src), src_cast_ty),
                 )));
 
-                let deinit_old = StatementKind::Deinit(Box::new(dst));
-
                 let copy_bytes = StatementKind::Intrinsic(Box::new(
                     NonDivergingIntrinsic::CopyNonOverlapping(CopyNonOverlapping {
                         src: Operand::Copy(src_cast_place),
@@ -148,7 +146,6 @@ impl<'tcx> crate::MirPass<'tcx> for EnumSizeOpt {
                     dst_cast,
                     src_ptr,
                     src_cast,
-                    deinit_old,
                     copy_bytes,
                     store_dead,
                 ];

compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs

@@ -113,7 +113,6 @@ impl RemoveNoopLandingPads {
 
                 StatementKind::Assign { .. }
                 | StatementKind::SetDiscriminant { .. }
-                | StatementKind::Deinit(..)
                 | StatementKind::Intrinsic(..)
                 | StatementKind::Retag { .. } => {
                     return false;

compiler/rustc_mir_transform/src/remove_zsts.rs

@@ -122,8 +122,7 @@ impl<'tcx> MutVisitor<'tcx> for Replacer<'_, 'tcx> {
             StatementKind::Assign(box (place, ref rvalue)) => {
                 rvalue.is_safe_to_remove().then_some(place)
             }
-            StatementKind::Deinit(box place)
-            | StatementKind::SetDiscriminant { box place, variant_index: _ }
+            StatementKind::SetDiscriminant { box place, variant_index: _ }
             | StatementKind::AscribeUserType(box (place, _), _)
             | StatementKind::Retag(_, box place)
             | StatementKind::PlaceMention(box place)

compiler/rustc_mir_transform/src/simplify.rs

@@ -590,7 +590,6 @@ impl<'tcx> Visitor<'tcx> for UsedLocals {
             }
 
             StatementKind::SetDiscriminant { ref place, variant_index: _ }
-            | StatementKind::Deinit(ref place)
             | StatementKind::BackwardIncompatibleDropHint { ref place, reason: _ } => {
                 self.visit_lhs(place, location);
             }
@@ -630,8 +629,9 @@ fn remove_unused_definitions_helper(used_locals: &mut UsedLocals, body: &mut Bod
                     }
                     StatementKind::Assign(box (place, _))
                     | StatementKind::SetDiscriminant { box place, .. }
-                    | StatementKind::BackwardIncompatibleDropHint { box place, .. }
-                    | StatementKind::Deinit(box place) => used_locals.is_used(place.local),
+                    | StatementKind::BackwardIncompatibleDropHint { box place, .. } => {
+                        used_locals.is_used(place.local)
+                    }
                     _ => continue,
                 };
                 if keep_statement {

compiler/rustc_mir_transform/src/sroa.rs

@@ -136,9 +136,7 @@ fn escaping_locals<'tcx>(
         fn visit_statement(&mut self, statement: &Statement<'tcx>, location: Location) {
             match statement.kind {
                 // Storage statements are expanded in run_pass.
-                StatementKind::StorageLive(..)
-                | StatementKind::StorageDead(..)
-                | StatementKind::Deinit(..) => return,
+                StatementKind::StorageLive(..) | StatementKind::StorageDead(..) => return,
                 _ => self.super_statement(statement, location),
             }
         }
@@ -331,16 +329,6 @@ impl<'tcx, 'll> MutVisitor<'tcx> for ReplacementVisitor<'tcx, 'll> {
                 }
                 return;
             }
-            StatementKind::Deinit(box place) => {
-                if let Some(final_locals) = self.replacements.place_fragments(place) {
-                    for (_, _, fl) in final_locals {
-                        self.patch
-                            .add_statement(location, StatementKind::Deinit(Box::new(fl.into())));
-                    }
-                    statement.make_nop(true);
-                    return;
-                }
-            }
 
             // We have `a = Struct { 0: x, 1: y, .. }`.
             // We replace it by

compiler/rustc_mir_transform/src/validate.rs

@@ -313,11 +313,6 @@ impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> {
                     self.fail(location, "`SetDiscriminant`is not allowed until deaggregation");
                 }
             }
-            StatementKind::Deinit(..) => {
-                if self.body.phase < MirPhase::Runtime(RuntimePhase::Initial) {
-                    self.fail(location, "`Deinit`is not allowed until deaggregation");
-                }
-            }
             StatementKind::Retag(kind, _) => {
                 // FIXME(JakobDegen) The validator should check that `self.body.phase <
                 // DropsLowered`. However, this causes ICEs with generation of drop shims, which
@@ -1501,11 +1496,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
                     );
                 }
             }
-            StatementKind::Deinit(..) => {
-                if self.body.phase < MirPhase::Runtime(RuntimePhase::Initial) {
-                    self.fail(location, "`Deinit`is not allowed until deaggregation");
-                }
-            }
             StatementKind::Retag(kind, _) => {
                 // FIXME(JakobDegen) The validator should check that `self.body.phase <
                 // DropsLowered`. However, this causes ICEs with generation of drop shims, which

compiler/rustc_public/src/mir/body.rs

@@ -478,7 +478,6 @@ pub enum StatementKind {
     Assign(Place, Rvalue),
     FakeRead(FakeReadCause, Place),
     SetDiscriminant { place: Place, variant_index: VariantIdx },
-    Deinit(Place),
     StorageLive(Local),
     StorageDead(Local),
     Retag(RetagKind, Place),

compiler/rustc_public/src/mir/pretty.rs

@@ -102,7 +102,6 @@ fn pretty_statement<W: Write>(writer: &mut W, statement: &StatementKind) -> io::
         StatementKind::SetDiscriminant { place, variant_index } => {
             writeln!(writer, "{INDENT}discriminant({place:?}) = {};", variant_index.to_index())
         }
-        StatementKind::Deinit(place) => writeln!(writer, "Deinit({place:?};"),
         StatementKind::StorageLive(local) => {
             writeln!(writer, "{INDENT}StorageLive(_{local});")
         }

compiler/rustc_public/src/mir/visit.rs

@@ -170,7 +170,6 @@ macro_rules! make_mir_visitor {
                         self.visit_place(place, PlaceContext::NON_MUTATING, location);
                     }
                     StatementKind::SetDiscriminant { place, .. }
-                    | StatementKind::Deinit(place)
                     | StatementKind::Retag(_, place) => {
                         self.visit_place(place, PlaceContext::MUTATING, location);
                     }