From c5d4e4d907047580f028c6ca7b36a82ef94d28d1 Mon Sep 17 00:00:00 2001 From: Giacomo Pasini Date: Sun, 5 Mar 2023 21:02:14 +0100 Subject: [PATCH 1/2] Remove DropAndReplace terminator PR 107844 made DropAndReplace unused, let's remove it completely from the codebase. --- compiler/rustc_borrowck/src/invalidation.rs | 9 -- compiler/rustc_borrowck/src/lib.rs | 10 -- .../src/type_check/liveness/trace.rs | 3 +- compiler/rustc_borrowck/src/type_check/mod.rs | 19 --- compiler/rustc_borrowck/src/used_muts.rs | 3 - compiler/rustc_codegen_cranelift/src/base.rs | 1 - .../rustc_codegen_cranelift/src/constant.rs | 3 +- compiler/rustc_codegen_ssa/src/mir/analyze.rs | 1 - compiler/rustc_codegen_ssa/src/mir/block.rs | 4 - .../src/interpret/terminator.rs | 6 +- .../src/transform/check_consts/check.rs | 3 +- .../check_consts/post_drop_elaboration.rs | 3 +- .../src/transform/check_consts/resolver.rs | 12 -- .../src/transform/validate.rs | 12 -- compiler/rustc_middle/src/mir/spanview.rs | 1 - compiler/rustc_middle/src/mir/syntax.rs | 38 ------ compiler/rustc_middle/src/mir/terminator.rs | 13 +- compiler/rustc_middle/src/mir/visit.rs | 14 --- .../src/build/custom/parse/instruction.rs | 8 -- compiler/rustc_mir_build/src/build/scope.rs | 4 +- compiler/rustc_mir_build/src/lints.rs | 1 - .../src/framework/direction.rs | 1 - .../src/impls/borrowed_locals.rs | 3 +- .../src/impls/storage_liveness.rs | 2 - .../src/move_paths/builder.rs | 5 - .../rustc_mir_dataflow/src/value_analysis.rs | 2 +- .../src/abort_unwinding_calls.rs | 2 +- .../src/add_moves_for_packed_drops.rs | 3 - compiler/rustc_mir_transform/src/add_retag.rs | 2 +- .../rustc_mir_transform/src/check_unsafety.rs | 1 - .../rustc_mir_transform/src/const_prop.rs | 1 - .../src/const_prop_lint.rs | 1 - .../rustc_mir_transform/src/coverage/debug.rs | 1 - .../rustc_mir_transform/src/coverage/graph.rs | 1 - .../rustc_mir_transform/src/coverage/spans.rs | 1 - .../rustc_mir_transform/src/coverage/tests.rs | 2 - compiler/rustc_mir_transform/src/dest_prop.rs | 3 +- .../src/elaborate_drops.rs | 119 +----------------- compiler/rustc_mir_transform/src/generator.rs | 2 - compiler/rustc_mir_transform/src/inline.rs | 10 +- .../src/remove_noop_landing_pads.rs | 1 - .../src/remove_uninit_drops.rs | 23 +--- .../src/separate_const_switch.rs | 2 - compiler/rustc_monomorphize/src/collector.rs | 3 +- library/core/src/intrinsics/mir.rs | 3 +- .../clippy_utils/src/qualify_min_const_fn.rs | 4 - .../terminators.drop_first.built.after.mir | 5 +- tests/mir-opt/building/custom/terminators.rs | 3 +- 48 files changed, 33 insertions(+), 341 deletions(-) diff --git a/compiler/rustc_borrowck/src/invalidation.rs b/compiler/rustc_borrowck/src/invalidation.rs index 6217676d5c150..1006a047cce09 100644 --- a/compiler/rustc_borrowck/src/invalidation.rs +++ b/compiler/rustc_borrowck/src/invalidation.rs @@ -118,15 +118,6 @@ impl<'cx, 'tcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx> { LocalMutationIsAllowed::Yes, ); } - TerminatorKind::DropAndReplace { - place: drop_place, - value: new_value, - target: _, - unwind: _, - } => { - self.mutate_place(location, *drop_place, Deep); - self.consume_operand(location, new_value); - } TerminatorKind::Call { func, args, diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs index 115e512a97429..18c465d18c6fe 100644 --- a/compiler/rustc_borrowck/src/lib.rs +++ b/compiler/rustc_borrowck/src/lib.rs @@ -744,15 +744,6 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx flow_state, ); } - TerminatorKind::DropAndReplace { - place: drop_place, - value: new_value, - target: _, - unwind: _, - } => { - self.mutate_place(loc, (*drop_place, span), Deep, flow_state); - self.consume_operand(loc, (new_value, span), flow_state); - } TerminatorKind::Call { func, args, @@ -867,7 +858,6 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx | TerminatorKind::Assert { .. } | TerminatorKind::Call { .. } | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseEdge { real_target: _, imaginary_target: _ } | TerminatorKind::FalseUnwind { real_target: _, unwind: _ } | TerminatorKind::Goto { .. } diff --git a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs index 473c059630073..5d4b1d10b1ebd 100644 --- a/compiler/rustc_borrowck/src/type_check/liveness/trace.rs +++ b/compiler/rustc_borrowck/src/type_check/liveness/trace.rs @@ -435,8 +435,7 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> { // // What we *actually* generate is a store to a temporary // for the call (`TMP = call()...`) and then a - // `DropAndReplace` to swap that with `X` - // (`DropAndReplace` has very particular semantics). + // `Drop(X)` followed by `X = TMP` to swap that with `X`. } } diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index a49da3da6c013..b32cda2719af0 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -1312,24 +1312,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { // no checks needed for these } - TerminatorKind::DropAndReplace { place, value, target: _, unwind: _ } => { - let place_ty = place.ty(body, tcx).ty; - let rv_ty = value.ty(body, tcx); - - let locations = term_location.to_locations(); - if let Err(terr) = - self.sub_types(rv_ty, place_ty, locations, ConstraintCategory::Assignment) - { - span_mirbug!( - self, - term, - "bad DropAndReplace ({:?} = {:?}): {:?}", - place_ty, - rv_ty, - terr - ); - } - } TerminatorKind::SwitchInt { discr, .. } => { self.check_operand(discr, term_location); @@ -1629,7 +1611,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { } TerminatorKind::Unreachable => {} TerminatorKind::Drop { target, unwind, .. } - | TerminatorKind::DropAndReplace { target, unwind, .. } | TerminatorKind::Assert { target, cleanup: unwind, .. } => { self.assert_iscleanup(body, block_data, target, is_cleanup); if let Some(unwind) = unwind { diff --git a/compiler/rustc_borrowck/src/used_muts.rs b/compiler/rustc_borrowck/src/used_muts.rs index e297b1230ea0c..10ade142b24dd 100644 --- a/compiler/rustc_borrowck/src/used_muts.rs +++ b/compiler/rustc_borrowck/src/used_muts.rs @@ -71,9 +71,6 @@ impl<'visit, 'cx, 'tcx> Visitor<'tcx> for GatherUsedMutsVisitor<'visit, 'cx, 'tc TerminatorKind::Call { destination, .. } => { self.remove_never_initialized_mut_locals(*destination); } - TerminatorKind::DropAndReplace { place, .. } => { - self.remove_never_initialized_mut_locals(*place); - } _ => {} } diff --git a/compiler/rustc_codegen_cranelift/src/base.rs b/compiler/rustc_codegen_cranelift/src/base.rs index 7f857528c7c5c..cb0e272cedaba 100644 --- a/compiler/rustc_codegen_cranelift/src/base.rs +++ b/compiler/rustc_codegen_cranelift/src/base.rs @@ -499,7 +499,6 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) { TerminatorKind::Yield { .. } | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::GeneratorDrop => { bug!("shouldn't exist at codegen {:?}", bb_data.terminator()); } diff --git a/compiler/rustc_codegen_cranelift/src/constant.rs b/compiler/rustc_codegen_cranelift/src/constant.rs index 49c4f1aaaefc6..1930db72ead44 100644 --- a/compiler/rustc_codegen_cranelift/src/constant.rs +++ b/compiler/rustc_codegen_cranelift/src/constant.rs @@ -543,8 +543,7 @@ pub(crate) fn mir_operand_get_const_val<'tcx>( | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } | TerminatorKind::Assert { .. } => {} - TerminatorKind::DropAndReplace { .. } - | TerminatorKind::Yield { .. } + TerminatorKind::Yield { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } => unreachable!(), diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs index 95aad10fdb0f9..0ce395e912db3 100644 --- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs +++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs @@ -295,7 +295,6 @@ pub fn cleanup_kinds(mir: &mir::Body<'_>) -> IndexVec { if let Some(unwind) = unwind { debug!( diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs index 57a19a4ab1eab..71c71d59b7ab9 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -1305,10 +1305,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { mergeable_succ(), ), - mir::TerminatorKind::DropAndReplace { .. } => { - bug!("undesugared DropAndReplace in codegen: {:?}", terminator); - } - mir::TerminatorKind::Call { ref func, ref args, diff --git a/compiler/rustc_const_eval/src/interpret/terminator.rs b/compiler/rustc_const_eval/src/interpret/terminator.rs index 2aea7c79b6d3e..685a5599cdedf 100644 --- a/compiler/rustc_const_eval/src/interpret/terminator.rs +++ b/compiler/rustc_const_eval/src/interpret/terminator.rs @@ -171,11 +171,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { Unreachable => throw_ub!(Unreachable), // These should never occur for MIR we actually run. - DropAndReplace { .. } - | FalseEdge { .. } - | FalseUnwind { .. } - | Yield { .. } - | GeneratorDrop => span_bug!( + FalseEdge { .. } | FalseUnwind { .. } | Yield { .. } | GeneratorDrop => span_bug!( terminator.source_info.span, "{:#?} should have been eliminated by MIR pass", terminator.kind diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index aa24d9053b98a..e8f8c87111f72 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -977,8 +977,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { // Forbid all `Drop` terminators unless the place being dropped is a local with no // projections that cannot be `NeedsNonConstDrop`. - TerminatorKind::Drop { place: dropped_place, .. } - | TerminatorKind::DropAndReplace { place: dropped_place, .. } => { + TerminatorKind::Drop { place: dropped_place, .. } => { // If we are checking live drops after drop-elaboration, don't emit duplicate // errors here. if super::post_drop_elaboration::checking_enabled(self.ccx) { diff --git a/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs b/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs index cf4e875c91f0b..43806035a44a0 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/post_drop_elaboration.rs @@ -80,8 +80,7 @@ impl<'tcx> Visitor<'tcx> for CheckLiveDrops<'_, 'tcx> { trace!("visit_terminator: terminator={:?} location={:?}", terminator, location); match &terminator.kind { - mir::TerminatorKind::Drop { place: dropped_place, .. } - | mir::TerminatorKind::DropAndReplace { place: dropped_place, .. } => { + mir::TerminatorKind::Drop { place: dropped_place, .. } => { let dropped_ty = dropped_place.ty(self.body, self.tcx).ty; if !NeedsNonConstDrop::in_any_value_of_ty(self.ccx, dropped_ty) { // Instead of throwing a bug, we just return here. This is because we have to diff --git a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs index 805e6096b35c8..148aff9be4b5b 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs @@ -222,18 +222,6 @@ where // The effect of assignment to the return place in `TerminatorKind::Call` is not applied // here; that occurs in `apply_call_return_effect`. - if let mir::TerminatorKind::DropAndReplace { value, place, .. } = &terminator.kind { - let qualif = qualifs::in_operand::( - self.ccx, - &mut |l| self.state.qualif.contains(l), - value, - ); - - if !place.is_indirect() { - self.assign_qualif_direct(place, qualif); - } - } - // We ignore borrow on drop because custom drop impls are not allowed in consts. // FIXME: Reconsider if accounting for borrows in drops is necessary for const drop. diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs index fb37eb79a335f..b83024cb6b949 100644 --- a/compiler/rustc_const_eval/src/transform/validate.rs +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -835,18 +835,6 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { self.check_edge(location, *unwind, EdgeKind::Unwind); } } - TerminatorKind::DropAndReplace { target, unwind, .. } => { - if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { - self.fail( - location, - "`DropAndReplace` should have been removed during drop elaboration", - ); - } - self.check_edge(location, *target, EdgeKind::Normal); - if let Some(unwind) = unwind { - self.check_edge(location, *unwind, EdgeKind::Unwind); - } - } TerminatorKind::Call { func, args, destination, target, cleanup, .. } => { let func_ty = func.ty(&self.body.local_decls, self.tcx); match func_ty.kind() { diff --git a/compiler/rustc_middle/src/mir/spanview.rs b/compiler/rustc_middle/src/mir/spanview.rs index 28a3b51b7fc92..e52610faf5af7 100644 --- a/compiler/rustc_middle/src/mir/spanview.rs +++ b/compiler/rustc_middle/src/mir/spanview.rs @@ -265,7 +265,6 @@ pub fn terminator_kind_name(term: &Terminator<'_>) -> &'static str { Return => "Return", Unreachable => "Unreachable", Drop { .. } => "Drop", - DropAndReplace { .. } => "DropAndReplace", Call { .. } => "Call", Assert { .. } => "Assert", Yield { .. } => "Yield", diff --git a/compiler/rustc_middle/src/mir/syntax.rs b/compiler/rustc_middle/src/mir/syntax.rs index ae09562a85e98..58c060db66003 100644 --- a/compiler/rustc_middle/src/mir/syntax.rs +++ b/compiler/rustc_middle/src/mir/syntax.rs @@ -133,7 +133,6 @@ pub enum AnalysisPhase { pub enum RuntimePhase { /// In addition to the semantic changes, beginning with this phase, the following variants are /// disallowed: - /// * [`TerminatorKind::DropAndReplace`] /// * [`TerminatorKind::Yield`] /// * [`TerminatorKind::GeneratorDrop`] /// * [`Rvalue::Aggregate`] for any `AggregateKind` except `Array` @@ -596,43 +595,6 @@ pub enum TerminatorKind<'tcx> { /// > consider indirect assignments. Drop { place: Place<'tcx>, target: BasicBlock, unwind: Option }, - /// Drops the place and assigns a new value to it. - /// - /// This first performs the exact same operation as the pre drop-elaboration `Drop` terminator; - /// it then additionally assigns the `value` to the `place` as if by an assignment statement. - /// This assignment occurs both in the unwind and the regular code paths. The semantics are best - /// explained by the elaboration: - /// - /// ```ignore (MIR) - /// BB0 { - /// DropAndReplace(P <- V, goto BB1, unwind BB2) - /// } - /// ``` - /// - /// becomes - /// - /// ```ignore (MIR) - /// BB0 { - /// Drop(P, goto BB1, unwind BB2) - /// } - /// BB1 { - /// // P is now uninitialized - /// P <- V - /// } - /// BB2 { - /// // P is now uninitialized -- its dtor panicked - /// P <- V - /// } - /// ``` - /// - /// Disallowed after drop elaboration. - DropAndReplace { - place: Place<'tcx>, - value: Operand<'tcx>, - target: BasicBlock, - unwind: Option, - }, - /// Roughly speaking, evaluates the `func` operand and the arguments, and starts execution of /// the referred to function. The operand types must match the argument types of the function. /// The return place type must match the return type. The type of the `func` operand must be diff --git a/compiler/rustc_middle/src/mir/terminator.rs b/compiler/rustc_middle/src/mir/terminator.rs index 6e905224c1336..cd970270727f9 100644 --- a/compiler/rustc_middle/src/mir/terminator.rs +++ b/compiler/rustc_middle/src/mir/terminator.rs @@ -148,7 +148,6 @@ impl<'tcx> TerminatorKind<'tcx> { | Call { target: None, cleanup: Some(t), .. } | Call { target: Some(t), cleanup: None, .. } | Yield { resume: t, drop: None, .. } - | DropAndReplace { target: t, unwind: None, .. } | Drop { target: t, unwind: None, .. } | Assert { target: t, cleanup: None, .. } | FalseUnwind { real_target: t, unwind: None } @@ -158,7 +157,6 @@ impl<'tcx> TerminatorKind<'tcx> { } Call { target: Some(t), cleanup: Some(ref u), .. } | Yield { resume: t, drop: Some(ref u), .. } - | DropAndReplace { target: t, unwind: Some(ref u), .. } | Drop { target: t, unwind: Some(ref u), .. } | Assert { target: t, cleanup: Some(ref u), .. } | FalseUnwind { real_target: t, unwind: Some(ref u) } @@ -188,7 +186,6 @@ impl<'tcx> TerminatorKind<'tcx> { | Call { target: None, cleanup: Some(ref mut t), .. } | Call { target: Some(ref mut t), cleanup: None, .. } | Yield { resume: ref mut t, drop: None, .. } - | DropAndReplace { target: ref mut t, unwind: None, .. } | Drop { target: ref mut t, unwind: None, .. } | Assert { target: ref mut t, cleanup: None, .. } | FalseUnwind { real_target: ref mut t, unwind: None } @@ -198,7 +195,6 @@ impl<'tcx> TerminatorKind<'tcx> { } Call { target: Some(ref mut t), cleanup: Some(ref mut u), .. } | Yield { resume: ref mut t, drop: Some(ref mut u), .. } - | DropAndReplace { target: ref mut t, unwind: Some(ref mut u), .. } | Drop { target: ref mut t, unwind: Some(ref mut u), .. } | Assert { target: ref mut t, cleanup: Some(ref mut u), .. } | FalseUnwind { real_target: ref mut t, unwind: Some(ref mut u) } @@ -225,7 +221,6 @@ impl<'tcx> TerminatorKind<'tcx> { | TerminatorKind::FalseEdge { .. } => None, TerminatorKind::Call { cleanup: ref unwind, .. } | TerminatorKind::Assert { cleanup: ref unwind, .. } - | TerminatorKind::DropAndReplace { ref unwind, .. } | TerminatorKind::Drop { ref unwind, .. } | TerminatorKind::FalseUnwind { ref unwind, .. } | TerminatorKind::InlineAsm { cleanup: ref unwind, .. } => Some(unwind), @@ -245,7 +240,6 @@ impl<'tcx> TerminatorKind<'tcx> { | TerminatorKind::FalseEdge { .. } => None, TerminatorKind::Call { cleanup: ref mut unwind, .. } | TerminatorKind::Assert { cleanup: ref mut unwind, .. } - | TerminatorKind::DropAndReplace { ref mut unwind, .. } | TerminatorKind::Drop { ref mut unwind, .. } | TerminatorKind::FalseUnwind { ref mut unwind, .. } | TerminatorKind::InlineAsm { cleanup: ref mut unwind, .. } => Some(unwind), @@ -309,9 +303,6 @@ impl<'tcx> TerminatorKind<'tcx> { Yield { value, resume_arg, .. } => write!(fmt, "{:?} = yield({:?})", resume_arg, value), Unreachable => write!(fmt, "unreachable"), Drop { place, .. } => write!(fmt, "drop({:?})", place), - DropAndReplace { place, value, .. } => { - write!(fmt, "replace({:?} <- {:?})", place, value) - } Call { func, args, destination, .. } => { write!(fmt, "{:?} = ", destination)?; write!(fmt, "{:?}(", func)?; @@ -403,10 +394,10 @@ impl<'tcx> TerminatorKind<'tcx> { Call { target: None, cleanup: None, .. } => vec![], Yield { drop: Some(_), .. } => vec!["resume".into(), "drop".into()], Yield { drop: None, .. } => vec!["resume".into()], - DropAndReplace { unwind: None, .. } | Drop { unwind: None, .. } => { + Drop { unwind: None, .. } => { vec!["return".into()] } - DropAndReplace { unwind: Some(_), .. } | Drop { unwind: Some(_), .. } => { + Drop { unwind: Some(_), .. } => { vec!["return".into(), "unwind".into()] } Assert { cleanup: None, .. } => vec!["".into()], diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs index 5c056b29975c4..14b18618aa8d8 100644 --- a/compiler/rustc_middle/src/mir/visit.rs +++ b/compiler/rustc_middle/src/mir/visit.rs @@ -495,20 +495,6 @@ macro_rules! make_mir_visitor { ); } - TerminatorKind::DropAndReplace { - place, - value, - target: _, - unwind: _, - } => { - self.visit_place( - place, - PlaceContext::MutatingUse(MutatingUseContext::Drop), - location - ); - self.visit_operand(value, location); - } - TerminatorKind::Call { func, args, diff --git a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs index dbba529aef7a5..42a948e78d768 100644 --- a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs +++ b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs @@ -58,14 +58,6 @@ impl<'tcx, 'body> ParseCtxt<'tcx, 'body> { unwind: None, }) }, - @call("mir_drop_and_replace", args) => { - Ok(TerminatorKind::DropAndReplace { - place: self.parse_place(args[0])?, - value: self.parse_operand(args[1])?, - target: self.parse_block(args[2])?, - unwind: None, - }) - }, @call("mir_call", args) => { let destination = self.parse_place(args[0])?; let target = self.parse_block(args[1])?; diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs index 770701b3750df..4bc2c0ca791e6 100644 --- a/compiler/rustc_mir_build/src/build/scope.rs +++ b/compiler/rustc_mir_build/src/build/scope.rs @@ -1072,7 +1072,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { TerminatorKind::Assert { .. } | TerminatorKind::Call { .. } | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::InlineAsm { .. } ), @@ -1432,8 +1431,7 @@ impl<'tcx> DropTreeBuilder<'tcx> for Unwind { *unwind = Some(to); } } - TerminatorKind::DropAndReplace { unwind, .. } - | TerminatorKind::FalseUnwind { unwind, .. } + TerminatorKind::FalseUnwind { unwind, .. } | TerminatorKind::Call { cleanup: unwind, .. } | TerminatorKind::Assert { cleanup: unwind, .. } | TerminatorKind::InlineAsm { cleanup: unwind, .. } => { diff --git a/compiler/rustc_mir_build/src/lints.rs b/compiler/rustc_mir_build/src/lints.rs index f67f24b43c4d7..f6db329fd7cfe 100644 --- a/compiler/rustc_mir_build/src/lints.rs +++ b/compiler/rustc_mir_build/src/lints.rs @@ -128,7 +128,6 @@ impl<'mir, 'tcx> TriColorVisitor> for Search<'mir, 'tcx> { TerminatorKind::Assert { .. } | TerminatorKind::Call { .. } | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::Goto { .. } diff --git a/compiler/rustc_mir_dataflow/src/framework/direction.rs b/compiler/rustc_mir_dataflow/src/framework/direction.rs index 2ae3ae02fcc4e..a40c38aa4c333 100644 --- a/compiler/rustc_mir_dataflow/src/framework/direction.rs +++ b/compiler/rustc_mir_dataflow/src/framework/direction.rs @@ -480,7 +480,6 @@ impl Direction for Forward { Assert { target, cleanup: unwind, expected: _, msg: _, cond: _ } | Drop { target, unwind, place: _ } - | DropAndReplace { target, unwind, value: _, place: _ } | FalseUnwind { real_target: target, unwind } => { if let Some(unwind) = unwind { propagate(unwind, exit_state); diff --git a/compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs b/compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs index 6f4e7fd4682c1..08fadfe68a17a 100644 --- a/compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs +++ b/compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs @@ -111,8 +111,7 @@ where self.super_terminator(terminator, location); match terminator.kind { - mir::TerminatorKind::Drop { place: dropped_place, .. } - | mir::TerminatorKind::DropAndReplace { place: dropped_place, .. } => { + mir::TerminatorKind::Drop { place: dropped_place, .. } => { // Drop terminators may call custom drop glue (`Drop::drop`), which takes `&mut // self` as a parameter. In the general case, a drop impl could launder that // reference into the surrounding environment through a raw pointer, thus creating diff --git a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs index fcf0ce9d82118..60fd5169054d3 100644 --- a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs +++ b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs @@ -202,7 +202,6 @@ impl<'mir, 'tcx> crate::GenKillAnalysis<'tcx> for MaybeRequiresStorage<'mir, 'tc TerminatorKind::Abort | TerminatorKind::Assert { .. } | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::GeneratorDrop @@ -240,7 +239,6 @@ impl<'mir, 'tcx> crate::GenKillAnalysis<'tcx> for MaybeRequiresStorage<'mir, 'tc | TerminatorKind::Abort | TerminatorKind::Assert { .. } | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::GeneratorDrop diff --git a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs index 4a163028fcf4a..fa62960eee0ff 100644 --- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs +++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs @@ -392,11 +392,6 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> { self.create_move_path(place); self.gather_init(place.as_ref(), InitKind::Deep); } - TerminatorKind::DropAndReplace { place, ref value, .. } => { - self.create_move_path(place); - self.gather_operand(value); - self.gather_init(place.as_ref(), InitKind::Deep); - } TerminatorKind::Call { ref func, ref args, diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs index 401db890a9810..4cb28aadbaf44 100644 --- a/compiler/rustc_mir_dataflow/src/value_analysis.rs +++ b/compiler/rustc_mir_dataflow/src/value_analysis.rs @@ -230,7 +230,7 @@ pub trait ValueAnalysis<'tcx> { TerminatorKind::Drop { place, .. } => { state.flood_with(place.as_ref(), self.map(), Self::Value::bottom()); } - TerminatorKind::DropAndReplace { .. } | TerminatorKind::Yield { .. } => { + TerminatorKind::Yield { .. } => { // They would have an effect, but are not allowed in this phase. bug!("encountered disallowed terminator"); } diff --git a/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs b/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs index 9b4b720702b6f..893018e0d8e73 100644 --- a/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs +++ b/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs @@ -74,7 +74,7 @@ impl<'tcx> MirPass<'tcx> for AbortUnwindingCalls { }; layout::fn_can_unwind(tcx, fn_def_id, sig.abi()) } - TerminatorKind::Drop { .. } | TerminatorKind::DropAndReplace { .. } => { + TerminatorKind::Drop { .. } => { tcx.sess.opts.unstable_opts.panic_in_drop == PanicStrategy::Unwind && layout::fn_can_unwind(tcx, None, Abi::Rust) } diff --git a/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs b/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs index 9b2260f68251a..896fcd9cdd608 100644 --- a/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs +++ b/compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs @@ -64,9 +64,6 @@ fn add_moves_for_packed_drops_patch<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) { add_move_for_packed_drop(tcx, body, &mut patch, terminator, loc, data.is_cleanup); } - TerminatorKind::DropAndReplace { .. } => { - span_bug!(terminator.source_info.span, "replace in AddMovesForPackedDrops"); - } _ => {} } } diff --git a/compiler/rustc_mir_transform/src/add_retag.rs b/compiler/rustc_mir_transform/src/add_retag.rs index 7d2146214c6dc..916f2904dda80 100644 --- a/compiler/rustc_mir_transform/src/add_retag.rs +++ b/compiler/rustc_mir_transform/src/add_retag.rs @@ -100,7 +100,7 @@ impl<'tcx> MirPass<'tcx> for AddRetag { } // `Drop` is also a call, but it doesn't return anything so we are good. - TerminatorKind::Drop { .. } | TerminatorKind::DropAndReplace { .. } => None, + TerminatorKind::Drop { .. } => None, // Not a block ending in a Call -> ignore. _ => None, } diff --git a/compiler/rustc_mir_transform/src/check_unsafety.rs b/compiler/rustc_mir_transform/src/check_unsafety.rs index d00ee1f4babe8..ada55a4bf6db1 100644 --- a/compiler/rustc_mir_transform/src/check_unsafety.rs +++ b/compiler/rustc_mir_transform/src/check_unsafety.rs @@ -55,7 +55,6 @@ impl<'tcx> Visitor<'tcx> for UnsafetyChecker<'_, 'tcx> { | TerminatorKind::Drop { .. } | TerminatorKind::Yield { .. } | TerminatorKind::Assert { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::Resume | TerminatorKind::Abort diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs index 6b2eefce24d50..9bc4b26db92eb 100644 --- a/compiler/rustc_mir_transform/src/const_prop.rs +++ b/compiler/rustc_mir_transform/src/const_prop.rs @@ -1007,7 +1007,6 @@ impl<'tcx> MutVisitor<'tcx> for ConstPropagator<'_, 'tcx> { | TerminatorKind::Return | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Yield { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::FalseEdge { .. } diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs index 6c1980ff3ad93..77402b8737e24 100644 --- a/compiler/rustc_mir_transform/src/const_prop_lint.rs +++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs @@ -686,7 +686,6 @@ impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> { | TerminatorKind::Return | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Yield { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::FalseEdge { .. } diff --git a/compiler/rustc_mir_transform/src/coverage/debug.rs b/compiler/rustc_mir_transform/src/coverage/debug.rs index 22ea8710e6a96..0e7dc171a5d0c 100644 --- a/compiler/rustc_mir_transform/src/coverage/debug.rs +++ b/compiler/rustc_mir_transform/src/coverage/debug.rs @@ -822,7 +822,6 @@ pub(super) fn term_type(kind: &TerminatorKind<'_>) -> &'static str { TerminatorKind::Return => "Return", TerminatorKind::Unreachable => "Unreachable", TerminatorKind::Drop { .. } => "Drop", - TerminatorKind::DropAndReplace { .. } => "DropAndReplace", TerminatorKind::Call { .. } => "Call", TerminatorKind::Assert { .. } => "Assert", TerminatorKind::Yield { .. } => "Yield", diff --git a/compiler/rustc_mir_transform/src/coverage/graph.rs b/compiler/rustc_mir_transform/src/coverage/graph.rs index a2671eef2e940..c03cacd8615e3 100644 --- a/compiler/rustc_mir_transform/src/coverage/graph.rs +++ b/compiler/rustc_mir_transform/src/coverage/graph.rs @@ -156,7 +156,6 @@ impl CoverageGraph { | TerminatorKind::Resume | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Call { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::Assert { .. } diff --git a/compiler/rustc_mir_transform/src/coverage/spans.rs b/compiler/rustc_mir_transform/src/coverage/spans.rs index 8ee316773aeaf..d9f68f5d93acc 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans.rs @@ -850,7 +850,6 @@ pub(super) fn filtered_terminator_span(terminator: &Terminator<'_>) -> Option MockBlocks<'tcx> { TerminatorKind::Assert { ref mut target, .. } | TerminatorKind::Call { target: Some(ref mut target), .. } | TerminatorKind::Drop { ref mut target, .. } - | TerminatorKind::DropAndReplace { ref mut target, .. } | TerminatorKind::FalseEdge { real_target: ref mut target, .. } | TerminatorKind::FalseUnwind { real_target: ref mut target, .. } | TerminatorKind::Goto { ref mut target } @@ -184,7 +183,6 @@ fn debug_basic_blocks(mir_body: &Body<'_>) -> String { TerminatorKind::Assert { target, .. } | TerminatorKind::Call { target: Some(target), .. } | TerminatorKind::Drop { target, .. } - | TerminatorKind::DropAndReplace { target, .. } | TerminatorKind::FalseEdge { real_target: target, .. } | TerminatorKind::FalseUnwind { real_target: target, .. } | TerminatorKind::Goto { target } diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs index 2e481b972781c..3823b6201c347 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -650,8 +650,7 @@ impl WriteInfo { TerminatorKind::Drop { .. } => { // `Drop`s create a `&mut` and so are not considered } - TerminatorKind::DropAndReplace { .. } - | TerminatorKind::Yield { .. } + TerminatorKind::Yield { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } => { diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs index 29424f09695f1..3faccca823a57 100644 --- a/compiler/rustc_mir_transform/src/elaborate_drops.rs +++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs @@ -18,15 +18,14 @@ use rustc_span::{DesugaringKind, Span}; use rustc_target::abi::VariantIdx; use std::fmt; -/// During MIR building, Drop and DropAndReplace terminators are inserted in every place where a drop may occur. +/// During MIR building, Drop terminators are inserted in every place where a drop may occur. /// However, in this phase, the presence of these terminators does not guarantee that a destructor will run, /// as the target of the drop may be uninitialized. /// In general, the compiler cannot determine at compile time whether a destructor will run or not. /// -/// At a high level, this pass refines Drop and DropAndReplace to only run the destructor if the +/// At a high level, this pass refines Drop to only run the destructor if the /// target is initialized. The way this is achievied is by inserting drop flags for every variable /// that may be dropped, and then using those flags to determine whether a destructor should run. -/// This pass also removes DropAndReplace, replacing it with a Drop paired with an assign statement. /// Once this is complete, Drop terminators in the MIR correspond to a call to the "drop glue" or /// "drop shim" for the type of the dropped place. /// @@ -121,8 +120,7 @@ fn remove_dead_unwinds<'tcx>( .into_results_cursor(body); for (bb, bb_data) in body.basic_blocks.iter_enumerated() { let place = match bb_data.terminator().kind { - TerminatorKind::Drop { ref place, unwind: Some(_), .. } - | TerminatorKind::DropAndReplace { ref place, unwind: Some(_), .. } => { + TerminatorKind::Drop { ref place, unwind: Some(_), .. } => { und.derefer(place.as_ref(), body).unwrap_or(*place) } _ => continue, @@ -343,8 +341,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { } let terminator = data.terminator(); let place = match terminator.kind { - TerminatorKind::Drop { ref place, .. } - | TerminatorKind::DropAndReplace { ref place, .. } => { + TerminatorKind::Drop { ref place, .. } => { self.un_derefer.derefer(place.as_ref(), self.body).unwrap_or(*place) } _ => continue, @@ -441,103 +438,11 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { } } } - TerminatorKind::DropAndReplace { mut place, ref value, target, unwind } => { - assert!(!data.is_cleanup); - - if let Some(new_place) = self.un_derefer.derefer(place.as_ref(), self.body) { - place = new_place; - } - self.elaborate_replace(loc, place, value, target, unwind); - } _ => continue, } } } - /// Elaborate a MIR `replace` terminator. This instruction - /// is not directly handled by codegen, and therefore - /// must be desugared. - /// - /// The desugaring drops the location if needed, and then writes - /// the value (including setting the drop flag) over it in *both* arms. - /// - /// The `replace` terminator can also be called on places that - /// are not tracked by elaboration (for example, - /// `replace x[i] <- tmp0`). The borrow checker requires that - /// these locations are initialized before the assignment, - /// so we just generate an unconditional drop. - fn elaborate_replace( - &mut self, - loc: Location, - place: Place<'tcx>, - value: &Operand<'tcx>, - target: BasicBlock, - unwind: Option, - ) { - let bb = loc.block; - let data = &self.body[bb]; - let terminator = data.terminator(); - assert!(!data.is_cleanup, "DropAndReplace in unwind path not supported"); - - let assign = Statement { - kind: StatementKind::Assign(Box::new((place, Rvalue::Use(value.clone())))), - source_info: terminator.source_info, - }; - - let unwind = unwind.unwrap_or_else(|| self.patch.resume_block()); - let unwind = self.patch.new_block(BasicBlockData { - statements: vec![assign.clone()], - terminator: Some(Terminator { - kind: TerminatorKind::Goto { target: unwind }, - ..*terminator - }), - is_cleanup: true, - }); - - let target = self.patch.new_block(BasicBlockData { - statements: vec![assign], - terminator: Some(Terminator { kind: TerminatorKind::Goto { target }, ..*terminator }), - is_cleanup: false, - }); - - match self.move_data().rev_lookup.find(place.as_ref()) { - LookupResult::Exact(path) => { - debug!("elaborate_drop_and_replace({:?}) - tracked {:?}", terminator, path); - self.init_data.seek_before(loc); - elaborate_drop( - &mut Elaborator { ctxt: self }, - terminator.source_info, - place, - path, - target, - Unwind::To(unwind), - bb, - ); - on_all_children_bits(self.tcx, self.body, self.move_data(), path, |child| { - self.set_drop_flag( - Location { block: target, statement_index: 0 }, - child, - DropFlagState::Present, - ); - self.set_drop_flag( - Location { block: unwind, statement_index: 0 }, - child, - DropFlagState::Present, - ); - }); - } - LookupResult::Parent(parent) => { - // drop and replace behind a pointer/array/whatever. The location - // must be initialized. - debug!("elaborate_drop_and_replace({:?}) - untracked {:?}", terminator, parent); - self.patch.patch_terminator( - bb, - TerminatorKind::Drop { place, target, unwind: Some(unwind) }, - ); - } - } - } - fn constant_bool(&self, span: Span, val: bool) -> Rvalue<'tcx> { Rvalue::Use(Operand::Constant(Box::new(Constant { span, @@ -609,22 +514,12 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { debug!("drop_flags_for_locs({:?})", data); for i in 0..(data.statements.len() + 1) { debug!("drop_flag_for_locs: stmt {}", i); - let mut allow_initializations = true; if i == data.statements.len() { match data.terminator().kind { TerminatorKind::Drop { .. } => { // drop elaboration should handle that by itself continue; } - TerminatorKind::DropAndReplace { .. } => { - // this contains the move of the source and - // the initialization of the destination. We - // only want the former - the latter is handled - // by the elaboration code and must be done - // *after* the destination is dropped. - assert!(self.patch.is_patched(bb)); - allow_initializations = false; - } TerminatorKind::Resume => { // It is possible for `Resume` to be patched // (in particular it can be patched to be replaced with @@ -641,11 +536,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { self.body, self.env, loc, - |path, ds| { - if ds == DropFlagState::Absent || allow_initializations { - self.set_drop_flag(loc, path, ds) - } - }, + |path, ds| self.set_drop_flag(loc, path, ds), ) } diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs index 2e97312ee5048..f43657e435835 100644 --- a/compiler/rustc_mir_transform/src/generator.rs +++ b/compiler/rustc_mir_transform/src/generator.rs @@ -1199,7 +1199,6 @@ fn can_unwind<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) -> bool { // These may unwind. TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Call { .. } | TerminatorKind::InlineAsm { .. } | TerminatorKind::Assert { .. } => return true, @@ -1691,7 +1690,6 @@ impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> { | TerminatorKind::Return | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Assert { .. } | TerminatorKind::GeneratorDrop | TerminatorKind::FalseEdge { .. } diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 6e6d6566f4bc0..9cba8870f2377 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -453,9 +453,7 @@ impl<'tcx> Inliner<'tcx> { checker.visit_basic_block_data(bb, blk); let term = blk.terminator(); - if let TerminatorKind::Drop { ref place, target, unwind } - | TerminatorKind::DropAndReplace { ref place, target, unwind, .. } = term.kind - { + if let TerminatorKind::Drop { ref place, target, unwind } = term.kind { work_list.push(target); // If the place doesn't actually need dropping, treat it like a regular goto. @@ -815,8 +813,7 @@ impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> { fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) { let tcx = self.tcx; match terminator.kind { - TerminatorKind::Drop { ref place, unwind, .. } - | TerminatorKind::DropAndReplace { ref place, unwind, .. } => { + TerminatorKind::Drop { ref place, unwind, .. } => { // If the place doesn't actually need dropping, treat it like a regular goto. let ty = self.instance.subst_mir(tcx, &place.ty(self.callee_body, tcx).ty); if ty.needs_drop(tcx, self.param_env) { @@ -1120,8 +1117,7 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> { *tgt = self.map_block(*tgt); } } - TerminatorKind::Drop { ref mut target, ref mut unwind, .. } - | TerminatorKind::DropAndReplace { ref mut target, ref mut unwind, .. } => { + TerminatorKind::Drop { ref mut target, ref mut unwind, .. } => { *target = self.map_block(*target); *unwind = self.map_unwind(*unwind); } diff --git a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs index e3a03aa08af4b..6c067f4529929 100644 --- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs +++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs @@ -75,7 +75,6 @@ impl RemoveNoopLandingPads { | TerminatorKind::Unreachable | TerminatorKind::Call { .. } | TerminatorKind::Assert { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Drop { .. } | TerminatorKind::InlineAsm { .. } => false, } diff --git a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs index 78b6f714a9b0b..e72729b152e69 100644 --- a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs +++ b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs @@ -1,5 +1,5 @@ use rustc_index::bit_set::ChunkedBitSet; -use rustc_middle::mir::{Body, Field, Rvalue, Statement, StatementKind, TerminatorKind}; +use rustc_middle::mir::{Body, Field, TerminatorKind}; use rustc_middle::ty::subst::SubstsRef; use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, VariantDef}; use rustc_mir_dataflow::impls::MaybeInitializedPlaces; @@ -8,7 +8,7 @@ use rustc_mir_dataflow::{self, move_path_children_matching, Analysis, MoveDataPa use crate::MirPass; -/// Removes `Drop` and `DropAndReplace` terminators whose target is known to be uninitialized at +/// Removes `Drop` terminators whose target is known to be uninitialized at /// that point. /// /// This is redundant with drop elaboration, but we need to do it prior to const-checking, and @@ -37,8 +37,7 @@ impl<'tcx> MirPass<'tcx> for RemoveUninitDrops { let mut to_remove = vec![]; for (bb, block) in body.basic_blocks.iter_enumerated() { let terminator = block.terminator(); - let (TerminatorKind::Drop { place, .. } | TerminatorKind::DropAndReplace { place, .. }) - = &terminator.kind + let TerminatorKind::Drop { place, .. } = &terminator.kind else { continue }; maybe_inits.seek_before_primary_effect(body.terminator_loc(bb)); @@ -64,24 +63,12 @@ impl<'tcx> MirPass<'tcx> for RemoveUninitDrops { for bb in to_remove { let block = &mut body.basic_blocks_mut()[bb]; - let (TerminatorKind::Drop { target, .. } | TerminatorKind::DropAndReplace { target, .. }) + let TerminatorKind::Drop { target, .. } = &block.terminator().kind else { unreachable!() }; // Replace block terminator with `Goto`. - let target = *target; - let old_terminator_kind = std::mem::replace( - &mut block.terminator_mut().kind, - TerminatorKind::Goto { target }, - ); - - // If this is a `DropAndReplace`, we need to emulate the assignment to the return place. - if let TerminatorKind::DropAndReplace { place, value, .. } = old_terminator_kind { - block.statements.push(Statement { - source_info: block.terminator().source_info, - kind: StatementKind::Assign(Box::new((place, Rvalue::Use(value)))), - }); - } + block.terminator_mut().kind = TerminatorKind::Goto { target: *target }; } } } diff --git a/compiler/rustc_mir_transform/src/separate_const_switch.rs b/compiler/rustc_mir_transform/src/separate_const_switch.rs index a24d2d34d791b..c3f5b881ab8b2 100644 --- a/compiler/rustc_mir_transform/src/separate_const_switch.rs +++ b/compiler/rustc_mir_transform/src/separate_const_switch.rs @@ -108,7 +108,6 @@ pub fn separate_const_switch(body: &mut Body<'_>) -> usize { // The following terminators are not allowed TerminatorKind::Resume | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::Call { .. } | TerminatorKind::Assert { .. } | TerminatorKind::FalseUnwind { .. } @@ -170,7 +169,6 @@ pub fn separate_const_switch(body: &mut Body<'_>) -> usize { | TerminatorKind::Unreachable | TerminatorKind::GeneratorDrop | TerminatorKind::Assert { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::Drop { .. } | TerminatorKind::Call { .. } diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 45e659eab6c85..f529944acce63 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -808,8 +808,7 @@ impl<'a, 'tcx> MirVisitor<'tcx> for MirNeighborCollector<'a, 'tcx> { let callee_ty = self.monomorphize(callee_ty); visit_fn_use(self.tcx, callee_ty, true, source, &mut self.output) } - mir::TerminatorKind::Drop { ref place, .. } - | mir::TerminatorKind::DropAndReplace { ref place, .. } => { + mir::TerminatorKind::Drop { ref place, .. } => { let ty = place.ty(self.body, self.tcx).ty; let ty = self.monomorphize(ty); visit_drop_use(self.tcx, ty, true, source, self.output); diff --git a/library/core/src/intrinsics/mir.rs b/library/core/src/intrinsics/mir.rs index 72db1d87ca3c0..d2d9771bdce2e 100644 --- a/library/core/src/intrinsics/mir.rs +++ b/library/core/src/intrinsics/mir.rs @@ -227,7 +227,7 @@ //! are no resume and abort terminators, and terminators that might unwind do not have any way to //! indicate the unwind block. //! -//! - [`Goto`], [`Return`], [`Unreachable`], [`Drop`](Drop()), and [`DropAndReplace`] have associated functions. +//! - [`Goto`], [`Return`], [`Unreachable`] and [`Drop`](Drop()) have associated functions. //! - `match some_int_operand` becomes a `SwitchInt`. Each arm should be `literal => basic_block` //! - The exception is the last arm, which must be `_ => basic_block` and corresponds to the //! otherwise branch. @@ -259,7 +259,6 @@ define!("mir_return", fn Return() -> BasicBlock); define!("mir_goto", fn Goto(destination: BasicBlock) -> BasicBlock); define!("mir_unreachable", fn Unreachable() -> BasicBlock); define!("mir_drop", fn Drop(place: T, goto: BasicBlock)); -define!("mir_drop_and_replace", fn DropAndReplace(place: T, value: T, goto: BasicBlock)); define!("mir_call", fn Call(place: T, goto: BasicBlock, call: T)); define!("mir_storage_live", fn StorageLive(local: T)); define!("mir_storage_dead", fn StorageDead(local: T)); diff --git a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs index 1a35fe05067fc..c00800291dbd3 100644 --- a/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs +++ b/src/tools/clippy/clippy_utils/src/qualify_min_const_fn.rs @@ -299,10 +299,6 @@ fn check_terminator<'tcx>( | TerminatorKind::Unreachable => Ok(()), TerminatorKind::Drop { place, .. } => check_place(tcx, *place, span, body), - TerminatorKind::DropAndReplace { place, value, .. } => { - check_place(tcx, *place, span, body)?; - check_operand(tcx, value, span, body) - }, TerminatorKind::SwitchInt { discr, targets: _ } => check_operand(tcx, discr, span, body), diff --git a/tests/mir-opt/building/custom/terminators.drop_first.built.after.mir b/tests/mir-opt/building/custom/terminators.drop_first.built.after.mir index c903e5946961b..ada78c0fc782e 100644 --- a/tests/mir-opt/building/custom/terminators.drop_first.built.after.mir +++ b/tests/mir-opt/building/custom/terminators.drop_first.built.after.mir @@ -4,10 +4,11 @@ fn drop_first(_1: WriteOnDrop<'_>, _2: WriteOnDrop<'_>) -> () { let mut _0: (); // return place in scope 0 at $DIR/terminators.rs:+0:59: +0:59 bb0: { - replace(_1 <- move _2) -> bb1; // scope 0 at $DIR/terminators.rs:+3:13: +3:49 + drop(_1) -> bb1; // scope 0 at $DIR/terminators.rs:+3:13: +3:30 } bb1: { - return; // scope 0 at $DIR/terminators.rs:+7:13: +7:21 + _1 = move _2; // scope 0 at $DIR/terminators.rs:+7:13: +7:24 + return; // scope 0 at $DIR/terminators.rs:+8:13: +8:21 } } diff --git a/tests/mir-opt/building/custom/terminators.rs b/tests/mir-opt/building/custom/terminators.rs index c23233fcf9aca..f12405661685b 100644 --- a/tests/mir-opt/building/custom/terminators.rs +++ b/tests/mir-opt/building/custom/terminators.rs @@ -48,10 +48,11 @@ impl<'a> Drop for WriteOnDrop<'a> { fn drop_first<'a>(a: WriteOnDrop<'a>, b: WriteOnDrop<'a>) { mir!( { - DropAndReplace(a, Move(b), retblock) + Drop(a, retblock) } retblock = { + a = Move(b); Return() } ) From 153bfa06e5b8ff57ac5d9274c174c8230a7399eb Mon Sep 17 00:00:00 2001 From: Giacomo Pasini Date: Tue, 7 Mar 2023 20:01:22 +0100 Subject: [PATCH 2/2] remove leftover comment --- .../rustc_const_eval/src/transform/check_consts/resolver.rs | 3 --- 1 file changed, 3 deletions(-) diff --git a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs index 148aff9be4b5b..78c74e1892dc5 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/resolver.rs @@ -224,9 +224,6 @@ where // We ignore borrow on drop because custom drop impls are not allowed in consts. // FIXME: Reconsider if accounting for borrows in drops is necessary for const drop. - - // We need to assign qualifs to the dropped location before visiting the operand that - // replaces it since qualifs can be cleared on move. self.super_terminator(terminator, location); } }