diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs index 63b16aa95a6a5..6ed9df6b75ae5 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mod.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs @@ -939,7 +939,22 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { return OtherUse(use_span); } - for stmt in &self.body[location.block].statements[location.statement_index + 1..] { + // drop and replace might have moved the assignment to the next block + let maybe_additional_statement = if let Some(Terminator { + kind: TerminatorKind::Drop { target: drop_target, .. }, + .. + }) = self.body[location.block].terminator + { + self.body[drop_target].statements.iter().take(1) + } else { + [].iter().take(0) + }; + + let statements = self.body[location.block].statements[location.statement_index + 1..] + .iter() + .chain(maybe_additional_statement); + + for stmt in statements { if let StatementKind::Assign(box (_, Rvalue::Aggregate(kind, places))) = &stmt.kind { let (&def_id, is_generator) = match kind { box AggregateKind::Closure(def_id, _) => (def_id, false), diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs index 6f6d1b01bd429..b1bed65ab2054 100644 --- a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs +++ b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs @@ -688,6 +688,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> { return; } }; + if let hir::ExprKind::Assign(place, rv, _sp) = expr.kind && let hir::ExprKind::Index(val, index) = place.kind && (expr.span == self.assign_span || place.span == self.assign_span) @@ -772,7 +773,13 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> { let Some(hir::Node::Item(item)) = node else { return; }; let hir::ItemKind::Fn(.., body_id) = item.kind else { return; }; let body = self.infcx.tcx.hir().body(body_id); - let mut v = V { assign_span: span, err, ty, suggested: false }; + let mut assign_span = span; + // Drop desugaring is done at MIR build so it's not in the HIR + if let Some(DesugaringKind::Replace) = span.desugaring_kind() { + assign_span.remove_mark(); + } + + let mut v = V { assign_span, err, ty, suggested: false }; v.visit_body(body); if !v.suggested { err.help(&format!( diff --git a/compiler/rustc_borrowck/src/invalidation.rs b/compiler/rustc_borrowck/src/invalidation.rs index 6fd9290058c36..a7a8cfbc89869 100644 --- a/compiler/rustc_borrowck/src/invalidation.rs +++ b/compiler/rustc_borrowck/src/invalidation.rs @@ -117,15 +117,6 @@ 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 278ffed07477b..7c8cd126e749b 100644 --- a/compiler/rustc_borrowck/src/lib.rs +++ b/compiler/rustc_borrowck/src/lib.rs @@ -35,7 +35,7 @@ use rustc_middle::mir::{InlineAsmOperand, Terminator, TerminatorKind}; use rustc_middle::ty::query::Providers; use rustc_middle::ty::{self, CapturedPlace, ParamEnv, RegionVid, TyCtxt}; use rustc_session::lint::builtin::UNUSED_MUT; -use rustc_span::{Span, Symbol}; +use rustc_span::{DesugaringKind, Span, Symbol}; use either::Either; use smallvec::SmallVec; @@ -657,16 +657,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx (AccessDepth::Drop, Write(WriteKind::StorageDeadOrDrop)), LocalMutationIsAllowed::Yes, 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, @@ -782,7 +773,6 @@ 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 { .. } @@ -1099,13 +1089,22 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { this.report_conflicting_borrow(location, place_span, bk, borrow); this.buffer_error(err); } - WriteKind::StorageDeadOrDrop => this - .report_borrowed_value_does_not_live_long_enough( - location, - borrow, - place_span, - Some(kind), - ), + WriteKind::StorageDeadOrDrop => { + if let Some(DesugaringKind::Replace) = place_span.1.desugaring_kind() { + // If this is a drop triggered by a reassignment, it's more user friendly + // to report a problem with the explicit assignment than the implicit drop. + this.report_illegal_mutation_of_borrowed( + location, place_span, borrow, + ) + } else { + this.report_borrowed_value_does_not_live_long_enough( + location, + borrow, + place_span, + Some(kind), + ) + } + } WriteKind::Mutate => { this.report_illegal_mutation_of_borrowed(location, place_span, borrow) } @@ -1592,7 +1591,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { (prefix, place_span.0, place_span.1), mpi, ); - } // Only query longest prefix with a MovePath, not further + } + // Only query longest prefix with a MovePath, not further // ancestors; dataflow recurs on children when parents // move (to support partial (re)inits). // diff --git a/compiler/rustc_borrowck/src/type_check/mod.rs b/compiler/rustc_borrowck/src/type_check/mod.rs index 247607ff29e20..4b02b251e95d1 100644 --- a/compiler/rustc_borrowck/src/type_check/mod.rs +++ b/compiler/rustc_borrowck/src/type_check/mod.rs @@ -1345,25 +1345,6 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { | TerminatorKind::InlineAsm { .. } => { // 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); @@ -1637,7 +1618,6 @@ 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 89d955e8bf2e1..af74fccd354df 100644 --- a/compiler/rustc_codegen_cranelift/src/base.rs +++ b/compiler/rustc_codegen_cranelift/src/base.rs @@ -474,7 +474,6 @@ 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 dee6fb5b5130d..530c00e17167a 100644 --- a/compiler/rustc_codegen_cranelift/src/constant.rs +++ b/compiler/rustc_codegen_cranelift/src/constant.rs @@ -542,8 +542,7 @@ 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 c7617d2e464fa..a9e31be998144 100644 --- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs +++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs @@ -281,7 +281,6 @@ 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 978aff511bfa7..d25812fd87f57 100644 --- a/compiler/rustc_codegen_ssa/src/mir/block.rs +++ b/compiler/rustc_codegen_ssa/src/mir/block.rs @@ -1322,10 +1322,6 @@ 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 550c7a44c4199..63764926a7524 100644 --- a/compiler/rustc_const_eval/src/interpret/terminator.rs +++ b/compiler/rustc_const_eval/src/interpret/terminator.rs @@ -164,11 +164,7 @@ 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 54213d55a2da7..a2624c7408cc4 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -961,8 +961,7 @@ 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 d4570c5988914..722b3eb7aac1f 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 94e1b95a0eb3c..0f0b663e91d2a 100644 --- a/compiler/rustc_const_eval/src/transform/validate.rs +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -736,18 +736,6 @@ 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 887ee57157540..613dc3bcfd508 100644 --- a/compiler/rustc_middle/src/mir/spanview.rs +++ b/compiler/rustc_middle/src/mir/spanview.rs @@ -264,7 +264,6 @@ 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 6b4489026d3d3..c6bd0eaf58e40 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` @@ -580,43 +579,6 @@ 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 438f36373ca91..a157ddf446232 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)?; @@ -403,12 +394,8 @@ 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, .. } => { - vec!["return".into()] - } - DropAndReplace { unwind: Some(_), .. } | Drop { unwind: Some(_), .. } => { - vec!["return".into(), "unwind".into()] - } + Drop { unwind: None, .. } => vec!["return".into()], + Drop { unwind: Some(_), .. } => vec!["return".into(), "unwind".into()], Assert { cleanup: None, .. } => vec!["".into()], Assert { .. } => vec!["success".into(), "unwind".into()], FalseEdge { .. } => vec!["real".into(), "imaginary".into()], diff --git a/compiler/rustc_middle/src/mir/visit.rs b/compiler/rustc_middle/src/mir/visit.rs index 1a264d2d5af9a..b5e1dd8884dd7 100644 --- a/compiler/rustc_middle/src/mir/visit.rs +++ b/compiler/rustc_middle/src/mir/visit.rs @@ -494,20 +494,6 @@ 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 dca4906c07de5..f27dd39c100c8 100644 --- a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs +++ b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs @@ -49,14 +49,6 @@ 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/expr/stmt.rs b/compiler/rustc_mir_build/src/build/expr/stmt.rs index e9f327978aab1..9a3eacdf91943 100644 --- a/compiler/rustc_mir_build/src/build/expr/stmt.rs +++ b/compiler/rustc_mir_build/src/build/expr/stmt.rs @@ -3,6 +3,7 @@ use crate::build::{BlockAnd, BlockAndExtension, BlockFrame, Builder}; use rustc_middle::middle::region; use rustc_middle::mir::*; use rustc_middle::thir::*; +use rustc_span::DesugaringKind; impl<'a, 'tcx> Builder<'a, 'tcx> { /// Builds a block of MIR statements to evaluate the THIR `expr`. @@ -28,7 +29,6 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { ExprKind::Assign { lhs, rhs } => { let lhs = &this.thir[lhs]; let rhs = &this.thir[rhs]; - let lhs_span = lhs.span; // Note: we evaluate assignments right-to-left. This // is better for borrowck interaction with overloaded @@ -39,16 +39,29 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { // Generate better code for things that don't need to be // dropped. - if lhs.ty.needs_drop(this.tcx, this.param_env) { - let rhs = unpack!(block = this.as_local_operand(block, rhs)); - let lhs = unpack!(block = this.as_place(block, lhs)); - unpack!(block = this.build_drop_and_replace(block, lhs_span, lhs, rhs)); + let needs_drop = lhs.ty.needs_drop(this.tcx, this.param_env); + let rhs = unpack!(block = this.as_local_rvalue(block, rhs)); + let lhs = unpack!(block = this.as_place(block, lhs)); + + let source_info = if needs_drop { + let span = this.tcx.with_stable_hashing_context(|hcx| { + expr_span.mark_with_reason( + None, + DesugaringKind::Replace, + this.tcx.sess.edition(), + hcx, + ) + }); + let source_info = this.source_info(span); + unpack!( + block = this.build_drop_and_replace(block, source_info, lhs, rhs.clone()) + ); + source_info } else { - let rhs = unpack!(block = this.as_local_rvalue(block, rhs)); - let lhs = unpack!(block = this.as_place(block, lhs)); - this.cfg.push_assign(block, source_info, lhs, rhs); - } + source_info + }; + this.cfg.push_assign(block, source_info, lhs, rhs); this.block_context.pop(); block.unit() } diff --git a/compiler/rustc_mir_build/src/build/scope.rs b/compiler/rustc_mir_build/src/build/scope.rs index c92634a609de0..29809cd13b1b9 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 { .. } ), @@ -1118,21 +1117,27 @@ impl<'a, 'tcx> Builder<'a, 'tcx> { } /// Utility function for *non*-scope code to build their own drops + /// Force a drop at this point in the MIR by creating a new block. + /// Should only be used for DropAndReplace. + /// Note that this does *not* insert the assignement in the MIR, + /// that should be added in the newly returned block by the caller. pub(crate) fn build_drop_and_replace( &mut self, block: BasicBlock, - span: Span, + source_info: SourceInfo, place: Place<'tcx>, - value: Operand<'tcx>, + value: Rvalue<'tcx>, ) -> BlockAnd<()> { - let source_info = self.source_info(span); let next_target = self.cfg.start_new_block(); + let assign = self.cfg.start_new_cleanup_block(); + self.cfg.push_assign(assign, source_info, place, value.clone()); self.cfg.terminate( block, source_info, - TerminatorKind::DropAndReplace { place, value, target: next_target, unwind: None }, + TerminatorKind::Drop { place, target: next_target, unwind: Some(assign) }, ); + self.diverge_from(block); next_target.unit() @@ -1413,14 +1418,18 @@ impl<'tcx> DropTreeBuilder<'tcx> for Unwind { fn add_entry(cfg: &mut CFG<'tcx>, from: BasicBlock, to: BasicBlock) { let term = &mut cfg.block_data_mut(from).terminator_mut(); match &mut term.kind { - TerminatorKind::Drop { unwind, .. } - | TerminatorKind::DropAndReplace { unwind, .. } - | TerminatorKind::FalseUnwind { unwind, .. } + TerminatorKind::Drop { unwind, .. } => { + if let Some(unwind) = unwind.clone() { + let source_info = term.source_info; + cfg.terminate(unwind, source_info, TerminatorKind::Goto { target: to }); + } else { + *unwind = Some(to); + } + } + TerminatorKind::FalseUnwind { unwind, .. } | TerminatorKind::Call { cleanup: unwind, .. } | TerminatorKind::Assert { cleanup: unwind, .. } - | TerminatorKind::InlineAsm { cleanup: unwind, .. } => { - *unwind = Some(to); - } + | TerminatorKind::InlineAsm { cleanup: unwind, .. } => *unwind = Some(to), TerminatorKind::Goto { .. } | TerminatorKind::SwitchInt { .. } | TerminatorKind::Resume diff --git a/compiler/rustc_mir_build/src/lints.rs b/compiler/rustc_mir_build/src/lints.rs index 8529c64cd5cca..9caab58963418 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 077a21fc8afc0..9816e071bf41c 100644 --- a/compiler/rustc_mir_dataflow/src/framework/direction.rs +++ b/compiler/rustc_mir_dataflow/src/framework/direction.rs @@ -282,7 +282,6 @@ impl Direction for Backward { mir::TerminatorKind::Call { cleanup: Some(unwind), .. } | mir::TerminatorKind::Assert { cleanup: Some(unwind), .. } | mir::TerminatorKind::Drop { unwind: Some(unwind), .. } - | mir::TerminatorKind::DropAndReplace { unwind: Some(unwind), .. } | mir::TerminatorKind::FalseUnwind { unwind: Some(unwind), .. } | mir::TerminatorKind::InlineAsm { cleanup: Some(unwind), .. } if unwind == bb => @@ -498,8 +497,7 @@ impl Direction for Forward { Goto { target } => propagate(target, exit_state), Assert { target, cleanup: unwind, expected: _, msg: _, cond: _ } - | Drop { target, unwind, place: _ } - | DropAndReplace { target, unwind, value: _, place: _ } + | Drop { target, unwind, .. } | FalseUnwind { real_target: target, unwind } => { if let Some(unwind) = unwind { if dead_unwinds.map_or(true, |dead| !dead.contains(bb)) { diff --git a/compiler/rustc_mir_dataflow/src/framework/engine.rs b/compiler/rustc_mir_dataflow/src/framework/engine.rs index 6ddbe69e17e75..5fe4c7a3031d0 100644 --- a/compiler/rustc_mir_dataflow/src/framework/engine.rs +++ b/compiler/rustc_mir_dataflow/src/framework/engine.rs @@ -201,11 +201,11 @@ where } = self; let mut dirty_queue: WorkQueue = WorkQueue::with_none(body.basic_blocks.len()); + // could be tracked in `entry_sets` + let mut visited = BitSet::new_empty(body.basic_blocks.len()); if A::Direction::IS_FORWARD { - for (bb, _) in traversal::reverse_postorder(body) { - dirty_queue.insert(bb); - } + dirty_queue.insert(mir::START_BLOCK); } else { // Reverse post-order on the reverse CFG may generate a better iteration order for // backward dataflow analyses, but probably not enough to matter. @@ -241,8 +241,9 @@ where (bb, bb_data), |target: BasicBlock, state: &A::Domain| { let set_changed = entry_sets[target].join(state); - if set_changed { + if set_changed || !visited.contains(target) { dirty_queue.insert(target); + visited.insert(target); } }, ); diff --git a/compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs b/compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs index 0f8e86d1d6679..6dd69ebe55793 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/mod.rs b/compiler/rustc_mir_dataflow/src/impls/mod.rs index bc31ec42b8b6e..85b177f093fb8 100644 --- a/compiler/rustc_mir_dataflow/src/impls/mod.rs +++ b/compiler/rustc_mir_dataflow/src/impls/mod.rs @@ -338,6 +338,14 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> { Self::update_bits(trans, path, s) }); + if let mir::TerminatorKind::Drop { place, .. } = terminator.kind { + if let LookupResult::Exact(mpi) = self.move_data().rev_lookup.find(place.as_ref()) { + on_all_children_bits(self.tcx, self.body, self.move_data(), mpi, |mpi| { + Self::update_bits(trans, mpi, DropFlagState::Absent) + }) + } + } + if !self.tcx.sess.opts.unstable_opts.precise_enum_drop_elaboration { return; } @@ -458,9 +466,16 @@ impl<'tcx> GenKillAnalysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> { fn terminator_effect( &self, trans: &mut impl GenKill, - _terminator: &mir::Terminator<'tcx>, + terminator: &mir::Terminator<'tcx>, location: Location, ) { + if let mir::TerminatorKind::Drop { place, .. } = terminator.kind { + if let LookupResult::Exact(mpi) = self.move_data().rev_lookup.find(place.as_ref()) { + on_all_children_bits(self.tcx, self.body, self.move_data(), mpi, |mpi| { + Self::update_bits(trans, mpi, DropFlagState::Absent) + }) + } + } drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| { Self::update_bits(trans, path, s) }); @@ -575,9 +590,16 @@ impl<'tcx> GenKillAnalysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> { fn terminator_effect( &self, trans: &mut impl GenKill, - _terminator: &mir::Terminator<'tcx>, + terminator: &mir::Terminator<'tcx>, location: Location, ) { + if let mir::TerminatorKind::Drop { place, .. } = terminator.kind { + if let LookupResult::Exact(mpi) = self.move_data().rev_lookup.find(place.as_ref()) { + on_all_children_bits(self.tcx, self.body, self.move_data(), mpi, |mpi| { + Self::update_bits(trans, mpi, DropFlagState::Absent) + }) + } + } drop_flag_effects_for_location(self.tcx, self.body, self.mdpe, location, |path, s| { Self::update_bits(trans, path, s) }) diff --git a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs index 8d379b90a86db..9c478bef8ecb1 100644 --- a/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs +++ b/compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs @@ -201,7 +201,6 @@ impl<'mir, 'tcx> crate::GenKillAnalysis<'tcx> for MaybeRequiresStorage<'mir, 'tc TerminatorKind::Abort | TerminatorKind::Assert { .. } | TerminatorKind::Drop { .. } - | TerminatorKind::DropAndReplace { .. } | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::GeneratorDrop @@ -239,7 +238,6 @@ 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 f46fd118bde5d..687c22f23f643 100644 --- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs +++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs @@ -391,13 +391,8 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> { self.gather_init(place.as_ref(), InitKind::Deep); } - TerminatorKind::Drop { place, target: _, unwind: _ } => { - self.gather_move(place); - } - TerminatorKind::DropAndReplace { place, ref value, .. } => { + TerminatorKind::Drop { place, .. } => { self.create_move_path(place); - self.gather_operand(value); - self.gather_init(place.as_ref(), InitKind::Deep); } TerminatorKind::Call { ref func, diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs index fe5ee4011ab84..8572e01d1575e 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 { .. } => { // We don't track dropped places. } - 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 d8f85d2e37982..3597eb48a1309 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 3d22035f0785e..387c4f11adfea 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 adf6ae4c7270f..60f43397576b4 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 e384cfe165990..1c00a43fcf266 100644 --- a/compiler/rustc_mir_transform/src/const_prop.rs +++ b/compiler/rustc_mir_transform/src/const_prop.rs @@ -1124,7 +1124,6 @@ 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 0ab67228f3f40..c30f8e60d1fc7 100644 --- a/compiler/rustc_mir_transform/src/const_prop_lint.rs +++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs @@ -684,7 +684,6 @@ 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 d6a298fade42e..d384d1be9bb4f 100644 --- a/compiler/rustc_mir_transform/src/coverage/debug.rs +++ b/compiler/rustc_mir_transform/src/coverage/debug.rs @@ -819,7 +819,6 @@ 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 78d28f1ebab7c..9b08cfa04f50b 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 9f842c929dc24..f49ae1f8b4593 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans.rs @@ -848,7 +848,6 @@ 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 08e296a837127..3a87c4d17f2bd 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -648,8 +648,7 @@ 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 65f4956d23acd..3d2719629ff64 100644 --- a/compiler/rustc_mir_transform/src/elaborate_drops.rs +++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs @@ -93,8 +93,7 @@ fn find_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, @@ -302,8 +301,7 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { for (bb, data) in self.body.basic_blocks.iter_enumerated() { 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, @@ -381,110 +379,30 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { bb, ), LookupResult::Parent(..) => { - self.tcx.sess.delay_span_bug( - terminator.source_info.span, - &format!("drop of untracked value {:?}", bb), + // drop and replace behind a pointer/array/whatever. The location + // must be initialized. + // FIXME: should we check that it's actually the case and we did + // not wrongly emit a drop terminator somewhere / missed move data? + Elaborator { ctxt: self }.patch().patch_terminator( + bb, + TerminatorKind::Drop { + place, + target, + unwind: if data.is_cleanup { + None + } else { + Some(Option::unwrap_or(unwind, resume_block)) + }, + }, ); } } } - 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, @@ -550,22 +468,23 @@ 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; + let 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; - } + // FIXME ?? + // 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 diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/generator.rs index c097af6161159..87b298de72f8d 100644 --- a/compiler/rustc_mir_transform/src/generator.rs +++ b/compiler/rustc_mir_transform/src/generator.rs @@ -1074,7 +1074,6 @@ 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, @@ -1519,7 +1518,6 @@ 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 4219e6280ebbc..d82b9f85d189e 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. @@ -790,8 +788,7 @@ 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) { @@ -1116,8 +1113,7 @@ 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 f1bbf2ea7e8ea..1746540744f1c 100644 --- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs +++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs @@ -74,7 +74,6 @@ 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..a9096ba3aad74 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; @@ -8,6 +8,7 @@ use rustc_mir_dataflow::{self, move_path_children_matching, Analysis, MoveDataPa use crate::MirPass; +// FIXME: can remove this altogether by moving drop elaboration *before* borrowck /// Removes `Drop` and `DropAndReplace` terminators whose target is known to be uninitialized at /// that point. /// @@ -37,7 +38,7 @@ 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, .. }) + let TerminatorKind::Drop { place, .. } = &terminator.kind else { continue }; @@ -64,24 +65,16 @@ 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( + let _ = 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)))), - }); - } } } } diff --git a/compiler/rustc_mir_transform/src/separate_const_switch.rs b/compiler/rustc_mir_transform/src/separate_const_switch.rs index 2f116aaa95849..151c02293bf2b 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_mir_transform/src/sroa.rs b/compiler/rustc_mir_transform/src/sroa.rs index 3a2bf05151655..48978a1fb7d1a 100644 --- a/compiler/rustc_mir_transform/src/sroa.rs +++ b/compiler/rustc_mir_transform/src/sroa.rs @@ -83,9 +83,7 @@ fn escaping_locals(body: &Body<'_>) -> BitSet { fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, location: Location) { // Drop implicitly calls `drop_in_place`, which takes a `&mut`. // This implies that `Drop` implicitly takes the address of the place. - if let TerminatorKind::Drop { place, .. } - | TerminatorKind::DropAndReplace { place, .. } = terminator.kind - { + if let TerminatorKind::Drop { place, .. } = terminator.kind { if !place.is_indirect() { // Raw pointers may be used to access anything inside the enclosing place. self.set.insert(place.local); diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs index 59cc500a99da7..e3bda9416abde 100644 --- a/compiler/rustc_monomorphize/src/collector.rs +++ b/compiler/rustc_monomorphize/src/collector.rs @@ -806,8 +806,7 @@ 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/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs index 4e70dfb614782..7b20c6a926b0f 100644 --- a/compiler/rustc_span/src/hygiene.rs +++ b/compiler/rustc_span/src/hygiene.rs @@ -1151,6 +1151,7 @@ pub enum DesugaringKind { Await, ForLoop, WhileLoop, + Replace, } impl DesugaringKind { @@ -1166,6 +1167,7 @@ impl DesugaringKind { DesugaringKind::OpaqueTy => "`impl Trait`", DesugaringKind::ForLoop => "`for` loop", DesugaringKind::WhileLoop => "`while` loop", + DesugaringKind::Replace => "drop and replace", } } } 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 e5d7da682813c..69fdc8590d6a0 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 @@ -296,10 +296,6 @@ 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),