diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/lib.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 50 |
1 files changed, 31 insertions, 19 deletions
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index 0bbbf047f63..84d07d38330 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -87,6 +87,7 @@ mod match_branches; mod mentioned_items; mod multiple_return_terminators; mod nrvo; +mod post_drop_elaboration; mod prettify; mod promote_consts; mod ref_prop; @@ -168,8 +169,9 @@ fn remap_mir_for_const_eval_select<'tcx>( let (method, place): (fn(Place<'tcx>) -> Operand<'tcx>, Place<'tcx>) = match tupled_args.node { Operand::Constant(_) => { - // there is no good way of extracting a tuple arg from a constant (const generic stuff) - // so we just create a temporary and deconstruct that. + // There is no good way of extracting a tuple arg from a constant + // (const generic stuff) so we just create a temporary and deconstruct + // that. let local = body.local_decls.push(LocalDecl::new(ty, fn_span)); bb.statements.push(Statement { source_info: SourceInfo::outermost(fn_span), @@ -222,14 +224,14 @@ fn is_mir_available(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool { /// MIR associated with them. fn mir_keys(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LocalDefId> { // All body-owners have MIR associated with them. - let mut set: FxIndexSet<_> = tcx.hir().body_owners().collect(); + let set: FxIndexSet<_> = tcx.hir().body_owners().collect(); // Additionally, tuple struct/variant constructors have MIR, but // they don't have a BodyId, so we need to build them separately. - struct GatherCtors<'a> { - set: &'a mut FxIndexSet<LocalDefId>, + struct GatherCtors { + set: FxIndexSet<LocalDefId>, } - impl<'tcx> Visitor<'tcx> for GatherCtors<'_> { + impl<'tcx> Visitor<'tcx> for GatherCtors { fn visit_variant_data(&mut self, v: &'tcx hir::VariantData<'tcx>) { if let hir::VariantData::Tuple(_, _, def_id) = *v { self.set.insert(def_id); @@ -237,9 +239,11 @@ fn mir_keys(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LocalDefId> { intravisit::walk_struct_def(self, v) } } - tcx.hir().visit_all_item_likes_in_crate(&mut GatherCtors { set: &mut set }); - set + let mut gather_ctors = GatherCtors { set }; + tcx.hir().visit_all_item_likes_in_crate(&mut gather_ctors); + + gather_ctors.set } fn mir_const_qualif(tcx: TyCtxt<'_>, def: LocalDefId) -> ConstQualifs { @@ -477,10 +481,13 @@ pub fn run_analysis_to_runtime_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<' pm::run_passes( tcx, body, - &[&remove_uninit_drops::RemoveUninitDrops, &simplify::SimplifyCfg::RemoveFalseEdges], + &[ + &remove_uninit_drops::RemoveUninitDrops, + &simplify::SimplifyCfg::RemoveFalseEdges, + &Lint(post_drop_elaboration::CheckLiveDrops), + ], None, ); - check_consts::post_drop_elaboration::check_live_drops(tcx, body); // FIXME: make this a MIR lint } debug!("runtime_mir_lowering({:?})", did); @@ -509,10 +516,12 @@ fn run_analysis_cleanup_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { /// Returns the sequence of passes that lowers analysis to runtime MIR. fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let passes: &[&dyn MirPass<'tcx>] = &[ - // These next passes must be executed together + // These next passes must be executed together. &add_call_guards::CriticalCallEdges, - &reveal_all::RevealAll, // has to be done before drop elaboration, since we need to drop opaque types, too. - &add_subtyping_projections::Subtyper, // calling this after reveal_all ensures that we don't deal with opaque types + // Must be done before drop elaboration because we need to drop opaque types, too. + &reveal_all::RevealAll, + // Calling this after reveal_all ensures that we don't deal with opaque types. + &add_subtyping_projections::Subtyper, &elaborate_drops::ElaborateDrops, // This will remove extraneous landing pads which are no longer // necessary as well as forcing any call in a non-unwinding @@ -521,8 +530,8 @@ fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { // AddMovesForPackedDrops needs to run after drop // elaboration. &add_moves_for_packed_drops::AddMovesForPackedDrops, - // `AddRetag` needs to run after `ElaborateDrops` but before `ElaborateBoxDerefs`. Otherwise it should run fairly late, - // but before optimizations begin. + // `AddRetag` needs to run after `ElaborateDrops` but before `ElaborateBoxDerefs`. + // Otherwise it should run fairly late, but before optimizations begin. &add_retag::AddRetag, &elaborate_box_derefs::ElaborateBoxDerefs, &coroutine::StateTransform, @@ -563,13 +572,15 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { // Before inlining: trim down MIR with passes to reduce inlining work. // Has to be done before inlining, otherwise actual call will be almost always inlined. - // Also simple, so can just do first + // Also simple, so can just do first. &lower_slice_len::LowerSliceLenCalls, - // Perform instsimplify before inline to eliminate some trivial calls (like clone shims). + // Perform instsimplify before inline to eliminate some trivial calls (like clone + // shims). &instsimplify::InstSimplify::BeforeInline, // Perform inlining, which may add a lot of code. &inline::Inline, - // Code from other crates may have storage markers, so this needs to happen after inlining. + // Code from other crates may have storage markers, so this needs to happen after + // inlining. &remove_storage_markers::RemoveStorageMarkers, // Inlining and instantiation may introduce ZST and useless drops. &remove_zsts::RemoveZsts, @@ -586,7 +597,8 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { &match_branches::MatchBranchSimplification, // inst combine is after MatchBranchSimplification to clean up Ne(_1, false) &multiple_return_terminators::MultipleReturnTerminators, - // After simplifycfg, it allows us to discover new opportunities for peephole optimizations. + // After simplifycfg, it allows us to discover new opportunities for peephole + // optimizations. &instsimplify::InstSimplify::AfterSimplifyCfg, &simplify::SimplifyLocals::BeforeConstProp, &dead_store_elimination::DeadStoreElimination::Initial, |