diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src')
24 files changed, 1302 insertions, 597 deletions
diff --git a/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs b/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs index 74243f1f8f2..2b3d423ea61 100644 --- a/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs +++ b/compiler/rustc_mir_transform/src/abort_unwinding_calls.rs @@ -40,7 +40,7 @@ impl<'tcx> MirPass<'tcx> for AbortUnwindingCalls { let body_abi = match body_ty.kind() { ty::FnDef(..) => body_ty.fn_sig(tcx).abi(), ty::Closure(..) => Abi::RustCall, - ty::Generator(..) => Abi::Rust, + ty::Coroutine(..) => Abi::Rust, _ => span_bug!(body.span, "unexpected body ty: {:?}", body_ty), }; let body_can_unwind = layout::fn_can_unwind(tcx, Some(def_id), body_abi); diff --git a/compiler/rustc_mir_transform/src/check_unsafety.rs b/compiler/rustc_mir_transform/src/check_unsafety.rs index 7e4731f5d8a..8872f9a97d7 100644 --- a/compiler/rustc_mir_transform/src/check_unsafety.rs +++ b/compiler/rustc_mir_transform/src/check_unsafety.rs @@ -56,7 +56,7 @@ impl<'tcx> Visitor<'tcx> for UnsafetyChecker<'_, 'tcx> { | TerminatorKind::Drop { .. } | TerminatorKind::Yield { .. } | TerminatorKind::Assert { .. } - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::UnwindResume | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return @@ -128,7 +128,7 @@ impl<'tcx> Visitor<'tcx> for UnsafetyChecker<'_, 'tcx> { ), } } - &AggregateKind::Closure(def_id, _) | &AggregateKind::Generator(def_id, _, _) => { + &AggregateKind::Closure(def_id, _) | &AggregateKind::Coroutine(def_id, _, _) => { let def_id = def_id.expect_local(); let UnsafetyCheckResult { violations, used_unsafe_blocks, .. } = self.tcx.unsafety_check_result(def_id); diff --git a/compiler/rustc_mir_transform/src/const_prop.rs b/compiler/rustc_mir_transform/src/const_prop.rs index 3450a0f3686..53c0d0dea29 100644 --- a/compiler/rustc_mir_transform/src/const_prop.rs +++ b/compiler/rustc_mir_transform/src/const_prop.rs @@ -82,11 +82,11 @@ impl<'tcx> MirPass<'tcx> for ConstProp { return; } - // FIXME(welseywiser) const prop doesn't work on generators because of query cycles + // FIXME(welseywiser) const prop doesn't work on coroutines because of query cycles // computing their layout. - let is_generator = def_kind == DefKind::Generator; - if is_generator { - trace!("ConstProp skipped for generator {:?}", def_id); + let is_coroutine = def_kind == DefKind::Coroutine; + if is_coroutine { + trace!("ConstProp skipped for coroutine {:?}", def_id); return; } @@ -512,7 +512,7 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { fn replace_with_const(&mut self, place: Place<'tcx>) -> Option<Const<'tcx>> { // This will return None if the above `const_prop` invocation only "wrote" a - // type whose creation requires no write. E.g. a generator whose initial state + // type whose creation requires no write. E.g. a coroutine whose initial state // consists solely of uninitialized memory (so it doesn't capture any locals). let value = self.get_const(place)?; if !self.tcx.consider_optimizing(|| format!("ConstantPropagation - {value:?}")) { diff --git a/compiler/rustc_mir_transform/src/const_prop_lint.rs b/compiler/rustc_mir_transform/src/const_prop_lint.rs index aad513d7355..a23ba9c4aa9 100644 --- a/compiler/rustc_mir_transform/src/const_prop_lint.rs +++ b/compiler/rustc_mir_transform/src/const_prop_lint.rs @@ -59,10 +59,10 @@ impl<'tcx> MirLint<'tcx> for ConstPropLint { return; } - // FIXME(welseywiser) const prop doesn't work on generators because of query cycles + // FIXME(welseywiser) const prop doesn't work on coroutines because of query cycles // computing their layout. - if let DefKind::Generator = def_kind { - trace!("ConstPropLint skipped for generator {:?}", def_id); + if let DefKind::Coroutine = def_kind { + trace!("ConstPropLint skipped for coroutine {:?}", def_id); return; } @@ -648,7 +648,7 @@ impl<'tcx> Visitor<'tcx> for ConstPropagator<'_, 'tcx> { | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } | TerminatorKind::Yield { .. } - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::Call { .. } diff --git a/compiler/rustc_mir_transform/src/generator.rs b/compiler/rustc_mir_transform/src/coroutine.rs index a6693519e54..fa56d59dd80 100644 --- a/compiler/rustc_mir_transform/src/generator.rs +++ b/compiler/rustc_mir_transform/src/coroutine.rs @@ -1,53 +1,53 @@ -//! This is the implementation of the pass which transforms generators into state machines. +//! This is the implementation of the pass which transforms coroutines into state machines. //! -//! MIR generation for generators creates a function which has a self argument which -//! passes by value. This argument is effectively a generator type which only contains upvars and -//! is only used for this argument inside the MIR for the generator. +//! MIR generation for coroutines creates a function which has a self argument which +//! passes by value. This argument is effectively a coroutine type which only contains upvars and +//! is only used for this argument inside the MIR for the coroutine. //! It is passed by value to enable upvars to be moved out of it. Drop elaboration runs on that //! MIR before this pass and creates drop flags for MIR locals. -//! It will also drop the generator argument (which only consists of upvars) if any of the upvars -//! are moved out of. This pass elaborates the drops of upvars / generator argument in the case +//! It will also drop the coroutine argument (which only consists of upvars) if any of the upvars +//! are moved out of. This pass elaborates the drops of upvars / coroutine argument in the case //! that none of the upvars were moved out of. This is because we cannot have any drops of this -//! generator in the MIR, since it is used to create the drop glue for the generator. We'd get +//! coroutine in the MIR, since it is used to create the drop glue for the coroutine. We'd get //! infinite recursion otherwise. //! -//! This pass creates the implementation for either the `Generator::resume` or `Future::poll` -//! function and the drop shim for the generator based on the MIR input. -//! It converts the generator argument from Self to &mut Self adding derefs in the MIR as needed. -//! It computes the final layout of the generator struct which looks like this: +//! This pass creates the implementation for either the `Coroutine::resume` or `Future::poll` +//! function and the drop shim for the coroutine based on the MIR input. +//! It converts the coroutine argument from Self to &mut Self adding derefs in the MIR as needed. +//! It computes the final layout of the coroutine struct which looks like this: //! First upvars are stored -//! It is followed by the generator state field. +//! It is followed by the coroutine state field. //! Then finally the MIR locals which are live across a suspension point are stored. //! ```ignore (illustrative) -//! struct Generator { +//! struct Coroutine { //! upvars..., //! state: u32, //! mir_locals..., //! } //! ``` //! This pass computes the meaning of the state field and the MIR locals which are live -//! across a suspension point. There are however three hardcoded generator states: -//! 0 - Generator have not been resumed yet -//! 1 - Generator has returned / is completed -//! 2 - Generator has been poisoned +//! across a suspension point. There are however three hardcoded coroutine states: +//! 0 - Coroutine have not been resumed yet +//! 1 - Coroutine has returned / is completed +//! 2 - Coroutine has been poisoned //! -//! It also rewrites `return x` and `yield y` as setting a new generator state and returning -//! `GeneratorState::Complete(x)` and `GeneratorState::Yielded(y)`, +//! It also rewrites `return x` and `yield y` as setting a new coroutine state and returning +//! `CoroutineState::Complete(x)` and `CoroutineState::Yielded(y)`, //! or `Poll::Ready(x)` and `Poll::Pending` respectively. -//! MIR locals which are live across a suspension point are moved to the generator struct -//! with references to them being updated with references to the generator struct. +//! MIR locals which are live across a suspension point are moved to the coroutine struct +//! with references to them being updated with references to the coroutine struct. //! -//! The pass creates two functions which have a switch on the generator state giving +//! The pass creates two functions which have a switch on the coroutine state giving //! the action to take. //! -//! One of them is the implementation of `Generator::resume` / `Future::poll`. -//! For generators with state 0 (unresumed) it starts the execution of the generator. -//! For generators with state 1 (returned) and state 2 (poisoned) it panics. +//! One of them is the implementation of `Coroutine::resume` / `Future::poll`. +//! For coroutines with state 0 (unresumed) it starts the execution of the coroutine. +//! For coroutines with state 1 (returned) and state 2 (poisoned) it panics. //! Otherwise it continues the execution from the last suspension point. //! -//! The other function is the drop glue for the generator. -//! For generators with state 0 (unresumed) it drops the upvars of the generator. -//! For generators with state 1 (returned) and state 2 (poisoned) it does nothing. +//! The other function is the drop glue for the coroutine. +//! For coroutines with state 0 (unresumed) it drops the upvars of the coroutine. +//! For coroutines with state 1 (returned) and state 2 (poisoned) it does nothing. //! Otherwise it drops all the values in scope at the last suspension point. use crate::abort_unwinding_calls; @@ -60,7 +60,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_errors::pluralize; use rustc_hir as hir; use rustc_hir::lang_items::LangItem; -use rustc_hir::GeneratorKind; +use rustc_hir::CoroutineKind; use rustc_index::bit_set::{BitMatrix, BitSet, GrowableBitSet}; use rustc_index::{Idx, IndexVec}; use rustc_middle::mir::dump_mir; @@ -68,7 +68,7 @@ use rustc_middle::mir::visit::{MutVisitor, PlaceContext, Visitor}; use rustc_middle::mir::*; use rustc_middle::ty::InstanceDef; use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt}; -use rustc_middle::ty::{GeneratorArgs, GenericArgsRef}; +use rustc_middle::ty::{CoroutineArgs, GenericArgsRef}; use rustc_mir_dataflow::impls::{ MaybeBorrowedLocals, MaybeLiveLocals, MaybeRequiresStorage, MaybeStorageLive, }; @@ -196,19 +196,19 @@ fn replace_base<'tcx>(place: &mut Place<'tcx>, new_base: Place<'tcx>, tcx: TyCtx const SELF_ARG: Local = Local::from_u32(1); -/// Generator has not been resumed yet. -const UNRESUMED: usize = GeneratorArgs::UNRESUMED; -/// Generator has returned / is completed. -const RETURNED: usize = GeneratorArgs::RETURNED; -/// Generator has panicked and is poisoned. -const POISONED: usize = GeneratorArgs::POISONED; +/// Coroutine has not been resumed yet. +const UNRESUMED: usize = CoroutineArgs::UNRESUMED; +/// Coroutine has returned / is completed. +const RETURNED: usize = CoroutineArgs::RETURNED; +/// Coroutine has panicked and is poisoned. +const POISONED: usize = CoroutineArgs::POISONED; -/// Number of variants to reserve in generator state. Corresponds to -/// `UNRESUMED` (beginning of a generator) and `RETURNED`/`POISONED` -/// (end of a generator) states. +/// Number of variants to reserve in coroutine state. Corresponds to +/// `UNRESUMED` (beginning of a coroutine) and `RETURNED`/`POISONED` +/// (end of a coroutine) states. const RESERVED_VARIANTS: usize = 3; -/// A `yield` point in the generator. +/// A `yield` point in the coroutine. struct SuspensionPoint<'tcx> { /// State discriminant used when suspending or resuming at this point. state: usize, @@ -216,7 +216,7 @@ struct SuspensionPoint<'tcx> { resume: BasicBlock, /// Where to move the resume argument after resumption. resume_arg: Place<'tcx>, - /// Which block to jump to if the generator is dropped in this state. + /// Which block to jump to if the coroutine is dropped in this state. drop: Option<BasicBlock>, /// Set of locals that have live storage while at this suspension point. storage_liveness: GrowableBitSet<Local>, @@ -228,10 +228,10 @@ struct TransformVisitor<'tcx> { state_adt_ref: AdtDef<'tcx>, state_args: GenericArgsRef<'tcx>, - // The type of the discriminant in the generator struct + // The type of the discriminant in the coroutine struct discr_ty: Ty<'tcx>, - // Mapping from Local to (type of local, generator struct index) + // Mapping from Local to (type of local, coroutine struct index) // FIXME(eddyb) This should use `IndexVec<Local, Option<_>>`. remap: FxHashMap<Local, (Ty<'tcx>, VariantIdx, FieldIdx)>, @@ -249,9 +249,9 @@ struct TransformVisitor<'tcx> { } impl<'tcx> TransformVisitor<'tcx> { - // Make a `GeneratorState` or `Poll` variant assignment. + // Make a `CoroutineState` or `Poll` variant assignment. // - // `core::ops::GeneratorState` only has single element tuple variants, + // `core::ops::CoroutineState` only has single element tuple variants, // so we can just write to the downcasted first field and then set the // discriminant to the appropriate variant. fn make_state( @@ -262,8 +262,8 @@ impl<'tcx> TransformVisitor<'tcx> { statements: &mut Vec<Statement<'tcx>>, ) { let idx = VariantIdx::new(match (is_return, self.is_async_kind) { - (true, false) => 1, // GeneratorState::Complete - (false, false) => 0, // GeneratorState::Yielded + (true, false) => 1, // CoroutineState::Complete + (false, false) => 0, // CoroutineState::Yielded (true, true) => 0, // Poll::Ready (false, true) => 1, // Poll::Pending }); @@ -285,7 +285,7 @@ impl<'tcx> TransformVisitor<'tcx> { return; } - // else: `Poll::Ready(x)`, `GeneratorState::Yielded(x)` or `GeneratorState::Complete(x)` + // else: `Poll::Ready(x)`, `CoroutineState::Yielded(x)` or `CoroutineState::Complete(x)` assert_eq!(self.state_adt_ref.variant(idx).fields.len(), 1); statements.push(Statement { @@ -297,7 +297,7 @@ impl<'tcx> TransformVisitor<'tcx> { }); } - // Create a Place referencing a generator struct field + // Create a Place referencing a coroutine struct field fn make_field(&self, variant_index: VariantIdx, idx: FieldIdx, ty: Ty<'tcx>) -> Place<'tcx> { let self_place = Place::from(SELF_ARG); let base = self.tcx.mk_place_downcast_unnamed(self_place, variant_index); @@ -349,7 +349,7 @@ impl<'tcx> MutVisitor<'tcx> for TransformVisitor<'tcx> { _context: PlaceContext, _location: Location, ) { - // Replace an Local in the remap with a generator struct access + // Replace an Local in the remap with a coroutine struct access if let Some(&(ty, variant_index, idx)) = self.remap.get(&place.local) { replace_base(place, self.make_field(variant_index, idx, ty), self.tcx); } @@ -413,7 +413,7 @@ impl<'tcx> MutVisitor<'tcx> for TransformVisitor<'tcx> { } } -fn make_generator_state_argument_indirect<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { +fn make_coroutine_state_argument_indirect<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let gen_ty = body.local_decls.raw[1].ty; let ref_gen_ty = Ty::new_ref( @@ -422,14 +422,14 @@ fn make_generator_state_argument_indirect<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Bo ty::TypeAndMut { ty: gen_ty, mutbl: Mutability::Mut }, ); - // Replace the by value generator argument + // Replace the by value coroutine argument body.local_decls.raw[1].ty = ref_gen_ty; - // Add a deref to accesses of the generator state + // Add a deref to accesses of the coroutine state DerefArgVisitor { tcx }.visit_body(body); } -fn make_generator_state_argument_pinned<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { +fn make_coroutine_state_argument_pinned<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let ref_gen_ty = body.local_decls.raw[1].ty; let pin_did = tcx.require_lang_item(LangItem::Pin, Some(body.span)); @@ -437,10 +437,10 @@ fn make_generator_state_argument_pinned<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body let args = tcx.mk_args(&[ref_gen_ty.into()]); let pin_ref_gen_ty = Ty::new_adt(tcx, pin_adt_ref, args); - // Replace the by ref generator argument + // Replace the by ref coroutine argument body.local_decls.raw[1].ty = pin_ref_gen_ty; - // Add the Pin field access to accesses of the generator state + // Add the Pin field access to accesses of the coroutine state PinArgVisitor { ref_gen_ty, tcx }.visit_body(body); } @@ -465,7 +465,7 @@ fn replace_local<'tcx>( new_local } -/// Transforms the `body` of the generator applying the following transforms: +/// Transforms the `body` of the coroutine applying the following transforms: /// /// - Eliminates all the `get_context` calls that async lowering created. /// - Replace all `Local` `ResumeTy` types with `&mut Context<'_>` (`context_mut_ref`). @@ -485,7 +485,7 @@ fn replace_local<'tcx>( /// /// The async lowering step and the type / lifetime inference / checking are /// still using the `ResumeTy` indirection for the time being, and that indirection -/// is removed here. After this transform, the generator body only knows about `&mut Context<'_>`. +/// is removed here. After this transform, the coroutine body only knows about `&mut Context<'_>`. fn transform_async_context<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let context_mut_ref = Ty::new_task_context(tcx); @@ -565,10 +565,10 @@ fn replace_resume_ty_local<'tcx>( struct LivenessInfo { /// Which locals are live across any suspension point. - saved_locals: GeneratorSavedLocals, + saved_locals: CoroutineSavedLocals, /// The set of saved locals live at each suspension point. - live_locals_at_suspension_points: Vec<BitSet<GeneratorSavedLocal>>, + live_locals_at_suspension_points: Vec<BitSet<CoroutineSavedLocal>>, /// Parallel vec to the above with SourceInfo for each yield terminator. source_info_at_suspension_points: Vec<SourceInfo>, @@ -576,7 +576,7 @@ struct LivenessInfo { /// For every saved local, the set of other saved locals that are /// storage-live at the same time as this local. We cannot overlap locals in /// the layout which have conflicting storage. - storage_conflicts: BitMatrix<GeneratorSavedLocal, GeneratorSavedLocal>, + storage_conflicts: BitMatrix<CoroutineSavedLocal, CoroutineSavedLocal>, /// For every suspending block, the locals which are storage-live across /// that suspension point. @@ -601,7 +601,7 @@ fn locals_live_across_suspend_points<'tcx>( // Calculate the MIR locals which have been previously // borrowed (even if they are still active). let borrowed_locals_results = - MaybeBorrowedLocals.into_engine(tcx, body_ref).pass_name("generator").iterate_to_fixpoint(); + MaybeBorrowedLocals.into_engine(tcx, body_ref).pass_name("coroutine").iterate_to_fixpoint(); let mut borrowed_locals_cursor = borrowed_locals_results.cloned_results_cursor(body_ref); @@ -616,7 +616,7 @@ fn locals_live_across_suspend_points<'tcx>( // Calculate the liveness of MIR locals ignoring borrows. let mut liveness = MaybeLiveLocals .into_engine(tcx, body_ref) - .pass_name("generator") + .pass_name("coroutine") .iterate_to_fixpoint() .into_results_cursor(body_ref); @@ -635,8 +635,8 @@ fn locals_live_across_suspend_points<'tcx>( if !movable { // The `liveness` variable contains the liveness of MIR locals ignoring borrows. - // This is correct for movable generators since borrows cannot live across - // suspension points. However for immovable generators we need to account for + // This is correct for movable coroutines since borrows cannot live across + // suspension points. However for immovable coroutines we need to account for // borrows, so we conservatively assume that all borrowed locals are live until // we find a StorageDead statement referencing the locals. // To do this we just union our `liveness` result with `borrowed_locals`, which @@ -659,7 +659,7 @@ fn locals_live_across_suspend_points<'tcx>( requires_storage_cursor.seek_before_primary_effect(loc); live_locals.intersect(requires_storage_cursor.get()); - // The generator argument is ignored. + // The coroutine argument is ignored. live_locals.remove(SELF_ARG); debug!("loc = {:?}, live_locals = {:?}", loc, live_locals); @@ -674,7 +674,7 @@ fn locals_live_across_suspend_points<'tcx>( } debug!("live_locals_anywhere = {:?}", live_locals_at_any_suspension_point); - let saved_locals = GeneratorSavedLocals(live_locals_at_any_suspension_point); + let saved_locals = CoroutineSavedLocals(live_locals_at_any_suspension_point); // Renumber our liveness_map bitsets to include only the locals we are // saving. @@ -701,21 +701,21 @@ fn locals_live_across_suspend_points<'tcx>( /// The set of `Local`s that must be saved across yield points. /// -/// `GeneratorSavedLocal` is indexed in terms of the elements in this set; -/// i.e. `GeneratorSavedLocal::new(1)` corresponds to the second local +/// `CoroutineSavedLocal` is indexed in terms of the elements in this set; +/// i.e. `CoroutineSavedLocal::new(1)` corresponds to the second local /// included in this set. -struct GeneratorSavedLocals(BitSet<Local>); +struct CoroutineSavedLocals(BitSet<Local>); -impl GeneratorSavedLocals { - /// Returns an iterator over each `GeneratorSavedLocal` along with the `Local` it corresponds +impl CoroutineSavedLocals { + /// Returns an iterator over each `CoroutineSavedLocal` along with the `Local` it corresponds /// to. - fn iter_enumerated(&self) -> impl '_ + Iterator<Item = (GeneratorSavedLocal, Local)> { - self.iter().enumerate().map(|(i, l)| (GeneratorSavedLocal::from(i), l)) + fn iter_enumerated(&self) -> impl '_ + Iterator<Item = (CoroutineSavedLocal, Local)> { + self.iter().enumerate().map(|(i, l)| (CoroutineSavedLocal::from(i), l)) } /// Transforms a `BitSet<Local>` that contains only locals saved across yield points to the - /// equivalent `BitSet<GeneratorSavedLocal>`. - fn renumber_bitset(&self, input: &BitSet<Local>) -> BitSet<GeneratorSavedLocal> { + /// equivalent `BitSet<CoroutineSavedLocal>`. + fn renumber_bitset(&self, input: &BitSet<Local>) -> BitSet<CoroutineSavedLocal> { assert!(self.superset(&input), "{:?} not a superset of {:?}", self.0, input); let mut out = BitSet::new_empty(self.count()); for (saved_local, local) in self.iter_enumerated() { @@ -726,17 +726,17 @@ impl GeneratorSavedLocals { out } - fn get(&self, local: Local) -> Option<GeneratorSavedLocal> { + fn get(&self, local: Local) -> Option<CoroutineSavedLocal> { if !self.contains(local) { return None; } let idx = self.iter().take_while(|&l| l < local).count(); - Some(GeneratorSavedLocal::new(idx)) + Some(CoroutineSavedLocal::new(idx)) } } -impl ops::Deref for GeneratorSavedLocals { +impl ops::Deref for CoroutineSavedLocals { type Target = BitSet<Local>; fn deref(&self) -> &Self::Target { @@ -747,13 +747,13 @@ impl ops::Deref for GeneratorSavedLocals { /// For every saved local, looks for which locals are StorageLive at the same /// time. Generates a bitset for every local of all the other locals that may be /// StorageLive simultaneously with that local. This is used in the layout -/// computation; see `GeneratorLayout` for more. +/// computation; see `CoroutineLayout` for more. fn compute_storage_conflicts<'mir, 'tcx>( body: &'mir Body<'tcx>, - saved_locals: &GeneratorSavedLocals, + saved_locals: &CoroutineSavedLocals, always_live_locals: BitSet<Local>, mut requires_storage: rustc_mir_dataflow::Results<'tcx, MaybeRequiresStorage<'_, 'mir, 'tcx>>, -) -> BitMatrix<GeneratorSavedLocal, GeneratorSavedLocal> { +) -> BitMatrix<CoroutineSavedLocal, CoroutineSavedLocal> { assert_eq!(body.local_decls.len(), saved_locals.domain_size()); debug!("compute_storage_conflicts({:?})", body.span); @@ -775,7 +775,7 @@ fn compute_storage_conflicts<'mir, 'tcx>( let local_conflicts = visitor.local_conflicts; - // Compress the matrix using only stored locals (Local -> GeneratorSavedLocal). + // Compress the matrix using only stored locals (Local -> CoroutineSavedLocal). // // NOTE: Today we store a full conflict bitset for every local. Technically // this is twice as many bits as we need, since the relation is symmetric. @@ -801,9 +801,9 @@ fn compute_storage_conflicts<'mir, 'tcx>( struct StorageConflictVisitor<'mir, 'tcx, 's> { body: &'mir Body<'tcx>, - saved_locals: &'s GeneratorSavedLocals, + saved_locals: &'s CoroutineSavedLocals, // FIXME(tmandry): Consider using sparse bitsets here once we have good - // benchmarks for generators. + // benchmarks for coroutines. local_conflicts: BitMatrix<Local, Local>, } @@ -858,7 +858,7 @@ fn compute_layout<'tcx>( body: &Body<'tcx>, ) -> ( FxHashMap<Local, (Ty<'tcx>, VariantIdx, FieldIdx)>, - GeneratorLayout<'tcx>, + CoroutineLayout<'tcx>, IndexVec<BasicBlock, Option<BitSet<Local>>>, ) { let LivenessInfo { @@ -870,10 +870,10 @@ fn compute_layout<'tcx>( } = liveness; // Gather live local types and their indices. - let mut locals = IndexVec::<GeneratorSavedLocal, _>::new(); - let mut tys = IndexVec::<GeneratorSavedLocal, _>::new(); + let mut locals = IndexVec::<CoroutineSavedLocal, _>::new(); + let mut tys = IndexVec::<CoroutineSavedLocal, _>::new(); for (saved_local, local) in saved_locals.iter_enumerated() { - debug!("generator saved local {:?} => {:?}", saved_local, local); + debug!("coroutine saved local {:?} => {:?}", saved_local, local); locals.push(local); let decl = &body.local_decls[local]; @@ -895,7 +895,7 @@ fn compute_layout<'tcx>( _ => false, }; let decl = - GeneratorSavedTy { ty: decl.ty, source_info: decl.source_info, ignore_for_traits }; + CoroutineSavedTy { ty: decl.ty, source_info: decl.source_info, ignore_for_traits }; debug!(?decl); tys.push(decl); @@ -914,9 +914,9 @@ fn compute_layout<'tcx>( .copied() .collect(); - // Build the generator variant field list. - // Create a map from local indices to generator struct indices. - let mut variant_fields: IndexVec<VariantIdx, IndexVec<FieldIdx, GeneratorSavedLocal>> = + // Build the coroutine variant field list. + // Create a map from local indices to coroutine struct indices. + let mut variant_fields: IndexVec<VariantIdx, IndexVec<FieldIdx, CoroutineSavedLocal>> = iter::repeat(IndexVec::new()).take(RESERVED_VARIANTS).collect(); let mut remap = FxHashMap::default(); for (suspension_point_idx, live_locals) in live_locals_at_suspension_points.iter().enumerate() { @@ -926,7 +926,7 @@ fn compute_layout<'tcx>( fields.push(saved_local); // Note that if a field is included in multiple variants, we will // just use the first one here. That's fine; fields do not move - // around inside generators, so it doesn't matter which variant + // around inside coroutines, so it doesn't matter which variant // index we access them by. let idx = FieldIdx::from_usize(idx); remap.entry(locals[saved_local]).or_insert((tys[saved_local].ty, variant_index, idx)); @@ -934,8 +934,8 @@ fn compute_layout<'tcx>( variant_fields.push(fields); variant_source_info.push(source_info_at_suspension_points[suspension_point_idx]); } - debug!("generator variant_fields = {:?}", variant_fields); - debug!("generator storage_conflicts = {:#?}", storage_conflicts); + debug!("coroutine variant_fields = {:?}", variant_fields); + debug!("coroutine storage_conflicts = {:#?}", storage_conflicts); let mut field_names = IndexVec::from_elem(None, &tys); for var in &body.var_debug_info { @@ -947,7 +947,7 @@ fn compute_layout<'tcx>( field_names.get_or_insert_with(saved_local, || var.name); } - let layout = GeneratorLayout { + let layout = CoroutineLayout { field_tys: tys, field_names, variant_fields, @@ -959,7 +959,7 @@ fn compute_layout<'tcx>( (remap, layout, storage_liveness) } -/// Replaces the entry point of `body` with a block that switches on the generator discriminant and +/// Replaces the entry point of `body` with a block that switches on the coroutine discriminant and /// dispatches to blocks according to `cases`. /// /// After this function, the former entry point of the function will be bb1. @@ -992,14 +992,14 @@ fn insert_switch<'tcx>( } } -fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { +fn elaborate_coroutine_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { use crate::shim::DropShimElaborator; use rustc_middle::mir::patch::MirPatch; use rustc_mir_dataflow::elaborate_drops::{elaborate_drop, Unwind}; - // Note that `elaborate_drops` only drops the upvars of a generator, and + // Note that `elaborate_drops` only drops the upvars of a coroutine, and // this is ok because `open_drop` can only be reached within that own - // generator's resume function. + // coroutine's resume function. let def_id = body.source.def_id(); let param_env = tcx.param_env(def_id); @@ -1047,7 +1047,7 @@ fn elaborate_generator_drops<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { elaborator.patch.apply(body); } -fn create_generator_drop_shim<'tcx>( +fn create_coroutine_drop_shim<'tcx>( tcx: TyCtxt<'tcx>, transform: &TransformVisitor<'tcx>, gen_ty: Ty<'tcx>, @@ -1070,7 +1070,7 @@ fn create_generator_drop_shim<'tcx>( for block in body.basic_blocks_mut() { let kind = &mut block.terminator_mut().kind; - if let TerminatorKind::GeneratorDrop = *kind { + if let TerminatorKind::CoroutineDrop = *kind { *kind = TerminatorKind::Return; } } @@ -1078,9 +1078,9 @@ fn create_generator_drop_shim<'tcx>( // Replace the return variable body.local_decls[RETURN_PLACE] = LocalDecl::with_source_info(Ty::new_unit(tcx), source_info); - make_generator_state_argument_indirect(tcx, &mut body); + make_coroutine_state_argument_indirect(tcx, &mut body); - // Change the generator argument from &mut to *mut + // Change the coroutine argument from &mut to *mut body.local_decls[SELF_ARG] = LocalDecl::with_source_info( Ty::new_ptr(tcx, ty::TypeAndMut { ty: gen_ty, mutbl: hir::Mutability::Mut }), source_info, @@ -1104,10 +1104,10 @@ fn create_generator_drop_shim<'tcx>( None, ); - // Temporary change MirSource to generator's instance so that dump_mir produces more sensible + // Temporary change MirSource to coroutine's instance so that dump_mir produces more sensible // filename. body.source.instance = gen_instance; - dump_mir(tcx, false, "generator_drop", &0, &body, |_, _| Ok(())); + dump_mir(tcx, false, "coroutine_drop", &0, &body, |_, _| Ok(())); body.source.instance = drop_instance; body @@ -1182,7 +1182,7 @@ fn can_unwind<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) -> bool { | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return | TerminatorKind::Unreachable - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } => {} @@ -1191,7 +1191,7 @@ fn can_unwind<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) -> bool { TerminatorKind::UnwindResume => {} TerminatorKind::Yield { .. } => { - unreachable!("`can_unwind` called before generator transform") + unreachable!("`can_unwind` called before coroutine transform") } // These may unwind. @@ -1206,7 +1206,7 @@ fn can_unwind<'tcx>(tcx: TyCtxt<'tcx>, body: &Body<'tcx>) -> bool { false } -fn create_generator_resume_function<'tcx>( +fn create_coroutine_resume_function<'tcx>( tcx: TyCtxt<'tcx>, transform: TransformVisitor<'tcx>, body: &mut Body<'tcx>, @@ -1214,7 +1214,7 @@ fn create_generator_resume_function<'tcx>( ) { let can_unwind = can_unwind(tcx, body); - // Poison the generator when it unwinds + // Poison the coroutine when it unwinds if can_unwind { let source_info = SourceInfo::outermost(body.span); let poison_block = body.basic_blocks_mut().push(BasicBlockData { @@ -1253,26 +1253,26 @@ fn create_generator_resume_function<'tcx>( cases.insert(0, (UNRESUMED, START_BLOCK)); // Panic when resumed on the returned or poisoned state - let generator_kind = body.generator_kind().unwrap(); + let coroutine_kind = body.coroutine_kind().unwrap(); if can_unwind { cases.insert( 1, - (POISONED, insert_panic_block(tcx, body, ResumedAfterPanic(generator_kind))), + (POISONED, insert_panic_block(tcx, body, ResumedAfterPanic(coroutine_kind))), ); } if can_return { cases.insert( 1, - (RETURNED, insert_panic_block(tcx, body, ResumedAfterReturn(generator_kind))), + (RETURNED, insert_panic_block(tcx, body, ResumedAfterReturn(coroutine_kind))), ); } insert_switch(body, cases, &transform, TerminatorKind::Unreachable); - make_generator_state_argument_indirect(tcx, body); - make_generator_state_argument_pinned(tcx, body); + make_coroutine_state_argument_indirect(tcx, body); + make_coroutine_state_argument_pinned(tcx, body); // Make sure we remove dead blocks to remove // unrelated code from the drop part of the function @@ -1280,7 +1280,7 @@ fn create_generator_resume_function<'tcx>( pm::run_passes_no_validate(tcx, body, &[&abort_unwinding_calls::AbortUnwindingCalls], None); - dump_mir(tcx, false, "generator_resume", &0, body, |_, _| Ok(())); + dump_mir(tcx, false, "coroutine_resume", &0, body, |_, _| Ok(())); } fn insert_clean_drop(body: &mut Body<'_>) -> BasicBlock { @@ -1294,7 +1294,7 @@ fn insert_clean_drop(body: &mut Body<'_>) -> BasicBlock { }; let source_info = SourceInfo::outermost(body.span); - // Create a block to destroy an unresumed generators. This can only destroy upvars. + // Create a block to destroy an unresumed coroutines. This can only destroy upvars. body.basic_blocks_mut().push(BasicBlockData { statements: Vec::new(), terminator: Some(Terminator { source_info, kind: term }), @@ -1302,7 +1302,7 @@ fn insert_clean_drop(body: &mut Body<'_>) -> BasicBlock { }) } -/// An operation that can be performed on a generator. +/// An operation that can be performed on a coroutine. #[derive(PartialEq, Copy, Clone)] enum Operation { Resume, @@ -1381,64 +1381,64 @@ fn create_cases<'tcx>( } #[instrument(level = "debug", skip(tcx), ret)] -pub(crate) fn mir_generator_witnesses<'tcx>( +pub(crate) fn mir_coroutine_witnesses<'tcx>( tcx: TyCtxt<'tcx>, def_id: LocalDefId, -) -> Option<GeneratorLayout<'tcx>> { +) -> Option<CoroutineLayout<'tcx>> { let (body, _) = tcx.mir_promoted(def_id); let body = body.borrow(); let body = &*body; - // The first argument is the generator type passed by value + // The first argument is the coroutine type passed by value let gen_ty = body.local_decls[ty::CAPTURE_STRUCT_LOCAL].ty; // Get the interior types and args which typeck computed let movable = match *gen_ty.kind() { - ty::Generator(_, _, movability) => movability == hir::Movability::Movable, + ty::Coroutine(_, _, movability) => movability == hir::Movability::Movable, ty::Error(_) => return None, - _ => span_bug!(body.span, "unexpected generator type {}", gen_ty), + _ => span_bug!(body.span, "unexpected coroutine type {}", gen_ty), }; - // When first entering the generator, move the resume argument into its new local. + // When first entering the coroutine, move the resume argument into its new local. let always_live_locals = always_storage_live_locals(&body); let liveness_info = locals_live_across_suspend_points(tcx, body, &always_live_locals, movable); // Extract locals which are live across suspension point into `layout` - // `remap` gives a mapping from local indices onto generator struct indices + // `remap` gives a mapping from local indices onto coroutine struct indices // `storage_liveness` tells us which locals have live storage at suspension points - let (_, generator_layout, _) = compute_layout(liveness_info, body); + let (_, coroutine_layout, _) = compute_layout(liveness_info, body); - check_suspend_tys(tcx, &generator_layout, &body); + check_suspend_tys(tcx, &coroutine_layout, &body); - Some(generator_layout) + Some(coroutine_layout) } impl<'tcx> MirPass<'tcx> for StateTransform { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let Some(yield_ty) = body.yield_ty() else { - // This only applies to generators + // This only applies to coroutines return; }; - assert!(body.generator_drop().is_none()); + assert!(body.coroutine_drop().is_none()); - // The first argument is the generator type passed by value + // The first argument is the coroutine type passed by value let gen_ty = body.local_decls.raw[1].ty; // Get the discriminant type and args which typeck computed let (discr_ty, movable) = match *gen_ty.kind() { - ty::Generator(_, args, movability) => { - let args = args.as_generator(); + ty::Coroutine(_, args, movability) => { + let args = args.as_coroutine(); (args.discr_ty(tcx), movability == hir::Movability::Movable) } _ => { - tcx.sess.delay_span_bug(body.span, format!("unexpected generator type {gen_ty}")); + tcx.sess.delay_span_bug(body.span, format!("unexpected coroutine type {gen_ty}")); return; } }; - let is_async_kind = matches!(body.generator_kind(), Some(GeneratorKind::Async(_))); + let is_async_kind = matches!(body.coroutine_kind(), Some(CoroutineKind::Async(_))); let (state_adt_ref, state_args) = if is_async_kind { // Compute Poll<return_ty> let poll_did = tcx.require_lang_item(LangItem::Poll, None); @@ -1446,8 +1446,8 @@ impl<'tcx> MirPass<'tcx> for StateTransform { let poll_args = tcx.mk_args(&[body.return_ty().into()]); (poll_adt_ref, poll_args) } else { - // Compute GeneratorState<yield_ty, return_ty> - let state_did = tcx.require_lang_item(LangItem::GeneratorState, None); + // Compute CoroutineState<yield_ty, return_ty> + let state_did = tcx.require_lang_item(LangItem::CoroutineState, None); let state_adt_ref = tcx.adt_def(state_did); let state_args = tcx.mk_args(&[yield_ty.into(), body.return_ty().into()]); (state_adt_ref, state_args) @@ -1465,8 +1465,8 @@ impl<'tcx> MirPass<'tcx> for StateTransform { // We also replace the resume argument and insert an `Assign`. // This is needed because the resume argument `_2` might be live across a `yield`, in which - // case there is no `Assign` to it that the transform can turn into a store to the generator - // state. After the yield the slot in the generator state would then be uninitialized. + // case there is no `Assign` to it that the transform can turn into a store to the coroutine + // state. After the yield the slot in the coroutine state would then be uninitialized. let resume_local = Local::new(2); let resume_ty = if is_async_kind { Ty::new_task_context(tcx) @@ -1475,7 +1475,7 @@ impl<'tcx> MirPass<'tcx> for StateTransform { }; let new_resume_local = replace_local(resume_local, resume_ty, body, tcx); - // When first entering the generator, move the resume argument into its new local. + // When first entering the coroutine, move the resume argument into its new local. let source_info = SourceInfo::outermost(body.span); let stmts = &mut body.basic_blocks_mut()[START_BLOCK].statements; stmts.insert( @@ -1495,7 +1495,7 @@ impl<'tcx> MirPass<'tcx> for StateTransform { locals_live_across_suspend_points(tcx, body, &always_live_locals, movable); if tcx.sess.opts.unstable_opts.validate_mir { - let mut vis = EnsureGeneratorFieldAssignmentsNeverAlias { + let mut vis = EnsureCoroutineFieldAssignmentsNeverAlias { assigned_local: None, saved_locals: &liveness_info.saved_locals, storage_conflicts: &liveness_info.storage_conflicts, @@ -1505,16 +1505,16 @@ impl<'tcx> MirPass<'tcx> for StateTransform { } // Extract locals which are live across suspension point into `layout` - // `remap` gives a mapping from local indices onto generator struct indices + // `remap` gives a mapping from local indices onto coroutine struct indices // `storage_liveness` tells us which locals have live storage at suspension points let (remap, layout, storage_liveness) = compute_layout(liveness_info, body); let can_return = can_return(tcx, body, tcx.param_env(body.source.def_id())); - // Run the transformation which converts Places from Local to generator struct + // Run the transformation which converts Places from Local to coroutine struct // accesses for locals in `remap`. - // It also rewrites `return x` and `yield y` as writing a new generator state and returning - // either GeneratorState::Complete(x) and GeneratorState::Yielded(y), + // It also rewrites `return x` and `yield y` as writing a new coroutine state and returning + // either CoroutineState::Complete(x) and CoroutineState::Yielded(y), // or Poll::Ready(x) and Poll::Pending respectively depending on `is_async_kind`. let mut transform = TransformVisitor { tcx, @@ -1541,30 +1541,30 @@ impl<'tcx> MirPass<'tcx> for StateTransform { var.argument_index = None; } - body.generator.as_mut().unwrap().yield_ty = None; - body.generator.as_mut().unwrap().generator_layout = Some(layout); + body.coroutine.as_mut().unwrap().yield_ty = None; + body.coroutine.as_mut().unwrap().coroutine_layout = Some(layout); - // Insert `drop(generator_struct)` which is used to drop upvars for generators in + // Insert `drop(coroutine_struct)` which is used to drop upvars for coroutines in // the unresumed state. - // This is expanded to a drop ladder in `elaborate_generator_drops`. + // This is expanded to a drop ladder in `elaborate_coroutine_drops`. let drop_clean = insert_clean_drop(body); - dump_mir(tcx, false, "generator_pre-elab", &0, body, |_, _| Ok(())); + dump_mir(tcx, false, "coroutine_pre-elab", &0, body, |_, _| Ok(())); - // Expand `drop(generator_struct)` to a drop ladder which destroys upvars. + // Expand `drop(coroutine_struct)` to a drop ladder which destroys upvars. // If any upvars are moved out of, drop elaboration will handle upvar destruction. // However we need to also elaborate the code generated by `insert_clean_drop`. - elaborate_generator_drops(tcx, body); + elaborate_coroutine_drops(tcx, body); - dump_mir(tcx, false, "generator_post-transform", &0, body, |_, _| Ok(())); + dump_mir(tcx, false, "coroutine_post-transform", &0, body, |_, _| Ok(())); - // Create a copy of our MIR and use it to create the drop shim for the generator - let drop_shim = create_generator_drop_shim(tcx, &transform, gen_ty, body, drop_clean); + // Create a copy of our MIR and use it to create the drop shim for the coroutine + let drop_shim = create_coroutine_drop_shim(tcx, &transform, gen_ty, body, drop_clean); - body.generator.as_mut().unwrap().generator_drop = Some(drop_shim); + body.coroutine.as_mut().unwrap().coroutine_drop = Some(drop_shim); - // Create the Generator::resume / Future::poll function - create_generator_resume_function(tcx, transform, body, can_return); + // Create the Coroutine::resume / Future::poll function + create_coroutine_resume_function(tcx, transform, body, can_return); // Run derefer to fix Derefs that are not in the first place deref_finder(tcx, body); @@ -1572,25 +1572,25 @@ impl<'tcx> MirPass<'tcx> for StateTransform { } /// Looks for any assignments between locals (e.g., `_4 = _5`) that will both be converted to fields -/// in the generator state machine but whose storage is not marked as conflicting +/// in the coroutine state machine but whose storage is not marked as conflicting /// /// Validation needs to happen immediately *before* `TransformVisitor` is invoked, not after. /// /// This condition would arise when the assignment is the last use of `_5` but the initial /// definition of `_4` if we weren't extra careful to mark all locals used inside a statement as -/// conflicting. Non-conflicting generator saved locals may be stored at the same location within -/// the generator state machine, which would result in ill-formed MIR: the left-hand and right-hand +/// conflicting. Non-conflicting coroutine saved locals may be stored at the same location within +/// the coroutine state machine, which would result in ill-formed MIR: the left-hand and right-hand /// sides of an assignment may not alias. This caused a miscompilation in [#73137]. /// /// [#73137]: https://github.com/rust-lang/rust/issues/73137 -struct EnsureGeneratorFieldAssignmentsNeverAlias<'a> { - saved_locals: &'a GeneratorSavedLocals, - storage_conflicts: &'a BitMatrix<GeneratorSavedLocal, GeneratorSavedLocal>, - assigned_local: Option<GeneratorSavedLocal>, +struct EnsureCoroutineFieldAssignmentsNeverAlias<'a> { + saved_locals: &'a CoroutineSavedLocals, + storage_conflicts: &'a BitMatrix<CoroutineSavedLocal, CoroutineSavedLocal>, + assigned_local: Option<CoroutineSavedLocal>, } -impl EnsureGeneratorFieldAssignmentsNeverAlias<'_> { - fn saved_local_for_direct_place(&self, place: Place<'_>) -> Option<GeneratorSavedLocal> { +impl EnsureCoroutineFieldAssignmentsNeverAlias<'_> { + fn saved_local_for_direct_place(&self, place: Place<'_>) -> Option<CoroutineSavedLocal> { if place.is_indirect() { return None; } @@ -1609,7 +1609,7 @@ impl EnsureGeneratorFieldAssignmentsNeverAlias<'_> { } } -impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> { +impl<'tcx> Visitor<'tcx> for EnsureCoroutineFieldAssignmentsNeverAlias<'_> { fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, location: Location) { let Some(lhs) = self.assigned_local else { // This visitor only invokes `visit_place` for the right-hand side of an assignment @@ -1624,7 +1624,7 @@ impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> { if !self.storage_conflicts.contains(lhs, rhs) { bug!( - "Assignment between generator saved locals whose storage is not \ + "Assignment between coroutine saved locals whose storage is not \ marked as conflicting: {:?}: {:?} = {:?}", location, lhs, @@ -1691,14 +1691,14 @@ impl<'tcx> Visitor<'tcx> for EnsureGeneratorFieldAssignmentsNeverAlias<'_> { | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } | TerminatorKind::Assert { .. } - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } => {} } } } -fn check_suspend_tys<'tcx>(tcx: TyCtxt<'tcx>, layout: &GeneratorLayout<'tcx>, body: &Body<'tcx>) { +fn check_suspend_tys<'tcx>(tcx: TyCtxt<'tcx>, layout: &CoroutineLayout<'tcx>, body: &Body<'tcx>) { let mut linted_tys = FxHashSet::default(); // We want a user-facing param-env. diff --git a/compiler/rustc_mir_transform/src/cost_checker.rs b/compiler/rustc_mir_transform/src/cost_checker.rs new file mode 100644 index 00000000000..9bb26693cb2 --- /dev/null +++ b/compiler/rustc_mir_transform/src/cost_checker.rs @@ -0,0 +1,98 @@ +use rustc_middle::mir::visit::*; +use rustc_middle::mir::*; +use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt}; + +const INSTR_COST: usize = 5; +const CALL_PENALTY: usize = 25; +const LANDINGPAD_PENALTY: usize = 50; +const RESUME_PENALTY: usize = 45; + +/// Verify that the callee body is compatible with the caller. +#[derive(Clone)] +pub(crate) struct CostChecker<'b, 'tcx> { + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + cost: usize, + callee_body: &'b Body<'tcx>, + instance: Option<ty::Instance<'tcx>>, +} + +impl<'b, 'tcx> CostChecker<'b, 'tcx> { + pub fn new( + tcx: TyCtxt<'tcx>, + param_env: ParamEnv<'tcx>, + instance: Option<ty::Instance<'tcx>>, + callee_body: &'b Body<'tcx>, + ) -> CostChecker<'b, 'tcx> { + CostChecker { tcx, param_env, callee_body, instance, cost: 0 } + } + + pub fn cost(&self) -> usize { + self.cost + } + + fn instantiate_ty(&self, v: Ty<'tcx>) -> Ty<'tcx> { + if let Some(instance) = self.instance { + instance.instantiate_mir(self.tcx, ty::EarlyBinder::bind(&v)) + } else { + v + } + } +} + +impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> { + fn visit_statement(&mut self, statement: &Statement<'tcx>, _: Location) { + // Don't count StorageLive/StorageDead in the inlining cost. + match statement.kind { + StatementKind::StorageLive(_) + | StatementKind::StorageDead(_) + | StatementKind::Deinit(_) + | StatementKind::Nop => {} + _ => self.cost += INSTR_COST, + } + } + + fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, _: Location) { + let tcx = self.tcx; + match terminator.kind { + TerminatorKind::Drop { ref place, unwind, .. } => { + // If the place doesn't actually need dropping, treat it like a regular goto. + let ty = self.instantiate_ty(place.ty(self.callee_body, tcx).ty); + if ty.needs_drop(tcx, self.param_env) { + self.cost += CALL_PENALTY; + if let UnwindAction::Cleanup(_) = unwind { + self.cost += LANDINGPAD_PENALTY; + } + } else { + self.cost += INSTR_COST; + } + } + TerminatorKind::Call { func: Operand::Constant(ref f), unwind, .. } => { + let fn_ty = self.instantiate_ty(f.const_.ty()); + self.cost += if let ty::FnDef(def_id, _) = *fn_ty.kind() && tcx.is_intrinsic(def_id) { + // Don't give intrinsics the extra penalty for calls + INSTR_COST + } else { + CALL_PENALTY + }; + if let UnwindAction::Cleanup(_) = unwind { + self.cost += LANDINGPAD_PENALTY; + } + } + TerminatorKind::Assert { unwind, .. } => { + self.cost += CALL_PENALTY; + if let UnwindAction::Cleanup(_) = unwind { + self.cost += LANDINGPAD_PENALTY; + } + } + TerminatorKind::UnwindResume => self.cost += RESUME_PENALTY, + TerminatorKind::InlineAsm { unwind, .. } => { + self.cost += INSTR_COST; + if let UnwindAction::Cleanup(_) = unwind { + self.cost += LANDINGPAD_PENALTY; + } + } + _ => self.cost += INSTR_COST, + } + } +} diff --git a/compiler/rustc_mir_transform/src/coverage/counters.rs b/compiler/rustc_mir_transform/src/coverage/counters.rs index a83ccf8fc3c..d07f59bc72a 100644 --- a/compiler/rustc_mir_transform/src/coverage/counters.rs +++ b/compiler/rustc_mir_transform/src/coverage/counters.rs @@ -169,22 +169,22 @@ impl CoverageCounters { self.bcb_counters[bcb].as_ref() } - pub(super) fn take_bcb_counter(&mut self, bcb: BasicCoverageBlock) -> Option<BcbCounter> { - self.bcb_counters[bcb].take() - } - - pub(super) fn drain_bcb_counters( - &mut self, - ) -> impl Iterator<Item = (BasicCoverageBlock, BcbCounter)> + '_ { + pub(super) fn bcb_node_counters( + &self, + ) -> impl Iterator<Item = (BasicCoverageBlock, &BcbCounter)> { self.bcb_counters - .iter_enumerated_mut() - .filter_map(|(bcb, counter)| Some((bcb, counter.take()?))) + .iter_enumerated() + .filter_map(|(bcb, counter_kind)| Some((bcb, counter_kind.as_ref()?))) } - pub(super) fn drain_bcb_edge_counters( - &mut self, - ) -> impl Iterator<Item = ((BasicCoverageBlock, BasicCoverageBlock), BcbCounter)> + '_ { - self.bcb_edge_counters.drain() + /// For each edge in the BCB graph that has an associated counter, yields + /// that edge's *from* and *to* nodes, and its counter. + pub(super) fn bcb_edge_counters( + &self, + ) -> impl Iterator<Item = (BasicCoverageBlock, BasicCoverageBlock, &BcbCounter)> { + self.bcb_edge_counters + .iter() + .map(|(&(from_bcb, to_bcb), counter_kind)| (from_bcb, to_bcb, counter_kind)) } pub(super) fn take_expressions(&mut self) -> IndexVec<ExpressionId, Expression> { diff --git a/compiler/rustc_mir_transform/src/coverage/graph.rs b/compiler/rustc_mir_transform/src/coverage/graph.rs index 9a7adaada09..6bab62aa854 100644 --- a/compiler/rustc_mir_transform/src/coverage/graph.rs +++ b/compiler/rustc_mir_transform/src/coverage/graph.rs @@ -147,7 +147,7 @@ impl CoverageGraph { | TerminatorKind::Unreachable | TerminatorKind::Drop { .. } | TerminatorKind::Call { .. } - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::Assert { .. } | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs index 6fdaff6b4c0..c9b36ba25ac 100644 --- a/compiler/rustc_mir_transform/src/coverage/mod.rs +++ b/compiler/rustc_mir_transform/src/coverage/mod.rs @@ -8,7 +8,7 @@ mod spans; mod tests; use self::counters::{BcbCounter, CoverageCounters}; -use self::graph::{BasicCoverageBlock, BasicCoverageBlockData, CoverageGraph}; +use self::graph::CoverageGraph; use self::spans::CoverageSpans; use crate::MirPass; @@ -104,7 +104,6 @@ struct Instrumentor<'a, 'tcx> { function_source_hash: u64, basic_coverage_blocks: CoverageGraph, coverage_counters: CoverageCounters, - mappings: Vec<Mapping>, } impl<'a, 'tcx> Instrumentor<'a, 'tcx> { @@ -145,7 +144,6 @@ impl<'a, 'tcx> Instrumentor<'a, 'tcx> { function_source_hash, basic_coverage_blocks, coverage_counters, - mappings: Vec::new(), } } @@ -168,148 +166,99 @@ impl<'a, 'tcx> Instrumentor<'a, 'tcx> { // and all `Expression` dependencies (operands) are also generated, for any other // `BasicCoverageBlock`s not already associated with a coverage span. let bcb_has_coverage_spans = |bcb| coverage_spans.bcb_has_coverage_spans(bcb); - let result = self - .coverage_counters - .make_bcb_counters(&mut self.basic_coverage_blocks, bcb_has_coverage_spans); - - if let Ok(()) = result { - //////////////////////////////////////////////////// - // Remove the counter or edge counter from of each coverage cpan's associated - // `BasicCoverageBlock`, and inject a `Coverage` statement into the MIR. - // - // `Coverage` statements injected from coverage spans will include the code regions - // (source code start and end positions) to be counted by the associated counter. - // - // These coverage-span-associated counters are removed from their associated - // `BasicCoverageBlock`s so that the only remaining counters in the `CoverageGraph` - // are indirect counters (to be injected next, without associated code regions). - self.inject_coverage_span_counters(&coverage_spans); - - //////////////////////////////////////////////////// - // For any remaining `BasicCoverageBlock` counters (that were not associated with - // any coverage span), inject `Coverage` statements (_without_ code region spans) - // to ensure `BasicCoverageBlock` counters that other `Expression`s may depend on - // are in fact counted, even though they don't directly contribute to counting - // their own independent code region's coverage. - self.inject_indirect_counters(); - }; + self.coverage_counters + .make_bcb_counters(&mut self.basic_coverage_blocks, bcb_has_coverage_spans) + .unwrap_or_else(|e| { + bug!("Error processing: {:?}: {:?}", self.mir_body.source.def_id(), e.message) + }); - if let Err(e) = result { - bug!("Error processing: {:?}: {:?}", self.mir_body.source.def_id(), e.message) - }; + let mappings = self.create_mappings_and_inject_coverage_statements(&coverage_spans); self.mir_body.function_coverage_info = Some(Box::new(FunctionCoverageInfo { function_source_hash: self.function_source_hash, num_counters: self.coverage_counters.num_counters(), expressions: self.coverage_counters.take_expressions(), - mappings: std::mem::take(&mut self.mappings), + mappings, })); } - /// Injects a single [`StatementKind::Coverage`] for each BCB that has one - /// or more coverage spans. - fn inject_coverage_span_counters(&mut self, coverage_spans: &CoverageSpans) { - let tcx = self.tcx; - let source_map = tcx.sess.source_map(); + /// For each [`BcbCounter`] associated with a BCB node or BCB edge, create + /// any corresponding mappings (for BCB nodes only), and inject any necessary + /// coverage statements into MIR. + fn create_mappings_and_inject_coverage_statements( + &mut self, + coverage_spans: &CoverageSpans, + ) -> Vec<Mapping> { + let source_map = self.tcx.sess.source_map(); let body_span = self.body_span; use rustc_session::RemapFileNameExt; let file_name = Symbol::intern(&self.source_file.name.for_codegen(self.tcx.sess).to_string_lossy()); - for (bcb, spans) in coverage_spans.bcbs_with_coverage_spans() { - let counter_kind = self.coverage_counters.take_bcb_counter(bcb).unwrap_or_else(|| { - bug!("Every BasicCoverageBlock should have a Counter or Expression"); - }); - - let term = counter_kind.as_term(); - self.mappings.extend(spans.iter().map(|&span| { - let code_region = make_code_region(source_map, file_name, span, body_span); - Mapping { code_region, term } - })); - - inject_statement( - self.mir_body, - self.make_mir_coverage_kind(&counter_kind), - self.bcb_leader_bb(bcb), - ); - } - } + let mut mappings = Vec::new(); + + // Process the counters and spans associated with BCB nodes. + for (bcb, counter_kind) in self.coverage_counters.bcb_node_counters() { + let spans = coverage_spans.spans_for_bcb(bcb); + let has_mappings = !spans.is_empty(); + + // If this BCB has any coverage spans, add corresponding mappings to + // the mappings table. + if has_mappings { + let term = counter_kind.as_term(); + mappings.extend(spans.iter().map(|&span| { + let code_region = make_code_region(source_map, file_name, span, body_span); + Mapping { code_region, term } + })); + } - /// At this point, any BCB with coverage counters has already had its counter injected - /// into MIR, and had its counter removed from `coverage_counters` (via `take_counter()`). - /// - /// Any other counter associated with a `BasicCoverageBlock`, or its incoming edge, but not - /// associated with a coverage span, should only exist if the counter is an `Expression` - /// dependency (one of the expression operands). Collect them, and inject the additional - /// counters into the MIR, without a reportable coverage span. - fn inject_indirect_counters(&mut self) { - let mut bcb_counters_without_direct_coverage_spans = Vec::new(); - for (target_bcb, counter_kind) in self.coverage_counters.drain_bcb_counters() { - bcb_counters_without_direct_coverage_spans.push((None, target_bcb, counter_kind)); - } - for ((from_bcb, target_bcb), counter_kind) in - self.coverage_counters.drain_bcb_edge_counters() - { - bcb_counters_without_direct_coverage_spans.push(( - Some(from_bcb), - target_bcb, - counter_kind, - )); + let do_inject = match counter_kind { + // Counter-increment statements always need to be injected. + BcbCounter::Counter { .. } => true, + // The only purpose of expression-used statements is to detect + // when a mapping is unreachable, so we only inject them for + // expressions with one or more mappings. + BcbCounter::Expression { .. } => has_mappings, + }; + if do_inject { + inject_statement( + self.mir_body, + self.make_mir_coverage_kind(counter_kind), + self.basic_coverage_blocks[bcb].leader_bb(), + ); + } } - for (edge_from_bcb, target_bcb, counter_kind) in bcb_counters_without_direct_coverage_spans - { - match counter_kind { - BcbCounter::Counter { .. } => { - let inject_to_bb = if let Some(from_bcb) = edge_from_bcb { - // The MIR edge starts `from_bb` (the outgoing / last BasicBlock in - // `from_bcb`) and ends at `to_bb` (the incoming / first BasicBlock in the - // `target_bcb`; also called the `leader_bb`). - let from_bb = self.bcb_last_bb(from_bcb); - let to_bb = self.bcb_leader_bb(target_bcb); - - let new_bb = inject_edge_counter_basic_block(self.mir_body, from_bb, to_bb); - debug!( - "Edge {:?} (last {:?}) -> {:?} (leader {:?}) requires a new MIR \ - BasicBlock {:?}, for unclaimed edge counter {:?}", - edge_from_bcb, from_bb, target_bcb, to_bb, new_bb, counter_kind, - ); - new_bb - } else { - let target_bb = self.bcb_last_bb(target_bcb); - debug!( - "{:?} ({:?}) gets a new Coverage statement for unclaimed counter {:?}", - target_bcb, target_bb, counter_kind, - ); - target_bb - }; - - inject_statement( - self.mir_body, - self.make_mir_coverage_kind(&counter_kind), - inject_to_bb, - ); - } - // Experessions with no associated spans don't need to inject a statement. - BcbCounter::Expression { .. } => {} + // Process the counters associated with BCB edges. + for (from_bcb, to_bcb, counter_kind) in self.coverage_counters.bcb_edge_counters() { + let do_inject = match counter_kind { + // Counter-increment statements always need to be injected. + BcbCounter::Counter { .. } => true, + // BCB-edge expressions never have mappings, so they never need + // a corresponding statement. + BcbCounter::Expression { .. } => false, + }; + if !do_inject { + continue; } - } - } - #[inline] - fn bcb_leader_bb(&self, bcb: BasicCoverageBlock) -> BasicBlock { - self.bcb_data(bcb).leader_bb() - } + // We need to inject a coverage statement into a new BB between the + // last BB of `from_bcb` and the first BB of `to_bcb`. + let from_bb = self.basic_coverage_blocks[from_bcb].last_bb(); + let to_bb = self.basic_coverage_blocks[to_bcb].leader_bb(); - #[inline] - fn bcb_last_bb(&self, bcb: BasicCoverageBlock) -> BasicBlock { - self.bcb_data(bcb).last_bb() - } + let new_bb = inject_edge_counter_basic_block(self.mir_body, from_bb, to_bb); + debug!( + "Edge {from_bcb:?} (last {from_bb:?}) -> {to_bcb:?} (leader {to_bb:?}) \ + requires a new MIR BasicBlock {new_bb:?} for edge counter {counter_kind:?}", + ); + + // Inject a counter into the newly-created BB. + inject_statement(self.mir_body, self.make_mir_coverage_kind(&counter_kind), new_bb); + } - #[inline] - fn bcb_data(&self, bcb: BasicCoverageBlock) -> &BasicCoverageBlockData { - &self.basic_coverage_blocks[bcb] + mappings } fn make_mir_coverage_kind(&self, counter_kind: &BcbCounter) -> CoverageKind { diff --git a/compiler/rustc_mir_transform/src/coverage/spans.rs b/compiler/rustc_mir_transform/src/coverage/spans.rs index f1a0f762041..704eea413e1 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans.rs @@ -2,7 +2,7 @@ use std::cell::OnceCell; use rustc_data_structures::graph::WithNumNodes; use rustc_index::IndexVec; -use rustc_middle::mir::{self, AggregateKind, Rvalue, Statement, StatementKind}; +use rustc_middle::mir; use rustc_span::{BytePos, ExpnKind, MacroKind, Span, Symbol, DUMMY_SP}; use super::graph::{BasicCoverageBlock, CoverageGraph, START_BCB}; @@ -41,13 +41,8 @@ impl CoverageSpans { !self.bcb_to_spans[bcb].is_empty() } - pub(super) fn bcbs_with_coverage_spans( - &self, - ) -> impl Iterator<Item = (BasicCoverageBlock, &[Span])> { - self.bcb_to_spans.iter_enumerated().filter_map(|(bcb, spans)| { - // Only yield BCBs that have at least one coverage span. - (!spans.is_empty()).then_some((bcb, spans.as_slice())) - }) + pub(super) fn spans_for_bcb(&self, bcb: BasicCoverageBlock) -> &[Span] { + &self.bcb_to_spans[bcb] } } @@ -75,29 +70,15 @@ struct CoverageSpan { impl CoverageSpan { pub fn for_fn_sig(fn_sig_span: Span) -> Self { - Self { - span: fn_sig_span, - expn_span: fn_sig_span, - current_macro_or_none: Default::default(), - bcb: START_BCB, - merged_spans: vec![], - is_closure: false, - } + Self::new(fn_sig_span, fn_sig_span, START_BCB, false) } - pub fn for_statement( - statement: &Statement<'_>, + pub(super) fn new( span: Span, expn_span: Span, bcb: BasicCoverageBlock, + is_closure: bool, ) -> Self { - let is_closure = match statement.kind { - StatementKind::Assign(box (_, Rvalue::Aggregate(box ref kind, _))) => { - matches!(kind, AggregateKind::Closure(_, _) | AggregateKind::Generator(_, _, _)) - } - _ => false, - }; - Self { span, expn_span, @@ -108,17 +89,6 @@ impl CoverageSpan { } } - pub fn for_terminator(span: Span, expn_span: Span, bcb: BasicCoverageBlock) -> Self { - Self { - span, - expn_span, - current_macro_or_none: Default::default(), - bcb, - merged_spans: vec![span], - is_closure: false, - } - } - pub fn merge_from(&mut self, mut other: CoverageSpan) { debug_assert!(self.is_mergeable(&other)); self.span = self.span.to(other.span); diff --git a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs index 4c20997e633..6189e5379ea 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs @@ -1,5 +1,7 @@ +use rustc_data_structures::captures::Captures; use rustc_middle::mir::{ - self, FakeReadCause, Statement, StatementKind, Terminator, TerminatorKind, + self, AggregateKind, FakeReadCause, Rvalue, Statement, StatementKind, Terminator, + TerminatorKind, }; use rustc_span::Span; @@ -12,7 +14,7 @@ pub(super) fn mir_to_initial_sorted_coverage_spans( body_span: Span, basic_coverage_blocks: &CoverageGraph, ) -> Vec<CoverageSpan> { - let mut initial_spans = Vec::<CoverageSpan>::with_capacity(mir_body.basic_blocks.len() * 2); + let mut initial_spans = Vec::with_capacity(mir_body.basic_blocks.len() * 2); for (bcb, bcb_data) in basic_coverage_blocks.iter_enumerated() { initial_spans.extend(bcb_to_initial_coverage_spans(mir_body, body_span, bcb, bcb_data)); } @@ -50,34 +52,41 @@ pub(super) fn mir_to_initial_sorted_coverage_spans( // for each `Statement` and `Terminator`. (Note that subsequent stages of coverage analysis will // merge some `CoverageSpan`s, at which point a `CoverageSpan` may represent multiple // `Statement`s and/or `Terminator`s.) -fn bcb_to_initial_coverage_spans( - mir_body: &mir::Body<'_>, +fn bcb_to_initial_coverage_spans<'a, 'tcx>( + mir_body: &'a mir::Body<'tcx>, body_span: Span, bcb: BasicCoverageBlock, - bcb_data: &BasicCoverageBlockData, -) -> Vec<CoverageSpan> { - bcb_data - .basic_blocks - .iter() - .flat_map(|&bb| { - let data = &mir_body[bb]; - data.statements - .iter() - .filter_map(move |statement| { - filtered_statement_span(statement).map(|span| { - CoverageSpan::for_statement( - statement, - function_source_span(span, body_span), - span, - bcb, - ) - }) - }) - .chain(filtered_terminator_span(data.terminator()).map(|span| { - CoverageSpan::for_terminator(function_source_span(span, body_span), span, bcb) - })) - }) - .collect() + bcb_data: &'a BasicCoverageBlockData, +) -> impl Iterator<Item = CoverageSpan> + Captures<'a> + Captures<'tcx> { + bcb_data.basic_blocks.iter().flat_map(move |&bb| { + let data = &mir_body[bb]; + + let statement_spans = data.statements.iter().filter_map(move |statement| { + let expn_span = filtered_statement_span(statement)?; + let span = function_source_span(expn_span, body_span); + + Some(CoverageSpan::new(span, expn_span, bcb, is_closure(statement))) + }); + + let terminator_span = Some(data.terminator()).into_iter().filter_map(move |terminator| { + let expn_span = filtered_terminator_span(terminator)?; + let span = function_source_span(expn_span, body_span); + + Some(CoverageSpan::new(span, expn_span, bcb, false)) + }); + + statement_spans.chain(terminator_span) + }) +} + +fn is_closure(statement: &Statement<'_>) -> bool { + match statement.kind { + StatementKind::Assign(box (_, Rvalue::Aggregate(box ref agg_kind, _))) => match agg_kind { + AggregateKind::Closure(_, _) | AggregateKind::Coroutine(_, _, _) => true, + _ => false, + }, + _ => false, + } } /// If the MIR `Statement` has a span contributive to computing coverage spans, @@ -160,7 +169,7 @@ fn filtered_terminator_span(terminator: &Terminator<'_>) -> Option<Span> { | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return | TerminatorKind::Yield { .. } - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::FalseUnwind { .. } | TerminatorKind::InlineAsm { .. } => { Some(terminator.source_info.span) diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs index 99b070c018e..15502adfb5a 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -114,7 +114,7 @@ //! approach that only works for some classes of CFGs: //! - rustc now has a powerful dataflow analysis framework that can handle forwards and backwards //! analyses efficiently. -//! - Layout optimizations for generators have been added to improve code generation for +//! - Layout optimizations for coroutines have been added to improve code generation for //! async/await, which are very similar in spirit to what this optimization does. //! //! Also, rustc now has a simple NRVO pass (see `nrvo.rs`), which handles a subset of the cases that @@ -655,7 +655,7 @@ impl WriteInfo { // `Drop`s create a `&mut` and so are not considered } TerminatorKind::Yield { .. } - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::FalseEdge { .. } | TerminatorKind::FalseUnwind { .. } => { bug!("{:?} not found in this MIR phase", terminator) diff --git a/compiler/rustc_mir_transform/src/elaborate_drops.rs b/compiler/rustc_mir_transform/src/elaborate_drops.rs index d18fdaaf22f..59156b2427c 100644 --- a/compiler/rustc_mir_transform/src/elaborate_drops.rs +++ b/compiler/rustc_mir_transform/src/elaborate_drops.rs @@ -9,9 +9,9 @@ use rustc_mir_dataflow::elaborate_drops::{elaborate_drop, DropFlagState, Unwind} use rustc_mir_dataflow::elaborate_drops::{DropElaborator, DropFlagMode, DropStyle}; use rustc_mir_dataflow::impls::{MaybeInitializedPlaces, MaybeUninitializedPlaces}; use rustc_mir_dataflow::move_paths::{LookupResult, MoveData, MovePathIndex}; +use rustc_mir_dataflow::on_all_children_bits; use rustc_mir_dataflow::on_lookup_result_bits; use rustc_mir_dataflow::MoveDataParamEnv; -use rustc_mir_dataflow::{on_all_children_bits, on_all_drop_children_bits}; use rustc_mir_dataflow::{Analysis, ResultsCursor}; use rustc_span::Span; use rustc_target::abi::{FieldIdx, VariantIdx}; @@ -54,16 +54,10 @@ impl<'tcx> MirPass<'tcx> for ElaborateDrops { let def_id = body.source.def_id(); let param_env = tcx.param_env_reveal_all_normalized(def_id); - let move_data = match MoveData::gather_moves(body, tcx, param_env) { - Ok(move_data) => move_data, - Err((move_data, _)) => { - tcx.sess.delay_span_bug( - body.span, - "No `move_errors` should be allowed in MIR borrowck", - ); - move_data - } - }; + // For types that do not need dropping, the behaviour is trivial. So we only need to track + // init/uninit for types that do need dropping. + let move_data = + MoveData::gather_moves(&body, tcx, param_env, |ty| ty.needs_drop(tcx, param_env)); let elaborate_patch = { let env = MoveDataParamEnv { move_data, param_env }; @@ -178,13 +172,19 @@ impl<'a, 'tcx> DropElaborator<'a, 'tcx> for Elaborator<'a, '_, 'tcx> { let mut some_live = false; let mut some_dead = false; let mut children_count = 0; - on_all_drop_children_bits(self.tcx(), self.body(), self.ctxt.env, path, |child| { - let (live, dead) = self.ctxt.init_data.maybe_live_dead(child); - debug!("elaborate_drop: state({:?}) = {:?}", child, (live, dead)); - some_live |= live; - some_dead |= dead; - children_count += 1; - }); + on_all_children_bits( + self.tcx(), + self.body(), + self.ctxt.move_data(), + path, + |child| { + let (live, dead) = self.ctxt.init_data.maybe_live_dead(child); + debug!("elaborate_drop: state({:?}) = {:?}", child, (live, dead)); + some_live |= live; + some_dead |= dead; + children_count += 1; + }, + ); ((some_live, some_dead), children_count != 1) } }; @@ -296,26 +296,36 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { fn collect_drop_flags(&mut self) { for (bb, data) in self.body.basic_blocks.iter_enumerated() { let terminator = data.terminator(); - let place = match terminator.kind { - TerminatorKind::Drop { ref place, .. } => place, - _ => continue, - }; - - self.init_data.seek_before(self.body.terminator_loc(bb)); + let TerminatorKind::Drop { ref place, .. } = terminator.kind else { continue }; let path = self.move_data().rev_lookup.find(place.as_ref()); debug!("collect_drop_flags: {:?}, place {:?} ({:?})", bb, place, path); - let path = match path { - LookupResult::Exact(e) => e, - LookupResult::Parent(None) => continue, + match path { + LookupResult::Exact(path) => { + self.init_data.seek_before(self.body.terminator_loc(bb)); + on_all_children_bits(self.tcx, self.body, self.move_data(), path, |child| { + let (maybe_live, maybe_dead) = self.init_data.maybe_live_dead(child); + debug!( + "collect_drop_flags: collecting {:?} from {:?}@{:?} - {:?}", + child, + place, + path, + (maybe_live, maybe_dead) + ); + if maybe_live && maybe_dead { + self.create_drop_flag(child, terminator.source_info.span) + } + }); + } + LookupResult::Parent(None) => {} LookupResult::Parent(Some(parent)) => { - let (_maybe_live, maybe_dead) = self.init_data.maybe_live_dead(parent); - if self.body.local_decls[place.local].is_deref_temp() { continue; } + self.init_data.seek_before(self.body.terminator_loc(bb)); + let (_maybe_live, maybe_dead) = self.init_data.maybe_live_dead(parent); if maybe_dead { self.tcx.sess.delay_span_bug( terminator.source_info.span, @@ -324,80 +334,74 @@ impl<'b, 'tcx> ElaborateDropsCtxt<'b, 'tcx> { ), ); } - continue; } }; - - on_all_drop_children_bits(self.tcx, self.body, self.env, path, |child| { - let (maybe_live, maybe_dead) = self.init_data.maybe_live_dead(child); - debug!( - "collect_drop_flags: collecting {:?} from {:?}@{:?} - {:?}", - child, - place, - path, - (maybe_live, maybe_dead) - ); - if maybe_live && maybe_dead { - self.create_drop_flag(child, terminator.source_info.span) - } - }); } } fn elaborate_drops(&mut self) { + // This function should mirror what `collect_drop_flags` does. for (bb, data) in self.body.basic_blocks.iter_enumerated() { - let loc = Location { block: bb, statement_index: data.statements.len() }; let terminator = data.terminator(); + let TerminatorKind::Drop { place, target, unwind, replace } = terminator.kind else { + continue; + }; - match terminator.kind { - TerminatorKind::Drop { place, target, unwind, replace } => { - self.init_data.seek_before(loc); - match self.move_data().rev_lookup.find(place.as_ref()) { - LookupResult::Exact(path) => { - let unwind = if data.is_cleanup { - Unwind::InCleanup - } else { - match unwind { - UnwindAction::Cleanup(cleanup) => Unwind::To(cleanup), - UnwindAction::Continue => Unwind::To(self.patch.resume_block()), - UnwindAction::Unreachable => { - Unwind::To(self.patch.unreachable_cleanup_block()) - } - UnwindAction::Terminate(reason) => { - debug_assert_ne!( - reason, - UnwindTerminateReason::InCleanup, - "we are not in a cleanup block, InCleanup reason should be impossible" - ); - Unwind::To(self.patch.terminate_block(reason)) - } - } - }; - elaborate_drop( - &mut Elaborator { ctxt: self }, - terminator.source_info, - place, - path, - target, - unwind, - bb, - ) + // This place does not need dropping. It does not have an associated move-path, so the + // match below will conservatively keep an unconditional drop. As that drop is useless, + // just remove it here and now. + if !place + .ty(&self.body.local_decls, self.tcx) + .ty + .needs_drop(self.tcx, self.env.param_env) + { + self.patch.patch_terminator(bb, TerminatorKind::Goto { target }); + continue; + } + + let path = self.move_data().rev_lookup.find(place.as_ref()); + match path { + LookupResult::Exact(path) => { + let unwind = match unwind { + _ if data.is_cleanup => Unwind::InCleanup, + UnwindAction::Cleanup(cleanup) => Unwind::To(cleanup), + UnwindAction::Continue => Unwind::To(self.patch.resume_block()), + UnwindAction::Unreachable => { + Unwind::To(self.patch.unreachable_cleanup_block()) } - LookupResult::Parent(..) => { - if !replace { - self.tcx.sess.delay_span_bug( - terminator.source_info.span, - format!("drop of untracked value {bb:?}"), - ); - } - // A drop and replace behind a pointer/array/whatever. - // The borrow checker requires that these locations are initialized before the assignment, - // so we just leave an unconditional drop. - assert!(!data.is_cleanup); + UnwindAction::Terminate(reason) => { + debug_assert_ne!( + reason, + UnwindTerminateReason::InCleanup, + "we are not in a cleanup block, InCleanup reason should be impossible" + ); + Unwind::To(self.patch.terminate_block(reason)) } + }; + self.init_data.seek_before(self.body.terminator_loc(bb)); + elaborate_drop( + &mut Elaborator { ctxt: self }, + terminator.source_info, + place, + path, + target, + unwind, + bb, + ) + } + LookupResult::Parent(None) => {} + LookupResult::Parent(Some(_)) => { + if !replace { + self.tcx.sess.delay_span_bug( + terminator.source_info.span, + format!("drop of untracked value {bb:?}"), + ); } + // A drop and replace behind a pointer/array/whatever. + // The borrow checker requires that these locations are initialized before the assignment, + // so we just leave an unconditional drop. + assert!(!data.is_cleanup); } - _ => continue, } } } diff --git a/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs b/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs index d202860840c..26fcfad8287 100644 --- a/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs +++ b/compiler/rustc_mir_transform/src/ffi_unwind_calls.rs @@ -58,7 +58,7 @@ fn has_ffi_unwind_calls(tcx: TyCtxt<'_>, local_def_id: LocalDefId) -> bool { let body_abi = match body_ty.kind() { ty::FnDef(..) => body_ty.fn_sig(tcx).abi(), ty::Closure(..) => Abi::RustCall, - ty::Generator(..) => Abi::Rust, + ty::Coroutine(..) => Abi::Rust, _ => span_bug!(body.span, "unexpected body ty: {:?}", body_ty), }; let body_can_unwind = layout::fn_can_unwind(tcx, Some(def_id), body_abi); diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs index c710e460dcb..eece7c3e834 100644 --- a/compiler/rustc_mir_transform/src/gvn.rs +++ b/compiler/rustc_mir_transform/src/gvn.rs @@ -383,7 +383,7 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { AggregateKind::Array(..) | AggregateKind::Tuple | AggregateKind::Closure(..) - | AggregateKind::Generator(..) => FIRST_VARIANT, + | AggregateKind::Coroutine(..) => FIRST_VARIANT, AggregateKind::Adt(_, variant_index, _, _, None) => variant_index, // Do not track unions. AggregateKind::Adt(_, _, _, _, Some(_)) => return None, diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 8f578b69694..8b33e00c63c 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -14,6 +14,7 @@ use rustc_session::config::OptLevel; use rustc_target::abi::FieldIdx; use rustc_target::spec::abi::Abi; +use crate::cost_checker::CostChecker; use crate::simplify::{remove_dead_blocks, CfgSimplifier}; use crate::util; use crate::MirPass; @@ -22,11 +23,6 @@ use std::ops::{Range, RangeFrom}; pub(crate) mod cycle; -const INSTR_COST: usize = 5; -const CALL_PENALTY: usize = 25; -const LANDINGPAD_PENALTY: usize = 50; -const RESUME_PENALTY: usize = 45; - const TOP_DOWN_DEPTH_LIMIT: usize = 5; pub struct Inline; @@ -79,10 +75,10 @@ fn inline<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool { if body.source.promoted.is_some() { return false; } - // Avoid inlining into generators, since their `optimized_mir` is used for layout computation, + // Avoid inlining into coroutines, since their `optimized_mir` is used for layout computation, // which can create a cycle, even when no attempt is made to inline the function in the other // direction. - if body.generator.is_some() { + if body.coroutine.is_some() { return false; } @@ -479,13 +475,8 @@ impl<'tcx> Inliner<'tcx> { // FIXME: Give a bonus to functions with only a single caller - let mut checker = CostChecker { - tcx: self.tcx, - param_env: self.param_env, - instance: callsite.callee, - callee_body, - cost: 0, - }; + let mut checker = + CostChecker::new(self.tcx, self.param_env, Some(callsite.callee), callee_body); // Traverse the MIR manually so we can account for the effects of inlining on the CFG. let mut work_list = vec![START_BLOCK]; @@ -530,7 +521,7 @@ impl<'tcx> Inliner<'tcx> { // That attribute is often applied to very large functions that exceed LLVM's (very // generous) inlining threshold. Such functions are very poor MIR inlining candidates. // Always inlining #[inline(always)] functions in MIR, on net, slows down the compiler. - let cost = checker.cost; + let cost = checker.cost(); if cost <= threshold { debug!("INLINING {:?} [cost={} <= threshold={}]", callsite, cost, threshold); Ok(()) @@ -803,81 +794,6 @@ impl<'tcx> Inliner<'tcx> { } } -/// Verify that the callee body is compatible with the caller. -/// -/// This visitor mostly computes the inlining cost, -/// but also needs to verify that types match because of normalization failure. -struct CostChecker<'b, 'tcx> { - tcx: TyCtxt<'tcx>, - param_env: ParamEnv<'tcx>, - cost: usize, - callee_body: &'b Body<'tcx>, - instance: ty::Instance<'tcx>, -} - -impl<'tcx> Visitor<'tcx> for CostChecker<'_, 'tcx> { - fn visit_statement(&mut self, statement: &Statement<'tcx>, _: Location) { - // Don't count StorageLive/StorageDead in the inlining cost. - match statement.kind { - StatementKind::StorageLive(_) - | StatementKind::StorageDead(_) - | StatementKind::Deinit(_) - | StatementKind::Nop => {} - _ => self.cost += INSTR_COST, - } - } - - fn visit_terminator(&mut self, terminator: &Terminator<'tcx>, _: Location) { - let tcx = self.tcx; - match terminator.kind { - TerminatorKind::Drop { ref place, unwind, .. } => { - // If the place doesn't actually need dropping, treat it like a regular goto. - let ty = self.instance.instantiate_mir( - tcx, - ty::EarlyBinder::bind(&place.ty(self.callee_body, tcx).ty), - ); - if ty.needs_drop(tcx, self.param_env) { - self.cost += CALL_PENALTY; - if let UnwindAction::Cleanup(_) = unwind { - self.cost += LANDINGPAD_PENALTY; - } - } else { - self.cost += INSTR_COST; - } - } - TerminatorKind::Call { func: Operand::Constant(ref f), unwind, .. } => { - let fn_ty = - self.instance.instantiate_mir(tcx, ty::EarlyBinder::bind(&f.const_.ty())); - self.cost += if let ty::FnDef(def_id, _) = *fn_ty.kind() - && tcx.is_intrinsic(def_id) - { - // Don't give intrinsics the extra penalty for calls - INSTR_COST - } else { - CALL_PENALTY - }; - if let UnwindAction::Cleanup(_) = unwind { - self.cost += LANDINGPAD_PENALTY; - } - } - TerminatorKind::Assert { unwind, .. } => { - self.cost += CALL_PENALTY; - if let UnwindAction::Cleanup(_) = unwind { - self.cost += LANDINGPAD_PENALTY; - } - } - TerminatorKind::UnwindResume => self.cost += RESUME_PENALTY, - TerminatorKind::InlineAsm { unwind, .. } => { - self.cost += INSTR_COST; - if let UnwindAction::Cleanup(_) = unwind { - self.cost += LANDINGPAD_PENALTY; - } - } - _ => self.cost += INSTR_COST, - } - } -} - /** * Integrator. * @@ -1014,7 +930,7 @@ impl<'tcx> MutVisitor<'tcx> for Integrator<'_, 'tcx> { } match terminator.kind { - TerminatorKind::GeneratorDrop | TerminatorKind::Yield { .. } => bug!(), + TerminatorKind::CoroutineDrop | TerminatorKind::Yield { .. } => bug!(), TerminatorKind::Goto { ref mut target } => { *target = self.map_block(*target); } diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs new file mode 100644 index 00000000000..7b918be4474 --- /dev/null +++ b/compiler/rustc_mir_transform/src/jump_threading.rs @@ -0,0 +1,759 @@ +//! A jump threading optimization. +//! +//! This optimization seeks to replace join-then-switch control flow patterns by straight jumps +//! X = 0 X = 0 +//! ------------\ /-------- ------------ +//! X = 1 X----X SwitchInt(X) => X = 1 +//! ------------/ \-------- ------------ +//! +//! +//! We proceed by walking the cfg backwards starting from each `SwitchInt` terminator, +//! looking for assignments that will turn the `SwitchInt` into a simple `Goto`. +//! +//! The algorithm maintains a set of replacement conditions: +//! - `conditions[place]` contains `Condition { value, polarity: Eq, target }` +//! if assigning `value` to `place` turns the `SwitchInt` into `Goto { target }`. +//! - `conditions[place]` contains `Condition { value, polarity: Ne, target }` +//! if assigning anything different from `value` to `place` turns the `SwitchInt` +//! into `Goto { target }`. +//! +//! In this file, we denote as `place ?= value` the existence of a replacement condition +//! on `place` with given `value`, irrespective of the polarity and target of that +//! replacement condition. +//! +//! We then walk the CFG backwards transforming the set of conditions. +//! When we find a fulfilling assignment, we record a `ThreadingOpportunity`. +//! All `ThreadingOpportunity`s are applied to the body, by duplicating blocks if required. +//! +//! The optimization search can be very heavy, as it performs a DFS on MIR starting from +//! each `SwitchInt` terminator. To manage the complexity, we: +//! - bound the maximum depth by a constant `MAX_BACKTRACK`; +//! - we only traverse `Goto` terminators. +//! +//! We try to avoid creating irreducible control-flow by not threading through a loop header. +//! +//! Likewise, applying the optimisation can create a lot of new MIR, so we bound the instruction +//! cost by `MAX_COST`. + +use rustc_arena::DroplessArena; +use rustc_data_structures::fx::FxHashSet; +use rustc_index::bit_set::BitSet; +use rustc_index::IndexVec; +use rustc_middle::mir::visit::Visitor; +use rustc_middle::mir::*; +use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt}; +use rustc_mir_dataflow::value_analysis::{Map, PlaceIndex, State, TrackElem}; + +use crate::cost_checker::CostChecker; +use crate::MirPass; + +pub struct JumpThreading; + +const MAX_BACKTRACK: usize = 5; +const MAX_COST: usize = 100; +const MAX_PLACES: usize = 100; + +impl<'tcx> MirPass<'tcx> for JumpThreading { + fn is_enabled(&self, sess: &rustc_session::Session) -> bool { + sess.mir_opt_level() >= 4 + } + + #[instrument(skip_all level = "debug")] + fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { + let def_id = body.source.def_id(); + debug!(?def_id); + + let param_env = tcx.param_env_reveal_all_normalized(def_id); + let map = Map::new(tcx, body, Some(MAX_PLACES)); + let loop_headers = loop_headers(body); + + let arena = DroplessArena::default(); + let mut finder = TOFinder { + tcx, + param_env, + body, + arena: &arena, + map: &map, + loop_headers: &loop_headers, + opportunities: Vec::new(), + }; + + for (bb, bbdata) in body.basic_blocks.iter_enumerated() { + debug!(?bb, term = ?bbdata.terminator()); + if bbdata.is_cleanup || loop_headers.contains(bb) { + continue; + } + let Some((discr, targets)) = bbdata.terminator().kind.as_switch() else { continue }; + let Some(discr) = discr.place() else { continue }; + debug!(?discr, ?bb); + + let discr_ty = discr.ty(body, tcx).ty; + let Ok(discr_layout) = tcx.layout_of(param_env.and(discr_ty)) else { continue }; + + let Some(discr) = finder.map.find(discr.as_ref()) else { continue }; + debug!(?discr); + + let cost = CostChecker::new(tcx, param_env, None, body); + + let mut state = State::new(ConditionSet::default(), &finder.map); + + let conds = if let Some((value, then, else_)) = targets.as_static_if() { + let Some(value) = ScalarInt::try_from_uint(value, discr_layout.size) else { + continue; + }; + arena.alloc_from_iter([ + Condition { value, polarity: Polarity::Eq, target: then }, + Condition { value, polarity: Polarity::Ne, target: else_ }, + ]) + } else { + arena.alloc_from_iter(targets.iter().filter_map(|(value, target)| { + let value = ScalarInt::try_from_uint(value, discr_layout.size)?; + Some(Condition { value, polarity: Polarity::Eq, target }) + })) + }; + let conds = ConditionSet(conds); + state.insert_value_idx(discr, conds, &finder.map); + + finder.find_opportunity(bb, state, cost, 0); + } + + let opportunities = finder.opportunities; + debug!(?opportunities); + if opportunities.is_empty() { + return; + } + + // Verify that we do not thread through a loop header. + for to in opportunities.iter() { + assert!(to.chain.iter().all(|&block| !loop_headers.contains(block))); + } + OpportunitySet::new(body, opportunities).apply(body); + } +} + +#[derive(Debug)] +struct ThreadingOpportunity { + /// The list of `BasicBlock`s from the one that found the opportunity to the `SwitchInt`. + chain: Vec<BasicBlock>, + /// The `SwitchInt` will be replaced by `Goto { target }`. + target: BasicBlock, +} + +struct TOFinder<'tcx, 'a> { + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + body: &'a Body<'tcx>, + map: &'a Map, + loop_headers: &'a BitSet<BasicBlock>, + /// We use an arena to avoid cloning the slices when cloning `state`. + arena: &'a DroplessArena, + opportunities: Vec<ThreadingOpportunity>, +} + +/// Represent the following statement. If we can prove that the current local is equal/not-equal +/// to `value`, jump to `target`. +#[derive(Copy, Clone, Debug)] +struct Condition { + value: ScalarInt, + polarity: Polarity, + target: BasicBlock, +} + +#[derive(Copy, Clone, Debug, Eq, PartialEq)] +enum Polarity { + Ne, + Eq, +} + +impl Condition { + fn matches(&self, value: ScalarInt) -> bool { + (self.value == value) == (self.polarity == Polarity::Eq) + } + + fn inv(mut self) -> Self { + self.polarity = match self.polarity { + Polarity::Eq => Polarity::Ne, + Polarity::Ne => Polarity::Eq, + }; + self + } +} + +#[derive(Copy, Clone, Debug, Default)] +struct ConditionSet<'a>(&'a [Condition]); + +impl<'a> ConditionSet<'a> { + fn iter(self) -> impl Iterator<Item = Condition> + 'a { + self.0.iter().copied() + } + + fn iter_matches(self, value: ScalarInt) -> impl Iterator<Item = Condition> + 'a { + self.iter().filter(move |c| c.matches(value)) + } + + fn map(self, arena: &'a DroplessArena, f: impl Fn(Condition) -> Condition) -> ConditionSet<'a> { + ConditionSet(arena.alloc_from_iter(self.iter().map(f))) + } +} + +impl<'tcx, 'a> TOFinder<'tcx, 'a> { + fn is_empty(&self, state: &State<ConditionSet<'a>>) -> bool { + state.all(|cs| cs.0.is_empty()) + } + + /// Recursion entry point to find threading opportunities. + #[instrument(level = "trace", skip(self, cost), ret)] + fn find_opportunity( + &mut self, + bb: BasicBlock, + mut state: State<ConditionSet<'a>>, + mut cost: CostChecker<'_, 'tcx>, + depth: usize, + ) { + // Do not thread through loop headers. + if self.loop_headers.contains(bb) { + return; + } + + debug!(cost = ?cost.cost()); + for (statement_index, stmt) in + self.body.basic_blocks[bb].statements.iter().enumerate().rev() + { + if self.is_empty(&state) { + return; + } + + cost.visit_statement(stmt, Location { block: bb, statement_index }); + if cost.cost() > MAX_COST { + return; + } + + // Attempt to turn the `current_condition` on `lhs` into a condition on another place. + self.process_statement(bb, stmt, &mut state); + + // When a statement mutates a place, assignments to that place that happen + // above the mutation cannot fulfill a condition. + // _1 = 5 // Whatever happens here, it won't change the result of a `SwitchInt`. + // _1 = 6 + if let Some((lhs, tail)) = self.mutated_statement(stmt) { + state.flood_with_tail_elem(lhs.as_ref(), tail, self.map, ConditionSet::default()); + } + } + + if self.is_empty(&state) || depth >= MAX_BACKTRACK { + return; + } + + let last_non_rec = self.opportunities.len(); + + let predecessors = &self.body.basic_blocks.predecessors()[bb]; + if let &[pred] = &predecessors[..] && bb != START_BLOCK { + let term = self.body.basic_blocks[pred].terminator(); + match term.kind { + TerminatorKind::SwitchInt { ref discr, ref targets } => { + self.process_switch_int(discr, targets, bb, &mut state); + self.find_opportunity(pred, state, cost, depth + 1); + } + _ => self.recurse_through_terminator(pred, &state, &cost, depth), + } + } else { + for &pred in predecessors { + self.recurse_through_terminator(pred, &state, &cost, depth); + } + } + + let new_tos = &mut self.opportunities[last_non_rec..]; + debug!(?new_tos); + + // Try to deduplicate threading opportunities. + if new_tos.len() > 1 + && new_tos.len() == predecessors.len() + && predecessors + .iter() + .zip(new_tos.iter()) + .all(|(&pred, to)| to.chain == &[pred] && to.target == new_tos[0].target) + { + // All predecessors have a threading opportunity, and they all point to the same block. + debug!(?new_tos, "dedup"); + let first = &mut new_tos[0]; + *first = ThreadingOpportunity { chain: vec![bb], target: first.target }; + self.opportunities.truncate(last_non_rec + 1); + return; + } + + for op in self.opportunities[last_non_rec..].iter_mut() { + op.chain.push(bb); + } + } + + /// Extract the mutated place from a statement. + /// + /// This method returns the `Place` so we can flood the state in case of a partial assignment. + /// (_1 as Ok).0 = _5; + /// (_1 as Err).0 = _6; + /// We want to ensure that a `SwitchInt((_1 as Ok).0)` does not see the first assignment, as + /// the value may have been mangled by the second assignment. + /// + /// In case we assign to a discriminant, we return `Some(TrackElem::Discriminant)`, so we can + /// stop at flooding the discriminant, and preserve the variant fields. + /// (_1 as Some).0 = _6; + /// SetDiscriminant(_1, 1); + /// switchInt((_1 as Some).0) + #[instrument(level = "trace", skip(self), ret)] + fn mutated_statement( + &self, + stmt: &Statement<'tcx>, + ) -> Option<(Place<'tcx>, Option<TrackElem>)> { + match stmt.kind { + StatementKind::Assign(box (place, _)) + | StatementKind::Deinit(box place) => Some((place, None)), + StatementKind::SetDiscriminant { box place, variant_index: _ } => { + Some((place, Some(TrackElem::Discriminant))) + } + StatementKind::StorageLive(local) | StatementKind::StorageDead(local) => { + Some((Place::from(local), None)) + } + StatementKind::Retag(..) + | StatementKind::Intrinsic(box NonDivergingIntrinsic::Assume(..)) + // copy_nonoverlapping takes pointers and mutated the pointed-to value. + | StatementKind::Intrinsic(box NonDivergingIntrinsic::CopyNonOverlapping(..)) + | StatementKind::AscribeUserType(..) + | StatementKind::Coverage(..) + | StatementKind::FakeRead(..) + | StatementKind::ConstEvalCounter + | StatementKind::PlaceMention(..) + | StatementKind::Nop => None, + } + } + + #[instrument(level = "trace", skip(self))] + fn process_operand( + &mut self, + bb: BasicBlock, + lhs: PlaceIndex, + rhs: &Operand<'tcx>, + state: &mut State<ConditionSet<'a>>, + ) -> Option<!> { + let register_opportunity = |c: Condition| { + debug!(?bb, ?c.target, "register"); + self.opportunities.push(ThreadingOpportunity { chain: vec![bb], target: c.target }) + }; + + match rhs { + // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`. + Operand::Constant(constant) => { + let conditions = state.try_get_idx(lhs, self.map)?; + let constant = + constant.const_.normalize(self.tcx, self.param_env).try_to_scalar_int()?; + conditions.iter_matches(constant).for_each(register_opportunity); + } + // Transfer the conditions on the copied rhs. + Operand::Move(rhs) | Operand::Copy(rhs) => { + let rhs = self.map.find(rhs.as_ref())?; + state.insert_place_idx(rhs, lhs, self.map); + } + } + + None + } + + #[instrument(level = "trace", skip(self))] + fn process_statement( + &mut self, + bb: BasicBlock, + stmt: &Statement<'tcx>, + state: &mut State<ConditionSet<'a>>, + ) -> Option<!> { + let register_opportunity = |c: Condition| { + debug!(?bb, ?c.target, "register"); + self.opportunities.push(ThreadingOpportunity { chain: vec![bb], target: c.target }) + }; + + // Below, `lhs` is the return value of `mutated_statement`, + // the place to which `conditions` apply. + + let discriminant_for_variant = |enum_ty: Ty<'tcx>, variant_index| { + let discr = enum_ty.discriminant_for_variant(self.tcx, variant_index)?; + let discr_layout = self.tcx.layout_of(self.param_env.and(discr.ty)).ok()?; + let scalar = ScalarInt::try_from_uint(discr.val, discr_layout.size)?; + Some(Operand::const_from_scalar( + self.tcx, + discr.ty, + scalar.into(), + rustc_span::DUMMY_SP, + )) + }; + + match &stmt.kind { + // If we expect `discriminant(place) ?= A`, + // we have an opportunity if `variant_index ?= A`. + StatementKind::SetDiscriminant { box place, variant_index } => { + let discr_target = self.map.find_discr(place.as_ref())?; + let enum_ty = place.ty(self.body, self.tcx).ty; + let discr = discriminant_for_variant(enum_ty, *variant_index)?; + self.process_operand(bb, discr_target, &discr, state)?; + } + // If we expect `lhs ?= true`, we have an opportunity if we assume `lhs == true`. + StatementKind::Intrinsic(box NonDivergingIntrinsic::Assume( + Operand::Copy(place) | Operand::Move(place), + )) => { + let conditions = state.try_get(place.as_ref(), self.map)?; + conditions.iter_matches(ScalarInt::TRUE).for_each(register_opportunity); + } + StatementKind::Assign(box (lhs_place, rhs)) => { + if let Some(lhs) = self.map.find(lhs_place.as_ref()) { + match rhs { + Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state)?, + // Transfer the conditions on the copy rhs. + Rvalue::CopyForDeref(rhs) => { + self.process_operand(bb, lhs, &Operand::Copy(*rhs), state)? + } + Rvalue::Discriminant(rhs) => { + let rhs = self.map.find_discr(rhs.as_ref())?; + state.insert_place_idx(rhs, lhs, self.map); + } + // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`. + Rvalue::Aggregate(box ref kind, ref operands) => { + let agg_ty = lhs_place.ty(self.body, self.tcx).ty; + let lhs = match kind { + // Do not support unions. + AggregateKind::Adt(.., Some(_)) => return None, + AggregateKind::Adt(_, variant_index, ..) if agg_ty.is_enum() => { + if let Some(discr_target) = self.map.apply(lhs, TrackElem::Discriminant) + && let Some(discr_value) = discriminant_for_variant(agg_ty, *variant_index) + { + self.process_operand(bb, discr_target, &discr_value, state); + } + self.map.apply(lhs, TrackElem::Variant(*variant_index))? + } + _ => lhs, + }; + for (field_index, operand) in operands.iter_enumerated() { + if let Some(field) = + self.map.apply(lhs, TrackElem::Field(field_index)) + { + self.process_operand(bb, field, operand, state); + } + } + } + // Transfer the conditions on the copy rhs, after inversing polarity. + Rvalue::UnaryOp(UnOp::Not, Operand::Move(place) | Operand::Copy(place)) => { + let conditions = state.try_get_idx(lhs, self.map)?; + let place = self.map.find(place.as_ref())?; + let conds = conditions.map(self.arena, Condition::inv); + state.insert_value_idx(place, conds, self.map); + } + // We expect `lhs ?= A`. We found `lhs = Eq(rhs, B)`. + // Create a condition on `rhs ?= B`. + Rvalue::BinaryOp( + op, + box ( + Operand::Move(place) | Operand::Copy(place), + Operand::Constant(value), + ) + | box ( + Operand::Constant(value), + Operand::Move(place) | Operand::Copy(place), + ), + ) => { + let conditions = state.try_get_idx(lhs, self.map)?; + let place = self.map.find(place.as_ref())?; + let equals = match op { + BinOp::Eq => ScalarInt::TRUE, + BinOp::Ne => ScalarInt::FALSE, + _ => return None, + }; + let value = value + .const_ + .normalize(self.tcx, self.param_env) + .try_to_scalar_int()?; + let conds = conditions.map(self.arena, |c| Condition { + value, + polarity: if c.matches(equals) { + Polarity::Eq + } else { + Polarity::Ne + }, + ..c + }); + state.insert_value_idx(place, conds, self.map); + } + + _ => {} + } + } + } + _ => {} + } + + None + } + + #[instrument(level = "trace", skip(self, cost))] + fn recurse_through_terminator( + &mut self, + bb: BasicBlock, + state: &State<ConditionSet<'a>>, + cost: &CostChecker<'_, 'tcx>, + depth: usize, + ) { + let register_opportunity = |c: Condition| { + debug!(?bb, ?c.target, "register"); + self.opportunities.push(ThreadingOpportunity { chain: vec![bb], target: c.target }) + }; + + let term = self.body.basic_blocks[bb].terminator(); + let place_to_flood = match term.kind { + // We come from a target, so those are not possible. + TerminatorKind::UnwindResume + | TerminatorKind::UnwindTerminate(_) + | TerminatorKind::Return + | TerminatorKind::Unreachable + | TerminatorKind::CoroutineDrop => bug!("{term:?} has no terminators"), + // Disallowed during optimizations. + TerminatorKind::FalseEdge { .. } + | TerminatorKind::FalseUnwind { .. } + | TerminatorKind::Yield { .. } => bug!("{term:?} invalid"), + // Cannot reason about inline asm. + TerminatorKind::InlineAsm { .. } => return, + // `SwitchInt` is handled specially. + TerminatorKind::SwitchInt { .. } => return, + // We can recurse, no thing particular to do. + TerminatorKind::Goto { .. } => None, + // Flood the overwritten place, and progress through. + TerminatorKind::Drop { place: destination, .. } + | TerminatorKind::Call { destination, .. } => Some(destination), + // Treat as an `assume(cond == expected)`. + TerminatorKind::Assert { ref cond, expected, .. } => { + if let Some(place) = cond.place() + && let Some(conditions) = state.try_get(place.as_ref(), self.map) + { + let expected = if expected { ScalarInt::TRUE } else { ScalarInt::FALSE }; + conditions.iter_matches(expected).for_each(register_opportunity); + } + None + } + }; + + // We can recurse through this terminator. + let mut state = state.clone(); + if let Some(place_to_flood) = place_to_flood { + state.flood_with(place_to_flood.as_ref(), self.map, ConditionSet::default()); + } + self.find_opportunity(bb, state, cost.clone(), depth + 1); + } + + #[instrument(level = "trace", skip(self))] + fn process_switch_int( + &mut self, + discr: &Operand<'tcx>, + targets: &SwitchTargets, + target_bb: BasicBlock, + state: &mut State<ConditionSet<'a>>, + ) -> Option<!> { + debug_assert_ne!(target_bb, START_BLOCK); + debug_assert_eq!(self.body.basic_blocks.predecessors()[target_bb].len(), 1); + + let discr = discr.place()?; + let discr_ty = discr.ty(self.body, self.tcx).ty; + let discr_layout = self.tcx.layout_of(self.param_env.and(discr_ty)).ok()?; + let conditions = state.try_get(discr.as_ref(), self.map)?; + + if let Some((value, _)) = targets.iter().find(|&(_, target)| target == target_bb) { + let value = ScalarInt::try_from_uint(value, discr_layout.size)?; + debug_assert_eq!(targets.iter().filter(|&(_, target)| target == target_bb).count(), 1); + + // We are inside `target_bb`. Since we have a single predecessor, we know we passed + // through the `SwitchInt` before arriving here. Therefore, we know that + // `discr == value`. If one condition can be fulfilled by `discr == value`, + // that's an opportunity. + for c in conditions.iter_matches(value) { + debug!(?target_bb, ?c.target, "register"); + self.opportunities.push(ThreadingOpportunity { chain: vec![], target: c.target }); + } + } else if let Some((value, _, else_bb)) = targets.as_static_if() + && target_bb == else_bb + { + let value = ScalarInt::try_from_uint(value, discr_layout.size)?; + + // We only know that `discr != value`. That's much weaker information than + // the equality we had in the previous arm. All we can conclude is that + // the replacement condition `discr != value` can be threaded, and nothing else. + for c in conditions.iter() { + if c.value == value && c.polarity == Polarity::Ne { + debug!(?target_bb, ?c.target, "register"); + self.opportunities + .push(ThreadingOpportunity { chain: vec![], target: c.target }); + } + } + } + + None + } +} + +struct OpportunitySet { + opportunities: Vec<ThreadingOpportunity>, + /// For each bb, give the TOs in which it appears. The pair corresponds to the index + /// in `opportunities` and the index in `ThreadingOpportunity::chain`. + involving_tos: IndexVec<BasicBlock, Vec<(usize, usize)>>, + /// Cache the number of predecessors for each block, as we clear the basic block cache.. + predecessors: IndexVec<BasicBlock, usize>, +} + +impl OpportunitySet { + fn new(body: &Body<'_>, opportunities: Vec<ThreadingOpportunity>) -> OpportunitySet { + let mut involving_tos = IndexVec::from_elem(Vec::new(), &body.basic_blocks); + for (index, to) in opportunities.iter().enumerate() { + for (ibb, &bb) in to.chain.iter().enumerate() { + involving_tos[bb].push((index, ibb)); + } + involving_tos[to.target].push((index, to.chain.len())); + } + let predecessors = predecessor_count(body); + OpportunitySet { opportunities, involving_tos, predecessors } + } + + /// Apply the opportunities on the graph. + fn apply(&mut self, body: &mut Body<'_>) { + for i in 0..self.opportunities.len() { + self.apply_once(i, body); + } + } + + #[instrument(level = "trace", skip(self, body))] + fn apply_once(&mut self, index: usize, body: &mut Body<'_>) { + debug!(?self.predecessors); + debug!(?self.involving_tos); + + // Check that `predecessors` satisfies its invariant. + debug_assert_eq!(self.predecessors, predecessor_count(body)); + + // Remove the TO from the vector to allow modifying the other ones later. + let op = &mut self.opportunities[index]; + debug!(?op); + let op_chain = std::mem::take(&mut op.chain); + let op_target = op.target; + debug_assert_eq!(op_chain.len(), op_chain.iter().collect::<FxHashSet<_>>().len()); + + let Some((current, chain)) = op_chain.split_first() else { return }; + let basic_blocks = body.basic_blocks.as_mut(); + + // Invariant: the control-flow is well-formed at the end of each iteration. + let mut current = *current; + for &succ in chain { + debug!(?current, ?succ); + + // `succ` must be a successor of `current`. If it is not, this means this TO is not + // satisfiable and a previous TO erased this edge, so we bail out. + if basic_blocks[current].terminator().successors().find(|s| *s == succ).is_none() { + debug!("impossible"); + return; + } + + // Fast path: `succ` is only used once, so we can reuse it directly. + if self.predecessors[succ] == 1 { + debug!("single"); + current = succ; + continue; + } + + let new_succ = basic_blocks.push(basic_blocks[succ].clone()); + debug!(?new_succ); + + // Replace `succ` by `new_succ` where it appears. + let mut num_edges = 0; + for s in basic_blocks[current].terminator_mut().successors_mut() { + if *s == succ { + *s = new_succ; + num_edges += 1; + } + } + + // Update predecessors with the new block. + let _new_succ = self.predecessors.push(num_edges); + debug_assert_eq!(new_succ, _new_succ); + self.predecessors[succ] -= num_edges; + self.update_predecessor_count(basic_blocks[new_succ].terminator(), Update::Incr); + + // Replace the `current -> succ` edge by `current -> new_succ` in all the following + // TOs. This is necessary to avoid trying to thread through a non-existing edge. We + // use `involving_tos` here to avoid traversing the full set of TOs on each iteration. + let mut new_involved = Vec::new(); + for &(to_index, in_to_index) in &self.involving_tos[current] { + // That TO has already been applied, do nothing. + if to_index <= index { + continue; + } + + let other_to = &mut self.opportunities[to_index]; + if other_to.chain.get(in_to_index) != Some(¤t) { + continue; + } + let s = other_to.chain.get_mut(in_to_index + 1).unwrap_or(&mut other_to.target); + if *s == succ { + // `other_to` references the `current -> succ` edge, so replace `succ`. + *s = new_succ; + new_involved.push((to_index, in_to_index + 1)); + } + } + + // The TOs that we just updated now reference `new_succ`. Update `involving_tos` + // in case we need to duplicate an edge starting at `new_succ` later. + let _new_succ = self.involving_tos.push(new_involved); + debug_assert_eq!(new_succ, _new_succ); + + current = new_succ; + } + + let current = &mut basic_blocks[current]; + self.update_predecessor_count(current.terminator(), Update::Decr); + current.terminator_mut().kind = TerminatorKind::Goto { target: op_target }; + self.predecessors[op_target] += 1; + } + + fn update_predecessor_count(&mut self, terminator: &Terminator<'_>, incr: Update) { + match incr { + Update::Incr => { + for s in terminator.successors() { + self.predecessors[s] += 1; + } + } + Update::Decr => { + for s in terminator.successors() { + self.predecessors[s] -= 1; + } + } + } + } +} + +fn predecessor_count(body: &Body<'_>) -> IndexVec<BasicBlock, usize> { + let mut predecessors: IndexVec<_, _> = + body.basic_blocks.predecessors().iter().map(|ps| ps.len()).collect(); + predecessors[START_BLOCK] += 1; // Account for the implicit entry edge. + predecessors +} + +enum Update { + Incr, + Decr, +} + +/// Compute the set of loop headers in the given body. We define a loop header as a block which has +/// at least a predecessor which it dominates. This definition is only correct for reducible CFGs. +/// But if the CFG is already irreducible, there is no point in trying much harder. +/// is already irreducible. +fn loop_headers(body: &Body<'_>) -> BitSet<BasicBlock> { + let mut loop_headers = BitSet::new_empty(body.basic_blocks.len()); + let dominators = body.basic_blocks.dominators(); + // Only visit reachable blocks. + for (bb, bbdata) in traversal::preorder(body) { + for succ in bbdata.terminator().successors() { + if dominators.dominates(succ, bb) { + loop_headers.insert(succ); + } + } + } + loop_headers +} diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index d579420ecb8..9aaa54110bd 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -61,6 +61,8 @@ mod const_goto; mod const_prop; mod const_prop_lint; mod copy_prop; +mod coroutine; +mod cost_checker; mod coverage; mod cross_crate_inline; mod ctfe_limit; @@ -77,10 +79,10 @@ mod elaborate_drops; mod errors; mod ffi_unwind_calls; mod function_item_references; -mod generator; mod gvn; pub mod inline; mod instsimplify; +mod jump_threading; mod large_enums; mod lower_intrinsics; mod lower_slice_len; @@ -132,7 +134,7 @@ pub fn provide(providers: &mut Providers) { mir_promoted, mir_drops_elaborated_and_const_checked, mir_for_ctfe, - mir_generator_witnesses: generator::mir_generator_witnesses, + mir_coroutine_witnesses: coroutine::mir_coroutine_witnesses, optimized_mir, is_mir_available, is_ctfe_mir_available: |tcx, did| is_mir_available(tcx, did), @@ -375,8 +377,8 @@ fn inner_mir_for_ctfe(tcx: TyCtxt<'_>, def: LocalDefId) -> Body<'_> { /// mir borrowck *before* doing so in order to ensure that borrowck can be run and doesn't /// end up missing the source MIR due to stealing happening. fn mir_drops_elaborated_and_const_checked(tcx: TyCtxt<'_>, def: LocalDefId) -> &Steal<Body<'_>> { - if let DefKind::Generator = tcx.def_kind(def) { - tcx.ensure_with_value().mir_generator_witnesses(def); + if let DefKind::Coroutine = tcx.def_kind(def) { + tcx.ensure_with_value().mir_coroutine_witnesses(def); } let mir_borrowck = tcx.mir_borrowck(def); @@ -509,7 +511,7 @@ fn run_runtime_lowering_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { // `AddRetag` needs to run after `ElaborateDrops`. Otherwise it should run fairly late, // but before optimizations begin. &elaborate_box_derefs::ElaborateBoxDerefs, - &generator::StateTransform, + &coroutine::StateTransform, &add_retag::AddRetag, &Lint(const_prop_lint::ConstPropLint), ]; @@ -571,6 +573,7 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { &dataflow_const_prop::DataflowConstProp, &const_debuginfo::ConstDebugInfo, &o1(simplify_branches::SimplifyConstCondition::AfterConstProp), + &jump_threading::JumpThreading, &early_otherwise_branch::EarlyOtherwiseBranch, &simplify_comparison_integral::SimplifyComparisonIntegral, &dead_store_elimination::DeadStoreElimination, 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 8c48a667786..54892442c87 100644 --- a/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs +++ b/compiler/rustc_mir_transform/src/remove_noop_landing_pads.rs @@ -69,7 +69,7 @@ impl RemoveNoopLandingPads { | TerminatorKind::FalseUnwind { .. } => { terminator.successors().all(|succ| nop_landing_pads.contains(succ)) } - TerminatorKind::GeneratorDrop + TerminatorKind::CoroutineDrop | TerminatorKind::Yield { .. } | TerminatorKind::Return | TerminatorKind::UnwindTerminate(_) diff --git a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs index 26384974798..87fee2410ec 100644 --- a/compiler/rustc_mir_transform/src/remove_uninit_drops.rs +++ b/compiler/rustc_mir_transform/src/remove_uninit_drops.rs @@ -24,11 +24,8 @@ pub struct RemoveUninitDrops; impl<'tcx> MirPass<'tcx> for RemoveUninitDrops { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let param_env = tcx.param_env(body.source.def_id()); - let Ok(move_data) = MoveData::gather_moves(body, tcx, param_env) else { - // We could continue if there are move errors, but there's not much point since our - // init data isn't complete. - return; - }; + let move_data = + MoveData::gather_moves(&body, tcx, param_env, |ty| ty.needs_drop(tcx, param_env)); let mdpe = MoveDataParamEnv { move_data, param_env }; let mut maybe_inits = MaybeInitializedPlaces::new(tcx, body, &mdpe) diff --git a/compiler/rustc_mir_transform/src/remove_zsts.rs b/compiler/rustc_mir_transform/src/remove_zsts.rs index b4784b69f7f..5aa3c3cfe4d 100644 --- a/compiler/rustc_mir_transform/src/remove_zsts.rs +++ b/compiler/rustc_mir_transform/src/remove_zsts.rs @@ -13,8 +13,8 @@ impl<'tcx> MirPass<'tcx> for RemoveZsts { } fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { - // Avoid query cycles (generators require optimized MIR for layout). - if tcx.type_of(body.source.def_id()).instantiate_identity().is_generator() { + // Avoid query cycles (coroutines require optimized MIR for layout). + if tcx.type_of(body.source.def_id()).instantiate_identity().is_coroutine() { return; } let param_env = tcx.param_env_reveal_all_normalized(body.source.def_id()); diff --git a/compiler/rustc_mir_transform/src/separate_const_switch.rs b/compiler/rustc_mir_transform/src/separate_const_switch.rs index e1e4acccccd..907cfe7581a 100644 --- a/compiler/rustc_mir_transform/src/separate_const_switch.rs +++ b/compiler/rustc_mir_transform/src/separate_const_switch.rs @@ -118,7 +118,7 @@ pub fn separate_const_switch(body: &mut Body<'_>) -> usize { | TerminatorKind::Return | TerminatorKind::Unreachable | TerminatorKind::InlineAsm { .. } - | TerminatorKind::GeneratorDrop => { + | TerminatorKind::CoroutineDrop => { continue 'predec_iter; } } @@ -169,7 +169,7 @@ pub fn separate_const_switch(body: &mut Body<'_>) -> usize { | TerminatorKind::UnwindTerminate(_) | TerminatorKind::Return | TerminatorKind::Unreachable - | TerminatorKind::GeneratorDrop + | TerminatorKind::CoroutineDrop | TerminatorKind::Assert { .. } | TerminatorKind::FalseUnwind { .. } | TerminatorKind::Drop { .. } diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs index e9895d97dfe..2400cfa21fb 100644 --- a/compiler/rustc_mir_transform/src/shim.rs +++ b/compiler/rustc_mir_transform/src/shim.rs @@ -4,7 +4,7 @@ use rustc_hir::lang_items::LangItem; use rustc_middle::mir::*; use rustc_middle::query::Providers; use rustc_middle::ty::GenericArgs; -use rustc_middle::ty::{self, EarlyBinder, GeneratorArgs, Ty, TyCtxt}; +use rustc_middle::ty::{self, CoroutineArgs, EarlyBinder, Ty, TyCtxt}; use rustc_target::abi::{FieldIdx, VariantIdx, FIRST_VARIANT}; use rustc_index::{Idx, IndexVec}; @@ -67,10 +67,10 @@ fn make_shim<'tcx>(tcx: TyCtxt<'tcx>, instance: ty::InstanceDef<'tcx>) -> Body<' } ty::InstanceDef::DropGlue(def_id, ty) => { - // FIXME(#91576): Drop shims for generators aren't subject to the MIR passes at the end + // FIXME(#91576): Drop shims for coroutines aren't subject to the MIR passes at the end // of this function. Is this intentional? - if let Some(ty::Generator(gen_def_id, args, _)) = ty.map(Ty::kind) { - let body = tcx.optimized_mir(*gen_def_id).generator_drop().unwrap(); + if let Some(ty::Coroutine(gen_def_id, args, _)) = ty.map(Ty::kind) { + let body = tcx.optimized_mir(*gen_def_id).coroutine_drop().unwrap(); let mut body = EarlyBinder::bind(body.clone()).instantiate(tcx, args); debug!("make_shim({:?}) = {:?}", instance, body); @@ -171,7 +171,7 @@ fn local_decls_for_sig<'tcx>( fn build_drop_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, ty: Option<Ty<'tcx>>) -> Body<'tcx> { debug!("build_drop_shim(def_id={:?}, ty={:?})", def_id, ty); - assert!(!matches!(ty, Some(ty) if ty.is_generator())); + assert!(!matches!(ty, Some(ty) if ty.is_coroutine())); let args = if let Some(ty) = ty { tcx.mk_args(&[ty.into()]) @@ -392,8 +392,8 @@ fn build_clone_shim<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, self_ty: Ty<'tcx>) - _ if is_copy => builder.copy_shim(), ty::Closure(_, args) => builder.tuple_like_shim(dest, src, args.as_closure().upvar_tys()), ty::Tuple(..) => builder.tuple_like_shim(dest, src, self_ty.tuple_fields()), - ty::Generator(gen_def_id, args, hir::Movability::Movable) => { - builder.generator_shim(dest, src, *gen_def_id, args.as_generator()) + ty::Coroutine(gen_def_id, args, hir::Movability::Movable) => { + builder.coroutine_shim(dest, src, *gen_def_id, args.as_coroutine()) } _ => bug!("clone shim for `{:?}` which is not `Copy` and is not an aggregate", self_ty), }; @@ -593,12 +593,12 @@ impl<'tcx> CloneShimBuilder<'tcx> { let _final_cleanup_block = self.clone_fields(dest, src, target, unwind, tys); } - fn generator_shim( + fn coroutine_shim( &mut self, dest: Place<'tcx>, src: Place<'tcx>, gen_def_id: DefId, - args: GeneratorArgs<'tcx>, + args: CoroutineArgs<'tcx>, ) { self.block(vec![], TerminatorKind::Goto { target: self.block_index_offset(3) }, false); let unwind = self.block(vec![], TerminatorKind::UnwindResume, true); diff --git a/compiler/rustc_mir_transform/src/sroa.rs b/compiler/rustc_mir_transform/src/sroa.rs index c21b1724cbb..427cc1e1924 100644 --- a/compiler/rustc_mir_transform/src/sroa.rs +++ b/compiler/rustc_mir_transform/src/sroa.rs @@ -20,8 +20,8 @@ impl<'tcx> MirPass<'tcx> for ScalarReplacementOfAggregates { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { debug!(def_id = ?body.source.def_id()); - // Avoid query cycles (generators require optimized MIR for layout). - if tcx.type_of(body.source.def_id()).instantiate_identity().is_generator() { + // Avoid query cycles (coroutines require optimized MIR for layout). + if tcx.type_of(body.source.def_id()).instantiate_identity().is_coroutine() { return; } |