diff options
| -rw-r--r-- | src/librustc_mir/borrow_check/nll/invalidation.rs | 88 | ||||
| -rw-r--r-- | src/librustc_mir/borrow_check/nll/mod.rs | 8 |
2 files changed, 60 insertions, 36 deletions
diff --git a/src/librustc_mir/borrow_check/nll/invalidation.rs b/src/librustc_mir/borrow_check/nll/invalidation.rs index dd3ad999fc6..5a677e142ce 100644 --- a/src/librustc_mir/borrow_check/nll/invalidation.rs +++ b/src/librustc_mir/borrow_check/nll/invalidation.rs @@ -17,10 +17,10 @@ use borrow_check::{Context, ContextKind}; use borrow_check::{LocalMutationIsAllowed, MutateMode}; use borrow_check::ArtificialField; use borrow_check::{ReadKind, WriteKind, Overlap}; -use borrow_check::nll::region_infer::RegionInferenceContext; use borrow_check::nll::facts::AllFacts; use dataflow::move_paths::indexes::BorrowIndex; use rustc::hir; +use rustc::hir::def_id::DefId; use rustc::infer::InferCtxt; use rustc::mir::visit::Visitor; use rustc::mir::{BasicBlock, Location, Mir, Place, Rvalue, Projection}; @@ -28,16 +28,16 @@ use rustc::mir::{Local, ProjectionElem}; use rustc::mir::{Statement, StatementKind}; use rustc::mir::{Terminator, TerminatorKind}; use rustc::mir::{Field, Operand, BorrowKind}; -use rustc::ty; +use rustc::ty::{self, ParamEnv}; use rustc_data_structures::indexed_vec::Idx; use std::iter; pub(super) fn generate_invalidates<'cx, 'gcx, 'tcx>( infcx: &InferCtxt<'cx, 'gcx, 'tcx>, - regioncx: &mut RegionInferenceContext<'tcx>, all_facts: &mut Option<AllFacts>, location_table: &LocationTable, mir: &Mir<'tcx>, + mir_def_id: DefId, borrow_set: &BorrowSet<'tcx>, ) { if !all_facts.is_some() { @@ -45,36 +45,42 @@ pub(super) fn generate_invalidates<'cx, 'gcx, 'tcx>( return; } - let mut ig = InvalidationGenerator { - all_facts: &mut all_facts.unwrap(), - borrow_set, - infcx, - regioncx, - location_table, - mir, - }; + let param_env = infcx.tcx.param_env(mir_def_id); + + let mut all_facts_taken = all_facts.take().unwrap(); + { + let mut ig = InvalidationGenerator { + all_facts: &mut all_facts_taken, + borrow_set, + infcx, + location_table, + mir, + param_env, + }; + ig.visit_mir(mir); + } + *all_facts = Some(all_facts_taken); } /// 'cg = the duration of the constraint generation process itself. -struct InvalidationGenerator<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> { +struct InvalidationGenerator<'cg, 'cx: 'cg, 'tcx: 'cx, 'gcx: 'tcx> { infcx: &'cg InferCtxt<'cx, 'gcx, 'tcx>, all_facts: &'cg mut AllFacts, location_table: &'cg LocationTable, - regioncx: &'cg mut RegionInferenceContext<'tcx>, mir: &'cg Mir<'tcx>, borrow_set: &'cg BorrowSet<'tcx>, + param_env: ParamEnv<'gcx>, } /// Visits the whole MIR and generates invalidates() facts /// Most of the code implementing this was stolen from borrow_check/mod.rs -impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> Visitor<'tcx> for InvalidationGenerator<'cg, 'cx, 'gcx, 'tcx> { +impl<'cg, 'cx, 'tcx, 'gcx> Visitor<'tcx> for InvalidationGenerator<'cg, 'cx, 'tcx, 'gcx> { fn visit_statement(&mut self, block: BasicBlock, statement: &Statement<'tcx>, location: Location) { match statement.kind { StatementKind::Assign(ref lhs, ref rhs) => { self.consume_rvalue( ContextKind::AssignRhs.new(location), rhs, - location ); self.mutate_place( @@ -170,6 +176,7 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> Visitor<'tcx> for InvalidationGenerat let gcx = tcx.global_tcx(); let drop_place_ty = drop_place.ty(self.mir, tcx); let drop_place_ty = tcx.erase_regions(&drop_place_ty).to_ty(tcx); + let drop_place_ty = gcx.lift(&drop_place_ty).unwrap(); self.visit_terminator_drop(location, terminator, drop_place, drop_place_ty); } TerminatorKind::DropAndReplace { @@ -275,7 +282,7 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> Visitor<'tcx> for InvalidationGenerat } } -impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, 'tcx> { +impl<'cg, 'cx, 'tcx, 'gcx> InvalidationGenerator<'cg, 'cx, 'tcx, 'gcx> { /// Simulates dropping of a variable fn visit_terminator_drop( &mut self, @@ -286,10 +293,10 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, ) { let gcx = self.infcx.tcx.global_tcx(); let drop_field = | - ig: &mut InvalidationGenerator<'cg, 'cx, 'gcx, 'tcx>, - (index, field): (usize, ty::Ty<'gcx>), + ig: &mut InvalidationGenerator<'cg, 'cx, 'gcx, 'tcx>, + (index, field): (usize, ty::Ty<'gcx>), | { - let field_ty = gcx.normalize_erasing_regions(self.mir.param_env, field); + let field_ty = gcx.normalize_erasing_regions(ig.param_env, field); let place = drop_place.clone().field(Field::new(index), field_ty); ig.visit_terminator_drop(loc, term, &place, field_ty); @@ -351,7 +358,7 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, context: Context, place: &Place<'tcx>, kind: ShallowOrDeep, - mode: MutateMode, + _mode: MutateMode, ) { self.access_place( context, @@ -393,7 +400,6 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, &mut self, context: Context, rvalue: &Rvalue<'tcx>, - location: Location, ) { match *rvalue { Rvalue::Ref(_ /*rgn*/, bk, ref place) => { @@ -447,7 +453,7 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, Rvalue::NullaryOp(_op, _ty) => { } - Rvalue::Aggregate(ref aggregate_kind, ref operands) => { + Rvalue::Aggregate(_, ref operands) => { for operand in operands { self.consume_operand(context, operand); } @@ -461,7 +467,7 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, context: Context, place: &Place<'tcx>, kind: (ShallowOrDeep, ReadOrWrite), - is_local_mutation_allowed: LocalMutationIsAllowed, + _is_local_mutation_allowed: LocalMutationIsAllowed, ) { let (sd, rw) = kind; // note: not doing check_access_permissions checks because they don't generate invalidates @@ -502,7 +508,7 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, // Reads/reservations don't invalidate shared borrows } - (Read(kind), BorrowKind::Unique) | (Read(kind), BorrowKind::Mut { .. }) => { + (Read(_), BorrowKind::Unique) | (Read(_), BorrowKind::Mut { .. }) => { // Reading from mere reservations of mutable-borrows is OK. if !this.is_active(borrow, context.loc) { // If the borrow isn't active yet, reads don't invalidate it @@ -512,20 +518,13 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, // Unique and mutable borrows are invalidated by reads from any // involved path - match kind { - ReadKind::Copy => { - this.generate_invalidates(borrow_index, context.loc); - } - ReadKind::Borrow(bk) => { - this.generate_invalidates(borrow_index, context.loc); - } - } + this.generate_invalidates(borrow_index, context.loc); } - (Reservation(kind), BorrowKind::Unique) - | (Reservation(kind), BorrowKind::Mut { .. }) - | (Activation(kind, _), _) - | (Write(kind), _) => { + (Reservation(_), BorrowKind::Unique) + | (Reservation(_), BorrowKind::Mut { .. }) + | (Activation(_, _), _) + | (Write(_), _) => { // unique or mutable borrows are invalidated by writes. // Reservations count as writes since we need to check // that activating the borrow will be OK @@ -588,6 +587,23 @@ impl<'cg, 'cx: 'cg, 'gcx: 'tcx, 'tcx: 'cx> InvalidationGenerator<'cg, 'cx, 'gcx, } } + /// Determine if a given two-phase borrow is active using dominator information + fn is_active(&self, borrow: &BorrowData, location: Location) -> bool { + // If it's not two-phase, the borrow is definitely active + if !self.allow_two_phase_borrow(borrow.kind) { + return true; + } + if borrow.activation_location.is_none() { + return false; + } + let activation_location = borrow.activation_location.unwrap(); + if activation_location.block == location.block { + activation_location.statement_index >= location.statement_index + } else { + self.mir.dominators().is_dominated_by(location.block, activation_location.block) + } + } + /// Returns whether an access of kind `access` to `access_place` conflicts with /// a borrow/full access to `borrow_place` (for deep accesses to mutable /// locations, this function is symmetric between `borrow_place` & `access_place`). diff --git a/src/librustc_mir/borrow_check/nll/mod.rs b/src/librustc_mir/borrow_check/nll/mod.rs index 12620ed3fc0..85dade1960e 100644 --- a/src/librustc_mir/borrow_check/nll/mod.rs +++ b/src/librustc_mir/borrow_check/nll/mod.rs @@ -131,6 +131,14 @@ pub(in borrow_check) fn compute_regions<'cx, 'gcx, 'tcx>( &mir, borrow_set, ); + invalidation::generate_invalidates( + infcx, + &mut all_facts, + location_table, + &mir, + def_id, + borrow_set + ); // Dump facts if requested. if let Some(all_facts) = all_facts { |