| use rustc_target::spec::abi::{Abi}; |
| use syntax::ast; |
| use syntax::symbol::sym; |
| use syntax_pos::Span; |
| |
| use rustc::ty::{self, TyCtxt}; |
| use rustc::hir::def_id::DefId; |
| use rustc::mir::{self, Body, Location}; |
| use rustc_data_structures::bit_set::BitSet; |
| use crate::transform::{MirPass, MirSource}; |
| |
| use crate::dataflow::{do_dataflow, DebugFormatted}; |
| use crate::dataflow::MoveDataParamEnv; |
| use crate::dataflow::BitDenotation; |
| use crate::dataflow::DataflowResults; |
| use crate::dataflow::{ |
| DefinitelyInitializedPlaces, MaybeInitializedPlaces, MaybeUninitializedPlaces |
| }; |
| use crate::dataflow::move_paths::{MovePathIndex, LookupResult}; |
| use crate::dataflow::move_paths::{HasMoveData, MoveData}; |
| |
| use crate::dataflow::has_rustc_mir_with; |
| |
| pub struct SanityCheck; |
| |
| impl MirPass for SanityCheck { |
| fn run_pass<'tcx>(&self, tcx: TyCtxt<'tcx>, src: MirSource<'tcx>, body: &mut Body<'tcx>) { |
| let def_id = src.def_id(); |
| if !tcx.has_attr(def_id, sym::rustc_mir) { |
| debug!("skipping rustc_peek::SanityCheck on {}", tcx.def_path_str(def_id)); |
| return; |
| } else { |
| debug!("running rustc_peek::SanityCheck on {}", tcx.def_path_str(def_id)); |
| } |
| |
| let attributes = tcx.get_attrs(def_id); |
| let param_env = tcx.param_env(def_id); |
| let move_data = MoveData::gather_moves(body, tcx).unwrap(); |
| let mdpe = MoveDataParamEnv { move_data: move_data, param_env: param_env }; |
| let dead_unwinds = BitSet::new_empty(body.basic_blocks().len()); |
| let flow_inits = |
| do_dataflow(tcx, body, def_id, &attributes, &dead_unwinds, |
| MaybeInitializedPlaces::new(tcx, body, &mdpe), |
| |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i])); |
| let flow_uninits = |
| do_dataflow(tcx, body, def_id, &attributes, &dead_unwinds, |
| MaybeUninitializedPlaces::new(tcx, body, &mdpe), |
| |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i])); |
| let flow_def_inits = |
| do_dataflow(tcx, body, def_id, &attributes, &dead_unwinds, |
| DefinitelyInitializedPlaces::new(tcx, body, &mdpe), |
| |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i])); |
| |
| if has_rustc_mir_with(&attributes, sym::rustc_peek_maybe_init).is_some() { |
| sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_inits); |
| } |
| if has_rustc_mir_with(&attributes, sym::rustc_peek_maybe_uninit).is_some() { |
| sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_uninits); |
| } |
| if has_rustc_mir_with(&attributes, sym::rustc_peek_definite_init).is_some() { |
| sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_def_inits); |
| } |
| if has_rustc_mir_with(&attributes, sym::stop_after_dataflow).is_some() { |
| tcx.sess.fatal("stop_after_dataflow ended compilation"); |
| } |
| } |
| } |
| |
| /// This function scans `mir` for all calls to the intrinsic |
| /// `rustc_peek` that have the expression form `rustc_peek(&expr)`. |
| /// |
| /// For each such call, determines what the dataflow bit-state is for |
| /// the L-value corresponding to `expr`; if the bit-state is a 1, then |
| /// that call to `rustc_peek` is ignored by the sanity check. If the |
| /// bit-state is a 0, then this pass emits a error message saying |
| /// "rustc_peek: bit not set". |
| /// |
| /// The intention is that one can write unit tests for dataflow by |
| /// putting code into a compile-fail test and using `rustc_peek` to |
| /// make observations about the results of dataflow static analyses. |
| /// |
| /// (If there are any calls to `rustc_peek` that do not match the |
| /// expression form above, then that emits an error as well, but those |
| /// errors are not intended to be used for unit tests.) |
| pub fn sanity_check_via_rustc_peek<'tcx, O>( |
| tcx: TyCtxt<'tcx>, |
| body: &Body<'tcx>, |
| def_id: DefId, |
| _attributes: &[ast::Attribute], |
| results: &DataflowResults<'tcx, O>, |
| ) where |
| O: BitDenotation<'tcx, Idx = MovePathIndex> + HasMoveData<'tcx>, |
| { |
| debug!("sanity_check_via_rustc_peek def_id: {:?}", def_id); |
| // FIXME: this is not DRY. Figure out way to abstract this and |
| // `dataflow::build_sets`. (But note it is doing non-standard |
| // stuff, so such generalization may not be realistic.) |
| |
| for bb in body.basic_blocks().indices() { |
| each_block(tcx, body, results, bb); |
| } |
| } |
| |
| fn each_block<'tcx, O>( |
| tcx: TyCtxt<'tcx>, |
| body: &Body<'tcx>, |
| results: &DataflowResults<'tcx, O>, |
| bb: mir::BasicBlock, |
| ) where |
| O: BitDenotation<'tcx, Idx = MovePathIndex> + HasMoveData<'tcx>, |
| { |
| let move_data = results.0.operator.move_data(); |
| let mir::BasicBlockData { ref statements, ref terminator, is_cleanup: _ } = body[bb]; |
| |
| let (args, span) = match is_rustc_peek(tcx, terminator) { |
| Some(args_and_span) => args_and_span, |
| None => return, |
| }; |
| assert!(args.len() == 1); |
| let peek_arg_place = match args[0] { |
| mir::Operand::Copy(ref place @ mir::Place::Base(mir::PlaceBase::Local(_))) | |
| mir::Operand::Move(ref place @ mir::Place::Base(mir::PlaceBase::Local(_))) => Some(place), |
| _ => None, |
| }; |
| |
| let peek_arg_place = match peek_arg_place { |
| Some(arg) => arg, |
| None => { |
| tcx.sess.diagnostic().span_err( |
| span, "dataflow::sanity_check cannot feed a non-temp to rustc_peek."); |
| return; |
| } |
| }; |
| |
| let mut on_entry = results.0.sets.entry_set_for(bb.index()).to_owned(); |
| let mut trans = results.0.sets.trans_for(bb.index()).clone(); |
| |
| // Emulate effect of all statements in the block up to (but not |
| // including) the borrow within `peek_arg_place`. Do *not* include |
| // call to `peek_arg_place` itself (since we are peeking the state |
| // of the argument at time immediate preceding Call to |
| // `rustc_peek`). |
| |
| for (j, stmt) in statements.iter().enumerate() { |
| debug!("rustc_peek: ({:?},{}) {:?}", bb, j, stmt); |
| let (place, rvalue) = match stmt.kind { |
| mir::StatementKind::Assign(ref place, ref rvalue) => { |
| (place, rvalue) |
| } |
| mir::StatementKind::FakeRead(..) | |
| mir::StatementKind::StorageLive(_) | |
| mir::StatementKind::StorageDead(_) | |
| mir::StatementKind::InlineAsm { .. } | |
| mir::StatementKind::Retag { .. } | |
| mir::StatementKind::AscribeUserType(..) | |
| mir::StatementKind::Nop => continue, |
| mir::StatementKind::SetDiscriminant{ .. } => |
| span_bug!(stmt.source_info.span, |
| "sanity_check should run before Deaggregator inserts SetDiscriminant"), |
| }; |
| |
| if place == peek_arg_place { |
| if let mir::Rvalue::Ref(_, mir::BorrowKind::Shared, ref peeking_at_place) = **rvalue { |
| // Okay, our search is over. |
| match move_data.rev_lookup.find(peeking_at_place) { |
| LookupResult::Exact(peek_mpi) => { |
| let bit_state = on_entry.contains(peek_mpi); |
| debug!("rustc_peek({:?} = &{:?}) bit_state: {}", |
| place, peeking_at_place, bit_state); |
| if !bit_state { |
| tcx.sess.span_err(span, "rustc_peek: bit not set"); |
| } |
| } |
| LookupResult::Parent(..) => { |
| tcx.sess.span_err(span, "rustc_peek: argument untracked"); |
| } |
| } |
| return; |
| } else { |
| // Our search should have been over, but the input |
| // does not match expectations of `rustc_peek` for |
| // this sanity_check. |
| let msg = "rustc_peek: argument expression \ |
| must be immediate borrow of form `&expr`"; |
| tcx.sess.span_err(span, msg); |
| } |
| } |
| |
| let lhs_mpi = move_data.rev_lookup.find(place); |
| |
| debug!("rustc_peek: computing effect on place: {:?} ({:?}) in stmt: {:?}", |
| place, lhs_mpi, stmt); |
| // reset GEN and KILL sets before emulating their effect. |
| trans.clear(); |
| results.0.operator.before_statement_effect( |
| &mut trans, |
| Location { block: bb, statement_index: j }); |
| results.0.operator.statement_effect( |
| &mut trans, |
| Location { block: bb, statement_index: j }); |
| trans.apply(&mut on_entry); |
| } |
| |
| results.0.operator.before_terminator_effect( |
| &mut trans, |
| Location { block: bb, statement_index: statements.len() }); |
| |
| tcx.sess.span_err(span, &format!("rustc_peek: MIR did not match \ |
| anticipated pattern; note that \ |
| rustc_peek expects input of \ |
| form `&expr`")); |
| } |
| |
| fn is_rustc_peek<'a, 'tcx>( |
| tcx: TyCtxt<'tcx>, |
| terminator: &'a Option<mir::Terminator<'tcx>>, |
| ) -> Option<(&'a [mir::Operand<'tcx>], Span)> { |
| if let Some(mir::Terminator { ref kind, source_info, .. }) = *terminator { |
| if let mir::TerminatorKind::Call { func: ref oper, ref args, .. } = *kind { |
| if let mir::Operand::Constant(ref func) = *oper { |
| if let ty::FnDef(def_id, _) = func.ty.sty { |
| let abi = tcx.fn_sig(def_id).abi(); |
| let name = tcx.item_name(def_id); |
| if abi == Abi::RustIntrinsic && name == sym::rustc_peek { |
| return Some((args, source_info.span)); |
| } |
| } |
| } |
| } |
| } |
| return None; |
| } |