1 use rustc_target::spec::abi::{Abi};
5 use rustc::ty::{self, TyCtxt};
6 use rustc::hir::def_id::DefId;
7 use rustc::mir::{self, Mir, Location};
8 use rustc_data_structures::bit_set::BitSet;
9 use crate::transform::{MirPass, MirSource};
11 use crate::dataflow::{do_dataflow, DebugFormatted};
12 use crate::dataflow::MoveDataParamEnv;
13 use crate::dataflow::BitDenotation;
14 use crate::dataflow::DataflowResults;
15 use crate::dataflow::{
16 DefinitelyInitializedPlaces, MaybeInitializedPlaces, MaybeUninitializedPlaces
18 use crate::dataflow::move_paths::{MovePathIndex, LookupResult};
19 use crate::dataflow::move_paths::{HasMoveData, MoveData};
22 use crate::dataflow::has_rustc_mir_with;
24 pub struct SanityCheck;
26 impl MirPass for SanityCheck {
27 fn run_pass<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
28 src: MirSource<'tcx>, mir: &mut Mir<'tcx>) {
29 let def_id = src.def_id();
30 if !tcx.has_attr(def_id, "rustc_mir") {
31 debug!("skipping rustc_peek::SanityCheck on {}", tcx.def_path_str(def_id));
34 debug!("running rustc_peek::SanityCheck on {}", tcx.def_path_str(def_id));
37 let attributes = tcx.get_attrs(def_id);
38 let param_env = tcx.param_env(def_id);
39 let move_data = MoveData::gather_moves(mir, tcx).unwrap();
40 let mdpe = MoveDataParamEnv { move_data: move_data, param_env: param_env };
41 let dead_unwinds = BitSet::new_empty(mir.basic_blocks().len());
43 do_dataflow(tcx, mir, def_id, &attributes, &dead_unwinds,
44 MaybeInitializedPlaces::new(tcx, mir, &mdpe),
45 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
47 do_dataflow(tcx, mir, def_id, &attributes, &dead_unwinds,
48 MaybeUninitializedPlaces::new(tcx, mir, &mdpe),
49 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
51 do_dataflow(tcx, mir, def_id, &attributes, &dead_unwinds,
52 DefinitelyInitializedPlaces::new(tcx, mir, &mdpe),
53 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
55 if has_rustc_mir_with(&attributes, "rustc_peek_maybe_init").is_some() {
56 sanity_check_via_rustc_peek(tcx, mir, def_id, &attributes, &flow_inits);
58 if has_rustc_mir_with(&attributes, "rustc_peek_maybe_uninit").is_some() {
59 sanity_check_via_rustc_peek(tcx, mir, def_id, &attributes, &flow_uninits);
61 if has_rustc_mir_with(&attributes, "rustc_peek_definite_init").is_some() {
62 sanity_check_via_rustc_peek(tcx, mir, def_id, &attributes, &flow_def_inits);
64 if has_rustc_mir_with(&attributes, "stop_after_dataflow").is_some() {
65 tcx.sess.fatal("stop_after_dataflow ended compilation");
70 /// This function scans `mir` for all calls to the intrinsic
71 /// `rustc_peek` that have the expression form `rustc_peek(&expr)`.
73 /// For each such call, determines what the dataflow bit-state is for
74 /// the L-value corresponding to `expr`; if the bit-state is a 1, then
75 /// that call to `rustc_peek` is ignored by the sanity check. If the
76 /// bit-state is a 0, then this pass emits a error message saying
77 /// "rustc_peek: bit not set".
79 /// The intention is that one can write unit tests for dataflow by
80 /// putting code into a compile-fail test and using `rustc_peek` to
81 /// make observations about the results of dataflow static analyses.
83 /// (If there are any calls to `rustc_peek` that do not match the
84 /// expression form above, then that emits an error as well, but those
85 /// errors are not intended to be used for unit tests.)
86 pub fn sanity_check_via_rustc_peek<'a, 'tcx, O>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
89 _attributes: &[ast::Attribute],
90 results: &DataflowResults<'tcx, O>)
91 where O: BitDenotation<'tcx, Idx=MovePathIndex> + HasMoveData<'tcx>
93 debug!("sanity_check_via_rustc_peek def_id: {:?}", def_id);
94 // FIXME: this is not DRY. Figure out way to abstract this and
95 // `dataflow::build_sets`. (But note it is doing non-standard
96 // stuff, so such generalization may not be realistic.)
98 for bb in mir.basic_blocks().indices() {
99 each_block(tcx, mir, results, bb);
103 fn each_block<'a, 'tcx, O>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
105 results: &DataflowResults<'tcx, O>,
106 bb: mir::BasicBlock) where
107 O: BitDenotation<'tcx, Idx=MovePathIndex> + HasMoveData<'tcx>
109 let move_data = results.0.operator.move_data();
110 let mir::BasicBlockData { ref statements, ref terminator, is_cleanup: _ } = mir[bb];
112 let (args, span) = match is_rustc_peek(tcx, terminator) {
113 Some(args_and_span) => args_and_span,
116 assert!(args.len() == 1);
117 let peek_arg_place = match args[0] {
118 mir::Operand::Copy(ref place @ mir::Place::Base(mir::PlaceBase::Local(_))) |
119 mir::Operand::Move(ref place @ mir::Place::Base(mir::PlaceBase::Local(_))) => Some(place),
123 let peek_arg_place = match peek_arg_place {
126 tcx.sess.diagnostic().span_err(
127 span, "dataflow::sanity_check cannot feed a non-temp to rustc_peek.");
132 let mut on_entry = results.0.sets.on_entry_set_for(bb.index()).to_owned();
133 let mut gen_set = results.0.sets.gen_set_for(bb.index()).clone();
134 let mut kill_set = results.0.sets.kill_set_for(bb.index()).clone();
136 // Emulate effect of all statements in the block up to (but not
137 // including) the borrow within `peek_arg_place`. Do *not* include
138 // call to `peek_arg_place` itself (since we are peeking the state
139 // of the argument at time immediate preceding Call to
142 let mut sets = dataflow::BlockSets { on_entry: &mut on_entry,
143 gen_set: &mut gen_set,
144 kill_set: &mut kill_set };
146 for (j, stmt) in statements.iter().enumerate() {
147 debug!("rustc_peek: ({:?},{}) {:?}", bb, j, stmt);
148 let (place, rvalue) = match stmt.kind {
149 mir::StatementKind::Assign(ref place, ref rvalue) => {
152 mir::StatementKind::FakeRead(..) |
153 mir::StatementKind::StorageLive(_) |
154 mir::StatementKind::StorageDead(_) |
155 mir::StatementKind::InlineAsm { .. } |
156 mir::StatementKind::Retag { .. } |
157 mir::StatementKind::AscribeUserType(..) |
158 mir::StatementKind::Nop => continue,
159 mir::StatementKind::SetDiscriminant{ .. } =>
160 span_bug!(stmt.source_info.span,
161 "sanity_check should run before Deaggregator inserts SetDiscriminant"),
164 if place == peek_arg_place {
165 if let mir::Rvalue::Ref(_, mir::BorrowKind::Shared, ref peeking_at_place) = **rvalue {
166 // Okay, our search is over.
167 match move_data.rev_lookup.find(peeking_at_place) {
168 LookupResult::Exact(peek_mpi) => {
169 let bit_state = sets.on_entry.contains(peek_mpi);
170 debug!("rustc_peek({:?} = &{:?}) bit_state: {}",
171 place, peeking_at_place, bit_state);
173 tcx.sess.span_err(span, "rustc_peek: bit not set");
176 LookupResult::Parent(..) => {
177 tcx.sess.span_err(span, "rustc_peek: argument untracked");
182 // Our search should have been over, but the input
183 // does not match expectations of `rustc_peek` for
184 // this sanity_check.
185 let msg = "rustc_peek: argument expression \
186 must be immediate borrow of form `&expr`";
187 tcx.sess.span_err(span, msg);
191 let lhs_mpi = move_data.rev_lookup.find(place);
193 debug!("rustc_peek: computing effect on place: {:?} ({:?}) in stmt: {:?}",
194 place, lhs_mpi, stmt);
195 // reset GEN and KILL sets before emulating their effect.
196 sets.gen_set.clear();
197 sets.kill_set.clear();
198 results.0.operator.before_statement_effect(
199 &mut sets, Location { block: bb, statement_index: j });
200 results.0.operator.statement_effect(
201 &mut sets, Location { block: bb, statement_index: j });
202 sets.on_entry.union(sets.gen_set);
203 sets.on_entry.subtract(sets.kill_set);
206 results.0.operator.before_terminator_effect(
208 Location { block: bb, statement_index: statements.len() });
210 tcx.sess.span_err(span, &format!("rustc_peek: MIR did not match \
211 anticipated pattern; note that \
212 rustc_peek expects input of \
216 fn is_rustc_peek<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
217 terminator: &'a Option<mir::Terminator<'tcx>>)
218 -> Option<(&'a [mir::Operand<'tcx>], Span)> {
219 if let Some(mir::Terminator { ref kind, source_info, .. }) = *terminator {
220 if let mir::TerminatorKind::Call { func: ref oper, ref args, .. } = *kind {
221 if let mir::Operand::Constant(ref func) = *oper {
222 if let ty::FnDef(def_id, _) = func.ty.sty {
223 let abi = tcx.fn_sig(def_id).abi();
224 let name = tcx.item_name(def_id);
225 if abi == Abi::RustIntrinsic && name == "rustc_peek" {
226 return Some((args, source_info.span));