1 use rustc_target::spec::abi::{Abi};
3 use syntax::symbol::sym;
6 use rustc::ty::{self, TyCtxt};
7 use rustc::hir::def_id::DefId;
8 use rustc::mir::{self, Body, Location};
9 use rustc_data_structures::bit_set::BitSet;
10 use crate::transform::{MirPass, MirSource};
12 use crate::dataflow::{do_dataflow, DebugFormatted};
13 use crate::dataflow::MoveDataParamEnv;
14 use crate::dataflow::BitDenotation;
15 use crate::dataflow::DataflowResults;
16 use crate::dataflow::{
17 DefinitelyInitializedPlaces, MaybeInitializedPlaces, MaybeUninitializedPlaces
19 use crate::dataflow::move_paths::{MovePathIndex, LookupResult};
20 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<'tcx>(&self, tcx: TyCtxt<'tcx>, src: MirSource<'tcx>, body: &mut Body<'tcx>) {
28 let def_id = src.def_id();
29 if !tcx.has_attr(def_id, sym::rustc_mir) {
30 debug!("skipping rustc_peek::SanityCheck on {}", tcx.def_path_str(def_id));
33 debug!("running rustc_peek::SanityCheck on {}", tcx.def_path_str(def_id));
36 let attributes = tcx.get_attrs(def_id);
37 let param_env = tcx.param_env(def_id);
38 let move_data = MoveData::gather_moves(body, tcx).unwrap();
39 let mdpe = MoveDataParamEnv { move_data: move_data, param_env: param_env };
40 let dead_unwinds = BitSet::new_empty(body.basic_blocks().len());
42 do_dataflow(tcx, body, def_id, &attributes, &dead_unwinds,
43 MaybeInitializedPlaces::new(tcx, body, &mdpe),
44 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
46 do_dataflow(tcx, body, def_id, &attributes, &dead_unwinds,
47 MaybeUninitializedPlaces::new(tcx, body, &mdpe),
48 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
50 do_dataflow(tcx, body, def_id, &attributes, &dead_unwinds,
51 DefinitelyInitializedPlaces::new(tcx, body, &mdpe),
52 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
54 if has_rustc_mir_with(&attributes, sym::rustc_peek_maybe_init).is_some() {
55 sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_inits);
57 if has_rustc_mir_with(&attributes, sym::rustc_peek_maybe_uninit).is_some() {
58 sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_uninits);
60 if has_rustc_mir_with(&attributes, sym::rustc_peek_definite_init).is_some() {
61 sanity_check_via_rustc_peek(tcx, body, def_id, &attributes, &flow_def_inits);
63 if has_rustc_mir_with(&attributes, sym::stop_after_dataflow).is_some() {
64 tcx.sess.fatal("stop_after_dataflow ended compilation");
69 /// This function scans `mir` for all calls to the intrinsic
70 /// `rustc_peek` that have the expression form `rustc_peek(&expr)`.
72 /// For each such call, determines what the dataflow bit-state is for
73 /// the L-value corresponding to `expr`; if the bit-state is a 1, then
74 /// that call to `rustc_peek` is ignored by the sanity check. If the
75 /// bit-state is a 0, then this pass emits a error message saying
76 /// "rustc_peek: bit not set".
78 /// The intention is that one can write unit tests for dataflow by
79 /// putting code into a compile-fail test and using `rustc_peek` to
80 /// make observations about the results of dataflow static analyses.
82 /// (If there are any calls to `rustc_peek` that do not match the
83 /// expression form above, then that emits an error as well, but those
84 /// errors are not intended to be used for unit tests.)
85 pub fn sanity_check_via_rustc_peek<'tcx, O>(
89 _attributes: &[ast::Attribute],
90 results: &DataflowResults<'tcx, O>,
92 O: BitDenotation<'tcx, Idx = MovePathIndex> + HasMoveData<'tcx>,
94 debug!("sanity_check_via_rustc_peek def_id: {:?}", def_id);
95 // FIXME: this is not DRY. Figure out way to abstract this and
96 // `dataflow::build_sets`. (But note it is doing non-standard
97 // stuff, so such generalization may not be realistic.)
99 for bb in body.basic_blocks().indices() {
100 each_block(tcx, body, results, bb);
104 fn each_block<'tcx, O>(
107 results: &DataflowResults<'tcx, O>,
110 O: BitDenotation<'tcx, Idx = MovePathIndex> + HasMoveData<'tcx>,
112 let move_data = results.0.operator.move_data();
113 let mir::BasicBlockData { ref statements, ref terminator, is_cleanup: _ } = body[bb];
115 let (args, span) = match is_rustc_peek(tcx, terminator) {
116 Some(args_and_span) => args_and_span,
119 assert!(args.len() == 1);
120 let peek_arg_place = match args[0] {
121 mir::Operand::Copy(ref place @ mir::Place {
122 base: mir::PlaceBase::Local(_),
125 mir::Operand::Move(ref place @ mir::Place {
126 base: mir::PlaceBase::Local(_),
132 let peek_arg_place = match peek_arg_place {
135 tcx.sess.diagnostic().span_err(
136 span, "dataflow::sanity_check cannot feed a non-temp to rustc_peek.");
141 let mut on_entry = results.0.sets.entry_set_for(bb.index()).to_owned();
142 let mut trans = results.0.sets.trans_for(bb.index()).clone();
144 // Emulate effect of all statements in the block up to (but not
145 // including) the borrow within `peek_arg_place`. Do *not* include
146 // call to `peek_arg_place` itself (since we are peeking the state
147 // of the argument at time immediate preceding Call to
150 for (j, stmt) in statements.iter().enumerate() {
151 debug!("rustc_peek: ({:?},{}) {:?}", bb, j, stmt);
152 let (place, rvalue) = match stmt.kind {
153 mir::StatementKind::Assign(ref place, ref rvalue) => {
156 mir::StatementKind::FakeRead(..) |
157 mir::StatementKind::StorageLive(_) |
158 mir::StatementKind::StorageDead(_) |
159 mir::StatementKind::InlineAsm { .. } |
160 mir::StatementKind::Retag { .. } |
161 mir::StatementKind::AscribeUserType(..) |
162 mir::StatementKind::Nop => continue,
163 mir::StatementKind::SetDiscriminant{ .. } =>
164 span_bug!(stmt.source_info.span,
165 "sanity_check should run before Deaggregator inserts SetDiscriminant"),
168 if place == peek_arg_place {
169 if let mir::Rvalue::Ref(_, mir::BorrowKind::Shared, ref peeking_at_place) = **rvalue {
170 // Okay, our search is over.
171 match move_data.rev_lookup.find(peeking_at_place.as_place_ref()) {
172 LookupResult::Exact(peek_mpi) => {
173 let bit_state = on_entry.contains(peek_mpi);
174 debug!("rustc_peek({:?} = &{:?}) bit_state: {}",
175 place, peeking_at_place, bit_state);
177 tcx.sess.span_err(span, "rustc_peek: bit not set");
180 LookupResult::Parent(..) => {
181 tcx.sess.span_err(span, "rustc_peek: argument untracked");
186 // Our search should have been over, but the input
187 // does not match expectations of `rustc_peek` for
188 // this sanity_check.
189 let msg = "rustc_peek: argument expression \
190 must be immediate borrow of form `&expr`";
191 tcx.sess.span_err(span, msg);
195 let lhs_mpi = move_data.rev_lookup.find(place.as_place_ref());
197 debug!("rustc_peek: computing effect on place: {:?} ({:?}) in stmt: {:?}",
198 place, lhs_mpi, stmt);
199 // reset GEN and KILL sets before emulating their effect.
201 results.0.operator.before_statement_effect(
203 Location { block: bb, statement_index: j });
204 results.0.operator.statement_effect(
206 Location { block: bb, statement_index: j });
207 trans.apply(&mut on_entry);
210 results.0.operator.before_terminator_effect(
212 Location { block: bb, statement_index: statements.len() });
214 tcx.sess.span_err(span, &format!("rustc_peek: MIR did not match \
215 anticipated pattern; note that \
216 rustc_peek expects input of \
220 fn is_rustc_peek<'a, 'tcx>(
222 terminator: &'a Option<mir::Terminator<'tcx>>,
223 ) -> Option<(&'a [mir::Operand<'tcx>], Span)> {
224 if let Some(mir::Terminator { ref kind, source_info, .. }) = *terminator {
225 if let mir::TerminatorKind::Call { func: ref oper, ref args, .. } = *kind {
226 if let mir::Operand::Constant(ref func) = *oper {
227 if let ty::FnDef(def_id, _) = func.ty.sty {
228 let abi = tcx.fn_sig(def_id).abi();
229 let name = tcx.item_name(def_id);
230 if abi == Abi::RustIntrinsic && name == sym::rustc_peek {
231 return Some((args, source_info.span));