1 // Copyright 2012-2016 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 use rustc_target::spec::abi::{Abi};
15 use rustc::ty::{self, TyCtxt};
16 use rustc::mir::{self, Mir, Location};
17 use rustc_data_structures::bit_set::BitSet;
18 use transform::{MirPass, MirSource};
20 use dataflow::{do_dataflow, DebugFormatted};
21 use dataflow::MoveDataParamEnv;
22 use dataflow::BitDenotation;
23 use dataflow::DataflowResults;
24 use dataflow::{DefinitelyInitializedPlaces, MaybeInitializedPlaces, MaybeUninitializedPlaces};
25 use dataflow::move_paths::{MovePathIndex, LookupResult};
26 use dataflow::move_paths::{HasMoveData, MoveData};
29 use dataflow::has_rustc_mir_with;
31 pub struct SanityCheck;
33 impl MirPass for SanityCheck {
34 fn run_pass<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>,
35 src: MirSource, mir: &mut Mir<'tcx>) {
36 let def_id = src.def_id;
37 let id = tcx.hir.as_local_node_id(def_id).unwrap();
38 if !tcx.has_attr(def_id, "rustc_mir") {
39 debug!("skipping rustc_peek::SanityCheck on {}", tcx.item_path_str(def_id));
42 debug!("running rustc_peek::SanityCheck on {}", tcx.item_path_str(def_id));
45 let attributes = tcx.get_attrs(def_id);
46 let param_env = tcx.param_env(def_id);
47 let move_data = MoveData::gather_moves(mir, tcx).unwrap();
48 let mdpe = MoveDataParamEnv { move_data: move_data, param_env: param_env };
49 let dead_unwinds = BitSet::new_empty(mir.basic_blocks().len());
51 do_dataflow(tcx, mir, id, &attributes, &dead_unwinds,
52 MaybeInitializedPlaces::new(tcx, mir, &mdpe),
53 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
55 do_dataflow(tcx, mir, id, &attributes, &dead_unwinds,
56 MaybeUninitializedPlaces::new(tcx, mir, &mdpe),
57 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
59 do_dataflow(tcx, mir, id, &attributes, &dead_unwinds,
60 DefinitelyInitializedPlaces::new(tcx, mir, &mdpe),
61 |bd, i| DebugFormatted::new(&bd.move_data().move_paths[i]));
63 if has_rustc_mir_with(&attributes, "rustc_peek_maybe_init").is_some() {
64 sanity_check_via_rustc_peek(tcx, mir, id, &attributes, &flow_inits);
66 if has_rustc_mir_with(&attributes, "rustc_peek_maybe_uninit").is_some() {
67 sanity_check_via_rustc_peek(tcx, mir, id, &attributes, &flow_uninits);
69 if has_rustc_mir_with(&attributes, "rustc_peek_definite_init").is_some() {
70 sanity_check_via_rustc_peek(tcx, mir, id, &attributes, &flow_def_inits);
72 if has_rustc_mir_with(&attributes, "stop_after_dataflow").is_some() {
73 tcx.sess.fatal("stop_after_dataflow ended compilation");
78 /// This function scans `mir` for all calls to the intrinsic
79 /// `rustc_peek` that have the expression form `rustc_peek(&expr)`.
81 /// For each such call, determines what the dataflow bit-state is for
82 /// the L-value corresponding to `expr`; if the bit-state is a 1, then
83 /// that call to `rustc_peek` is ignored by the sanity check. If the
84 /// bit-state is a 0, then this pass emits a error message saying
85 /// "rustc_peek: bit not set".
87 /// The intention is that one can write unit tests for dataflow by
88 /// putting code into a compile-fail test and using `rustc_peek` to
89 /// make observations about the results of dataflow static analyses.
91 /// (If there are any calls to `rustc_peek` that do not match the
92 /// expression form above, then that emits an error as well, but those
93 /// errors are not intended to be used for unit tests.)
94 pub fn sanity_check_via_rustc_peek<'a, 'tcx, O>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
97 _attributes: &[ast::Attribute],
98 results: &DataflowResults<O>)
99 where O: BitDenotation<Idx=MovePathIndex> + HasMoveData<'tcx>
101 debug!("sanity_check_via_rustc_peek id: {:?}", id);
102 // FIXME: this is not DRY. Figure out way to abstract this and
103 // `dataflow::build_sets`. (But note it is doing non-standard
104 // stuff, so such generalization may not be realistic.)
106 for bb in mir.basic_blocks().indices() {
107 each_block(tcx, mir, results, bb);
111 fn each_block<'a, 'tcx, O>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
113 results: &DataflowResults<O>,
114 bb: mir::BasicBlock) where
115 O: BitDenotation<Idx=MovePathIndex> + HasMoveData<'tcx>
117 let move_data = results.0.operator.move_data();
118 let mir::BasicBlockData { ref statements, ref terminator, is_cleanup: _ } = mir[bb];
120 let (args, span) = match is_rustc_peek(tcx, terminator) {
121 Some(args_and_span) => args_and_span,
124 assert!(args.len() == 1);
125 let peek_arg_place = match args[0] {
126 mir::Operand::Copy(ref place @ mir::Place::Local(_)) |
127 mir::Operand::Move(ref place @ mir::Place::Local(_)) => Some(place),
131 let peek_arg_place = match peek_arg_place {
134 tcx.sess.diagnostic().span_err(
135 span, "dataflow::sanity_check cannot feed a non-temp to rustc_peek.");
140 let mut on_entry = results.0.sets.on_entry_set_for(bb.index()).to_owned();
141 let mut gen_set = results.0.sets.gen_set_for(bb.index()).clone();
142 let mut kill_set = results.0.sets.kill_set_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 let mut sets = dataflow::BlockSets { on_entry: &mut on_entry,
151 gen_set: &mut gen_set,
152 kill_set: &mut kill_set };
154 for (j, stmt) in statements.iter().enumerate() {
155 debug!("rustc_peek: ({:?},{}) {:?}", bb, j, stmt);
156 let (place, rvalue) = match stmt.kind {
157 mir::StatementKind::Assign(ref place, ref rvalue) => {
160 mir::StatementKind::FakeRead(..) |
161 mir::StatementKind::StorageLive(_) |
162 mir::StatementKind::StorageDead(_) |
163 mir::StatementKind::InlineAsm { .. } |
164 mir::StatementKind::EndRegion(_) |
165 mir::StatementKind::Validate(..) |
166 mir::StatementKind::AscribeUserType(..) |
167 mir::StatementKind::Nop => continue,
168 mir::StatementKind::SetDiscriminant{ .. } =>
169 span_bug!(stmt.source_info.span,
170 "sanity_check should run before Deaggregator inserts SetDiscriminant"),
173 if place == peek_arg_place {
174 if let mir::Rvalue::Ref(_, mir::BorrowKind::Shared, ref peeking_at_place) = **rvalue {
175 // Okay, our search is over.
176 match move_data.rev_lookup.find(peeking_at_place) {
177 LookupResult::Exact(peek_mpi) => {
178 let bit_state = sets.on_entry.contains(peek_mpi);
179 debug!("rustc_peek({:?} = &{:?}) bit_state: {}",
180 place, peeking_at_place, bit_state);
182 tcx.sess.span_err(span, "rustc_peek: bit not set");
185 LookupResult::Parent(..) => {
186 tcx.sess.span_err(span, "rustc_peek: argument untracked");
191 // Our search should have been over, but the input
192 // does not match expectations of `rustc_peek` for
193 // this sanity_check.
194 let msg = "rustc_peek: argument expression \
195 must be immediate borrow of form `&expr`";
196 tcx.sess.span_err(span, msg);
200 let lhs_mpi = move_data.rev_lookup.find(place);
202 debug!("rustc_peek: computing effect on place: {:?} ({:?}) in stmt: {:?}",
203 place, lhs_mpi, stmt);
204 // reset GEN and KILL sets before emulating their effect.
205 sets.gen_set.clear();
206 sets.kill_set.clear();
207 results.0.operator.before_statement_effect(
208 &mut sets, Location { block: bb, statement_index: j });
209 results.0.operator.statement_effect(
210 &mut sets, Location { block: bb, statement_index: j });
211 sets.on_entry.union(sets.gen_set);
212 sets.on_entry.subtract(sets.kill_set);
215 results.0.operator.before_terminator_effect(
217 Location { block: bb, statement_index: statements.len() });
219 tcx.sess.span_err(span, &format!("rustc_peek: MIR did not match \
220 anticipated pattern; note that \
221 rustc_peek expects input of \
225 fn is_rustc_peek<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
226 terminator: &'a Option<mir::Terminator<'tcx>>)
227 -> Option<(&'a [mir::Operand<'tcx>], Span)> {
228 if let Some(mir::Terminator { ref kind, source_info, .. }) = *terminator {
229 if let mir::TerminatorKind::Call { func: ref oper, ref args, .. } = *kind {
230 if let mir::Operand::Constant(ref func) = *oper {
231 if let ty::FnDef(def_id, _) = func.ty.sty {
232 let abi = tcx.fn_sig(def_id).abi();
233 let name = tcx.item_name(def_id);
234 if abi == Abi::RustIntrinsic && name == "rustc_peek" {
235 return Some((args, source_info.span));