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Commit | Line | Data |
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add651ee FG |
1 | use crate::un_derefer::UnDerefer; |
2 | use rustc_data_structures::fx::FxHashMap; | |
49aad941 | 3 | use rustc_index::{IndexSlice, IndexVec}; |
ba9703b0 XL |
4 | use rustc_middle::mir::*; |
5 | use rustc_middle::ty::{ParamEnv, Ty, TyCtxt}; | |
dfeec247 | 6 | use rustc_span::Span; |
a1dfa0c6 | 7 | use smallvec::SmallVec; |
9e0c209e | 8 | |
54a0048b | 9 | use std::fmt; |
9e0c209e | 10 | use std::ops::{Index, IndexMut}; |
54a0048b | 11 | |
041b39d2 XL |
12 | use self::abs_domain::{AbstractElem, Lift}; |
13 | ||
14 | mod abs_domain; | |
54a0048b | 15 | |
e74abb32 | 16 | rustc_index::newtype_index! { |
4b012472 | 17 | #[orderable] |
9c376795 FG |
18 | #[debug_format = "mp{}"] |
19 | pub struct MovePathIndex {} | |
48663c56 | 20 | } |
54a0048b | 21 | |
c295e0f8 XL |
22 | impl polonius_engine::Atom for MovePathIndex { |
23 | fn index(self) -> usize { | |
49aad941 | 24 | rustc_index::Idx::index(self) |
c295e0f8 XL |
25 | } |
26 | } | |
27 | ||
e74abb32 | 28 | rustc_index::newtype_index! { |
4b012472 | 29 | #[orderable] |
9c376795 FG |
30 | #[debug_format = "mo{}"] |
31 | pub struct MoveOutIndex {} | |
54a0048b SL |
32 | } |
33 | ||
e74abb32 | 34 | rustc_index::newtype_index! { |
9c376795 FG |
35 | #[debug_format = "in{}"] |
36 | pub struct InitIndex {} | |
48663c56 | 37 | } |
54a0048b | 38 | |
041b39d2 | 39 | impl MoveOutIndex { |
5e7ed085 FG |
40 | pub fn move_path_index(self, move_data: &MoveData<'_>) -> MovePathIndex { |
41 | move_data.moves[self].path | |
3157f602 XL |
42 | } |
43 | } | |
44 | ||
54a0048b SL |
45 | /// `MovePath` is a canonicalized representation of a path that is |
46 | /// moved or assigned to. | |
47 | /// | |
48 | /// It follows a tree structure. | |
49 | /// | |
50 | /// Given `struct X { m: M, n: N }` and `x: X`, moves like `drop x.m;` | |
2c00a5a8 | 51 | /// move *out* of the place `x.m`. |
54a0048b SL |
52 | /// |
53 | /// The MovePaths representing `x.m` and `x.n` are siblings (that is, | |
54 | /// one of them will link to the other via the `next_sibling` field, | |
55 | /// and the other will have no entry in its `next_sibling` field), and | |
56 | /// they both have the MovePath representing `x` as their parent. | |
57 | #[derive(Clone)] | |
58 | pub struct MovePath<'tcx> { | |
59 | pub next_sibling: Option<MovePathIndex>, | |
60 | pub first_child: Option<MovePathIndex>, | |
61 | pub parent: Option<MovePathIndex>, | |
ff7c6d11 | 62 | pub place: Place<'tcx>, |
54a0048b SL |
63 | } |
64 | ||
0bf4aa26 | 65 | impl<'tcx> MovePath<'tcx> { |
74b04a01 XL |
66 | /// Returns an iterator over the parents of `self`. |
67 | pub fn parents<'a>( | |
68 | &self, | |
353b0b11 | 69 | move_paths: &'a IndexSlice<MovePathIndex, MovePath<'tcx>>, |
74b04a01 XL |
70 | ) -> impl 'a + Iterator<Item = (MovePathIndex, &'a MovePath<'tcx>)> { |
71 | let first = self.parent.map(|mpi| (mpi, &move_paths[mpi])); | |
72 | MovePathLinearIter { | |
73 | next: first, | |
74 | fetch_next: move |_, parent: &MovePath<'_>| { | |
75 | parent.parent.map(|mpi| (mpi, &move_paths[mpi])) | |
76 | }, | |
77 | } | |
78 | } | |
79 | ||
80 | /// Returns an iterator over the immediate children of `self`. | |
81 | pub fn children<'a>( | |
82 | &self, | |
353b0b11 | 83 | move_paths: &'a IndexSlice<MovePathIndex, MovePath<'tcx>>, |
74b04a01 XL |
84 | ) -> impl 'a + Iterator<Item = (MovePathIndex, &'a MovePath<'tcx>)> { |
85 | let first = self.first_child.map(|mpi| (mpi, &move_paths[mpi])); | |
86 | MovePathLinearIter { | |
87 | next: first, | |
88 | fetch_next: move |_, child: &MovePath<'_>| { | |
89 | child.next_sibling.map(|mpi| (mpi, &move_paths[mpi])) | |
90 | }, | |
91 | } | |
92 | } | |
93 | ||
94 | /// Finds the closest descendant of `self` for which `f` returns `true` using a breadth-first | |
95 | /// search. | |
96 | /// | |
97 | /// `f` will **not** be called on `self`. | |
98 | pub fn find_descendant( | |
9fa01778 | 99 | &self, |
353b0b11 | 100 | move_paths: &IndexSlice<MovePathIndex, MovePath<'_>>, |
74b04a01 XL |
101 | f: impl Fn(MovePathIndex) -> bool, |
102 | ) -> Option<MovePathIndex> { | |
103 | let mut todo = if let Some(child) = self.first_child { | |
104 | vec![child] | |
105 | } else { | |
106 | return None; | |
107 | }; | |
108 | ||
109 | while let Some(mpi) = todo.pop() { | |
110 | if f(mpi) { | |
111 | return Some(mpi); | |
112 | } | |
113 | ||
114 | let move_path = &move_paths[mpi]; | |
115 | if let Some(child) = move_path.first_child { | |
116 | todo.push(child); | |
117 | } | |
0bf4aa26 | 118 | |
74b04a01 XL |
119 | // After we've processed the original `mpi`, we should always |
120 | // traverse the siblings of any of its children. | |
121 | if let Some(sibling) = move_path.next_sibling { | |
122 | todo.push(sibling); | |
123 | } | |
0bf4aa26 XL |
124 | } |
125 | ||
74b04a01 | 126 | None |
0bf4aa26 XL |
127 | } |
128 | } | |
129 | ||
54a0048b | 130 | impl<'tcx> fmt::Debug for MovePath<'tcx> { |
9fa01778 | 131 | fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { |
54a0048b SL |
132 | write!(w, "MovePath {{")?; |
133 | if let Some(parent) = self.parent { | |
9c376795 | 134 | write!(w, " parent: {parent:?},")?; |
54a0048b SL |
135 | } |
136 | if let Some(first_child) = self.first_child { | |
9c376795 | 137 | write!(w, " first_child: {first_child:?},")?; |
54a0048b SL |
138 | } |
139 | if let Some(next_sibling) = self.next_sibling { | |
9c376795 | 140 | write!(w, " next_sibling: {next_sibling:?}")?; |
54a0048b | 141 | } |
ff7c6d11 | 142 | write!(w, " place: {:?} }}", self.place) |
54a0048b SL |
143 | } |
144 | } | |
145 | ||
3b2f2976 | 146 | impl<'tcx> fmt::Display for MovePath<'tcx> { |
9fa01778 | 147 | fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { |
ff7c6d11 | 148 | write!(w, "{:?}", self.place) |
3b2f2976 XL |
149 | } |
150 | } | |
151 | ||
74b04a01 XL |
152 | struct MovePathLinearIter<'a, 'tcx, F> { |
153 | next: Option<(MovePathIndex, &'a MovePath<'tcx>)>, | |
154 | fetch_next: F, | |
155 | } | |
156 | ||
157 | impl<'a, 'tcx, F> Iterator for MovePathLinearIter<'a, 'tcx, F> | |
158 | where | |
159 | F: FnMut(MovePathIndex, &'a MovePath<'tcx>) -> Option<(MovePathIndex, &'a MovePath<'tcx>)>, | |
160 | { | |
161 | type Item = (MovePathIndex, &'a MovePath<'tcx>); | |
162 | ||
163 | fn next(&mut self) -> Option<Self::Item> { | |
164 | let ret = self.next.take()?; | |
165 | self.next = (self.fetch_next)(ret.0, ret.1); | |
166 | Some(ret) | |
167 | } | |
168 | } | |
169 | ||
3157f602 | 170 | #[derive(Debug)] |
54a0048b | 171 | pub struct MoveData<'tcx> { |
9e0c209e SL |
172 | pub move_paths: IndexVec<MovePathIndex, MovePath<'tcx>>, |
173 | pub moves: IndexVec<MoveOutIndex, MoveOut>, | |
174 | /// Each Location `l` is mapped to the MoveOut's that are effects | |
175 | /// of executing the code at `l`. (There can be multiple MoveOut's | |
176 | /// for a given `l` because each MoveOut is associated with one | |
177 | /// particular path being moved.) | |
a1dfa0c6 XL |
178 | pub loc_map: LocationMap<SmallVec<[MoveOutIndex; 4]>>, |
179 | pub path_map: IndexVec<MovePathIndex, SmallVec<[MoveOutIndex; 4]>>, | |
fe692bf9 | 180 | pub rev_lookup: MovePathLookup<'tcx>, |
ff7c6d11 XL |
181 | pub inits: IndexVec<InitIndex, Init>, |
182 | /// Each Location `l` is mapped to the Inits that are effects | |
183 | /// of executing the code at `l`. | |
a1dfa0c6 XL |
184 | pub init_loc_map: LocationMap<SmallVec<[InitIndex; 4]>>, |
185 | pub init_path_map: IndexVec<MovePathIndex, SmallVec<[InitIndex; 4]>>, | |
54a0048b SL |
186 | } |
187 | ||
32a655c1 SL |
188 | pub trait HasMoveData<'tcx> { |
189 | fn move_data(&self) -> &MoveData<'tcx>; | |
190 | } | |
191 | ||
3157f602 | 192 | #[derive(Debug)] |
9e0c209e | 193 | pub struct LocationMap<T> { |
54a0048b | 194 | /// Location-indexed (BasicBlock for outer index, index within BB |
9e0c209e | 195 | /// for inner index) map. |
041b39d2 | 196 | pub(crate) map: IndexVec<BasicBlock, Vec<T>>, |
54a0048b SL |
197 | } |
198 | ||
9e0c209e SL |
199 | impl<T> Index<Location> for LocationMap<T> { |
200 | type Output = T; | |
54a0048b | 201 | fn index(&self, index: Location) -> &Self::Output { |
9e0c209e | 202 | &self.map[index.block][index.statement_index] |
54a0048b SL |
203 | } |
204 | } | |
205 | ||
9e0c209e SL |
206 | impl<T> IndexMut<Location> for LocationMap<T> { |
207 | fn index_mut(&mut self, index: Location) -> &mut Self::Output { | |
208 | &mut self.map[index.block][index.statement_index] | |
209 | } | |
54a0048b SL |
210 | } |
211 | ||
e1599b0c XL |
212 | impl<T> LocationMap<T> |
213 | where | |
214 | T: Default + Clone, | |
215 | { | |
dc9dc135 | 216 | fn new(body: &Body<'_>) -> Self { |
9e0c209e | 217 | LocationMap { |
e1599b0c | 218 | map: body |
f2b60f7d | 219 | .basic_blocks |
e1599b0c XL |
220 | .iter() |
221 | .map(|block| vec![T::default(); block.statements.len() + 1]) | |
222 | .collect(), | |
9e0c209e | 223 | } |
54a0048b SL |
224 | } |
225 | } | |
226 | ||
227 | /// `MoveOut` represents a point in a program that moves out of some | |
228 | /// L-value; i.e., "creates" uninitialized memory. | |
229 | /// | |
230 | /// With respect to dataflow analysis: | |
231 | /// - Generated by moves and declaration of uninitialized variables. | |
232 | /// - Killed by assignments to the memory. | |
233 | #[derive(Copy, Clone)] | |
234 | pub struct MoveOut { | |
235 | /// path being moved | |
236 | pub path: MovePathIndex, | |
237 | /// location of move | |
238 | pub source: Location, | |
239 | } | |
240 | ||
241 | impl fmt::Debug for MoveOut { | |
9fa01778 | 242 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
9e0c209e | 243 | write!(fmt, "{:?}@{:?}", self.path, self.source) |
54a0048b SL |
244 | } |
245 | } | |
246 | ||
ff7c6d11 XL |
247 | /// `Init` represents a point in a program that initializes some L-value; |
248 | #[derive(Copy, Clone)] | |
249 | pub struct Init { | |
250 | /// path being initialized | |
251 | pub path: MovePathIndex, | |
b7449926 XL |
252 | /// location of initialization |
253 | pub location: InitLocation, | |
ff7c6d11 XL |
254 | /// Extra information about this initialization |
255 | pub kind: InitKind, | |
256 | } | |
257 | ||
b7449926 XL |
258 | /// Initializations can be from an argument or from a statement. Arguments |
259 | /// do not have locations, in those cases the `Local` is kept.. | |
260 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] | |
261 | pub enum InitLocation { | |
262 | Argument(Local), | |
263 | Statement(Location), | |
264 | } | |
265 | ||
ff7c6d11 XL |
266 | /// Additional information about the initialization. |
267 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] | |
268 | pub enum InitKind { | |
269 | /// Deep init, even on panic | |
270 | Deep, | |
271 | /// Only does a shallow init | |
272 | Shallow, | |
8faf50e0 | 273 | /// This doesn't initialize the variable on panic (and a panic is possible). |
ff7c6d11 XL |
274 | NonPanicPathOnly, |
275 | } | |
276 | ||
277 | impl fmt::Debug for Init { | |
9fa01778 | 278 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
b7449926 XL |
279 | write!(fmt, "{:?}@{:?} ({:?})", self.path, self.location, self.kind) |
280 | } | |
281 | } | |
282 | ||
283 | impl Init { | |
c295e0f8 | 284 | pub fn span<'tcx>(&self, body: &Body<'tcx>) -> Span { |
b7449926 | 285 | match self.location { |
dc9dc135 XL |
286 | InitLocation::Argument(local) => body.local_decls[local].source_info.span, |
287 | InitLocation::Statement(location) => body.source_info(location).span, | |
b7449926 | 288 | } |
ff7c6d11 XL |
289 | } |
290 | } | |
291 | ||
2c00a5a8 | 292 | /// Tables mapping from a place to its MovePathIndex. |
3157f602 | 293 | #[derive(Debug)] |
fe692bf9 | 294 | pub struct MovePathLookup<'tcx> { |
ed00b5ec | 295 | locals: IndexVec<Local, Option<MovePathIndex>>, |
54a0048b | 296 | |
ff7c6d11 XL |
297 | /// projections are made from a base-place and a projection |
298 | /// elem. The base-place will have a unique MovePathIndex; we use | |
54a0048b SL |
299 | /// the latter as the index into the outer vector (narrowing |
300 | /// subsequent search so that it is solely relative to that | |
ff7c6d11 | 301 | /// base-place). For the remaining lookup, we map the projection |
54a0048b | 302 | /// elem to the associated MovePathIndex. |
e1599b0c | 303 | projections: FxHashMap<(MovePathIndex, AbstractElem), MovePathIndex>, |
fe692bf9 | 304 | |
add651ee | 305 | un_derefer: UnDerefer<'tcx>, |
9e0c209e SL |
306 | } |
307 | ||
3b2f2976 | 308 | mod builder; |
54a0048b | 309 | |
9e0c209e SL |
310 | #[derive(Copy, Clone, Debug)] |
311 | pub enum LookupResult { | |
312 | Exact(MovePathIndex), | |
e1599b0c | 313 | Parent(Option<MovePathIndex>), |
54a0048b SL |
314 | } |
315 | ||
fe692bf9 | 316 | impl<'tcx> MovePathLookup<'tcx> { |
54a0048b SL |
317 | // Unlike the builder `fn move_path_for` below, this lookup |
318 | // alternative will *not* create a MovePath on the fly for an | |
2c00a5a8 | 319 | // unknown place, but will rather return the nearest available |
9e0c209e | 320 | // parent. |
add651ee | 321 | pub fn find(&self, place: PlaceRef<'tcx>) -> LookupResult { |
ed00b5ec FG |
322 | let Some(mut result) = self.find_local(place.local) else { |
323 | return LookupResult::Parent(None); | |
324 | }; | |
fe692bf9 | 325 | |
add651ee FG |
326 | for (_, elem) in self.un_derefer.iter_projections(place) { |
327 | if let Some(&subpath) = self.projections.get(&(result, elem.lift())) { | |
328 | result = subpath; | |
329 | } else { | |
e1599b0c | 330 | return LookupResult::Parent(Some(result)); |
54a0048b | 331 | } |
e1599b0c | 332 | } |
dc9dc135 | 333 | |
e1599b0c | 334 | LookupResult::Exact(result) |
54a0048b | 335 | } |
ff7c6d11 | 336 | |
add651ee | 337 | #[inline] |
ed00b5ec | 338 | pub fn find_local(&self, local: Local) -> Option<MovePathIndex> { |
add651ee | 339 | self.locals[local] |
ff7c6d11 | 340 | } |
e1599b0c XL |
341 | |
342 | /// An enumerated iterator of `local`s and their associated | |
343 | /// `MovePathIndex`es. | |
c295e0f8 XL |
344 | pub fn iter_locals_enumerated( |
345 | &self, | |
ed00b5ec FG |
346 | ) -> impl DoubleEndedIterator<Item = (Local, MovePathIndex)> + '_ { |
347 | self.locals.iter_enumerated().filter_map(|(l, &idx)| Some((l, idx?))) | |
ea8adc8c XL |
348 | } |
349 | } | |
350 | ||
dc9dc135 XL |
351 | impl<'tcx> MoveData<'tcx> { |
352 | pub fn gather_moves( | |
353 | body: &Body<'tcx>, | |
354 | tcx: TyCtxt<'tcx>, | |
60c5eb7d | 355 | param_env: ParamEnv<'tcx>, |
ed00b5ec FG |
356 | filter: impl Fn(Ty<'tcx>) -> bool, |
357 | ) -> MoveData<'tcx> { | |
358 | builder::gather_moves(body, tcx, param_env, filter) | |
54a0048b | 359 | } |
b7449926 XL |
360 | |
361 | /// For the move path `mpi`, returns the root local variable (if any) that starts the path. | |
362 | /// (e.g., for a path like `a.b.c` returns `Some(a)`) | |
363 | pub fn base_local(&self, mut mpi: MovePathIndex) -> Option<Local> { | |
364 | loop { | |
365 | let path = &self.move_paths[mpi]; | |
e74abb32 | 366 | if let Some(l) = path.place.as_local() { |
e1599b0c XL |
367 | return Some(l); |
368 | } | |
369 | if let Some(parent) = path.parent { | |
370 | mpi = parent; | |
371 | continue; | |
372 | } else { | |
373 | return None; | |
374 | } | |
b7449926 XL |
375 | } |
376 | } | |
74b04a01 XL |
377 | |
378 | pub fn find_in_move_path_or_its_descendants( | |
379 | &self, | |
380 | root: MovePathIndex, | |
381 | pred: impl Fn(MovePathIndex) -> bool, | |
382 | ) -> Option<MovePathIndex> { | |
383 | if pred(root) { | |
384 | return Some(root); | |
385 | } | |
386 | ||
387 | self.move_paths[root].find_descendant(&self.move_paths, pred) | |
388 | } | |
54a0048b | 389 | } |