]>
Commit | Line | Data |
---|---|---|
064997fb | 1 | use crate::move_paths::builder::MoveDat; |
dfeec247 | 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! { |
9c376795 FG |
17 | #[debug_format = "mp{}"] |
18 | pub struct MovePathIndex {} | |
48663c56 | 19 | } |
54a0048b | 20 | |
c295e0f8 XL |
21 | impl polonius_engine::Atom for MovePathIndex { |
22 | fn index(self) -> usize { | |
49aad941 | 23 | rustc_index::Idx::index(self) |
c295e0f8 XL |
24 | } |
25 | } | |
26 | ||
e74abb32 | 27 | rustc_index::newtype_index! { |
9c376795 FG |
28 | #[debug_format = "mo{}"] |
29 | pub struct MoveOutIndex {} | |
54a0048b SL |
30 | } |
31 | ||
e74abb32 | 32 | rustc_index::newtype_index! { |
9c376795 FG |
33 | #[debug_format = "in{}"] |
34 | pub struct InitIndex {} | |
48663c56 | 35 | } |
54a0048b | 36 | |
041b39d2 | 37 | impl MoveOutIndex { |
5e7ed085 FG |
38 | pub fn move_path_index(self, move_data: &MoveData<'_>) -> MovePathIndex { |
39 | move_data.moves[self].path | |
3157f602 XL |
40 | } |
41 | } | |
42 | ||
54a0048b SL |
43 | /// `MovePath` is a canonicalized representation of a path that is |
44 | /// moved or assigned to. | |
45 | /// | |
46 | /// It follows a tree structure. | |
47 | /// | |
48 | /// Given `struct X { m: M, n: N }` and `x: X`, moves like `drop x.m;` | |
2c00a5a8 | 49 | /// move *out* of the place `x.m`. |
54a0048b SL |
50 | /// |
51 | /// The MovePaths representing `x.m` and `x.n` are siblings (that is, | |
52 | /// one of them will link to the other via the `next_sibling` field, | |
53 | /// and the other will have no entry in its `next_sibling` field), and | |
54 | /// they both have the MovePath representing `x` as their parent. | |
55 | #[derive(Clone)] | |
56 | pub struct MovePath<'tcx> { | |
57 | pub next_sibling: Option<MovePathIndex>, | |
58 | pub first_child: Option<MovePathIndex>, | |
59 | pub parent: Option<MovePathIndex>, | |
ff7c6d11 | 60 | pub place: Place<'tcx>, |
54a0048b SL |
61 | } |
62 | ||
0bf4aa26 | 63 | impl<'tcx> MovePath<'tcx> { |
74b04a01 XL |
64 | /// Returns an iterator over the parents of `self`. |
65 | pub fn parents<'a>( | |
66 | &self, | |
353b0b11 | 67 | move_paths: &'a IndexSlice<MovePathIndex, MovePath<'tcx>>, |
74b04a01 XL |
68 | ) -> impl 'a + Iterator<Item = (MovePathIndex, &'a MovePath<'tcx>)> { |
69 | let first = self.parent.map(|mpi| (mpi, &move_paths[mpi])); | |
70 | MovePathLinearIter { | |
71 | next: first, | |
72 | fetch_next: move |_, parent: &MovePath<'_>| { | |
73 | parent.parent.map(|mpi| (mpi, &move_paths[mpi])) | |
74 | }, | |
75 | } | |
76 | } | |
77 | ||
78 | /// Returns an iterator over the immediate children of `self`. | |
79 | pub fn children<'a>( | |
80 | &self, | |
353b0b11 | 81 | move_paths: &'a IndexSlice<MovePathIndex, MovePath<'tcx>>, |
74b04a01 XL |
82 | ) -> impl 'a + Iterator<Item = (MovePathIndex, &'a MovePath<'tcx>)> { |
83 | let first = self.first_child.map(|mpi| (mpi, &move_paths[mpi])); | |
84 | MovePathLinearIter { | |
85 | next: first, | |
86 | fetch_next: move |_, child: &MovePath<'_>| { | |
87 | child.next_sibling.map(|mpi| (mpi, &move_paths[mpi])) | |
88 | }, | |
89 | } | |
90 | } | |
91 | ||
92 | /// Finds the closest descendant of `self` for which `f` returns `true` using a breadth-first | |
93 | /// search. | |
94 | /// | |
95 | /// `f` will **not** be called on `self`. | |
96 | pub fn find_descendant( | |
9fa01778 | 97 | &self, |
353b0b11 | 98 | move_paths: &IndexSlice<MovePathIndex, MovePath<'_>>, |
74b04a01 XL |
99 | f: impl Fn(MovePathIndex) -> bool, |
100 | ) -> Option<MovePathIndex> { | |
101 | let mut todo = if let Some(child) = self.first_child { | |
102 | vec![child] | |
103 | } else { | |
104 | return None; | |
105 | }; | |
106 | ||
107 | while let Some(mpi) = todo.pop() { | |
108 | if f(mpi) { | |
109 | return Some(mpi); | |
110 | } | |
111 | ||
112 | let move_path = &move_paths[mpi]; | |
113 | if let Some(child) = move_path.first_child { | |
114 | todo.push(child); | |
115 | } | |
0bf4aa26 | 116 | |
74b04a01 XL |
117 | // After we've processed the original `mpi`, we should always |
118 | // traverse the siblings of any of its children. | |
119 | if let Some(sibling) = move_path.next_sibling { | |
120 | todo.push(sibling); | |
121 | } | |
0bf4aa26 XL |
122 | } |
123 | ||
74b04a01 | 124 | None |
0bf4aa26 XL |
125 | } |
126 | } | |
127 | ||
54a0048b | 128 | impl<'tcx> fmt::Debug for MovePath<'tcx> { |
9fa01778 | 129 | fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { |
54a0048b SL |
130 | write!(w, "MovePath {{")?; |
131 | if let Some(parent) = self.parent { | |
9c376795 | 132 | write!(w, " parent: {parent:?},")?; |
54a0048b SL |
133 | } |
134 | if let Some(first_child) = self.first_child { | |
9c376795 | 135 | write!(w, " first_child: {first_child:?},")?; |
54a0048b SL |
136 | } |
137 | if let Some(next_sibling) = self.next_sibling { | |
9c376795 | 138 | write!(w, " next_sibling: {next_sibling:?}")?; |
54a0048b | 139 | } |
ff7c6d11 | 140 | write!(w, " place: {:?} }}", self.place) |
54a0048b SL |
141 | } |
142 | } | |
143 | ||
3b2f2976 | 144 | impl<'tcx> fmt::Display for MovePath<'tcx> { |
9fa01778 | 145 | fn fmt(&self, w: &mut fmt::Formatter<'_>) -> fmt::Result { |
ff7c6d11 | 146 | write!(w, "{:?}", self.place) |
3b2f2976 XL |
147 | } |
148 | } | |
149 | ||
74b04a01 XL |
150 | struct MovePathLinearIter<'a, 'tcx, F> { |
151 | next: Option<(MovePathIndex, &'a MovePath<'tcx>)>, | |
152 | fetch_next: F, | |
153 | } | |
154 | ||
155 | impl<'a, 'tcx, F> Iterator for MovePathLinearIter<'a, 'tcx, F> | |
156 | where | |
157 | F: FnMut(MovePathIndex, &'a MovePath<'tcx>) -> Option<(MovePathIndex, &'a MovePath<'tcx>)>, | |
158 | { | |
159 | type Item = (MovePathIndex, &'a MovePath<'tcx>); | |
160 | ||
161 | fn next(&mut self) -> Option<Self::Item> { | |
162 | let ret = self.next.take()?; | |
163 | self.next = (self.fetch_next)(ret.0, ret.1); | |
164 | Some(ret) | |
165 | } | |
166 | } | |
167 | ||
3157f602 | 168 | #[derive(Debug)] |
54a0048b | 169 | pub struct MoveData<'tcx> { |
9e0c209e SL |
170 | pub move_paths: IndexVec<MovePathIndex, MovePath<'tcx>>, |
171 | pub moves: IndexVec<MoveOutIndex, MoveOut>, | |
172 | /// Each Location `l` is mapped to the MoveOut's that are effects | |
173 | /// of executing the code at `l`. (There can be multiple MoveOut's | |
174 | /// for a given `l` because each MoveOut is associated with one | |
175 | /// particular path being moved.) | |
a1dfa0c6 XL |
176 | pub loc_map: LocationMap<SmallVec<[MoveOutIndex; 4]>>, |
177 | pub path_map: IndexVec<MovePathIndex, SmallVec<[MoveOutIndex; 4]>>, | |
532ac7d7 | 178 | pub rev_lookup: MovePathLookup, |
ff7c6d11 XL |
179 | pub inits: IndexVec<InitIndex, Init>, |
180 | /// Each Location `l` is mapped to the Inits that are effects | |
181 | /// of executing the code at `l`. | |
a1dfa0c6 XL |
182 | pub init_loc_map: LocationMap<SmallVec<[InitIndex; 4]>>, |
183 | pub init_path_map: IndexVec<MovePathIndex, SmallVec<[InitIndex; 4]>>, | |
54a0048b SL |
184 | } |
185 | ||
32a655c1 SL |
186 | pub trait HasMoveData<'tcx> { |
187 | fn move_data(&self) -> &MoveData<'tcx>; | |
188 | } | |
189 | ||
3157f602 | 190 | #[derive(Debug)] |
9e0c209e | 191 | pub struct LocationMap<T> { |
54a0048b | 192 | /// Location-indexed (BasicBlock for outer index, index within BB |
9e0c209e | 193 | /// for inner index) map. |
041b39d2 | 194 | pub(crate) map: IndexVec<BasicBlock, Vec<T>>, |
54a0048b SL |
195 | } |
196 | ||
9e0c209e SL |
197 | impl<T> Index<Location> for LocationMap<T> { |
198 | type Output = T; | |
54a0048b | 199 | fn index(&self, index: Location) -> &Self::Output { |
9e0c209e | 200 | &self.map[index.block][index.statement_index] |
54a0048b SL |
201 | } |
202 | } | |
203 | ||
9e0c209e SL |
204 | impl<T> IndexMut<Location> for LocationMap<T> { |
205 | fn index_mut(&mut self, index: Location) -> &mut Self::Output { | |
206 | &mut self.map[index.block][index.statement_index] | |
207 | } | |
54a0048b SL |
208 | } |
209 | ||
e1599b0c XL |
210 | impl<T> LocationMap<T> |
211 | where | |
212 | T: Default + Clone, | |
213 | { | |
dc9dc135 | 214 | fn new(body: &Body<'_>) -> Self { |
9e0c209e | 215 | LocationMap { |
e1599b0c | 216 | map: body |
f2b60f7d | 217 | .basic_blocks |
e1599b0c XL |
218 | .iter() |
219 | .map(|block| vec![T::default(); block.statements.len() + 1]) | |
220 | .collect(), | |
9e0c209e | 221 | } |
54a0048b SL |
222 | } |
223 | } | |
224 | ||
225 | /// `MoveOut` represents a point in a program that moves out of some | |
226 | /// L-value; i.e., "creates" uninitialized memory. | |
227 | /// | |
228 | /// With respect to dataflow analysis: | |
229 | /// - Generated by moves and declaration of uninitialized variables. | |
230 | /// - Killed by assignments to the memory. | |
231 | #[derive(Copy, Clone)] | |
232 | pub struct MoveOut { | |
233 | /// path being moved | |
234 | pub path: MovePathIndex, | |
235 | /// location of move | |
236 | pub source: Location, | |
237 | } | |
238 | ||
239 | impl fmt::Debug for MoveOut { | |
9fa01778 | 240 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
9e0c209e | 241 | write!(fmt, "{:?}@{:?}", self.path, self.source) |
54a0048b SL |
242 | } |
243 | } | |
244 | ||
ff7c6d11 XL |
245 | /// `Init` represents a point in a program that initializes some L-value; |
246 | #[derive(Copy, Clone)] | |
247 | pub struct Init { | |
248 | /// path being initialized | |
249 | pub path: MovePathIndex, | |
b7449926 XL |
250 | /// location of initialization |
251 | pub location: InitLocation, | |
ff7c6d11 XL |
252 | /// Extra information about this initialization |
253 | pub kind: InitKind, | |
254 | } | |
255 | ||
b7449926 XL |
256 | /// Initializations can be from an argument or from a statement. Arguments |
257 | /// do not have locations, in those cases the `Local` is kept.. | |
258 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] | |
259 | pub enum InitLocation { | |
260 | Argument(Local), | |
261 | Statement(Location), | |
262 | } | |
263 | ||
ff7c6d11 XL |
264 | /// Additional information about the initialization. |
265 | #[derive(Copy, Clone, Debug, PartialEq, Eq)] | |
266 | pub enum InitKind { | |
267 | /// Deep init, even on panic | |
268 | Deep, | |
269 | /// Only does a shallow init | |
270 | Shallow, | |
8faf50e0 | 271 | /// This doesn't initialize the variable on panic (and a panic is possible). |
ff7c6d11 XL |
272 | NonPanicPathOnly, |
273 | } | |
274 | ||
275 | impl fmt::Debug for Init { | |
9fa01778 | 276 | fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
b7449926 XL |
277 | write!(fmt, "{:?}@{:?} ({:?})", self.path, self.location, self.kind) |
278 | } | |
279 | } | |
280 | ||
281 | impl Init { | |
c295e0f8 | 282 | pub fn span<'tcx>(&self, body: &Body<'tcx>) -> Span { |
b7449926 | 283 | match self.location { |
dc9dc135 XL |
284 | InitLocation::Argument(local) => body.local_decls[local].source_info.span, |
285 | InitLocation::Statement(location) => body.source_info(location).span, | |
b7449926 | 286 | } |
ff7c6d11 XL |
287 | } |
288 | } | |
289 | ||
2c00a5a8 | 290 | /// Tables mapping from a place to its MovePathIndex. |
3157f602 | 291 | #[derive(Debug)] |
532ac7d7 | 292 | pub struct MovePathLookup { |
c30ab7b3 | 293 | locals: IndexVec<Local, MovePathIndex>, |
54a0048b | 294 | |
ff7c6d11 XL |
295 | /// projections are made from a base-place and a projection |
296 | /// elem. The base-place will have a unique MovePathIndex; we use | |
54a0048b SL |
297 | /// the latter as the index into the outer vector (narrowing |
298 | /// subsequent search so that it is solely relative to that | |
ff7c6d11 | 299 | /// base-place). For the remaining lookup, we map the projection |
54a0048b | 300 | /// elem to the associated MovePathIndex. |
e1599b0c | 301 | projections: FxHashMap<(MovePathIndex, AbstractElem), MovePathIndex>, |
9e0c209e SL |
302 | } |
303 | ||
3b2f2976 | 304 | mod builder; |
54a0048b | 305 | |
9e0c209e SL |
306 | #[derive(Copy, Clone, Debug)] |
307 | pub enum LookupResult { | |
308 | Exact(MovePathIndex), | |
e1599b0c | 309 | Parent(Option<MovePathIndex>), |
54a0048b SL |
310 | } |
311 | ||
532ac7d7 | 312 | impl MovePathLookup { |
54a0048b SL |
313 | // Unlike the builder `fn move_path_for` below, this lookup |
314 | // alternative will *not* create a MovePath on the fly for an | |
2c00a5a8 | 315 | // unknown place, but will rather return the nearest available |
9e0c209e | 316 | // parent. |
74b04a01 XL |
317 | pub fn find(&self, place: PlaceRef<'_>) -> LookupResult { |
318 | let mut result = self.locals[place.local]; | |
e1599b0c XL |
319 | |
320 | for elem in place.projection.iter() { | |
321 | if let Some(&subpath) = self.projections.get(&(result, elem.lift())) { | |
322 | result = subpath; | |
323 | } else { | |
324 | return LookupResult::Parent(Some(result)); | |
54a0048b | 325 | } |
e1599b0c | 326 | } |
dc9dc135 | 327 | |
e1599b0c | 328 | LookupResult::Exact(result) |
54a0048b | 329 | } |
ff7c6d11 XL |
330 | |
331 | pub fn find_local(&self, local: Local) -> MovePathIndex { | |
332 | self.locals[local] | |
333 | } | |
e1599b0c XL |
334 | |
335 | /// An enumerated iterator of `local`s and their associated | |
336 | /// `MovePathIndex`es. | |
c295e0f8 XL |
337 | pub fn iter_locals_enumerated( |
338 | &self, | |
5e7ed085 FG |
339 | ) -> impl DoubleEndedIterator<Item = (Local, MovePathIndex)> + ExactSizeIterator + '_ { |
340 | self.locals.iter_enumerated().map(|(l, &idx)| (l, idx)) | |
e1599b0c | 341 | } |
54a0048b SL |
342 | } |
343 | ||
ea8adc8c XL |
344 | #[derive(Debug)] |
345 | pub struct IllegalMoveOrigin<'tcx> { | |
c295e0f8 XL |
346 | pub location: Location, |
347 | pub kind: IllegalMoveOriginKind<'tcx>, | |
ea8adc8c XL |
348 | } |
349 | ||
350 | #[derive(Debug)] | |
c295e0f8 | 351 | pub enum IllegalMoveOriginKind<'tcx> { |
94b46f34 XL |
352 | /// Illegal move due to attempt to move from behind a reference. |
353 | BorrowedContent { | |
8faf50e0 XL |
354 | /// The place the reference refers to: if erroneous code was trying to |
355 | /// move from `(*x).f` this will be `*x`. | |
356 | target_place: Place<'tcx>, | |
94b46f34 XL |
357 | }, |
358 | ||
359 | /// Illegal move due to attempt to move from field of an ADT that | |
360 | /// implements `Drop`. Rust maintains invariant that all `Drop` | |
361 | /// ADT's remain fully-initialized so that user-defined destructor | |
362 | /// can safely read from all of the ADT's fields. | |
48663c56 | 363 | InteriorOfTypeWithDestructor { container_ty: Ty<'tcx> }, |
94b46f34 XL |
364 | |
365 | /// Illegal move due to attempt to move out of a slice or array. | |
e1599b0c | 366 | InteriorOfSliceOrArray { ty: Ty<'tcx>, is_index: bool }, |
ea8adc8c XL |
367 | } |
368 | ||
369 | #[derive(Debug)] | |
370 | pub enum MoveError<'tcx> { | |
371 | IllegalMove { cannot_move_out_of: IllegalMoveOrigin<'tcx> }, | |
372 | UnionMove { path: MovePathIndex }, | |
373 | } | |
374 | ||
375 | impl<'tcx> MoveError<'tcx> { | |
8faf50e0 XL |
376 | fn cannot_move_out_of(location: Location, kind: IllegalMoveOriginKind<'tcx>) -> Self { |
377 | let origin = IllegalMoveOrigin { location, kind }; | |
ea8adc8c XL |
378 | MoveError::IllegalMove { cannot_move_out_of: origin } |
379 | } | |
380 | } | |
381 | ||
dc9dc135 XL |
382 | impl<'tcx> MoveData<'tcx> { |
383 | pub fn gather_moves( | |
384 | body: &Body<'tcx>, | |
385 | tcx: TyCtxt<'tcx>, | |
60c5eb7d | 386 | param_env: ParamEnv<'tcx>, |
064997fb | 387 | ) -> MoveDat<'tcx> { |
60c5eb7d | 388 | builder::gather_moves(body, tcx, param_env) |
54a0048b | 389 | } |
b7449926 XL |
390 | |
391 | /// For the move path `mpi`, returns the root local variable (if any) that starts the path. | |
392 | /// (e.g., for a path like `a.b.c` returns `Some(a)`) | |
393 | pub fn base_local(&self, mut mpi: MovePathIndex) -> Option<Local> { | |
394 | loop { | |
395 | let path = &self.move_paths[mpi]; | |
e74abb32 | 396 | if let Some(l) = path.place.as_local() { |
e1599b0c XL |
397 | return Some(l); |
398 | } | |
399 | if let Some(parent) = path.parent { | |
400 | mpi = parent; | |
401 | continue; | |
402 | } else { | |
403 | return None; | |
404 | } | |
b7449926 XL |
405 | } |
406 | } | |
74b04a01 XL |
407 | |
408 | pub fn find_in_move_path_or_its_descendants( | |
409 | &self, | |
410 | root: MovePathIndex, | |
411 | pred: impl Fn(MovePathIndex) -> bool, | |
412 | ) -> Option<MovePathIndex> { | |
413 | if pred(root) { | |
414 | return Some(root); | |
415 | } | |
416 | ||
417 | self.move_paths[root].find_descendant(&self.move_paths, pred) | |
418 | } | |
54a0048b | 419 | } |