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Commit | Line | Data |
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f035d41b | 1 | //! Machinery for hygienic macros. |
5bcae85e | 2 | //! |
f035d41b XL |
3 | //! Inspired by Matthew Flatt et al., “Macros That Work Together: Compile-Time Bindings, Partial |
4 | //! Expansion, and Definition Contexts,” *Journal of Functional Programming* 22, no. 2 | |
5 | //! (March 1, 2012): 181–216, <https://doi.org/10.1017/S0956796812000093>. | |
5bcae85e | 6 | |
dc9dc135 XL |
7 | // Hygiene data is stored in a global variable and accessed via TLS, which |
8 | // means that accesses are somewhat expensive. (`HygieneData::with` | |
9 | // encapsulates a single access.) Therefore, on hot code paths it is worth | |
10 | // ensuring that multiple HygieneData accesses are combined into a single | |
11 | // `HygieneData::with`. | |
12 | // | |
416331ca | 13 | // This explains why `HygieneData`, `SyntaxContext` and `ExpnId` have interfaces |
dc9dc135 | 14 | // with a certain amount of redundancy in them. For example, |
e1599b0c XL |
15 | // `SyntaxContext::outer_expn_data` combines `SyntaxContext::outer` and |
16 | // `ExpnId::expn_data` so that two `HygieneData` accesses can be performed within | |
dc9dc135 XL |
17 | // a single `HygieneData::with` call. |
18 | // | |
19 | // It also explains why many functions appear in `HygieneData` and again in | |
416331ca | 20 | // `SyntaxContext` or `ExpnId`. For example, `HygieneData::outer` and |
dc9dc135 XL |
21 | // `SyntaxContext::outer` do the same thing, but the former is for use within a |
22 | // `HygieneData::with` call while the latter is for use outside such a call. | |
23 | // When modifying this file it is important to understand this distinction, | |
24 | // because getting it wrong can lead to nested `HygieneData::with` calls that | |
25 | // trigger runtime aborts. (Fortunately these are obvious and easy to fix.) | |
26 | ||
dc9dc135 | 27 | use crate::edition::Edition; |
60c5eb7d | 28 | use crate::symbol::{kw, sym, Symbol}; |
136023e0 XL |
29 | use crate::with_session_globals; |
30 | use crate::{HashStableContext, Span, DUMMY_SP}; | |
cc61c64b | 31 | |
136023e0 | 32 | use crate::def_id::{CrateNum, DefId, StableCrateId, CRATE_DEF_ID, LOCAL_CRATE}; |
5869c6ff | 33 | use rustc_data_structures::fingerprint::Fingerprint; |
3dfed10e | 34 | use rustc_data_structures::fx::{FxHashMap, FxHashSet}; |
5099ac24 | 35 | use rustc_data_structures::stable_hasher::HashingControls; |
5869c6ff | 36 | use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; |
3dfed10e | 37 | use rustc_data_structures::sync::{Lock, Lrc}; |
136023e0 XL |
38 | use rustc_data_structures::unhash::UnhashMap; |
39 | use rustc_index::vec::IndexVec; | |
dfeec247 XL |
40 | use rustc_macros::HashStable_Generic; |
41 | use rustc_serialize::{Decodable, Decoder, Encodable, Encoder}; | |
416331ca | 42 | use std::fmt; |
5869c6ff | 43 | use std::hash::Hash; |
3dfed10e | 44 | use tracing::*; |
5bcae85e | 45 | |
416331ca XL |
46 | /// A `SyntaxContext` represents a chain of pairs `(ExpnId, Transparency)` named "marks". |
47 | #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] | |
8faf50e0 XL |
48 | pub struct SyntaxContext(u32); |
49 | ||
3dfed10e XL |
50 | #[derive(Debug, Encodable, Decodable, Clone)] |
51 | pub struct SyntaxContextData { | |
416331ca XL |
52 | outer_expn: ExpnId, |
53 | outer_transparency: Transparency, | |
54 | parent: SyntaxContext, | |
55 | /// This context, but with all transparent and semi-transparent expansions filtered away. | |
8faf50e0 | 56 | opaque: SyntaxContext, |
416331ca | 57 | /// This context, but with all transparent expansions filtered away. |
8faf50e0 | 58 | opaque_and_semitransparent: SyntaxContext, |
48663c56 | 59 | /// Name of the crate to which `$crate` with this context would resolve. |
0731742a | 60 | dollar_crate_name: Symbol, |
5bcae85e SL |
61 | } |
62 | ||
136023e0 XL |
63 | rustc_index::newtype_index! { |
64 | /// A unique ID associated with a macro invocation and expansion. | |
65 | pub struct ExpnIndex { | |
66 | ENCODABLE = custom | |
67 | } | |
68 | } | |
69 | ||
416331ca | 70 | /// A unique ID associated with a macro invocation and expansion. |
136023e0 XL |
71 | #[derive(Clone, Copy, PartialEq, Eq, Hash)] |
72 | pub struct ExpnId { | |
73 | pub krate: CrateNum, | |
74 | pub local_id: ExpnIndex, | |
75 | } | |
76 | ||
77 | impl fmt::Debug for ExpnId { | |
78 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
79 | // Generate crate_::{{expn_}}. | |
80 | write!(f, "{:?}::{{{{expn{}}}}}", self.krate, self.local_id.private) | |
81 | } | |
82 | } | |
83 | ||
84 | rustc_index::newtype_index! { | |
85 | /// A unique ID associated with a macro invocation and expansion. | |
86 | pub struct LocalExpnId { | |
87 | ENCODABLE = custom | |
ee023bcb | 88 | ORD_IMPL = custom |
136023e0 XL |
89 | DEBUG_FORMAT = "expn{}" |
90 | } | |
91 | } | |
92 | ||
ee023bcb FG |
93 | // To ensure correctness of incremental compilation, |
94 | // `LocalExpnId` must not implement `Ord` or `PartialOrd`. | |
95 | // See https://github.com/rust-lang/rust/issues/90317. | |
96 | impl !Ord for LocalExpnId {} | |
97 | impl !PartialOrd for LocalExpnId {} | |
98 | ||
5099ac24 FG |
99 | /// Assert that the provided `HashStableContext` is configured with the 'default' |
100 | /// `HashingControls`. We should always have bailed out before getting to here | |
101 | /// with a non-default mode. With this check in place, we can avoid the need | |
102 | /// to maintain separate versions of `ExpnData` hashes for each permutation | |
103 | /// of `HashingControls` settings. | |
104 | fn assert_default_hashing_controls<CTX: HashStableContext>(ctx: &CTX, msg: &str) { | |
105 | match ctx.hashing_controls() { | |
106 | // Ideally, we would also check that `node_id_hashing_mode` was always | |
107 | // `NodeIdHashingMode::HashDefPath`. However, we currently end up hashing | |
108 | // `Span`s in this mode, and there's not an easy way to change that. | |
109 | // All of the span-related data that we hash is pretty self-contained | |
110 | // (in particular, we don't hash any `HirId`s), so this shouldn't result | |
111 | // in any caching problems. | |
112 | // FIXME: Enforce that we don't end up transitively hashing any `HirId`s, | |
113 | // or ensure that this method is always invoked with the same | |
114 | // `NodeIdHashingMode` | |
115 | // | |
116 | // Note that we require that `hash_spans` be set according to the global | |
117 | // `-Z incremental-ignore-spans` option. Normally, this option is disabled, | |
118 | // which will cause us to require that this method always be called with `Span` hashing | |
119 | // enabled. | |
ee023bcb | 120 | HashingControls { hash_spans } |
5099ac24 FG |
121 | if hash_spans == !ctx.debug_opts_incremental_ignore_spans() => {} |
122 | other => panic!("Attempted hashing of {msg} with non-default HashingControls: {:?}", other), | |
123 | } | |
124 | } | |
125 | ||
136023e0 XL |
126 | /// A unique hash value associated to an expansion. |
127 | #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Encodable, Decodable, HashStable_Generic)] | |
128 | pub struct ExpnHash(Fingerprint); | |
129 | ||
130 | impl ExpnHash { | |
131 | /// Returns the [StableCrateId] identifying the crate this [ExpnHash] | |
132 | /// originates from. | |
133 | #[inline] | |
134 | pub fn stable_crate_id(self) -> StableCrateId { | |
135 | StableCrateId(self.0.as_value().0) | |
136 | } | |
137 | ||
138 | /// Returns the crate-local part of the [ExpnHash]. | |
139 | /// | |
140 | /// Used for tests. | |
141 | #[inline] | |
142 | pub fn local_hash(self) -> u64 { | |
143 | self.0.as_value().1 | |
144 | } | |
145 | ||
146 | #[inline] | |
147 | pub fn is_root(self) -> bool { | |
148 | self.0 == Fingerprint::ZERO | |
149 | } | |
150 | ||
151 | /// Builds a new [ExpnHash] with the given [StableCrateId] and | |
152 | /// `local_hash`, where `local_hash` must be unique within its crate. | |
153 | fn new(stable_crate_id: StableCrateId, local_hash: u64) -> ExpnHash { | |
154 | ExpnHash(Fingerprint::new(stable_crate_id.0, local_hash)) | |
155 | } | |
156 | } | |
5bcae85e | 157 | |
8faf50e0 XL |
158 | /// A property of a macro expansion that determines how identifiers |
159 | /// produced by that expansion are resolved. | |
3dfed10e | 160 | #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Hash, Debug, Encodable, Decodable)] |
ba9703b0 | 161 | #[derive(HashStable_Generic)] |
8faf50e0 XL |
162 | pub enum Transparency { |
163 | /// Identifier produced by a transparent expansion is always resolved at call-site. | |
164 | /// Call-site spans in procedural macros, hygiene opt-out in `macro` should use this. | |
165 | Transparent, | |
166 | /// Identifier produced by a semi-transparent expansion may be resolved | |
167 | /// either at call-site or at definition-site. | |
168 | /// If it's a local variable, label or `$crate` then it's resolved at def-site. | |
169 | /// Otherwise it's resolved at call-site. | |
170 | /// `macro_rules` macros behave like this, built-in macros currently behave like this too, | |
171 | /// but that's an implementation detail. | |
172 | SemiTransparent, | |
173 | /// Identifier produced by an opaque expansion is always resolved at definition-site. | |
174 | /// Def-site spans in procedural macros, identifiers from `macro` by default use this. | |
175 | Opaque, | |
ff7c6d11 XL |
176 | } |
177 | ||
136023e0 XL |
178 | impl LocalExpnId { |
179 | /// The ID of the theoretical expansion that generates freshly parsed, unexpanded AST. | |
180 | pub const ROOT: LocalExpnId = LocalExpnId::from_u32(0); | |
181 | ||
5099ac24 | 182 | #[inline] |
136023e0 XL |
183 | pub fn from_raw(idx: ExpnIndex) -> LocalExpnId { |
184 | LocalExpnId::from_u32(idx.as_u32()) | |
5bcae85e | 185 | } |
9e0c209e | 186 | |
5099ac24 | 187 | #[inline] |
136023e0 XL |
188 | pub fn as_raw(self) -> ExpnIndex { |
189 | ExpnIndex::from_u32(self.as_u32()) | |
9e0c209e SL |
190 | } |
191 | ||
136023e0 XL |
192 | pub fn fresh_empty() -> LocalExpnId { |
193 | HygieneData::with(|data| { | |
194 | let expn_id = data.local_expn_data.push(None); | |
195 | let _eid = data.local_expn_hashes.push(ExpnHash(Fingerprint::ZERO)); | |
196 | debug_assert_eq!(expn_id, _eid); | |
197 | expn_id | |
198 | }) | |
199 | } | |
200 | ||
201 | pub fn fresh(mut expn_data: ExpnData, ctx: impl HashStableContext) -> LocalExpnId { | |
202 | debug_assert_eq!(expn_data.parent.krate, LOCAL_CRATE); | |
203 | let expn_hash = update_disambiguator(&mut expn_data, ctx); | |
204 | HygieneData::with(|data| { | |
205 | let expn_id = data.local_expn_data.push(Some(expn_data)); | |
206 | let _eid = data.local_expn_hashes.push(expn_hash); | |
207 | debug_assert_eq!(expn_id, _eid); | |
208 | let _old_id = data.expn_hash_to_expn_id.insert(expn_hash, expn_id.to_expn_id()); | |
209 | debug_assert!(_old_id.is_none()); | |
210 | expn_id | |
211 | }) | |
c30ab7b3 SL |
212 | } |
213 | ||
ff7c6d11 | 214 | #[inline] |
136023e0 XL |
215 | pub fn expn_hash(self) -> ExpnHash { |
216 | HygieneData::with(|data| data.local_expn_hash(self)) | |
32a655c1 SL |
217 | } |
218 | ||
b7449926 | 219 | #[inline] |
e1599b0c | 220 | pub fn expn_data(self) -> ExpnData { |
136023e0 | 221 | HygieneData::with(|data| data.local_expn_data(self).clone()) |
b7449926 XL |
222 | } |
223 | ||
ff7c6d11 | 224 | #[inline] |
136023e0 XL |
225 | pub fn to_expn_id(self) -> ExpnId { |
226 | ExpnId { krate: LOCAL_CRATE, local_id: self.as_raw() } | |
227 | } | |
228 | ||
229 | #[inline] | |
230 | pub fn set_expn_data(self, mut expn_data: ExpnData, ctx: impl HashStableContext) { | |
231 | debug_assert_eq!(expn_data.parent.krate, LOCAL_CRATE); | |
232 | let expn_hash = update_disambiguator(&mut expn_data, ctx); | |
416331ca | 233 | HygieneData::with(|data| { |
136023e0 | 234 | let old_expn_data = &mut data.local_expn_data[self]; |
e1599b0c XL |
235 | assert!(old_expn_data.is_none(), "expansion data is reset for an expansion ID"); |
236 | *old_expn_data = Some(expn_data); | |
136023e0 XL |
237 | debug_assert_eq!(data.local_expn_hashes[self].0, Fingerprint::ZERO); |
238 | data.local_expn_hashes[self] = expn_hash; | |
239 | let _old_id = data.expn_hash_to_expn_id.insert(expn_hash, self.to_expn_id()); | |
240 | debug_assert!(_old_id.is_none()); | |
5869c6ff | 241 | }); |
136023e0 XL |
242 | } |
243 | ||
244 | #[inline] | |
245 | pub fn is_descendant_of(self, ancestor: LocalExpnId) -> bool { | |
246 | self.to_expn_id().is_descendant_of(ancestor.to_expn_id()) | |
247 | } | |
248 | ||
249 | /// `expn_id.outer_expn_is_descendant_of(ctxt)` is equivalent to but faster than | |
250 | /// `expn_id.is_descendant_of(ctxt.outer_expn())`. | |
251 | #[inline] | |
252 | pub fn outer_expn_is_descendant_of(self, ctxt: SyntaxContext) -> bool { | |
253 | self.to_expn_id().outer_expn_is_descendant_of(ctxt) | |
254 | } | |
255 | ||
256 | /// Returns span for the macro which originally caused this expansion to happen. | |
257 | /// | |
258 | /// Stops backtracing at include! boundary. | |
259 | #[inline] | |
260 | pub fn expansion_cause(self) -> Option<Span> { | |
261 | self.to_expn_id().expansion_cause() | |
262 | } | |
263 | ||
264 | #[inline] | |
265 | #[track_caller] | |
266 | pub fn parent(self) -> LocalExpnId { | |
267 | self.expn_data().parent.as_local().unwrap() | |
268 | } | |
269 | } | |
270 | ||
271 | impl ExpnId { | |
272 | /// The ID of the theoretical expansion that generates freshly parsed, unexpanded AST. | |
273 | /// Invariant: we do not create any ExpnId with local_id == 0 and krate != 0. | |
274 | pub const fn root() -> ExpnId { | |
275 | ExpnId { krate: LOCAL_CRATE, local_id: ExpnIndex::from_u32(0) } | |
276 | } | |
277 | ||
278 | #[inline] | |
279 | pub fn expn_hash(self) -> ExpnHash { | |
280 | HygieneData::with(|data| data.expn_hash(self)) | |
281 | } | |
282 | ||
283 | #[inline] | |
284 | pub fn from_hash(hash: ExpnHash) -> Option<ExpnId> { | |
285 | HygieneData::with(|data| data.expn_hash_to_expn_id.get(&hash).copied()) | |
286 | } | |
287 | ||
288 | #[inline] | |
289 | pub fn as_local(self) -> Option<LocalExpnId> { | |
290 | if self.krate == LOCAL_CRATE { Some(LocalExpnId::from_raw(self.local_id)) } else { None } | |
291 | } | |
292 | ||
293 | #[inline] | |
294 | #[track_caller] | |
295 | pub fn expect_local(self) -> LocalExpnId { | |
296 | self.as_local().unwrap() | |
297 | } | |
298 | ||
299 | #[inline] | |
300 | pub fn expn_data(self) -> ExpnData { | |
301 | HygieneData::with(|data| data.expn_data(self).clone()) | |
7cac9316 XL |
302 | } |
303 | ||
a2a8927a | 304 | #[inline] |
416331ca | 305 | pub fn is_descendant_of(self, ancestor: ExpnId) -> bool { |
a2a8927a XL |
306 | // a few "fast path" cases to avoid locking HygieneData |
307 | if ancestor == ExpnId::root() || ancestor == self { | |
308 | return true; | |
309 | } | |
310 | if ancestor.krate != self.krate { | |
311 | return false; | |
312 | } | |
dc9dc135 | 313 | HygieneData::with(|data| data.is_descendant_of(self, ancestor)) |
7cac9316 XL |
314 | } |
315 | ||
416331ca XL |
316 | /// `expn_id.outer_expn_is_descendant_of(ctxt)` is equivalent to but faster than |
317 | /// `expn_id.is_descendant_of(ctxt.outer_expn())`. | |
318 | pub fn outer_expn_is_descendant_of(self, ctxt: SyntaxContext) -> bool { | |
319 | HygieneData::with(|data| data.is_descendant_of(self, data.outer_expn(ctxt))) | |
83c7162d | 320 | } |
60c5eb7d XL |
321 | |
322 | /// Returns span for the macro which originally caused this expansion to happen. | |
323 | /// | |
324 | /// Stops backtracing at include! boundary. | |
325 | pub fn expansion_cause(mut self) -> Option<Span> { | |
326 | let mut last_macro = None; | |
327 | loop { | |
328 | let expn_data = self.expn_data(); | |
329 | // Stop going up the backtrace once include! is encountered | |
dfeec247 | 330 | if expn_data.is_root() |
136023e0 | 331 | || expn_data.kind == ExpnKind::Macro(MacroKind::Bang, sym::include) |
dfeec247 | 332 | { |
60c5eb7d XL |
333 | break; |
334 | } | |
335 | self = expn_data.call_site.ctxt().outer_expn(); | |
336 | last_macro = Some(expn_data.call_site); | |
337 | } | |
338 | last_macro | |
339 | } | |
5bcae85e SL |
340 | } |
341 | ||
8faf50e0 | 342 | #[derive(Debug)] |
3dfed10e | 343 | pub struct HygieneData { |
e1599b0c XL |
344 | /// Each expansion should have an associated expansion data, but sometimes there's a delay |
345 | /// between creation of an expansion ID and obtaining its data (e.g. macros are collected | |
346 | /// first and then resolved later), so we use an `Option` here. | |
136023e0 XL |
347 | local_expn_data: IndexVec<LocalExpnId, Option<ExpnData>>, |
348 | local_expn_hashes: IndexVec<LocalExpnId, ExpnHash>, | |
349 | /// Data and hash information from external crates. We may eventually want to remove these | |
350 | /// maps, and fetch the information directly from the other crate's metadata like DefIds do. | |
351 | foreign_expn_data: FxHashMap<ExpnId, ExpnData>, | |
352 | foreign_expn_hashes: FxHashMap<ExpnId, ExpnHash>, | |
353 | expn_hash_to_expn_id: UnhashMap<ExpnHash, ExpnId>, | |
416331ca XL |
354 | syntax_context_data: Vec<SyntaxContextData>, |
355 | syntax_context_map: FxHashMap<(SyntaxContext, ExpnId, Transparency), SyntaxContext>, | |
136023e0 | 356 | /// Maps the `local_hash` of an `ExpnData` to the next disambiguator value. |
5869c6ff XL |
357 | /// This is used by `update_disambiguator` to keep track of which `ExpnData`s |
358 | /// would have collisions without a disambiguator. | |
359 | /// The keys of this map are always computed with `ExpnData.disambiguator` | |
360 | /// set to 0. | |
136023e0 | 361 | expn_data_disambiguators: FxHashMap<u64, u32>, |
5bcae85e SL |
362 | } |
363 | ||
364 | impl HygieneData { | |
416331ca | 365 | crate fn new(edition: Edition) -> Self { |
136023e0 | 366 | let root_data = ExpnData::default( |
3dfed10e XL |
367 | ExpnKind::Root, |
368 | DUMMY_SP, | |
369 | edition, | |
136023e0 XL |
370 | Some(CRATE_DEF_ID.to_def_id()), |
371 | None, | |
3dfed10e | 372 | ); |
3dfed10e | 373 | |
5bcae85e | 374 | HygieneData { |
136023e0 XL |
375 | local_expn_data: IndexVec::from_elem_n(Some(root_data), 1), |
376 | local_expn_hashes: IndexVec::from_elem_n(ExpnHash(Fingerprint::ZERO), 1), | |
377 | foreign_expn_data: FxHashMap::default(), | |
378 | foreign_expn_hashes: FxHashMap::default(), | |
379 | expn_hash_to_expn_id: std::iter::once((ExpnHash(Fingerprint::ZERO), ExpnId::root())) | |
380 | .collect(), | |
416331ca XL |
381 | syntax_context_data: vec![SyntaxContextData { |
382 | outer_expn: ExpnId::root(), | |
383 | outer_transparency: Transparency::Opaque, | |
384 | parent: SyntaxContext(0), | |
8faf50e0 XL |
385 | opaque: SyntaxContext(0), |
386 | opaque_and_semitransparent: SyntaxContext(0), | |
dc9dc135 | 387 | dollar_crate_name: kw::DollarCrate, |
ff7c6d11 | 388 | }], |
416331ca | 389 | syntax_context_map: FxHashMap::default(), |
5869c6ff | 390 | expn_data_disambiguators: FxHashMap::default(), |
5bcae85e SL |
391 | } |
392 | } | |
393 | ||
3dfed10e | 394 | pub fn with<T, F: FnOnce(&mut HygieneData) -> T>(f: F) -> T { |
136023e0 | 395 | with_session_globals(|session_globals| f(&mut *session_globals.hygiene_data.borrow_mut())) |
5bcae85e | 396 | } |
5bcae85e | 397 | |
136023e0 XL |
398 | #[inline] |
399 | fn local_expn_hash(&self, expn_id: LocalExpnId) -> ExpnHash { | |
400 | self.local_expn_hashes[expn_id] | |
401 | } | |
402 | ||
403 | #[inline] | |
404 | fn expn_hash(&self, expn_id: ExpnId) -> ExpnHash { | |
405 | match expn_id.as_local() { | |
406 | Some(expn_id) => self.local_expn_hashes[expn_id], | |
407 | None => self.foreign_expn_hashes[&expn_id], | |
3dfed10e | 408 | } |
136023e0 XL |
409 | } |
410 | ||
411 | fn local_expn_data(&self, expn_id: LocalExpnId) -> &ExpnData { | |
412 | self.local_expn_data[expn_id].as_ref().expect("no expansion data for an expansion ID") | |
dc9dc135 XL |
413 | } |
414 | ||
e1599b0c | 415 | fn expn_data(&self, expn_id: ExpnId) -> &ExpnData { |
136023e0 XL |
416 | if let Some(expn_id) = expn_id.as_local() { |
417 | self.local_expn_data[expn_id].as_ref().expect("no expansion data for an expansion ID") | |
418 | } else { | |
419 | &self.foreign_expn_data[&expn_id] | |
420 | } | |
416331ca XL |
421 | } |
422 | ||
423 | fn is_descendant_of(&self, mut expn_id: ExpnId, ancestor: ExpnId) -> bool { | |
a2a8927a XL |
424 | // a couple "fast path" cases to avoid traversing parents in the loop below |
425 | if ancestor == ExpnId::root() { | |
426 | return true; | |
427 | } | |
428 | if expn_id.krate != ancestor.krate { | |
429 | return false; | |
430 | } | |
431 | loop { | |
432 | if expn_id == ancestor { | |
433 | return true; | |
434 | } | |
416331ca | 435 | if expn_id == ExpnId::root() { |
dc9dc135 XL |
436 | return false; |
437 | } | |
e1599b0c | 438 | expn_id = self.expn_data(expn_id).parent; |
dc9dc135 | 439 | } |
dc9dc135 XL |
440 | } |
441 | ||
ba9703b0 | 442 | fn normalize_to_macros_2_0(&self, ctxt: SyntaxContext) -> SyntaxContext { |
416331ca | 443 | self.syntax_context_data[ctxt.0 as usize].opaque |
dc9dc135 XL |
444 | } |
445 | ||
ba9703b0 | 446 | fn normalize_to_macro_rules(&self, ctxt: SyntaxContext) -> SyntaxContext { |
416331ca | 447 | self.syntax_context_data[ctxt.0 as usize].opaque_and_semitransparent |
dc9dc135 XL |
448 | } |
449 | ||
416331ca XL |
450 | fn outer_expn(&self, ctxt: SyntaxContext) -> ExpnId { |
451 | self.syntax_context_data[ctxt.0 as usize].outer_expn | |
dc9dc135 XL |
452 | } |
453 | ||
e1599b0c XL |
454 | fn outer_mark(&self, ctxt: SyntaxContext) -> (ExpnId, Transparency) { |
455 | let data = &self.syntax_context_data[ctxt.0 as usize]; | |
456 | (data.outer_expn, data.outer_transparency) | |
dc9dc135 XL |
457 | } |
458 | ||
416331ca XL |
459 | fn parent_ctxt(&self, ctxt: SyntaxContext) -> SyntaxContext { |
460 | self.syntax_context_data[ctxt.0 as usize].parent | |
dc9dc135 XL |
461 | } |
462 | ||
e1599b0c XL |
463 | fn remove_mark(&self, ctxt: &mut SyntaxContext) -> (ExpnId, Transparency) { |
464 | let outer_mark = self.outer_mark(*ctxt); | |
416331ca | 465 | *ctxt = self.parent_ctxt(*ctxt); |
e1599b0c | 466 | outer_mark |
dc9dc135 XL |
467 | } |
468 | ||
416331ca | 469 | fn marks(&self, mut ctxt: SyntaxContext) -> Vec<(ExpnId, Transparency)> { |
dc9dc135 | 470 | let mut marks = Vec::new(); |
e1599b0c | 471 | while ctxt != SyntaxContext::root() { |
3dfed10e | 472 | debug!("marks: getting parent of {:?}", ctxt); |
e1599b0c | 473 | marks.push(self.outer_mark(ctxt)); |
416331ca | 474 | ctxt = self.parent_ctxt(ctxt); |
dc9dc135 XL |
475 | } |
476 | marks.reverse(); | |
477 | marks | |
478 | } | |
479 | ||
480 | fn walk_chain(&self, mut span: Span, to: SyntaxContext) -> Span { | |
3dfed10e XL |
481 | debug!("walk_chain({:?}, {:?})", span, to); |
482 | debug!("walk_chain: span ctxt = {:?}", span.ctxt()); | |
e1599b0c | 483 | while span.from_expansion() && span.ctxt() != to { |
3dfed10e XL |
484 | let outer_expn = self.outer_expn(span.ctxt()); |
485 | debug!("walk_chain({:?}): outer_expn={:?}", span, outer_expn); | |
486 | let expn_data = self.expn_data(outer_expn); | |
487 | debug!("walk_chain({:?}): expn_data={:?}", span, expn_data); | |
488 | span = expn_data.call_site; | |
dc9dc135 XL |
489 | } |
490 | span | |
491 | } | |
492 | ||
416331ca | 493 | fn adjust(&self, ctxt: &mut SyntaxContext, expn_id: ExpnId) -> Option<ExpnId> { |
dc9dc135 | 494 | let mut scope = None; |
416331ca | 495 | while !self.is_descendant_of(expn_id, self.outer_expn(*ctxt)) { |
e1599b0c | 496 | scope = Some(self.remove_mark(ctxt).0); |
dc9dc135 XL |
497 | } |
498 | scope | |
499 | } | |
500 | ||
e1599b0c | 501 | fn apply_mark( |
dfeec247 XL |
502 | &mut self, |
503 | ctxt: SyntaxContext, | |
504 | expn_id: ExpnId, | |
505 | transparency: Transparency, | |
e1599b0c | 506 | ) -> SyntaxContext { |
416331ca | 507 | assert_ne!(expn_id, ExpnId::root()); |
dc9dc135 | 508 | if transparency == Transparency::Opaque { |
416331ca | 509 | return self.apply_mark_internal(ctxt, expn_id, transparency); |
dc9dc135 XL |
510 | } |
511 | ||
e1599b0c | 512 | let call_site_ctxt = self.expn_data(expn_id).call_site.ctxt(); |
dc9dc135 | 513 | let mut call_site_ctxt = if transparency == Transparency::SemiTransparent { |
ba9703b0 | 514 | self.normalize_to_macros_2_0(call_site_ctxt) |
dc9dc135 | 515 | } else { |
ba9703b0 | 516 | self.normalize_to_macro_rules(call_site_ctxt) |
dc9dc135 XL |
517 | }; |
518 | ||
e1599b0c | 519 | if call_site_ctxt == SyntaxContext::root() { |
416331ca | 520 | return self.apply_mark_internal(ctxt, expn_id, transparency); |
dc9dc135 XL |
521 | } |
522 | ||
416331ca | 523 | // Otherwise, `expn_id` is a macros 1.0 definition and the call site is in a |
dc9dc135 XL |
524 | // macros 2.0 expansion, i.e., a macros 1.0 invocation is in a macros 2.0 definition. |
525 | // | |
526 | // In this case, the tokens from the macros 1.0 definition inherit the hygiene | |
527 | // at their invocation. That is, we pretend that the macros 1.0 definition | |
528 | // was defined at its invocation (i.e., inside the macros 2.0 definition) | |
529 | // so that the macros 2.0 definition remains hygienic. | |
530 | // | |
416331ca XL |
531 | // See the example at `test/ui/hygiene/legacy_interaction.rs`. |
532 | for (expn_id, transparency) in self.marks(ctxt) { | |
533 | call_site_ctxt = self.apply_mark_internal(call_site_ctxt, expn_id, transparency); | |
dc9dc135 | 534 | } |
416331ca | 535 | self.apply_mark_internal(call_site_ctxt, expn_id, transparency) |
dc9dc135 XL |
536 | } |
537 | ||
416331ca | 538 | fn apply_mark_internal( |
dfeec247 XL |
539 | &mut self, |
540 | ctxt: SyntaxContext, | |
541 | expn_id: ExpnId, | |
542 | transparency: Transparency, | |
416331ca XL |
543 | ) -> SyntaxContext { |
544 | let syntax_context_data = &mut self.syntax_context_data; | |
545 | let mut opaque = syntax_context_data[ctxt.0 as usize].opaque; | |
dc9dc135 | 546 | let mut opaque_and_semitransparent = |
416331ca | 547 | syntax_context_data[ctxt.0 as usize].opaque_and_semitransparent; |
dc9dc135 XL |
548 | |
549 | if transparency >= Transparency::Opaque { | |
416331ca | 550 | let parent = opaque; |
dfeec247 XL |
551 | opaque = *self |
552 | .syntax_context_map | |
553 | .entry((parent, expn_id, transparency)) | |
554 | .or_insert_with(|| { | |
555 | let new_opaque = SyntaxContext(syntax_context_data.len() as u32); | |
556 | syntax_context_data.push(SyntaxContextData { | |
557 | outer_expn: expn_id, | |
558 | outer_transparency: transparency, | |
559 | parent, | |
560 | opaque: new_opaque, | |
561 | opaque_and_semitransparent: new_opaque, | |
562 | dollar_crate_name: kw::DollarCrate, | |
563 | }); | |
564 | new_opaque | |
dc9dc135 | 565 | }); |
dc9dc135 XL |
566 | } |
567 | ||
568 | if transparency >= Transparency::SemiTransparent { | |
416331ca | 569 | let parent = opaque_and_semitransparent; |
dfeec247 XL |
570 | opaque_and_semitransparent = *self |
571 | .syntax_context_map | |
572 | .entry((parent, expn_id, transparency)) | |
573 | .or_insert_with(|| { | |
574 | let new_opaque_and_semitransparent = | |
575 | SyntaxContext(syntax_context_data.len() as u32); | |
576 | syntax_context_data.push(SyntaxContextData { | |
577 | outer_expn: expn_id, | |
578 | outer_transparency: transparency, | |
579 | parent, | |
580 | opaque, | |
581 | opaque_and_semitransparent: new_opaque_and_semitransparent, | |
582 | dollar_crate_name: kw::DollarCrate, | |
583 | }); | |
584 | new_opaque_and_semitransparent | |
dc9dc135 | 585 | }); |
dc9dc135 XL |
586 | } |
587 | ||
416331ca XL |
588 | let parent = ctxt; |
589 | *self.syntax_context_map.entry((parent, expn_id, transparency)).or_insert_with(|| { | |
dc9dc135 | 590 | let new_opaque_and_semitransparent_and_transparent = |
416331ca XL |
591 | SyntaxContext(syntax_context_data.len() as u32); |
592 | syntax_context_data.push(SyntaxContextData { | |
593 | outer_expn: expn_id, | |
594 | outer_transparency: transparency, | |
595 | parent, | |
dc9dc135 XL |
596 | opaque, |
597 | opaque_and_semitransparent, | |
598 | dollar_crate_name: kw::DollarCrate, | |
599 | }); | |
600 | new_opaque_and_semitransparent_and_transparent | |
601 | }) | |
602 | } | |
94b46f34 XL |
603 | } |
604 | ||
416331ca XL |
605 | pub fn clear_syntax_context_map() { |
606 | HygieneData::with(|data| data.syntax_context_map = FxHashMap::default()); | |
5bcae85e SL |
607 | } |
608 | ||
dc9dc135 XL |
609 | pub fn walk_chain(span: Span, to: SyntaxContext) -> Span { |
610 | HygieneData::with(|data| data.walk_chain(span, to)) | |
611 | } | |
612 | ||
416331ca XL |
613 | pub fn update_dollar_crate_names(mut get_name: impl FnMut(SyntaxContext) -> Symbol) { |
614 | // The new contexts that need updating are at the end of the list and have `$crate` as a name. | |
dfeec247 XL |
615 | let (len, to_update) = HygieneData::with(|data| { |
616 | ( | |
617 | data.syntax_context_data.len(), | |
618 | data.syntax_context_data | |
619 | .iter() | |
620 | .rev() | |
621 | .take_while(|scdata| scdata.dollar_crate_name == kw::DollarCrate) | |
622 | .count(), | |
623 | ) | |
624 | }); | |
416331ca XL |
625 | // The callback must be called from outside of the `HygieneData` lock, |
626 | // since it will try to acquire it too. | |
dfeec247 | 627 | let range_to_update = len - to_update..len; |
416331ca XL |
628 | let names: Vec<_> = |
629 | range_to_update.clone().map(|idx| get_name(SyntaxContext::from_u32(idx as u32))).collect(); | |
dfeec247 | 630 | HygieneData::with(|data| { |
cdc7bbd5 | 631 | range_to_update.zip(names).for_each(|(idx, name)| { |
dfeec247 XL |
632 | data.syntax_context_data[idx].dollar_crate_name = name; |
633 | }) | |
634 | }) | |
416331ca XL |
635 | } |
636 | ||
e1599b0c XL |
637 | pub fn debug_hygiene_data(verbose: bool) -> String { |
638 | HygieneData::with(|data| { | |
639 | if verbose { | |
640 | format!("{:#?}", data) | |
641 | } else { | |
642 | let mut s = String::from(""); | |
643 | s.push_str("Expansions:"); | |
136023e0 | 644 | let mut debug_expn_data = |(id, expn_data): (&ExpnId, &ExpnData)| { |
e1599b0c | 645 | s.push_str(&format!( |
136023e0 | 646 | "\n{:?}: parent: {:?}, call_site_ctxt: {:?}, def_site_ctxt: {:?}, kind: {:?}", |
e1599b0c | 647 | id, |
136023e0 XL |
648 | expn_data.parent, |
649 | expn_data.call_site.ctxt(), | |
650 | expn_data.def_site.ctxt(), | |
651 | expn_data.kind, | |
652 | )) | |
653 | }; | |
654 | data.local_expn_data.iter_enumerated().for_each(|(id, expn_data)| { | |
655 | let expn_data = expn_data.as_ref().expect("no expansion data for an expansion ID"); | |
656 | debug_expn_data((&id.to_expn_id(), expn_data)) | |
e1599b0c | 657 | }); |
c295e0f8 XL |
658 | // Sort the hash map for more reproducible output. |
659 | let mut foreign_expn_data: Vec<_> = data.foreign_expn_data.iter().collect(); | |
660 | foreign_expn_data.sort_by_key(|(id, _)| (id.krate, id.local_id)); | |
661 | foreign_expn_data.into_iter().for_each(debug_expn_data); | |
e1599b0c XL |
662 | s.push_str("\n\nSyntaxContexts:"); |
663 | data.syntax_context_data.iter().enumerate().for_each(|(id, ctxt)| { | |
664 | s.push_str(&format!( | |
665 | "\n#{}: parent: {:?}, outer_mark: ({:?}, {:?})", | |
dfeec247 | 666 | id, ctxt.parent, ctxt.outer_expn, ctxt.outer_transparency, |
e1599b0c XL |
667 | )); |
668 | }); | |
669 | s | |
670 | } | |
671 | }) | |
672 | } | |
673 | ||
5bcae85e | 674 | impl SyntaxContext { |
48663c56 | 675 | #[inline] |
e1599b0c | 676 | pub const fn root() -> Self { |
5bcae85e SL |
677 | SyntaxContext(0) |
678 | } | |
679 | ||
48663c56 | 680 | #[inline] |
8faf50e0 XL |
681 | crate fn as_u32(self) -> u32 { |
682 | self.0 | |
683 | } | |
684 | ||
48663c56 | 685 | #[inline] |
8faf50e0 XL |
686 | crate fn from_u32(raw: u32) -> SyntaxContext { |
687 | SyntaxContext(raw) | |
688 | } | |
689 | ||
416331ca | 690 | /// Extend a syntax context with a given expansion and transparency. |
e1599b0c XL |
691 | crate fn apply_mark(self, expn_id: ExpnId, transparency: Transparency) -> SyntaxContext { |
692 | HygieneData::with(|data| data.apply_mark(self, expn_id, transparency)) | |
5bcae85e | 693 | } |
cc61c64b | 694 | |
83c7162d XL |
695 | /// Pulls a single mark off of the syntax context. This effectively moves the |
696 | /// context up one macro definition level. That is, if we have a nested macro | |
697 | /// definition as follows: | |
698 | /// | |
699 | /// ```rust | |
700 | /// macro_rules! f { | |
701 | /// macro_rules! g { | |
702 | /// ... | |
703 | /// } | |
704 | /// } | |
705 | /// ``` | |
706 | /// | |
707 | /// and we have a SyntaxContext that is referring to something declared by an invocation | |
708 | /// of g (call it g1), calling remove_mark will result in the SyntaxContext for the | |
709 | /// invocation of f that created g1. | |
710 | /// Returns the mark that was removed. | |
416331ca | 711 | pub fn remove_mark(&mut self) -> ExpnId { |
e1599b0c | 712 | HygieneData::with(|data| data.remove_mark(self).0) |
7cac9316 XL |
713 | } |
714 | ||
416331ca | 715 | pub fn marks(self) -> Vec<(ExpnId, Transparency)> { |
dc9dc135 | 716 | HygieneData::with(|data| data.marks(self)) |
2c00a5a8 XL |
717 | } |
718 | ||
7cac9316 XL |
719 | /// Adjust this context for resolution in a scope created by the given expansion. |
720 | /// For example, consider the following three resolutions of `f`: | |
ff7c6d11 | 721 | /// |
7cac9316 XL |
722 | /// ```rust |
723 | /// mod foo { pub fn f() {} } // `f`'s `SyntaxContext` is empty. | |
724 | /// m!(f); | |
725 | /// macro m($f:ident) { | |
726 | /// mod bar { | |
416331ca | 727 | /// pub fn f() {} // `f`'s `SyntaxContext` has a single `ExpnId` from `m`. |
7cac9316 XL |
728 | /// pub fn $f() {} // `$f`'s `SyntaxContext` is empty. |
729 | /// } | |
416331ca | 730 | /// foo::f(); // `f`'s `SyntaxContext` has a single `ExpnId` from `m` |
7cac9316 XL |
731 | /// //^ Since `mod foo` is outside this expansion, `adjust` removes the mark from `f`, |
732 | /// //| and it resolves to `::foo::f`. | |
416331ca | 733 | /// bar::f(); // `f`'s `SyntaxContext` has a single `ExpnId` from `m` |
7cac9316 XL |
734 | /// //^ Since `mod bar` not outside this expansion, `adjust` does not change `f`, |
735 | /// //| and it resolves to `::bar::f`. | |
736 | /// bar::$f(); // `f`'s `SyntaxContext` is empty. | |
737 | /// //^ Since `mod bar` is not outside this expansion, `adjust` does not change `$f`, | |
738 | /// //| and it resolves to `::bar::$f`. | |
739 | /// } | |
740 | /// ``` | |
741 | /// This returns the expansion whose definition scope we use to privacy check the resolution, | |
0731742a | 742 | /// or `None` if we privacy check as usual (i.e., not w.r.t. a macro definition scope). |
416331ca XL |
743 | pub fn adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> { |
744 | HygieneData::with(|data| data.adjust(self, expn_id)) | |
dc9dc135 XL |
745 | } |
746 | ||
ba9703b0 XL |
747 | /// Like `SyntaxContext::adjust`, but also normalizes `self` to macros 2.0. |
748 | pub fn normalize_to_macros_2_0_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> { | |
dc9dc135 | 749 | HygieneData::with(|data| { |
ba9703b0 | 750 | *self = data.normalize_to_macros_2_0(*self); |
416331ca | 751 | data.adjust(self, expn_id) |
dc9dc135 | 752 | }) |
7cac9316 XL |
753 | } |
754 | ||
755 | /// Adjust this context for resolution in a scope created by the given expansion | |
756 | /// via a glob import with the given `SyntaxContext`. | |
ff7c6d11 XL |
757 | /// For example: |
758 | /// | |
7cac9316 XL |
759 | /// ```rust |
760 | /// m!(f); | |
761 | /// macro m($i:ident) { | |
762 | /// mod foo { | |
416331ca | 763 | /// pub fn f() {} // `f`'s `SyntaxContext` has a single `ExpnId` from `m`. |
7cac9316 XL |
764 | /// pub fn $i() {} // `$i`'s `SyntaxContext` is empty. |
765 | /// } | |
3c0e092e | 766 | /// n!(f); |
7cac9316 XL |
767 | /// macro n($j:ident) { |
768 | /// use foo::*; | |
769 | /// f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n` | |
770 | /// //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::f`. | |
771 | /// $i(); // `$i`'s `SyntaxContext` has a mark from `n` | |
772 | /// //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::$i`. | |
773 | /// $j(); // `$j`'s `SyntaxContext` has a mark from `m` | |
774 | /// //^ This cannot be glob-adjusted, so this is a resolution error. | |
775 | /// } | |
776 | /// } | |
777 | /// ``` | |
778 | /// This returns `None` if the context cannot be glob-adjusted. | |
779 | /// Otherwise, it returns the scope to use when privacy checking (see `adjust` for details). | |
416331ca | 780 | pub fn glob_adjust(&mut self, expn_id: ExpnId, glob_span: Span) -> Option<Option<ExpnId>> { |
dc9dc135 XL |
781 | HygieneData::with(|data| { |
782 | let mut scope = None; | |
ba9703b0 | 783 | let mut glob_ctxt = data.normalize_to_macros_2_0(glob_span.ctxt()); |
416331ca | 784 | while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) { |
e1599b0c XL |
785 | scope = Some(data.remove_mark(&mut glob_ctxt).0); |
786 | if data.remove_mark(self).0 != scope.unwrap() { | |
dc9dc135 XL |
787 | return None; |
788 | } | |
789 | } | |
416331ca | 790 | if data.adjust(self, expn_id).is_some() { |
7cac9316 XL |
791 | return None; |
792 | } | |
dc9dc135 XL |
793 | Some(scope) |
794 | }) | |
7cac9316 XL |
795 | } |
796 | ||
797 | /// Undo `glob_adjust` if possible: | |
ff7c6d11 | 798 | /// |
7cac9316 XL |
799 | /// ```rust |
800 | /// if let Some(privacy_checking_scope) = self.reverse_glob_adjust(expansion, glob_ctxt) { | |
801 | /// assert!(self.glob_adjust(expansion, glob_ctxt) == Some(privacy_checking_scope)); | |
802 | /// } | |
803 | /// ``` | |
dfeec247 XL |
804 | pub fn reverse_glob_adjust( |
805 | &mut self, | |
806 | expn_id: ExpnId, | |
807 | glob_span: Span, | |
808 | ) -> Option<Option<ExpnId>> { | |
dc9dc135 | 809 | HygieneData::with(|data| { |
416331ca | 810 | if data.adjust(self, expn_id).is_some() { |
dc9dc135 XL |
811 | return None; |
812 | } | |
7cac9316 | 813 | |
ba9703b0 | 814 | let mut glob_ctxt = data.normalize_to_macros_2_0(glob_span.ctxt()); |
dc9dc135 | 815 | let mut marks = Vec::new(); |
416331ca | 816 | while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) { |
dc9dc135 XL |
817 | marks.push(data.remove_mark(&mut glob_ctxt)); |
818 | } | |
7cac9316 | 819 | |
e1599b0c XL |
820 | let scope = marks.last().map(|mark| mark.0); |
821 | while let Some((expn_id, transparency)) = marks.pop() { | |
822 | *self = data.apply_mark(*self, expn_id, transparency); | |
dc9dc135 XL |
823 | } |
824 | Some(scope) | |
825 | }) | |
826 | } | |
827 | ||
416331ca | 828 | pub fn hygienic_eq(self, other: SyntaxContext, expn_id: ExpnId) -> bool { |
dc9dc135 | 829 | HygieneData::with(|data| { |
ba9703b0 XL |
830 | let mut self_normalized = data.normalize_to_macros_2_0(self); |
831 | data.adjust(&mut self_normalized, expn_id); | |
832 | self_normalized == data.normalize_to_macros_2_0(other) | |
dc9dc135 | 833 | }) |
7cac9316 XL |
834 | } |
835 | ||
ff7c6d11 | 836 | #[inline] |
ba9703b0 XL |
837 | pub fn normalize_to_macros_2_0(self) -> SyntaxContext { |
838 | HygieneData::with(|data| data.normalize_to_macros_2_0(self)) | |
8faf50e0 XL |
839 | } |
840 | ||
841 | #[inline] | |
ba9703b0 XL |
842 | pub fn normalize_to_macro_rules(self) -> SyntaxContext { |
843 | HygieneData::with(|data| data.normalize_to_macro_rules(self)) | |
7cac9316 XL |
844 | } |
845 | ||
ff7c6d11 | 846 | #[inline] |
416331ca XL |
847 | pub fn outer_expn(self) -> ExpnId { |
848 | HygieneData::with(|data| data.outer_expn(self)) | |
dc9dc135 XL |
849 | } |
850 | ||
e1599b0c XL |
851 | /// `ctxt.outer_expn_data()` is equivalent to but faster than |
852 | /// `ctxt.outer_expn().expn_data()`. | |
dc9dc135 | 853 | #[inline] |
e1599b0c XL |
854 | pub fn outer_expn_data(self) -> ExpnData { |
855 | HygieneData::with(|data| data.expn_data(data.outer_expn(self)).clone()) | |
dc9dc135 XL |
856 | } |
857 | ||
3dfed10e XL |
858 | #[inline] |
859 | pub fn outer_mark(self) -> (ExpnId, Transparency) { | |
860 | HygieneData::with(|data| data.outer_mark(self)) | |
861 | } | |
862 | ||
0731742a | 863 | pub fn dollar_crate_name(self) -> Symbol { |
416331ca | 864 | HygieneData::with(|data| data.syntax_context_data[self.0 as usize].dollar_crate_name) |
0731742a | 865 | } |
5869c6ff XL |
866 | |
867 | pub fn edition(self) -> Edition { | |
136023e0 | 868 | HygieneData::with(|data| data.expn_data(data.outer_expn(self)).edition) |
5869c6ff | 869 | } |
5bcae85e SL |
870 | } |
871 | ||
872 | impl fmt::Debug for SyntaxContext { | |
9fa01778 | 873 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
5bcae85e SL |
874 | write!(f, "#{}", self.0) |
875 | } | |
876 | } | |
cc61c64b | 877 | |
416331ca XL |
878 | impl Span { |
879 | /// Creates a fresh expansion with given properties. | |
880 | /// Expansions are normally created by macros, but in some cases expansions are created for | |
881 | /// other compiler-generated code to set per-span properties like allowed unstable features. | |
882 | /// The returned span belongs to the created expansion and has the new properties, | |
883 | /// but its location is inherited from the current span. | |
ee023bcb | 884 | pub fn fresh_expansion(self, expn_id: LocalExpnId) -> Span { |
416331ca | 885 | HygieneData::with(|data| { |
ee023bcb FG |
886 | self.with_ctxt(data.apply_mark( |
887 | SyntaxContext::root(), | |
888 | expn_id.to_expn_id(), | |
889 | Transparency::Transparent, | |
890 | )) | |
416331ca XL |
891 | }) |
892 | } | |
5869c6ff XL |
893 | |
894 | /// Reuses the span but adds information like the kind of the desugaring and features that are | |
895 | /// allowed inside this span. | |
896 | pub fn mark_with_reason( | |
897 | self, | |
898 | allow_internal_unstable: Option<Lrc<[Symbol]>>, | |
899 | reason: DesugaringKind, | |
900 | edition: Edition, | |
136023e0 | 901 | ctx: impl HashStableContext, |
5869c6ff | 902 | ) -> Span { |
136023e0 | 903 | let expn_data = ExpnData { |
5869c6ff | 904 | allow_internal_unstable, |
136023e0 XL |
905 | ..ExpnData::default(ExpnKind::Desugaring(reason), self, edition, None, None) |
906 | }; | |
ee023bcb FG |
907 | let expn_id = LocalExpnId::fresh(expn_data, ctx); |
908 | self.fresh_expansion(expn_id) | |
5869c6ff | 909 | } |
416331ca XL |
910 | } |
911 | ||
912 | /// A subset of properties from both macro definition and macro call available through global data. | |
913 | /// Avoid using this if you have access to the original definition or call structures. | |
3dfed10e | 914 | #[derive(Clone, Debug, Encodable, Decodable, HashStable_Generic)] |
e1599b0c | 915 | pub struct ExpnData { |
dc9dc135 | 916 | // --- The part unique to each expansion. |
e1599b0c XL |
917 | /// The kind of this expansion - macro or compiler desugaring. |
918 | pub kind: ExpnKind, | |
919 | /// The expansion that produced this expansion. | |
920 | pub parent: ExpnId, | |
cc61c64b XL |
921 | /// The location of the actual macro invocation or syntax sugar , e.g. |
922 | /// `let x = foo!();` or `if let Some(y) = x {}` | |
923 | /// | |
0731742a | 924 | /// This may recursively refer to other macro invocations, e.g., if |
cc61c64b XL |
925 | /// `foo!()` invoked `bar!()` internally, and there was an |
926 | /// expression inside `bar!`; the call_site of the expression in | |
927 | /// the expansion would point to the `bar!` invocation; that | |
e1599b0c | 928 | /// call_site span would have its own ExpnData, with the call_site |
cc61c64b XL |
929 | /// pointing to the `foo!` invocation. |
930 | pub call_site: Span, | |
136023e0 XL |
931 | /// Used to force two `ExpnData`s to have different `Fingerprint`s. |
932 | /// Due to macro expansion, it's possible to end up with two `ExpnId`s | |
933 | /// that have identical `ExpnData`s. This violates the contract of `HashStable` | |
934 | /// - the two `ExpnId`s are not equal, but their `Fingerprint`s are equal | |
935 | /// (since the numerical `ExpnId` value is not considered by the `HashStable` | |
936 | /// implementation). | |
937 | /// | |
938 | /// The `disambiguator` field is set by `update_disambiguator` when two distinct | |
939 | /// `ExpnId`s would end up with the same `Fingerprint`. Since `ExpnData` includes | |
940 | /// a `krate` field, this value only needs to be unique within a single crate. | |
941 | disambiguator: u32, | |
dc9dc135 XL |
942 | |
943 | // --- The part specific to the macro/desugaring definition. | |
e1599b0c XL |
944 | // --- It may be reasonable to share this part between expansions with the same definition, |
945 | // --- but such sharing is known to bring some minor inconveniences without also bringing | |
946 | // --- noticeable perf improvements (PR #62898). | |
416331ca | 947 | /// The span of the macro definition (possibly dummy). |
8faf50e0 | 948 | /// This span serves only informational purpose and is not used for resolution. |
416331ca | 949 | pub def_site: Span, |
f9f354fc | 950 | /// List of `#[unstable]`/feature-gated features that the macro is allowed to use |
9fa01778 | 951 | /// internally without forcing the whole crate to opt-in |
cc61c64b | 952 | /// to them. |
9fa01778 | 953 | pub allow_internal_unstable: Option<Lrc<[Symbol]>>, |
3b2f2976 XL |
954 | /// Whether the macro is allowed to use `unsafe` internally |
955 | /// even if the user crate has `#![forbid(unsafe_code)]`. | |
956 | pub allow_internal_unsafe: bool, | |
8faf50e0 XL |
957 | /// Enables the macro helper hack (`ident!(...)` -> `$crate::ident!(...)`) |
958 | /// for a given macro. | |
959 | pub local_inner_macros: bool, | |
94b46f34 XL |
960 | /// Edition of the crate in which the macro is defined. |
961 | pub edition: Edition, | |
f9f354fc XL |
962 | /// The `DefId` of the macro being invoked, |
963 | /// if this `ExpnData` corresponds to a macro invocation | |
964 | pub macro_def_id: Option<DefId>, | |
136023e0 XL |
965 | /// The normal module (`mod`) in which the expanded macro was defined. |
966 | pub parent_module: Option<DefId>, | |
cc61c64b XL |
967 | } |
968 | ||
3dfed10e | 969 | impl !PartialEq for ExpnData {} |
5869c6ff | 970 | impl !Hash for ExpnData {} |
3dfed10e | 971 | |
e1599b0c | 972 | impl ExpnData { |
5869c6ff XL |
973 | pub fn new( |
974 | kind: ExpnKind, | |
975 | parent: ExpnId, | |
976 | call_site: Span, | |
977 | def_site: Span, | |
978 | allow_internal_unstable: Option<Lrc<[Symbol]>>, | |
979 | allow_internal_unsafe: bool, | |
980 | local_inner_macros: bool, | |
981 | edition: Edition, | |
982 | macro_def_id: Option<DefId>, | |
136023e0 | 983 | parent_module: Option<DefId>, |
5869c6ff XL |
984 | ) -> ExpnData { |
985 | ExpnData { | |
986 | kind, | |
987 | parent, | |
988 | call_site, | |
989 | def_site, | |
990 | allow_internal_unstable, | |
991 | allow_internal_unsafe, | |
992 | local_inner_macros, | |
993 | edition, | |
994 | macro_def_id, | |
136023e0 | 995 | parent_module, |
5869c6ff XL |
996 | disambiguator: 0, |
997 | } | |
998 | } | |
999 | ||
e1599b0c | 1000 | /// Constructs expansion data with default properties. |
f9f354fc XL |
1001 | pub fn default( |
1002 | kind: ExpnKind, | |
1003 | call_site: Span, | |
1004 | edition: Edition, | |
1005 | macro_def_id: Option<DefId>, | |
136023e0 | 1006 | parent_module: Option<DefId>, |
f9f354fc | 1007 | ) -> ExpnData { |
e1599b0c | 1008 | ExpnData { |
416331ca | 1009 | kind, |
e1599b0c XL |
1010 | parent: ExpnId::root(), |
1011 | call_site, | |
416331ca | 1012 | def_site: DUMMY_SP, |
dc9dc135 XL |
1013 | allow_internal_unstable: None, |
1014 | allow_internal_unsafe: false, | |
1015 | local_inner_macros: false, | |
1016 | edition, | |
f9f354fc | 1017 | macro_def_id, |
136023e0 | 1018 | parent_module, |
5869c6ff | 1019 | disambiguator: 0, |
dc9dc135 XL |
1020 | } |
1021 | } | |
1022 | ||
dfeec247 XL |
1023 | pub fn allow_unstable( |
1024 | kind: ExpnKind, | |
1025 | call_site: Span, | |
1026 | edition: Edition, | |
1027 | allow_internal_unstable: Lrc<[Symbol]>, | |
f9f354fc | 1028 | macro_def_id: Option<DefId>, |
136023e0 | 1029 | parent_module: Option<DefId>, |
dfeec247 | 1030 | ) -> ExpnData { |
e1599b0c | 1031 | ExpnData { |
416331ca | 1032 | allow_internal_unstable: Some(allow_internal_unstable), |
136023e0 | 1033 | ..ExpnData::default(kind, call_site, edition, macro_def_id, parent_module) |
dc9dc135 XL |
1034 | } |
1035 | } | |
e1599b0c XL |
1036 | |
1037 | #[inline] | |
1038 | pub fn is_root(&self) -> bool { | |
1b1a35ee | 1039 | matches!(self.kind, ExpnKind::Root) |
e1599b0c | 1040 | } |
136023e0 XL |
1041 | |
1042 | #[inline] | |
1043 | fn hash_expn(&self, ctx: &mut impl HashStableContext) -> u64 { | |
1044 | let mut hasher = StableHasher::new(); | |
1045 | self.hash_stable(ctx, &mut hasher); | |
1046 | hasher.finish() | |
1047 | } | |
dc9dc135 XL |
1048 | } |
1049 | ||
416331ca | 1050 | /// Expansion kind. |
3dfed10e | 1051 | #[derive(Clone, Debug, PartialEq, Encodable, Decodable, HashStable_Generic)] |
416331ca XL |
1052 | pub enum ExpnKind { |
1053 | /// No expansion, aka root expansion. Only `ExpnId::root()` has this kind. | |
1054 | Root, | |
1055 | /// Expansion produced by a macro. | |
136023e0 | 1056 | Macro(MacroKind, Symbol), |
e1599b0c XL |
1057 | /// Transform done by the compiler on the AST. |
1058 | AstPass(AstPass), | |
cc61c64b | 1059 | /// Desugaring done by the compiler during HIR lowering. |
dfeec247 | 1060 | Desugaring(DesugaringKind), |
29967ef6 XL |
1061 | /// MIR inlining |
1062 | Inlined, | |
3b2f2976 XL |
1063 | } |
1064 | ||
416331ca | 1065 | impl ExpnKind { |
dfeec247 | 1066 | pub fn descr(&self) -> String { |
8faf50e0 | 1067 | match *self { |
dfeec247 | 1068 | ExpnKind::Root => kw::PathRoot.to_string(), |
136023e0 | 1069 | ExpnKind::Macro(macro_kind, name) => match macro_kind { |
dfeec247 XL |
1070 | MacroKind::Bang => format!("{}!", name), |
1071 | MacroKind::Attr => format!("#[{}]", name), | |
1072 | MacroKind::Derive => format!("#[derive({})]", name), | |
1073 | }, | |
1074 | ExpnKind::AstPass(kind) => kind.descr().to_string(), | |
1075 | ExpnKind::Desugaring(kind) => format!("desugaring of {}", kind.descr()), | |
29967ef6 | 1076 | ExpnKind::Inlined => "inlined source".to_string(), |
416331ca XL |
1077 | } |
1078 | } | |
1079 | } | |
1080 | ||
1081 | /// The kind of macro invocation or definition. | |
3dfed10e | 1082 | #[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)] |
ba9703b0 | 1083 | #[derive(HashStable_Generic)] |
416331ca XL |
1084 | pub enum MacroKind { |
1085 | /// A bang macro `foo!()`. | |
1086 | Bang, | |
1087 | /// An attribute macro `#[foo]`. | |
1088 | Attr, | |
1089 | /// A derive macro `#[derive(Foo)]` | |
1090 | Derive, | |
1091 | } | |
1092 | ||
1093 | impl MacroKind { | |
1094 | pub fn descr(self) -> &'static str { | |
1095 | match self { | |
1096 | MacroKind::Bang => "macro", | |
1097 | MacroKind::Attr => "attribute macro", | |
1098 | MacroKind::Derive => "derive macro", | |
1099 | } | |
1100 | } | |
1101 | ||
e1599b0c XL |
1102 | pub fn descr_expected(self) -> &'static str { |
1103 | match self { | |
1104 | MacroKind::Attr => "attribute", | |
1105 | _ => self.descr(), | |
1106 | } | |
1107 | } | |
1108 | ||
416331ca XL |
1109 | pub fn article(self) -> &'static str { |
1110 | match self { | |
1111 | MacroKind::Attr => "an", | |
1112 | _ => "a", | |
8faf50e0 XL |
1113 | } |
1114 | } | |
1115 | } | |
1116 | ||
e1599b0c | 1117 | /// The kind of AST transform. |
3dfed10e | 1118 | #[derive(Clone, Copy, Debug, PartialEq, Encodable, Decodable, HashStable_Generic)] |
e1599b0c XL |
1119 | pub enum AstPass { |
1120 | StdImports, | |
1121 | TestHarness, | |
1122 | ProcMacroHarness, | |
e1599b0c XL |
1123 | } |
1124 | ||
1125 | impl AstPass { | |
136023e0 | 1126 | pub fn descr(self) -> &'static str { |
e1599b0c XL |
1127 | match self { |
1128 | AstPass::StdImports => "standard library imports", | |
1129 | AstPass::TestHarness => "test harness", | |
1130 | AstPass::ProcMacroHarness => "proc macro harness", | |
e1599b0c XL |
1131 | } |
1132 | } | |
1133 | } | |
1134 | ||
3b2f2976 | 1135 | /// The kind of compiler desugaring. |
3dfed10e | 1136 | #[derive(Clone, Copy, PartialEq, Debug, Encodable, Decodable, HashStable_Generic)] |
416331ca | 1137 | pub enum DesugaringKind { |
48663c56 XL |
1138 | /// We desugar `if c { i } else { e }` to `match $ExprKind::Use(c) { true => i, _ => e }`. |
1139 | /// However, we do not want to blame `c` for unreachability but rather say that `i` | |
1140 | /// is unreachable. This desugaring kind allows us to avoid blaming `c`. | |
416331ca XL |
1141 | /// This also applies to `while` loops. |
1142 | CondTemporary, | |
3b2f2976 | 1143 | QuestionMark, |
b7449926 | 1144 | TryBlock, |
94b46f34 | 1145 | /// Desugaring of an `impl Trait` in return type position |
416331ca | 1146 | /// to an `type Foo = impl Trait;` and replacing the |
94b46f34 | 1147 | /// `impl Trait` with `Foo`. |
416331ca | 1148 | OpaqueTy, |
8faf50e0 | 1149 | Async, |
48663c56 | 1150 | Await, |
3c0e092e | 1151 | ForLoop, |
94222f64 | 1152 | LetElse, |
c295e0f8 | 1153 | WhileLoop, |
f035d41b XL |
1154 | } |
1155 | ||
416331ca XL |
1156 | impl DesugaringKind { |
1157 | /// The description wording should combine well with "desugaring of {}". | |
136023e0 | 1158 | pub fn descr(self) -> &'static str { |
416331ca XL |
1159 | match self { |
1160 | DesugaringKind::CondTemporary => "`if` or `while` condition", | |
1161 | DesugaringKind::Async => "`async` block or function", | |
1162 | DesugaringKind::Await => "`await` expression", | |
1163 | DesugaringKind::QuestionMark => "operator `?`", | |
1164 | DesugaringKind::TryBlock => "`try` block", | |
1165 | DesugaringKind::OpaqueTy => "`impl Trait`", | |
3c0e092e | 1166 | DesugaringKind::ForLoop => "`for` loop", |
94222f64 | 1167 | DesugaringKind::LetElse => "`let...else`", |
c295e0f8 | 1168 | DesugaringKind::WhileLoop => "`while` loop", |
416331ca | 1169 | } |
3b2f2976 | 1170 | } |
cc61c64b XL |
1171 | } |
1172 | ||
3dfed10e XL |
1173 | #[derive(Default)] |
1174 | pub struct HygieneEncodeContext { | |
1175 | /// All `SyntaxContexts` for which we have written `SyntaxContextData` into crate metadata. | |
1176 | /// This is `None` after we finish encoding `SyntaxContexts`, to ensure | |
1177 | /// that we don't accidentally try to encode any more `SyntaxContexts` | |
1178 | serialized_ctxts: Lock<FxHashSet<SyntaxContext>>, | |
1179 | /// The `SyntaxContexts` that we have serialized (e.g. as a result of encoding `Spans`) | |
ee023bcb | 1180 | /// in the most recent 'round' of serializing. Serializing `SyntaxContextData` |
3dfed10e XL |
1181 | /// may cause us to serialize more `SyntaxContext`s, so serialize in a loop |
1182 | /// until we reach a fixed point. | |
1183 | latest_ctxts: Lock<FxHashSet<SyntaxContext>>, | |
1184 | ||
1185 | serialized_expns: Lock<FxHashSet<ExpnId>>, | |
1186 | ||
1187 | latest_expns: Lock<FxHashSet<ExpnId>>, | |
1188 | } | |
1189 | ||
1190 | impl HygieneEncodeContext { | |
136023e0 XL |
1191 | /// Record the fact that we need to serialize the corresponding `ExpnData`. |
1192 | pub fn schedule_expn_data_for_encoding(&self, expn: ExpnId) { | |
1193 | if !self.serialized_expns.lock().contains(&expn) { | |
1194 | self.latest_expns.lock().insert(expn); | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | pub fn encode<T, R>( | |
3dfed10e XL |
1199 | &self, |
1200 | encoder: &mut T, | |
136023e0 XL |
1201 | mut encode_ctxt: impl FnMut(&mut T, u32, &SyntaxContextData) -> Result<(), R>, |
1202 | mut encode_expn: impl FnMut(&mut T, ExpnId, &ExpnData, ExpnHash) -> Result<(), R>, | |
3dfed10e XL |
1203 | ) -> Result<(), R> { |
1204 | // When we serialize a `SyntaxContextData`, we may end up serializing | |
1205 | // a `SyntaxContext` that we haven't seen before | |
1206 | while !self.latest_ctxts.lock().is_empty() || !self.latest_expns.lock().is_empty() { | |
1207 | debug!( | |
1208 | "encode_hygiene: Serializing a round of {:?} SyntaxContextDatas: {:?}", | |
1209 | self.latest_ctxts.lock().len(), | |
1210 | self.latest_ctxts | |
1211 | ); | |
1212 | ||
1213 | // Consume the current round of SyntaxContexts. | |
1214 | // Drop the lock() temporary early | |
1215 | let latest_ctxts = { std::mem::take(&mut *self.latest_ctxts.lock()) }; | |
1216 | ||
1217 | // It's fine to iterate over a HashMap, because the serialization | |
1218 | // of the table that we insert data into doesn't depend on insertion | |
1219 | // order | |
136023e0 | 1220 | for_all_ctxts_in(latest_ctxts.into_iter(), |index, ctxt, data| { |
3dfed10e XL |
1221 | if self.serialized_ctxts.lock().insert(ctxt) { |
1222 | encode_ctxt(encoder, index, data)?; | |
1223 | } | |
1224 | Ok(()) | |
1225 | })?; | |
1226 | ||
1227 | let latest_expns = { std::mem::take(&mut *self.latest_expns.lock()) }; | |
1228 | ||
136023e0 | 1229 | for_all_expns_in(latest_expns.into_iter(), |expn, data, hash| { |
3dfed10e | 1230 | if self.serialized_expns.lock().insert(expn) { |
136023e0 | 1231 | encode_expn(encoder, expn, data, hash)?; |
3dfed10e XL |
1232 | } |
1233 | Ok(()) | |
1234 | })?; | |
1235 | } | |
1236 | debug!("encode_hygiene: Done serializing SyntaxContextData"); | |
1237 | Ok(()) | |
1238 | } | |
1239 | } | |
1240 | ||
1241 | #[derive(Default)] | |
1242 | /// Additional information used to assist in decoding hygiene data | |
1243 | pub struct HygieneDecodeContext { | |
1244 | // Maps serialized `SyntaxContext` ids to a `SyntaxContext` in the current | |
1245 | // global `HygieneData`. When we deserialize a `SyntaxContext`, we need to create | |
1246 | // a new id in the global `HygieneData`. This map tracks the ID we end up picking, | |
1247 | // so that multiple occurrences of the same serialized id are decoded to the same | |
1248 | // `SyntaxContext` | |
1249 | remapped_ctxts: Lock<Vec<Option<SyntaxContext>>>, | |
3dfed10e XL |
1250 | } |
1251 | ||
136023e0 XL |
1252 | /// Register an expansion which has been decoded from the on-disk-cache for the local crate. |
1253 | pub fn register_local_expn_id(data: ExpnData, hash: ExpnHash) -> ExpnId { | |
1254 | HygieneData::with(|hygiene_data| { | |
1255 | let expn_id = hygiene_data.local_expn_data.next_index(); | |
1256 | hygiene_data.local_expn_data.push(Some(data)); | |
1257 | let _eid = hygiene_data.local_expn_hashes.push(hash); | |
1258 | debug_assert_eq!(expn_id, _eid); | |
1259 | ||
1260 | let expn_id = expn_id.to_expn_id(); | |
3dfed10e | 1261 | |
136023e0 XL |
1262 | let _old_id = hygiene_data.expn_hash_to_expn_id.insert(hash, expn_id); |
1263 | debug_assert!(_old_id.is_none()); | |
1264 | expn_id | |
1265 | }) | |
1266 | } | |
1267 | ||
1268 | /// Register an expansion which has been decoded from the metadata of a foreign crate. | |
1269 | pub fn register_expn_id( | |
1270 | krate: CrateNum, | |
1271 | local_id: ExpnIndex, | |
1272 | data: ExpnData, | |
1273 | hash: ExpnHash, | |
1274 | ) -> ExpnId { | |
a2a8927a | 1275 | debug_assert!(data.parent == ExpnId::root() || krate == data.parent.krate); |
136023e0 XL |
1276 | let expn_id = ExpnId { krate, local_id }; |
1277 | HygieneData::with(|hygiene_data| { | |
1278 | let _old_data = hygiene_data.foreign_expn_data.insert(expn_id, data); | |
1279 | debug_assert!(_old_data.is_none()); | |
1280 | let _old_hash = hygiene_data.foreign_expn_hashes.insert(expn_id, hash); | |
1281 | debug_assert!(_old_hash.is_none()); | |
1282 | let _old_id = hygiene_data.expn_hash_to_expn_id.insert(hash, expn_id); | |
1283 | debug_assert!(_old_id.is_none()); | |
1284 | }); | |
1285 | expn_id | |
1286 | } | |
1287 | ||
1288 | /// Decode an expansion from the metadata of a foreign crate. | |
1289 | pub fn decode_expn_id( | |
1290 | krate: CrateNum, | |
1291 | index: u32, | |
1292 | decode_data: impl FnOnce(ExpnId) -> (ExpnData, ExpnHash), | |
1293 | ) -> ExpnId { | |
1294 | if index == 0 { | |
3dfed10e | 1295 | debug!("decode_expn_id: deserialized root"); |
136023e0 | 1296 | return ExpnId::root(); |
3dfed10e XL |
1297 | } |
1298 | ||
136023e0 | 1299 | let index = ExpnIndex::from_u32(index); |
3dfed10e | 1300 | |
136023e0 XL |
1301 | // This function is used to decode metadata, so it cannot decode information about LOCAL_CRATE. |
1302 | debug_assert_ne!(krate, LOCAL_CRATE); | |
1303 | let expn_id = ExpnId { krate, local_id: index }; | |
1304 | ||
1305 | // Fast path if the expansion has already been decoded. | |
1306 | if HygieneData::with(|hygiene_data| hygiene_data.foreign_expn_data.contains_key(&expn_id)) { | |
1307 | return expn_id; | |
3dfed10e XL |
1308 | } |
1309 | ||
1310 | // Don't decode the data inside `HygieneData::with`, since we need to recursively decode | |
1311 | // other ExpnIds | |
136023e0 | 1312 | let (expn_data, hash) = decode_data(expn_id); |
3dfed10e | 1313 | |
136023e0 | 1314 | register_expn_id(krate, index, expn_data, hash) |
3dfed10e XL |
1315 | } |
1316 | ||
1317 | // Decodes `SyntaxContext`, using the provided `HygieneDecodeContext` | |
1318 | // to track which `SyntaxContext`s we have already decoded. | |
1319 | // The provided closure will be invoked to deserialize a `SyntaxContextData` | |
1320 | // if we haven't already seen the id of the `SyntaxContext` we are deserializing. | |
5099ac24 | 1321 | pub fn decode_syntax_context<D: Decoder, F: FnOnce(&mut D, u32) -> SyntaxContextData>( |
3dfed10e XL |
1322 | d: &mut D, |
1323 | context: &HygieneDecodeContext, | |
1324 | decode_data: F, | |
5099ac24 FG |
1325 | ) -> SyntaxContext { |
1326 | let raw_id: u32 = Decodable::decode(d); | |
3dfed10e XL |
1327 | if raw_id == 0 { |
1328 | debug!("decode_syntax_context: deserialized root"); | |
1329 | // The root is special | |
5099ac24 | 1330 | return SyntaxContext::root(); |
3dfed10e XL |
1331 | } |
1332 | ||
1333 | let outer_ctxts = &context.remapped_ctxts; | |
1334 | ||
1335 | // Ensure that the lock() temporary is dropped early | |
1336 | { | |
1337 | if let Some(ctxt) = outer_ctxts.lock().get(raw_id as usize).copied().flatten() { | |
5099ac24 | 1338 | return ctxt; |
3dfed10e XL |
1339 | } |
1340 | } | |
1341 | ||
1342 | // Allocate and store SyntaxContext id *before* calling the decoder function, | |
1343 | // as the SyntaxContextData may reference itself. | |
1344 | let new_ctxt = HygieneData::with(|hygiene_data| { | |
1345 | let new_ctxt = SyntaxContext(hygiene_data.syntax_context_data.len() as u32); | |
1346 | // Push a dummy SyntaxContextData to ensure that nobody else can get the | |
1347 | // same ID as us. This will be overwritten after call `decode_Data` | |
1348 | hygiene_data.syntax_context_data.push(SyntaxContextData { | |
1349 | outer_expn: ExpnId::root(), | |
1350 | outer_transparency: Transparency::Transparent, | |
1351 | parent: SyntaxContext::root(), | |
1352 | opaque: SyntaxContext::root(), | |
1353 | opaque_and_semitransparent: SyntaxContext::root(), | |
5869c6ff | 1354 | dollar_crate_name: kw::Empty, |
3dfed10e XL |
1355 | }); |
1356 | let mut ctxts = outer_ctxts.lock(); | |
1357 | let new_len = raw_id as usize + 1; | |
1358 | if ctxts.len() < new_len { | |
1359 | ctxts.resize(new_len, None); | |
1360 | } | |
1361 | ctxts[raw_id as usize] = Some(new_ctxt); | |
1362 | drop(ctxts); | |
1363 | new_ctxt | |
1364 | }); | |
1365 | ||
1366 | // Don't try to decode data while holding the lock, since we need to | |
1367 | // be able to recursively decode a SyntaxContext | |
5099ac24 | 1368 | let mut ctxt_data = decode_data(d, raw_id); |
3dfed10e XL |
1369 | // Reset `dollar_crate_name` so that it will be updated by `update_dollar_crate_names` |
1370 | // We don't care what the encoding crate set this to - we want to resolve it | |
1371 | // from the perspective of the current compilation session | |
1372 | ctxt_data.dollar_crate_name = kw::DollarCrate; | |
1373 | ||
1374 | // Overwrite the dummy data with our decoded SyntaxContextData | |
1375 | HygieneData::with(|hygiene_data| { | |
1376 | let dummy = std::mem::replace( | |
1377 | &mut hygiene_data.syntax_context_data[new_ctxt.as_u32() as usize], | |
1378 | ctxt_data, | |
1379 | ); | |
1380 | // Make sure nothing weird happening while `decode_data` was running | |
5869c6ff | 1381 | assert_eq!(dummy.dollar_crate_name, kw::Empty); |
3dfed10e XL |
1382 | }); |
1383 | ||
5099ac24 | 1384 | new_ctxt |
3dfed10e XL |
1385 | } |
1386 | ||
136023e0 | 1387 | fn for_all_ctxts_in<E, F: FnMut(u32, SyntaxContext, &SyntaxContextData) -> Result<(), E>>( |
3dfed10e XL |
1388 | ctxts: impl Iterator<Item = SyntaxContext>, |
1389 | mut f: F, | |
1390 | ) -> Result<(), E> { | |
1391 | let all_data: Vec<_> = HygieneData::with(|data| { | |
1392 | ctxts.map(|ctxt| (ctxt, data.syntax_context_data[ctxt.0 as usize].clone())).collect() | |
1393 | }); | |
1394 | for (ctxt, data) in all_data.into_iter() { | |
136023e0 | 1395 | f(ctxt.0, ctxt, &data)?; |
3dfed10e XL |
1396 | } |
1397 | Ok(()) | |
1398 | } | |
1399 | ||
136023e0 | 1400 | fn for_all_expns_in<E>( |
3dfed10e | 1401 | expns: impl Iterator<Item = ExpnId>, |
136023e0 | 1402 | mut f: impl FnMut(ExpnId, &ExpnData, ExpnHash) -> Result<(), E>, |
3dfed10e XL |
1403 | ) -> Result<(), E> { |
1404 | let all_data: Vec<_> = HygieneData::with(|data| { | |
c295e0f8 | 1405 | expns.map(|expn| (expn, data.expn_data(expn).clone(), data.expn_hash(expn))).collect() |
3dfed10e | 1406 | }); |
136023e0 XL |
1407 | for (expn, data, hash) in all_data.into_iter() { |
1408 | f(expn, &data, hash)?; | |
3dfed10e XL |
1409 | } |
1410 | Ok(()) | |
1411 | } | |
1412 | ||
136023e0 XL |
1413 | impl<E: Encoder> Encodable<E> for LocalExpnId { |
1414 | fn encode(&self, e: &mut E) -> Result<(), E::Error> { | |
1415 | self.to_expn_id().encode(e) | |
1416 | } | |
1417 | } | |
1418 | ||
3dfed10e XL |
1419 | impl<E: Encoder> Encodable<E> for ExpnId { |
1420 | default fn encode(&self, _: &mut E) -> Result<(), E::Error> { | |
1421 | panic!("cannot encode `ExpnId` with `{}`", std::any::type_name::<E>()); | |
1422 | } | |
1423 | } | |
1424 | ||
136023e0 | 1425 | impl<D: Decoder> Decodable<D> for LocalExpnId { |
5099ac24 FG |
1426 | fn decode(d: &mut D) -> Self { |
1427 | ExpnId::expect_local(ExpnId::decode(d)) | |
136023e0 XL |
1428 | } |
1429 | } | |
1430 | ||
3dfed10e | 1431 | impl<D: Decoder> Decodable<D> for ExpnId { |
5099ac24 | 1432 | default fn decode(_: &mut D) -> Self { |
3dfed10e XL |
1433 | panic!("cannot decode `ExpnId` with `{}`", std::any::type_name::<D>()); |
1434 | } | |
1435 | } | |
1436 | ||
3dfed10e XL |
1437 | pub fn raw_encode_syntax_context<E: Encoder>( |
1438 | ctxt: SyntaxContext, | |
1439 | context: &HygieneEncodeContext, | |
1440 | e: &mut E, | |
1441 | ) -> Result<(), E::Error> { | |
1442 | if !context.serialized_ctxts.lock().contains(&ctxt) { | |
1443 | context.latest_ctxts.lock().insert(ctxt); | |
1444 | } | |
1445 | ctxt.0.encode(e) | |
1446 | } | |
1447 | ||
3dfed10e XL |
1448 | impl<E: Encoder> Encodable<E> for SyntaxContext { |
1449 | default fn encode(&self, _: &mut E) -> Result<(), E::Error> { | |
1450 | panic!("cannot encode `SyntaxContext` with `{}`", std::any::type_name::<E>()); | |
cc61c64b XL |
1451 | } |
1452 | } | |
1453 | ||
3dfed10e | 1454 | impl<D: Decoder> Decodable<D> for SyntaxContext { |
5099ac24 | 1455 | default fn decode(_: &mut D) -> Self { |
3dfed10e | 1456 | panic!("cannot decode `SyntaxContext` with `{}`", std::any::type_name::<D>()); |
cc61c64b XL |
1457 | } |
1458 | } | |
5869c6ff XL |
1459 | |
1460 | /// Updates the `disambiguator` field of the corresponding `ExpnData` | |
1461 | /// such that the `Fingerprint` of the `ExpnData` does not collide with | |
1462 | /// any other `ExpnIds`. | |
1463 | /// | |
1464 | /// This method is called only when an `ExpnData` is first associated | |
1465 | /// with an `ExpnId` (when the `ExpnId` is initially constructed, or via | |
1466 | /// `set_expn_data`). It is *not* called for foreign `ExpnId`s deserialized | |
136023e0 | 1467 | /// from another crate's metadata - since `ExpnHash` includes the stable crate id, |
5869c6ff | 1468 | /// collisions are only possible between `ExpnId`s within the same crate. |
136023e0 | 1469 | fn update_disambiguator(expn_data: &mut ExpnData, mut ctx: impl HashStableContext) -> ExpnHash { |
5869c6ff XL |
1470 | // This disambiguator should not have been set yet. |
1471 | assert_eq!( | |
1472 | expn_data.disambiguator, 0, | |
1473 | "Already set disambiguator for ExpnData: {:?}", | |
1474 | expn_data | |
1475 | ); | |
5099ac24 | 1476 | assert_default_hashing_controls(&ctx, "ExpnData (disambiguator)"); |
136023e0 | 1477 | let mut expn_hash = expn_data.hash_expn(&mut ctx); |
5869c6ff | 1478 | |
136023e0 | 1479 | let disambiguator = HygieneData::with(|data| { |
5869c6ff XL |
1480 | // If this is the first ExpnData with a given hash, then keep our |
1481 | // disambiguator at 0 (the default u32 value) | |
136023e0 XL |
1482 | let disambig = data.expn_data_disambiguators.entry(expn_hash).or_default(); |
1483 | let disambiguator = *disambig; | |
5869c6ff | 1484 | *disambig += 1; |
136023e0 | 1485 | disambiguator |
5869c6ff XL |
1486 | }); |
1487 | ||
136023e0 XL |
1488 | if disambiguator != 0 { |
1489 | debug!("Set disambiguator for expn_data={:?} expn_hash={:?}", expn_data, expn_hash); | |
1490 | ||
1491 | expn_data.disambiguator = disambiguator; | |
1492 | expn_hash = expn_data.hash_expn(&mut ctx); | |
5869c6ff XL |
1493 | |
1494 | // Verify that the new disambiguator makes the hash unique | |
1495 | #[cfg(debug_assertions)] | |
136023e0 XL |
1496 | HygieneData::with(|data| { |
1497 | assert_eq!( | |
1498 | data.expn_data_disambiguators.get(&expn_hash), | |
1499 | None, | |
1500 | "Hash collision after disambiguator update!", | |
1501 | ); | |
1502 | }); | |
1503 | } | |
1504 | ||
1505 | ExpnHash::new(ctx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(), expn_hash) | |
1506 | } | |
1507 | ||
1508 | impl<CTX: HashStableContext> HashStable<CTX> for SyntaxContext { | |
1509 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { | |
1510 | const TAG_EXPANSION: u8 = 0; | |
1511 | const TAG_NO_EXPANSION: u8 = 1; | |
1512 | ||
1513 | if *self == SyntaxContext::root() { | |
1514 | TAG_NO_EXPANSION.hash_stable(ctx, hasher); | |
1515 | } else { | |
1516 | TAG_EXPANSION.hash_stable(ctx, hasher); | |
1517 | let (expn_id, transparency) = self.outer_mark(); | |
1518 | expn_id.hash_stable(ctx, hasher); | |
1519 | transparency.hash_stable(ctx, hasher); | |
1520 | } | |
1521 | } | |
1522 | } | |
1523 | ||
1524 | impl<CTX: HashStableContext> HashStable<CTX> for ExpnId { | |
1525 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { | |
5099ac24 | 1526 | assert_default_hashing_controls(ctx, "ExpnId"); |
136023e0 XL |
1527 | let hash = if *self == ExpnId::root() { |
1528 | // Avoid fetching TLS storage for a trivial often-used value. | |
1529 | Fingerprint::ZERO | |
1530 | } else { | |
1531 | self.expn_hash().0 | |
5869c6ff | 1532 | }; |
136023e0 XL |
1533 | |
1534 | hash.hash_stable(ctx, hasher); | |
5869c6ff XL |
1535 | } |
1536 | } |