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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; |
5bcae85e | 44 | |
416331ca XL |
45 | /// A `SyntaxContext` represents a chain of pairs `(ExpnId, Transparency)` named "marks". |
46 | #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)] | |
8faf50e0 XL |
47 | pub struct SyntaxContext(u32); |
48 | ||
3dfed10e XL |
49 | #[derive(Debug, Encodable, Decodable, Clone)] |
50 | pub struct SyntaxContextData { | |
416331ca XL |
51 | outer_expn: ExpnId, |
52 | outer_transparency: Transparency, | |
53 | parent: SyntaxContext, | |
54 | /// This context, but with all transparent and semi-transparent expansions filtered away. | |
8faf50e0 | 55 | opaque: SyntaxContext, |
416331ca | 56 | /// This context, but with all transparent expansions filtered away. |
8faf50e0 | 57 | opaque_and_semitransparent: SyntaxContext, |
48663c56 | 58 | /// Name of the crate to which `$crate` with this context would resolve. |
0731742a | 59 | dollar_crate_name: Symbol, |
5bcae85e SL |
60 | } |
61 | ||
136023e0 XL |
62 | rustc_index::newtype_index! { |
63 | /// A unique ID associated with a macro invocation and expansion. | |
9c376795 FG |
64 | #[custom_encodable] |
65 | pub struct ExpnIndex {} | |
136023e0 XL |
66 | } |
67 | ||
416331ca | 68 | /// A unique ID associated with a macro invocation and expansion. |
136023e0 XL |
69 | #[derive(Clone, Copy, PartialEq, Eq, Hash)] |
70 | pub struct ExpnId { | |
71 | pub krate: CrateNum, | |
72 | pub local_id: ExpnIndex, | |
73 | } | |
74 | ||
75 | impl fmt::Debug for ExpnId { | |
76 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { | |
77 | // Generate crate_::{{expn_}}. | |
487cf647 | 78 | write!(f, "{:?}::{{{{expn{}}}}}", self.krate, self.local_id.as_u32()) |
136023e0 XL |
79 | } |
80 | } | |
81 | ||
82 | rustc_index::newtype_index! { | |
83 | /// A unique ID associated with a macro invocation and expansion. | |
9c376795 FG |
84 | #[custom_encodable] |
85 | #[no_ord_impl] | |
86 | #[debug_format = "expn{}"] | |
87 | pub struct LocalExpnId {} | |
136023e0 XL |
88 | } |
89 | ||
5e7ed085 FG |
90 | // To ensure correctness of incremental compilation, |
91 | // `LocalExpnId` must not implement `Ord` or `PartialOrd`. | |
92 | // See https://github.com/rust-lang/rust/issues/90317. | |
93 | impl !Ord for LocalExpnId {} | |
94 | impl !PartialOrd for LocalExpnId {} | |
95 | ||
5099ac24 FG |
96 | /// Assert that the provided `HashStableContext` is configured with the 'default' |
97 | /// `HashingControls`. We should always have bailed out before getting to here | |
98 | /// with a non-default mode. With this check in place, we can avoid the need | |
99 | /// to maintain separate versions of `ExpnData` hashes for each permutation | |
100 | /// of `HashingControls` settings. | |
101 | fn assert_default_hashing_controls<CTX: HashStableContext>(ctx: &CTX, msg: &str) { | |
102 | match ctx.hashing_controls() { | |
5099ac24 FG |
103 | // Note that we require that `hash_spans` be set according to the global |
104 | // `-Z incremental-ignore-spans` option. Normally, this option is disabled, | |
105 | // which will cause us to require that this method always be called with `Span` hashing | |
106 | // enabled. | |
9c376795 FG |
107 | // |
108 | // Span hashing can also be disabled without `-Z incremental-ignore-spans`. | |
109 | // This is the case for instance when building a hash for name mangling. | |
110 | // Such configuration must not be used for metadata. | |
5e7ed085 | 111 | HashingControls { hash_spans } |
064997fb | 112 | if hash_spans == !ctx.unstable_opts_incremental_ignore_spans() => {} |
9c376795 | 113 | other => panic!("Attempted hashing of {msg} with non-default HashingControls: {other:?}"), |
5099ac24 FG |
114 | } |
115 | } | |
116 | ||
136023e0 XL |
117 | /// A unique hash value associated to an expansion. |
118 | #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Encodable, Decodable, HashStable_Generic)] | |
119 | pub struct ExpnHash(Fingerprint); | |
120 | ||
121 | impl ExpnHash { | |
122 | /// Returns the [StableCrateId] identifying the crate this [ExpnHash] | |
123 | /// originates from. | |
124 | #[inline] | |
125 | pub fn stable_crate_id(self) -> StableCrateId { | |
126 | StableCrateId(self.0.as_value().0) | |
127 | } | |
128 | ||
129 | /// Returns the crate-local part of the [ExpnHash]. | |
130 | /// | |
131 | /// Used for tests. | |
132 | #[inline] | |
133 | pub fn local_hash(self) -> u64 { | |
134 | self.0.as_value().1 | |
135 | } | |
136 | ||
137 | #[inline] | |
138 | pub fn is_root(self) -> bool { | |
139 | self.0 == Fingerprint::ZERO | |
140 | } | |
141 | ||
142 | /// Builds a new [ExpnHash] with the given [StableCrateId] and | |
143 | /// `local_hash`, where `local_hash` must be unique within its crate. | |
144 | fn new(stable_crate_id: StableCrateId, local_hash: u64) -> ExpnHash { | |
145 | ExpnHash(Fingerprint::new(stable_crate_id.0, local_hash)) | |
146 | } | |
147 | } | |
5bcae85e | 148 | |
8faf50e0 XL |
149 | /// A property of a macro expansion that determines how identifiers |
150 | /// produced by that expansion are resolved. | |
3dfed10e | 151 | #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Hash, Debug, Encodable, Decodable)] |
ba9703b0 | 152 | #[derive(HashStable_Generic)] |
8faf50e0 XL |
153 | pub enum Transparency { |
154 | /// Identifier produced by a transparent expansion is always resolved at call-site. | |
155 | /// Call-site spans in procedural macros, hygiene opt-out in `macro` should use this. | |
156 | Transparent, | |
157 | /// Identifier produced by a semi-transparent expansion may be resolved | |
158 | /// either at call-site or at definition-site. | |
159 | /// If it's a local variable, label or `$crate` then it's resolved at def-site. | |
160 | /// Otherwise it's resolved at call-site. | |
161 | /// `macro_rules` macros behave like this, built-in macros currently behave like this too, | |
162 | /// but that's an implementation detail. | |
163 | SemiTransparent, | |
164 | /// Identifier produced by an opaque expansion is always resolved at definition-site. | |
165 | /// Def-site spans in procedural macros, identifiers from `macro` by default use this. | |
166 | Opaque, | |
ff7c6d11 XL |
167 | } |
168 | ||
136023e0 XL |
169 | impl LocalExpnId { |
170 | /// The ID of the theoretical expansion that generates freshly parsed, unexpanded AST. | |
171 | pub const ROOT: LocalExpnId = LocalExpnId::from_u32(0); | |
172 | ||
5099ac24 | 173 | #[inline] |
136023e0 XL |
174 | pub fn from_raw(idx: ExpnIndex) -> LocalExpnId { |
175 | LocalExpnId::from_u32(idx.as_u32()) | |
5bcae85e | 176 | } |
9e0c209e | 177 | |
5099ac24 | 178 | #[inline] |
136023e0 XL |
179 | pub fn as_raw(self) -> ExpnIndex { |
180 | ExpnIndex::from_u32(self.as_u32()) | |
9e0c209e SL |
181 | } |
182 | ||
136023e0 XL |
183 | pub fn fresh_empty() -> LocalExpnId { |
184 | HygieneData::with(|data| { | |
185 | let expn_id = data.local_expn_data.push(None); | |
186 | let _eid = data.local_expn_hashes.push(ExpnHash(Fingerprint::ZERO)); | |
187 | debug_assert_eq!(expn_id, _eid); | |
188 | expn_id | |
189 | }) | |
190 | } | |
191 | ||
192 | pub fn fresh(mut expn_data: ExpnData, ctx: impl HashStableContext) -> LocalExpnId { | |
193 | debug_assert_eq!(expn_data.parent.krate, LOCAL_CRATE); | |
194 | let expn_hash = update_disambiguator(&mut expn_data, ctx); | |
195 | HygieneData::with(|data| { | |
196 | let expn_id = data.local_expn_data.push(Some(expn_data)); | |
197 | let _eid = data.local_expn_hashes.push(expn_hash); | |
198 | debug_assert_eq!(expn_id, _eid); | |
199 | let _old_id = data.expn_hash_to_expn_id.insert(expn_hash, expn_id.to_expn_id()); | |
200 | debug_assert!(_old_id.is_none()); | |
201 | expn_id | |
202 | }) | |
c30ab7b3 SL |
203 | } |
204 | ||
ff7c6d11 | 205 | #[inline] |
136023e0 XL |
206 | pub fn expn_hash(self) -> ExpnHash { |
207 | HygieneData::with(|data| data.local_expn_hash(self)) | |
32a655c1 SL |
208 | } |
209 | ||
b7449926 | 210 | #[inline] |
e1599b0c | 211 | pub fn expn_data(self) -> ExpnData { |
136023e0 | 212 | HygieneData::with(|data| data.local_expn_data(self).clone()) |
b7449926 XL |
213 | } |
214 | ||
ff7c6d11 | 215 | #[inline] |
136023e0 XL |
216 | pub fn to_expn_id(self) -> ExpnId { |
217 | ExpnId { krate: LOCAL_CRATE, local_id: self.as_raw() } | |
218 | } | |
219 | ||
220 | #[inline] | |
221 | pub fn set_expn_data(self, mut expn_data: ExpnData, ctx: impl HashStableContext) { | |
222 | debug_assert_eq!(expn_data.parent.krate, LOCAL_CRATE); | |
223 | let expn_hash = update_disambiguator(&mut expn_data, ctx); | |
416331ca | 224 | HygieneData::with(|data| { |
136023e0 | 225 | let old_expn_data = &mut data.local_expn_data[self]; |
e1599b0c XL |
226 | assert!(old_expn_data.is_none(), "expansion data is reset for an expansion ID"); |
227 | *old_expn_data = Some(expn_data); | |
136023e0 XL |
228 | debug_assert_eq!(data.local_expn_hashes[self].0, Fingerprint::ZERO); |
229 | data.local_expn_hashes[self] = expn_hash; | |
230 | let _old_id = data.expn_hash_to_expn_id.insert(expn_hash, self.to_expn_id()); | |
231 | debug_assert!(_old_id.is_none()); | |
5869c6ff | 232 | }); |
136023e0 XL |
233 | } |
234 | ||
235 | #[inline] | |
236 | pub fn is_descendant_of(self, ancestor: LocalExpnId) -> bool { | |
237 | self.to_expn_id().is_descendant_of(ancestor.to_expn_id()) | |
238 | } | |
239 | ||
240 | /// `expn_id.outer_expn_is_descendant_of(ctxt)` is equivalent to but faster than | |
241 | /// `expn_id.is_descendant_of(ctxt.outer_expn())`. | |
242 | #[inline] | |
243 | pub fn outer_expn_is_descendant_of(self, ctxt: SyntaxContext) -> bool { | |
244 | self.to_expn_id().outer_expn_is_descendant_of(ctxt) | |
245 | } | |
246 | ||
247 | /// Returns span for the macro which originally caused this expansion to happen. | |
248 | /// | |
249 | /// Stops backtracing at include! boundary. | |
250 | #[inline] | |
251 | pub fn expansion_cause(self) -> Option<Span> { | |
252 | self.to_expn_id().expansion_cause() | |
253 | } | |
254 | ||
255 | #[inline] | |
256 | #[track_caller] | |
257 | pub fn parent(self) -> LocalExpnId { | |
258 | self.expn_data().parent.as_local().unwrap() | |
259 | } | |
260 | } | |
261 | ||
262 | impl ExpnId { | |
263 | /// The ID of the theoretical expansion that generates freshly parsed, unexpanded AST. | |
264 | /// Invariant: we do not create any ExpnId with local_id == 0 and krate != 0. | |
265 | pub const fn root() -> ExpnId { | |
266 | ExpnId { krate: LOCAL_CRATE, local_id: ExpnIndex::from_u32(0) } | |
267 | } | |
268 | ||
269 | #[inline] | |
270 | pub fn expn_hash(self) -> ExpnHash { | |
271 | HygieneData::with(|data| data.expn_hash(self)) | |
272 | } | |
273 | ||
274 | #[inline] | |
275 | pub fn from_hash(hash: ExpnHash) -> Option<ExpnId> { | |
276 | HygieneData::with(|data| data.expn_hash_to_expn_id.get(&hash).copied()) | |
277 | } | |
278 | ||
279 | #[inline] | |
280 | pub fn as_local(self) -> Option<LocalExpnId> { | |
281 | if self.krate == LOCAL_CRATE { Some(LocalExpnId::from_raw(self.local_id)) } else { None } | |
282 | } | |
283 | ||
284 | #[inline] | |
285 | #[track_caller] | |
286 | pub fn expect_local(self) -> LocalExpnId { | |
287 | self.as_local().unwrap() | |
288 | } | |
289 | ||
290 | #[inline] | |
291 | pub fn expn_data(self) -> ExpnData { | |
292 | HygieneData::with(|data| data.expn_data(self).clone()) | |
7cac9316 XL |
293 | } |
294 | ||
a2a8927a | 295 | #[inline] |
416331ca | 296 | pub fn is_descendant_of(self, ancestor: ExpnId) -> bool { |
a2a8927a XL |
297 | // a few "fast path" cases to avoid locking HygieneData |
298 | if ancestor == ExpnId::root() || ancestor == self { | |
299 | return true; | |
300 | } | |
301 | if ancestor.krate != self.krate { | |
302 | return false; | |
303 | } | |
dc9dc135 | 304 | HygieneData::with(|data| data.is_descendant_of(self, ancestor)) |
7cac9316 XL |
305 | } |
306 | ||
416331ca XL |
307 | /// `expn_id.outer_expn_is_descendant_of(ctxt)` is equivalent to but faster than |
308 | /// `expn_id.is_descendant_of(ctxt.outer_expn())`. | |
309 | pub fn outer_expn_is_descendant_of(self, ctxt: SyntaxContext) -> bool { | |
310 | HygieneData::with(|data| data.is_descendant_of(self, data.outer_expn(ctxt))) | |
83c7162d | 311 | } |
60c5eb7d XL |
312 | |
313 | /// Returns span for the macro which originally caused this expansion to happen. | |
314 | /// | |
315 | /// Stops backtracing at include! boundary. | |
316 | pub fn expansion_cause(mut self) -> Option<Span> { | |
317 | let mut last_macro = None; | |
318 | loop { | |
319 | let expn_data = self.expn_data(); | |
320 | // Stop going up the backtrace once include! is encountered | |
dfeec247 | 321 | if expn_data.is_root() |
136023e0 | 322 | || expn_data.kind == ExpnKind::Macro(MacroKind::Bang, sym::include) |
9c376795 | 323 | || expn_data.kind == ExpnKind::Inlined |
dfeec247 | 324 | { |
60c5eb7d XL |
325 | break; |
326 | } | |
327 | self = expn_data.call_site.ctxt().outer_expn(); | |
328 | last_macro = Some(expn_data.call_site); | |
329 | } | |
330 | last_macro | |
331 | } | |
5bcae85e SL |
332 | } |
333 | ||
8faf50e0 | 334 | #[derive(Debug)] |
3dfed10e | 335 | pub struct HygieneData { |
e1599b0c XL |
336 | /// Each expansion should have an associated expansion data, but sometimes there's a delay |
337 | /// between creation of an expansion ID and obtaining its data (e.g. macros are collected | |
338 | /// first and then resolved later), so we use an `Option` here. | |
136023e0 XL |
339 | local_expn_data: IndexVec<LocalExpnId, Option<ExpnData>>, |
340 | local_expn_hashes: IndexVec<LocalExpnId, ExpnHash>, | |
9c376795 | 341 | /// Data and hash information from external crates. We may eventually want to remove these |
136023e0 XL |
342 | /// maps, and fetch the information directly from the other crate's metadata like DefIds do. |
343 | foreign_expn_data: FxHashMap<ExpnId, ExpnData>, | |
344 | foreign_expn_hashes: FxHashMap<ExpnId, ExpnHash>, | |
345 | expn_hash_to_expn_id: UnhashMap<ExpnHash, ExpnId>, | |
416331ca XL |
346 | syntax_context_data: Vec<SyntaxContextData>, |
347 | syntax_context_map: FxHashMap<(SyntaxContext, ExpnId, Transparency), SyntaxContext>, | |
136023e0 | 348 | /// Maps the `local_hash` of an `ExpnData` to the next disambiguator value. |
5869c6ff XL |
349 | /// This is used by `update_disambiguator` to keep track of which `ExpnData`s |
350 | /// would have collisions without a disambiguator. | |
351 | /// The keys of this map are always computed with `ExpnData.disambiguator` | |
352 | /// set to 0. | |
136023e0 | 353 | expn_data_disambiguators: FxHashMap<u64, u32>, |
5bcae85e SL |
354 | } |
355 | ||
356 | impl HygieneData { | |
923072b8 | 357 | pub(crate) fn new(edition: Edition) -> Self { |
136023e0 | 358 | let root_data = ExpnData::default( |
3dfed10e XL |
359 | ExpnKind::Root, |
360 | DUMMY_SP, | |
361 | edition, | |
136023e0 XL |
362 | Some(CRATE_DEF_ID.to_def_id()), |
363 | None, | |
3dfed10e | 364 | ); |
3dfed10e | 365 | |
5bcae85e | 366 | HygieneData { |
136023e0 XL |
367 | local_expn_data: IndexVec::from_elem_n(Some(root_data), 1), |
368 | local_expn_hashes: IndexVec::from_elem_n(ExpnHash(Fingerprint::ZERO), 1), | |
369 | foreign_expn_data: FxHashMap::default(), | |
370 | foreign_expn_hashes: FxHashMap::default(), | |
371 | expn_hash_to_expn_id: std::iter::once((ExpnHash(Fingerprint::ZERO), ExpnId::root())) | |
372 | .collect(), | |
416331ca XL |
373 | syntax_context_data: vec![SyntaxContextData { |
374 | outer_expn: ExpnId::root(), | |
375 | outer_transparency: Transparency::Opaque, | |
376 | parent: SyntaxContext(0), | |
8faf50e0 XL |
377 | opaque: SyntaxContext(0), |
378 | opaque_and_semitransparent: SyntaxContext(0), | |
dc9dc135 | 379 | dollar_crate_name: kw::DollarCrate, |
ff7c6d11 | 380 | }], |
416331ca | 381 | syntax_context_map: FxHashMap::default(), |
5869c6ff | 382 | expn_data_disambiguators: FxHashMap::default(), |
5bcae85e SL |
383 | } |
384 | } | |
385 | ||
3dfed10e | 386 | pub fn with<T, F: FnOnce(&mut HygieneData) -> T>(f: F) -> T { |
487cf647 | 387 | with_session_globals(|session_globals| f(&mut session_globals.hygiene_data.borrow_mut())) |
5bcae85e | 388 | } |
5bcae85e | 389 | |
136023e0 XL |
390 | #[inline] |
391 | fn local_expn_hash(&self, expn_id: LocalExpnId) -> ExpnHash { | |
392 | self.local_expn_hashes[expn_id] | |
393 | } | |
394 | ||
395 | #[inline] | |
396 | fn expn_hash(&self, expn_id: ExpnId) -> ExpnHash { | |
397 | match expn_id.as_local() { | |
398 | Some(expn_id) => self.local_expn_hashes[expn_id], | |
399 | None => self.foreign_expn_hashes[&expn_id], | |
3dfed10e | 400 | } |
136023e0 XL |
401 | } |
402 | ||
403 | fn local_expn_data(&self, expn_id: LocalExpnId) -> &ExpnData { | |
404 | self.local_expn_data[expn_id].as_ref().expect("no expansion data for an expansion ID") | |
dc9dc135 XL |
405 | } |
406 | ||
e1599b0c | 407 | fn expn_data(&self, expn_id: ExpnId) -> &ExpnData { |
136023e0 XL |
408 | if let Some(expn_id) = expn_id.as_local() { |
409 | self.local_expn_data[expn_id].as_ref().expect("no expansion data for an expansion ID") | |
410 | } else { | |
411 | &self.foreign_expn_data[&expn_id] | |
412 | } | |
416331ca XL |
413 | } |
414 | ||
415 | fn is_descendant_of(&self, mut expn_id: ExpnId, ancestor: ExpnId) -> bool { | |
a2a8927a XL |
416 | // a couple "fast path" cases to avoid traversing parents in the loop below |
417 | if ancestor == ExpnId::root() { | |
418 | return true; | |
419 | } | |
420 | if expn_id.krate != ancestor.krate { | |
421 | return false; | |
422 | } | |
423 | loop { | |
424 | if expn_id == ancestor { | |
425 | return true; | |
426 | } | |
416331ca | 427 | if expn_id == ExpnId::root() { |
dc9dc135 XL |
428 | return false; |
429 | } | |
e1599b0c | 430 | expn_id = self.expn_data(expn_id).parent; |
dc9dc135 | 431 | } |
dc9dc135 XL |
432 | } |
433 | ||
ba9703b0 | 434 | fn normalize_to_macros_2_0(&self, ctxt: SyntaxContext) -> SyntaxContext { |
416331ca | 435 | self.syntax_context_data[ctxt.0 as usize].opaque |
dc9dc135 XL |
436 | } |
437 | ||
ba9703b0 | 438 | fn normalize_to_macro_rules(&self, ctxt: SyntaxContext) -> SyntaxContext { |
416331ca | 439 | self.syntax_context_data[ctxt.0 as usize].opaque_and_semitransparent |
dc9dc135 XL |
440 | } |
441 | ||
416331ca XL |
442 | fn outer_expn(&self, ctxt: SyntaxContext) -> ExpnId { |
443 | self.syntax_context_data[ctxt.0 as usize].outer_expn | |
dc9dc135 XL |
444 | } |
445 | ||
e1599b0c XL |
446 | fn outer_mark(&self, ctxt: SyntaxContext) -> (ExpnId, Transparency) { |
447 | let data = &self.syntax_context_data[ctxt.0 as usize]; | |
448 | (data.outer_expn, data.outer_transparency) | |
dc9dc135 XL |
449 | } |
450 | ||
416331ca XL |
451 | fn parent_ctxt(&self, ctxt: SyntaxContext) -> SyntaxContext { |
452 | self.syntax_context_data[ctxt.0 as usize].parent | |
dc9dc135 XL |
453 | } |
454 | ||
e1599b0c XL |
455 | fn remove_mark(&self, ctxt: &mut SyntaxContext) -> (ExpnId, Transparency) { |
456 | let outer_mark = self.outer_mark(*ctxt); | |
416331ca | 457 | *ctxt = self.parent_ctxt(*ctxt); |
e1599b0c | 458 | outer_mark |
dc9dc135 XL |
459 | } |
460 | ||
416331ca | 461 | fn marks(&self, mut ctxt: SyntaxContext) -> Vec<(ExpnId, Transparency)> { |
dc9dc135 | 462 | let mut marks = Vec::new(); |
e1599b0c | 463 | while ctxt != SyntaxContext::root() { |
3dfed10e | 464 | debug!("marks: getting parent of {:?}", ctxt); |
e1599b0c | 465 | marks.push(self.outer_mark(ctxt)); |
416331ca | 466 | ctxt = self.parent_ctxt(ctxt); |
dc9dc135 XL |
467 | } |
468 | marks.reverse(); | |
469 | marks | |
470 | } | |
471 | ||
472 | fn walk_chain(&self, mut span: Span, to: SyntaxContext) -> Span { | |
3dfed10e XL |
473 | debug!("walk_chain({:?}, {:?})", span, to); |
474 | debug!("walk_chain: span ctxt = {:?}", span.ctxt()); | |
e1599b0c | 475 | while span.from_expansion() && span.ctxt() != to { |
3dfed10e XL |
476 | let outer_expn = self.outer_expn(span.ctxt()); |
477 | debug!("walk_chain({:?}): outer_expn={:?}", span, outer_expn); | |
478 | let expn_data = self.expn_data(outer_expn); | |
479 | debug!("walk_chain({:?}): expn_data={:?}", span, expn_data); | |
480 | span = expn_data.call_site; | |
dc9dc135 XL |
481 | } |
482 | span | |
483 | } | |
484 | ||
416331ca | 485 | fn adjust(&self, ctxt: &mut SyntaxContext, expn_id: ExpnId) -> Option<ExpnId> { |
dc9dc135 | 486 | let mut scope = None; |
416331ca | 487 | while !self.is_descendant_of(expn_id, self.outer_expn(*ctxt)) { |
e1599b0c | 488 | scope = Some(self.remove_mark(ctxt).0); |
dc9dc135 XL |
489 | } |
490 | scope | |
491 | } | |
492 | ||
e1599b0c | 493 | fn apply_mark( |
dfeec247 XL |
494 | &mut self, |
495 | ctxt: SyntaxContext, | |
496 | expn_id: ExpnId, | |
497 | transparency: Transparency, | |
e1599b0c | 498 | ) -> SyntaxContext { |
416331ca | 499 | assert_ne!(expn_id, ExpnId::root()); |
dc9dc135 | 500 | if transparency == Transparency::Opaque { |
416331ca | 501 | return self.apply_mark_internal(ctxt, expn_id, transparency); |
dc9dc135 XL |
502 | } |
503 | ||
e1599b0c | 504 | let call_site_ctxt = self.expn_data(expn_id).call_site.ctxt(); |
dc9dc135 | 505 | let mut call_site_ctxt = if transparency == Transparency::SemiTransparent { |
ba9703b0 | 506 | self.normalize_to_macros_2_0(call_site_ctxt) |
dc9dc135 | 507 | } else { |
ba9703b0 | 508 | self.normalize_to_macro_rules(call_site_ctxt) |
dc9dc135 XL |
509 | }; |
510 | ||
e1599b0c | 511 | if call_site_ctxt == SyntaxContext::root() { |
416331ca | 512 | return self.apply_mark_internal(ctxt, expn_id, transparency); |
dc9dc135 XL |
513 | } |
514 | ||
416331ca | 515 | // Otherwise, `expn_id` is a macros 1.0 definition and the call site is in a |
dc9dc135 XL |
516 | // macros 2.0 expansion, i.e., a macros 1.0 invocation is in a macros 2.0 definition. |
517 | // | |
518 | // In this case, the tokens from the macros 1.0 definition inherit the hygiene | |
519 | // at their invocation. That is, we pretend that the macros 1.0 definition | |
520 | // was defined at its invocation (i.e., inside the macros 2.0 definition) | |
521 | // so that the macros 2.0 definition remains hygienic. | |
522 | // | |
416331ca XL |
523 | // See the example at `test/ui/hygiene/legacy_interaction.rs`. |
524 | for (expn_id, transparency) in self.marks(ctxt) { | |
525 | call_site_ctxt = self.apply_mark_internal(call_site_ctxt, expn_id, transparency); | |
dc9dc135 | 526 | } |
416331ca | 527 | self.apply_mark_internal(call_site_ctxt, expn_id, transparency) |
dc9dc135 XL |
528 | } |
529 | ||
416331ca | 530 | fn apply_mark_internal( |
dfeec247 XL |
531 | &mut self, |
532 | ctxt: SyntaxContext, | |
533 | expn_id: ExpnId, | |
534 | transparency: Transparency, | |
416331ca XL |
535 | ) -> SyntaxContext { |
536 | let syntax_context_data = &mut self.syntax_context_data; | |
537 | let mut opaque = syntax_context_data[ctxt.0 as usize].opaque; | |
dc9dc135 | 538 | let mut opaque_and_semitransparent = |
416331ca | 539 | syntax_context_data[ctxt.0 as usize].opaque_and_semitransparent; |
dc9dc135 XL |
540 | |
541 | if transparency >= Transparency::Opaque { | |
416331ca | 542 | let parent = opaque; |
dfeec247 XL |
543 | opaque = *self |
544 | .syntax_context_map | |
545 | .entry((parent, expn_id, transparency)) | |
546 | .or_insert_with(|| { | |
547 | let new_opaque = SyntaxContext(syntax_context_data.len() as u32); | |
548 | syntax_context_data.push(SyntaxContextData { | |
549 | outer_expn: expn_id, | |
550 | outer_transparency: transparency, | |
551 | parent, | |
552 | opaque: new_opaque, | |
553 | opaque_and_semitransparent: new_opaque, | |
554 | dollar_crate_name: kw::DollarCrate, | |
555 | }); | |
556 | new_opaque | |
dc9dc135 | 557 | }); |
dc9dc135 XL |
558 | } |
559 | ||
560 | if transparency >= Transparency::SemiTransparent { | |
416331ca | 561 | let parent = opaque_and_semitransparent; |
dfeec247 XL |
562 | opaque_and_semitransparent = *self |
563 | .syntax_context_map | |
564 | .entry((parent, expn_id, transparency)) | |
565 | .or_insert_with(|| { | |
566 | let new_opaque_and_semitransparent = | |
567 | SyntaxContext(syntax_context_data.len() as u32); | |
568 | syntax_context_data.push(SyntaxContextData { | |
569 | outer_expn: expn_id, | |
570 | outer_transparency: transparency, | |
571 | parent, | |
572 | opaque, | |
573 | opaque_and_semitransparent: new_opaque_and_semitransparent, | |
574 | dollar_crate_name: kw::DollarCrate, | |
575 | }); | |
576 | new_opaque_and_semitransparent | |
dc9dc135 | 577 | }); |
dc9dc135 XL |
578 | } |
579 | ||
416331ca XL |
580 | let parent = ctxt; |
581 | *self.syntax_context_map.entry((parent, expn_id, transparency)).or_insert_with(|| { | |
dc9dc135 | 582 | let new_opaque_and_semitransparent_and_transparent = |
416331ca XL |
583 | SyntaxContext(syntax_context_data.len() as u32); |
584 | syntax_context_data.push(SyntaxContextData { | |
585 | outer_expn: expn_id, | |
586 | outer_transparency: transparency, | |
587 | parent, | |
dc9dc135 XL |
588 | opaque, |
589 | opaque_and_semitransparent, | |
590 | dollar_crate_name: kw::DollarCrate, | |
591 | }); | |
592 | new_opaque_and_semitransparent_and_transparent | |
593 | }) | |
594 | } | |
94b46f34 XL |
595 | } |
596 | ||
416331ca XL |
597 | pub fn clear_syntax_context_map() { |
598 | HygieneData::with(|data| data.syntax_context_map = FxHashMap::default()); | |
5bcae85e SL |
599 | } |
600 | ||
dc9dc135 XL |
601 | pub fn walk_chain(span: Span, to: SyntaxContext) -> Span { |
602 | HygieneData::with(|data| data.walk_chain(span, to)) | |
603 | } | |
604 | ||
416331ca XL |
605 | pub fn update_dollar_crate_names(mut get_name: impl FnMut(SyntaxContext) -> Symbol) { |
606 | // The new contexts that need updating are at the end of the list and have `$crate` as a name. | |
dfeec247 XL |
607 | let (len, to_update) = HygieneData::with(|data| { |
608 | ( | |
609 | data.syntax_context_data.len(), | |
610 | data.syntax_context_data | |
611 | .iter() | |
612 | .rev() | |
613 | .take_while(|scdata| scdata.dollar_crate_name == kw::DollarCrate) | |
614 | .count(), | |
615 | ) | |
616 | }); | |
416331ca XL |
617 | // The callback must be called from outside of the `HygieneData` lock, |
618 | // since it will try to acquire it too. | |
dfeec247 | 619 | let range_to_update = len - to_update..len; |
416331ca XL |
620 | let names: Vec<_> = |
621 | range_to_update.clone().map(|idx| get_name(SyntaxContext::from_u32(idx as u32))).collect(); | |
dfeec247 | 622 | HygieneData::with(|data| { |
cdc7bbd5 | 623 | range_to_update.zip(names).for_each(|(idx, name)| { |
dfeec247 XL |
624 | data.syntax_context_data[idx].dollar_crate_name = name; |
625 | }) | |
626 | }) | |
416331ca XL |
627 | } |
628 | ||
e1599b0c XL |
629 | pub fn debug_hygiene_data(verbose: bool) -> String { |
630 | HygieneData::with(|data| { | |
631 | if verbose { | |
9c376795 | 632 | format!("{data:#?}") |
e1599b0c | 633 | } else { |
064997fb | 634 | let mut s = String::from("Expansions:"); |
136023e0 | 635 | let mut debug_expn_data = |(id, expn_data): (&ExpnId, &ExpnData)| { |
e1599b0c | 636 | s.push_str(&format!( |
136023e0 | 637 | "\n{:?}: parent: {:?}, call_site_ctxt: {:?}, def_site_ctxt: {:?}, kind: {:?}", |
e1599b0c | 638 | id, |
136023e0 XL |
639 | expn_data.parent, |
640 | expn_data.call_site.ctxt(), | |
641 | expn_data.def_site.ctxt(), | |
642 | expn_data.kind, | |
643 | )) | |
644 | }; | |
645 | data.local_expn_data.iter_enumerated().for_each(|(id, expn_data)| { | |
646 | let expn_data = expn_data.as_ref().expect("no expansion data for an expansion ID"); | |
647 | debug_expn_data((&id.to_expn_id(), expn_data)) | |
e1599b0c | 648 | }); |
064997fb | 649 | |
c295e0f8 | 650 | // Sort the hash map for more reproducible output. |
064997fb FG |
651 | // Because of this, it is fine to rely on the unstable iteration order of the map. |
652 | #[allow(rustc::potential_query_instability)] | |
c295e0f8 XL |
653 | let mut foreign_expn_data: Vec<_> = data.foreign_expn_data.iter().collect(); |
654 | foreign_expn_data.sort_by_key(|(id, _)| (id.krate, id.local_id)); | |
655 | foreign_expn_data.into_iter().for_each(debug_expn_data); | |
e1599b0c XL |
656 | s.push_str("\n\nSyntaxContexts:"); |
657 | data.syntax_context_data.iter().enumerate().for_each(|(id, ctxt)| { | |
658 | s.push_str(&format!( | |
659 | "\n#{}: parent: {:?}, outer_mark: ({:?}, {:?})", | |
dfeec247 | 660 | id, ctxt.parent, ctxt.outer_expn, ctxt.outer_transparency, |
e1599b0c XL |
661 | )); |
662 | }); | |
663 | s | |
664 | } | |
665 | }) | |
666 | } | |
667 | ||
5bcae85e | 668 | impl SyntaxContext { |
48663c56 | 669 | #[inline] |
e1599b0c | 670 | pub const fn root() -> Self { |
5bcae85e SL |
671 | SyntaxContext(0) |
672 | } | |
673 | ||
48663c56 | 674 | #[inline] |
923072b8 | 675 | pub(crate) fn as_u32(self) -> u32 { |
8faf50e0 XL |
676 | self.0 |
677 | } | |
678 | ||
48663c56 | 679 | #[inline] |
923072b8 | 680 | pub(crate) fn from_u32(raw: u32) -> SyntaxContext { |
8faf50e0 XL |
681 | SyntaxContext(raw) |
682 | } | |
683 | ||
416331ca | 684 | /// Extend a syntax context with a given expansion and transparency. |
923072b8 | 685 | pub(crate) fn apply_mark(self, expn_id: ExpnId, transparency: Transparency) -> SyntaxContext { |
e1599b0c | 686 | HygieneData::with(|data| data.apply_mark(self, expn_id, transparency)) |
5bcae85e | 687 | } |
cc61c64b | 688 | |
83c7162d XL |
689 | /// Pulls a single mark off of the syntax context. This effectively moves the |
690 | /// context up one macro definition level. That is, if we have a nested macro | |
691 | /// definition as follows: | |
692 | /// | |
04454e1e | 693 | /// ```ignore (illustrative) |
83c7162d XL |
694 | /// macro_rules! f { |
695 | /// macro_rules! g { | |
696 | /// ... | |
697 | /// } | |
698 | /// } | |
699 | /// ``` | |
700 | /// | |
701 | /// and we have a SyntaxContext that is referring to something declared by an invocation | |
702 | /// of g (call it g1), calling remove_mark will result in the SyntaxContext for the | |
703 | /// invocation of f that created g1. | |
704 | /// Returns the mark that was removed. | |
416331ca | 705 | pub fn remove_mark(&mut self) -> ExpnId { |
e1599b0c | 706 | HygieneData::with(|data| data.remove_mark(self).0) |
7cac9316 XL |
707 | } |
708 | ||
416331ca | 709 | pub fn marks(self) -> Vec<(ExpnId, Transparency)> { |
dc9dc135 | 710 | HygieneData::with(|data| data.marks(self)) |
2c00a5a8 XL |
711 | } |
712 | ||
7cac9316 XL |
713 | /// Adjust this context for resolution in a scope created by the given expansion. |
714 | /// For example, consider the following three resolutions of `f`: | |
ff7c6d11 | 715 | /// |
7cac9316 | 716 | /// ```rust |
04454e1e | 717 | /// #![feature(decl_macro)] |
7cac9316 XL |
718 | /// mod foo { pub fn f() {} } // `f`'s `SyntaxContext` is empty. |
719 | /// m!(f); | |
720 | /// macro m($f:ident) { | |
721 | /// mod bar { | |
416331ca | 722 | /// pub fn f() {} // `f`'s `SyntaxContext` has a single `ExpnId` from `m`. |
7cac9316 XL |
723 | /// pub fn $f() {} // `$f`'s `SyntaxContext` is empty. |
724 | /// } | |
416331ca | 725 | /// foo::f(); // `f`'s `SyntaxContext` has a single `ExpnId` from `m` |
7cac9316 XL |
726 | /// //^ Since `mod foo` is outside this expansion, `adjust` removes the mark from `f`, |
727 | /// //| and it resolves to `::foo::f`. | |
416331ca | 728 | /// bar::f(); // `f`'s `SyntaxContext` has a single `ExpnId` from `m` |
7cac9316 XL |
729 | /// //^ Since `mod bar` not outside this expansion, `adjust` does not change `f`, |
730 | /// //| and it resolves to `::bar::f`. | |
731 | /// bar::$f(); // `f`'s `SyntaxContext` is empty. | |
732 | /// //^ Since `mod bar` is not outside this expansion, `adjust` does not change `$f`, | |
733 | /// //| and it resolves to `::bar::$f`. | |
734 | /// } | |
735 | /// ``` | |
736 | /// This returns the expansion whose definition scope we use to privacy check the resolution, | |
0731742a | 737 | /// or `None` if we privacy check as usual (i.e., not w.r.t. a macro definition scope). |
416331ca XL |
738 | pub fn adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> { |
739 | HygieneData::with(|data| data.adjust(self, expn_id)) | |
dc9dc135 XL |
740 | } |
741 | ||
ba9703b0 XL |
742 | /// Like `SyntaxContext::adjust`, but also normalizes `self` to macros 2.0. |
743 | pub fn normalize_to_macros_2_0_and_adjust(&mut self, expn_id: ExpnId) -> Option<ExpnId> { | |
dc9dc135 | 744 | HygieneData::with(|data| { |
ba9703b0 | 745 | *self = data.normalize_to_macros_2_0(*self); |
416331ca | 746 | data.adjust(self, expn_id) |
dc9dc135 | 747 | }) |
7cac9316 XL |
748 | } |
749 | ||
750 | /// Adjust this context for resolution in a scope created by the given expansion | |
751 | /// via a glob import with the given `SyntaxContext`. | |
ff7c6d11 XL |
752 | /// For example: |
753 | /// | |
04454e1e FG |
754 | /// ```compile_fail,E0425 |
755 | /// #![feature(decl_macro)] | |
7cac9316 XL |
756 | /// m!(f); |
757 | /// macro m($i:ident) { | |
758 | /// mod foo { | |
416331ca | 759 | /// pub fn f() {} // `f`'s `SyntaxContext` has a single `ExpnId` from `m`. |
7cac9316 XL |
760 | /// pub fn $i() {} // `$i`'s `SyntaxContext` is empty. |
761 | /// } | |
3c0e092e | 762 | /// n!(f); |
7cac9316 XL |
763 | /// macro n($j:ident) { |
764 | /// use foo::*; | |
765 | /// f(); // `f`'s `SyntaxContext` has a mark from `m` and a mark from `n` | |
766 | /// //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::f`. | |
767 | /// $i(); // `$i`'s `SyntaxContext` has a mark from `n` | |
768 | /// //^ `glob_adjust` removes the mark from `n`, so this resolves to `foo::$i`. | |
769 | /// $j(); // `$j`'s `SyntaxContext` has a mark from `m` | |
770 | /// //^ This cannot be glob-adjusted, so this is a resolution error. | |
771 | /// } | |
772 | /// } | |
773 | /// ``` | |
774 | /// This returns `None` if the context cannot be glob-adjusted. | |
775 | /// Otherwise, it returns the scope to use when privacy checking (see `adjust` for details). | |
416331ca | 776 | pub fn glob_adjust(&mut self, expn_id: ExpnId, glob_span: Span) -> Option<Option<ExpnId>> { |
dc9dc135 XL |
777 | HygieneData::with(|data| { |
778 | let mut scope = None; | |
ba9703b0 | 779 | let mut glob_ctxt = data.normalize_to_macros_2_0(glob_span.ctxt()); |
416331ca | 780 | while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) { |
e1599b0c XL |
781 | scope = Some(data.remove_mark(&mut glob_ctxt).0); |
782 | if data.remove_mark(self).0 != scope.unwrap() { | |
dc9dc135 XL |
783 | return None; |
784 | } | |
785 | } | |
416331ca | 786 | if data.adjust(self, expn_id).is_some() { |
7cac9316 XL |
787 | return None; |
788 | } | |
dc9dc135 XL |
789 | Some(scope) |
790 | }) | |
7cac9316 XL |
791 | } |
792 | ||
793 | /// Undo `glob_adjust` if possible: | |
ff7c6d11 | 794 | /// |
04454e1e | 795 | /// ```ignore (illustrative) |
7cac9316 XL |
796 | /// if let Some(privacy_checking_scope) = self.reverse_glob_adjust(expansion, glob_ctxt) { |
797 | /// assert!(self.glob_adjust(expansion, glob_ctxt) == Some(privacy_checking_scope)); | |
798 | /// } | |
799 | /// ``` | |
dfeec247 XL |
800 | pub fn reverse_glob_adjust( |
801 | &mut self, | |
802 | expn_id: ExpnId, | |
803 | glob_span: Span, | |
804 | ) -> Option<Option<ExpnId>> { | |
dc9dc135 | 805 | HygieneData::with(|data| { |
416331ca | 806 | if data.adjust(self, expn_id).is_some() { |
dc9dc135 XL |
807 | return None; |
808 | } | |
7cac9316 | 809 | |
ba9703b0 | 810 | let mut glob_ctxt = data.normalize_to_macros_2_0(glob_span.ctxt()); |
dc9dc135 | 811 | let mut marks = Vec::new(); |
416331ca | 812 | while !data.is_descendant_of(expn_id, data.outer_expn(glob_ctxt)) { |
dc9dc135 XL |
813 | marks.push(data.remove_mark(&mut glob_ctxt)); |
814 | } | |
7cac9316 | 815 | |
e1599b0c XL |
816 | let scope = marks.last().map(|mark| mark.0); |
817 | while let Some((expn_id, transparency)) = marks.pop() { | |
818 | *self = data.apply_mark(*self, expn_id, transparency); | |
dc9dc135 XL |
819 | } |
820 | Some(scope) | |
821 | }) | |
822 | } | |
823 | ||
416331ca | 824 | pub fn hygienic_eq(self, other: SyntaxContext, expn_id: ExpnId) -> bool { |
dc9dc135 | 825 | HygieneData::with(|data| { |
ba9703b0 XL |
826 | let mut self_normalized = data.normalize_to_macros_2_0(self); |
827 | data.adjust(&mut self_normalized, expn_id); | |
828 | self_normalized == data.normalize_to_macros_2_0(other) | |
dc9dc135 | 829 | }) |
7cac9316 XL |
830 | } |
831 | ||
ff7c6d11 | 832 | #[inline] |
ba9703b0 XL |
833 | pub fn normalize_to_macros_2_0(self) -> SyntaxContext { |
834 | HygieneData::with(|data| data.normalize_to_macros_2_0(self)) | |
8faf50e0 XL |
835 | } |
836 | ||
837 | #[inline] | |
ba9703b0 XL |
838 | pub fn normalize_to_macro_rules(self) -> SyntaxContext { |
839 | HygieneData::with(|data| data.normalize_to_macro_rules(self)) | |
7cac9316 XL |
840 | } |
841 | ||
ff7c6d11 | 842 | #[inline] |
416331ca XL |
843 | pub fn outer_expn(self) -> ExpnId { |
844 | HygieneData::with(|data| data.outer_expn(self)) | |
dc9dc135 XL |
845 | } |
846 | ||
e1599b0c XL |
847 | /// `ctxt.outer_expn_data()` is equivalent to but faster than |
848 | /// `ctxt.outer_expn().expn_data()`. | |
dc9dc135 | 849 | #[inline] |
e1599b0c XL |
850 | pub fn outer_expn_data(self) -> ExpnData { |
851 | HygieneData::with(|data| data.expn_data(data.outer_expn(self)).clone()) | |
dc9dc135 XL |
852 | } |
853 | ||
3dfed10e XL |
854 | #[inline] |
855 | pub fn outer_mark(self) -> (ExpnId, Transparency) { | |
856 | HygieneData::with(|data| data.outer_mark(self)) | |
857 | } | |
858 | ||
0731742a | 859 | pub fn dollar_crate_name(self) -> Symbol { |
416331ca | 860 | HygieneData::with(|data| data.syntax_context_data[self.0 as usize].dollar_crate_name) |
0731742a | 861 | } |
5869c6ff XL |
862 | |
863 | pub fn edition(self) -> Edition { | |
136023e0 | 864 | HygieneData::with(|data| data.expn_data(data.outer_expn(self)).edition) |
5869c6ff | 865 | } |
5bcae85e SL |
866 | } |
867 | ||
868 | impl fmt::Debug for SyntaxContext { | |
9fa01778 | 869 | fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
5bcae85e SL |
870 | write!(f, "#{}", self.0) |
871 | } | |
872 | } | |
cc61c64b | 873 | |
416331ca XL |
874 | impl Span { |
875 | /// Creates a fresh expansion with given properties. | |
876 | /// Expansions are normally created by macros, but in some cases expansions are created for | |
877 | /// other compiler-generated code to set per-span properties like allowed unstable features. | |
878 | /// The returned span belongs to the created expansion and has the new properties, | |
879 | /// but its location is inherited from the current span. | |
5e7ed085 | 880 | pub fn fresh_expansion(self, expn_id: LocalExpnId) -> Span { |
416331ca | 881 | HygieneData::with(|data| { |
5e7ed085 FG |
882 | self.with_ctxt(data.apply_mark( |
883 | SyntaxContext::root(), | |
884 | expn_id.to_expn_id(), | |
885 | Transparency::Transparent, | |
886 | )) | |
416331ca XL |
887 | }) |
888 | } | |
5869c6ff XL |
889 | |
890 | /// Reuses the span but adds information like the kind of the desugaring and features that are | |
891 | /// allowed inside this span. | |
892 | pub fn mark_with_reason( | |
893 | self, | |
894 | allow_internal_unstable: Option<Lrc<[Symbol]>>, | |
895 | reason: DesugaringKind, | |
896 | edition: Edition, | |
136023e0 | 897 | ctx: impl HashStableContext, |
5869c6ff | 898 | ) -> Span { |
136023e0 | 899 | let expn_data = ExpnData { |
5869c6ff | 900 | allow_internal_unstable, |
136023e0 XL |
901 | ..ExpnData::default(ExpnKind::Desugaring(reason), self, edition, None, None) |
902 | }; | |
5e7ed085 FG |
903 | let expn_id = LocalExpnId::fresh(expn_data, ctx); |
904 | self.fresh_expansion(expn_id) | |
5869c6ff | 905 | } |
416331ca XL |
906 | } |
907 | ||
908 | /// A subset of properties from both macro definition and macro call available through global data. | |
909 | /// Avoid using this if you have access to the original definition or call structures. | |
3dfed10e | 910 | #[derive(Clone, Debug, Encodable, Decodable, HashStable_Generic)] |
e1599b0c | 911 | pub struct ExpnData { |
dc9dc135 | 912 | // --- The part unique to each expansion. |
e1599b0c XL |
913 | /// The kind of this expansion - macro or compiler desugaring. |
914 | pub kind: ExpnKind, | |
915 | /// The expansion that produced this expansion. | |
916 | pub parent: ExpnId, | |
cc61c64b XL |
917 | /// The location of the actual macro invocation or syntax sugar , e.g. |
918 | /// `let x = foo!();` or `if let Some(y) = x {}` | |
919 | /// | |
0731742a | 920 | /// This may recursively refer to other macro invocations, e.g., if |
cc61c64b XL |
921 | /// `foo!()` invoked `bar!()` internally, and there was an |
922 | /// expression inside `bar!`; the call_site of the expression in | |
923 | /// the expansion would point to the `bar!` invocation; that | |
e1599b0c | 924 | /// call_site span would have its own ExpnData, with the call_site |
cc61c64b XL |
925 | /// pointing to the `foo!` invocation. |
926 | pub call_site: Span, | |
136023e0 XL |
927 | /// Used to force two `ExpnData`s to have different `Fingerprint`s. |
928 | /// Due to macro expansion, it's possible to end up with two `ExpnId`s | |
929 | /// that have identical `ExpnData`s. This violates the contract of `HashStable` | |
930 | /// - the two `ExpnId`s are not equal, but their `Fingerprint`s are equal | |
931 | /// (since the numerical `ExpnId` value is not considered by the `HashStable` | |
932 | /// implementation). | |
933 | /// | |
934 | /// The `disambiguator` field is set by `update_disambiguator` when two distinct | |
935 | /// `ExpnId`s would end up with the same `Fingerprint`. Since `ExpnData` includes | |
936 | /// a `krate` field, this value only needs to be unique within a single crate. | |
937 | disambiguator: u32, | |
dc9dc135 XL |
938 | |
939 | // --- The part specific to the macro/desugaring definition. | |
e1599b0c XL |
940 | // --- It may be reasonable to share this part between expansions with the same definition, |
941 | // --- but such sharing is known to bring some minor inconveniences without also bringing | |
942 | // --- noticeable perf improvements (PR #62898). | |
416331ca | 943 | /// The span of the macro definition (possibly dummy). |
8faf50e0 | 944 | /// This span serves only informational purpose and is not used for resolution. |
416331ca | 945 | pub def_site: Span, |
f9f354fc | 946 | /// List of `#[unstable]`/feature-gated features that the macro is allowed to use |
9fa01778 | 947 | /// internally without forcing the whole crate to opt-in |
cc61c64b | 948 | /// to them. |
9fa01778 | 949 | pub allow_internal_unstable: Option<Lrc<[Symbol]>>, |
94b46f34 XL |
950 | /// Edition of the crate in which the macro is defined. |
951 | pub edition: Edition, | |
f9f354fc XL |
952 | /// The `DefId` of the macro being invoked, |
953 | /// if this `ExpnData` corresponds to a macro invocation | |
954 | pub macro_def_id: Option<DefId>, | |
136023e0 XL |
955 | /// The normal module (`mod`) in which the expanded macro was defined. |
956 | pub parent_module: Option<DefId>, | |
f2b60f7d FG |
957 | /// Suppresses the `unsafe_code` lint for code produced by this macro. |
958 | pub allow_internal_unsafe: bool, | |
959 | /// Enables the macro helper hack (`ident!(...)` -> `$crate::ident!(...)`) for this macro. | |
960 | pub local_inner_macros: bool, | |
961 | /// Should debuginfo for the macro be collapsed to the outermost expansion site (in other | |
962 | /// words, was the macro definition annotated with `#[collapse_debuginfo]`)? | |
963 | pub collapse_debuginfo: bool, | |
cc61c64b XL |
964 | } |
965 | ||
3dfed10e | 966 | impl !PartialEq for ExpnData {} |
5869c6ff | 967 | impl !Hash for ExpnData {} |
3dfed10e | 968 | |
e1599b0c | 969 | impl ExpnData { |
5869c6ff XL |
970 | pub fn new( |
971 | kind: ExpnKind, | |
972 | parent: ExpnId, | |
973 | call_site: Span, | |
974 | def_site: Span, | |
975 | allow_internal_unstable: Option<Lrc<[Symbol]>>, | |
5869c6ff XL |
976 | edition: Edition, |
977 | macro_def_id: Option<DefId>, | |
136023e0 | 978 | parent_module: Option<DefId>, |
f2b60f7d FG |
979 | allow_internal_unsafe: bool, |
980 | local_inner_macros: bool, | |
981 | collapse_debuginfo: bool, | |
5869c6ff XL |
982 | ) -> ExpnData { |
983 | ExpnData { | |
984 | kind, | |
985 | parent, | |
986 | call_site, | |
987 | def_site, | |
988 | allow_internal_unstable, | |
5869c6ff XL |
989 | edition, |
990 | macro_def_id, | |
136023e0 | 991 | parent_module, |
5869c6ff | 992 | disambiguator: 0, |
f2b60f7d FG |
993 | allow_internal_unsafe, |
994 | local_inner_macros, | |
995 | collapse_debuginfo, | |
5869c6ff XL |
996 | } |
997 | } | |
998 | ||
e1599b0c | 999 | /// Constructs expansion data with default properties. |
f9f354fc XL |
1000 | pub fn default( |
1001 | kind: ExpnKind, | |
1002 | call_site: Span, | |
1003 | edition: Edition, | |
1004 | macro_def_id: Option<DefId>, | |
136023e0 | 1005 | parent_module: Option<DefId>, |
f9f354fc | 1006 | ) -> ExpnData { |
e1599b0c | 1007 | ExpnData { |
416331ca | 1008 | kind, |
e1599b0c XL |
1009 | parent: ExpnId::root(), |
1010 | call_site, | |
416331ca | 1011 | def_site: DUMMY_SP, |
dc9dc135 | 1012 | allow_internal_unstable: None, |
dc9dc135 | 1013 | edition, |
f9f354fc | 1014 | macro_def_id, |
136023e0 | 1015 | parent_module, |
5869c6ff | 1016 | disambiguator: 0, |
f2b60f7d FG |
1017 | allow_internal_unsafe: false, |
1018 | local_inner_macros: false, | |
1019 | collapse_debuginfo: false, | |
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 { |
9c376795 FG |
1070 | MacroKind::Bang => format!("{name}!"), |
1071 | MacroKind::Attr => format!("#[{name}]"), | |
1072 | MacroKind::Derive => format!("#[derive({name})]"), | |
dfeec247 XL |
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, |
04454e1e | 1145 | YeetExpr, |
94b46f34 | 1146 | /// Desugaring of an `impl Trait` in return type position |
416331ca | 1147 | /// to an `type Foo = impl Trait;` and replacing the |
94b46f34 | 1148 | /// `impl Trait` with `Foo`. |
416331ca | 1149 | OpaqueTy, |
8faf50e0 | 1150 | Async, |
48663c56 | 1151 | Await, |
3c0e092e | 1152 | ForLoop, |
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", | |
04454e1e | 1165 | DesugaringKind::YeetExpr => "`do yeet` expression", |
416331ca | 1166 | DesugaringKind::OpaqueTy => "`impl Trait`", |
3c0e092e | 1167 | DesugaringKind::ForLoop => "`for` loop", |
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`) | |
5e7ed085 | 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 | ||
923072b8 | 1198 | pub fn encode<T>( |
3dfed10e XL |
1199 | &self, |
1200 | encoder: &mut T, | |
923072b8 FG |
1201 | mut encode_ctxt: impl FnMut(&mut T, u32, &SyntaxContextData), |
1202 | mut encode_expn: impl FnMut(&mut T, ExpnId, &ExpnData, ExpnHash), | |
1203 | ) { | |
3dfed10e XL |
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 | |
064997fb | 1220 | #[allow(rustc::potential_query_instability)] |
136023e0 | 1221 | for_all_ctxts_in(latest_ctxts.into_iter(), |index, ctxt, data| { |
3dfed10e | 1222 | if self.serialized_ctxts.lock().insert(ctxt) { |
923072b8 | 1223 | encode_ctxt(encoder, index, data); |
3dfed10e | 1224 | } |
923072b8 | 1225 | }); |
3dfed10e XL |
1226 | |
1227 | let latest_expns = { std::mem::take(&mut *self.latest_expns.lock()) }; | |
1228 | ||
064997fb FG |
1229 | // Same as above, this is fine as we are inserting into a order-independent hashset |
1230 | #[allow(rustc::potential_query_instability)] | |
136023e0 | 1231 | for_all_expns_in(latest_expns.into_iter(), |expn, data, hash| { |
3dfed10e | 1232 | if self.serialized_expns.lock().insert(expn) { |
923072b8 | 1233 | encode_expn(encoder, expn, data, hash); |
3dfed10e | 1234 | } |
923072b8 | 1235 | }); |
3dfed10e XL |
1236 | } |
1237 | debug!("encode_hygiene: Done serializing SyntaxContextData"); | |
3dfed10e XL |
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 | ||
923072b8 | 1387 | fn for_all_ctxts_in<F: FnMut(u32, SyntaxContext, &SyntaxContextData)>( |
3dfed10e XL |
1388 | ctxts: impl Iterator<Item = SyntaxContext>, |
1389 | mut f: F, | |
923072b8 | 1390 | ) { |
3dfed10e XL |
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() { | |
923072b8 | 1395 | f(ctxt.0, ctxt, &data); |
3dfed10e | 1396 | } |
3dfed10e XL |
1397 | } |
1398 | ||
923072b8 | 1399 | fn for_all_expns_in( |
3dfed10e | 1400 | expns: impl Iterator<Item = ExpnId>, |
923072b8 FG |
1401 | mut f: impl FnMut(ExpnId, &ExpnData, ExpnHash), |
1402 | ) { | |
3dfed10e | 1403 | let all_data: Vec<_> = HygieneData::with(|data| { |
c295e0f8 | 1404 | expns.map(|expn| (expn, data.expn_data(expn).clone(), data.expn_hash(expn))).collect() |
3dfed10e | 1405 | }); |
136023e0 | 1406 | for (expn, data, hash) in all_data.into_iter() { |
923072b8 | 1407 | f(expn, &data, hash); |
3dfed10e | 1408 | } |
3dfed10e XL |
1409 | } |
1410 | ||
136023e0 | 1411 | impl<E: Encoder> Encodable<E> for LocalExpnId { |
923072b8 FG |
1412 | fn encode(&self, e: &mut E) { |
1413 | self.to_expn_id().encode(e); | |
136023e0 XL |
1414 | } |
1415 | } | |
1416 | ||
3dfed10e | 1417 | impl<E: Encoder> Encodable<E> for ExpnId { |
923072b8 | 1418 | default fn encode(&self, _: &mut E) { |
3dfed10e XL |
1419 | panic!("cannot encode `ExpnId` with `{}`", std::any::type_name::<E>()); |
1420 | } | |
1421 | } | |
1422 | ||
136023e0 | 1423 | impl<D: Decoder> Decodable<D> for LocalExpnId { |
5099ac24 FG |
1424 | fn decode(d: &mut D) -> Self { |
1425 | ExpnId::expect_local(ExpnId::decode(d)) | |
136023e0 XL |
1426 | } |
1427 | } | |
1428 | ||
3dfed10e | 1429 | impl<D: Decoder> Decodable<D> for ExpnId { |
5099ac24 | 1430 | default fn decode(_: &mut D) -> Self { |
3dfed10e XL |
1431 | panic!("cannot decode `ExpnId` with `{}`", std::any::type_name::<D>()); |
1432 | } | |
1433 | } | |
1434 | ||
3dfed10e XL |
1435 | pub fn raw_encode_syntax_context<E: Encoder>( |
1436 | ctxt: SyntaxContext, | |
1437 | context: &HygieneEncodeContext, | |
1438 | e: &mut E, | |
923072b8 | 1439 | ) { |
3dfed10e XL |
1440 | if !context.serialized_ctxts.lock().contains(&ctxt) { |
1441 | context.latest_ctxts.lock().insert(ctxt); | |
1442 | } | |
923072b8 | 1443 | ctxt.0.encode(e); |
3dfed10e XL |
1444 | } |
1445 | ||
3dfed10e | 1446 | impl<E: Encoder> Encodable<E> for SyntaxContext { |
923072b8 | 1447 | default fn encode(&self, _: &mut E) { |
3dfed10e | 1448 | panic!("cannot encode `SyntaxContext` with `{}`", std::any::type_name::<E>()); |
cc61c64b XL |
1449 | } |
1450 | } | |
1451 | ||
3dfed10e | 1452 | impl<D: Decoder> Decodable<D> for SyntaxContext { |
5099ac24 | 1453 | default fn decode(_: &mut D) -> Self { |
3dfed10e | 1454 | panic!("cannot decode `SyntaxContext` with `{}`", std::any::type_name::<D>()); |
cc61c64b XL |
1455 | } |
1456 | } | |
5869c6ff XL |
1457 | |
1458 | /// Updates the `disambiguator` field of the corresponding `ExpnData` | |
1459 | /// such that the `Fingerprint` of the `ExpnData` does not collide with | |
1460 | /// any other `ExpnIds`. | |
1461 | /// | |
1462 | /// This method is called only when an `ExpnData` is first associated | |
1463 | /// with an `ExpnId` (when the `ExpnId` is initially constructed, or via | |
1464 | /// `set_expn_data`). It is *not* called for foreign `ExpnId`s deserialized | |
136023e0 | 1465 | /// from another crate's metadata - since `ExpnHash` includes the stable crate id, |
5869c6ff | 1466 | /// collisions are only possible between `ExpnId`s within the same crate. |
136023e0 | 1467 | fn update_disambiguator(expn_data: &mut ExpnData, mut ctx: impl HashStableContext) -> ExpnHash { |
5869c6ff | 1468 | // This disambiguator should not have been set yet. |
9c376795 | 1469 | assert_eq!(expn_data.disambiguator, 0, "Already set disambiguator for ExpnData: {expn_data:?}"); |
5099ac24 | 1470 | assert_default_hashing_controls(&ctx, "ExpnData (disambiguator)"); |
136023e0 | 1471 | let mut expn_hash = expn_data.hash_expn(&mut ctx); |
5869c6ff | 1472 | |
136023e0 | 1473 | let disambiguator = HygieneData::with(|data| { |
5869c6ff XL |
1474 | // If this is the first ExpnData with a given hash, then keep our |
1475 | // disambiguator at 0 (the default u32 value) | |
136023e0 XL |
1476 | let disambig = data.expn_data_disambiguators.entry(expn_hash).or_default(); |
1477 | let disambiguator = *disambig; | |
5869c6ff | 1478 | *disambig += 1; |
136023e0 | 1479 | disambiguator |
5869c6ff XL |
1480 | }); |
1481 | ||
136023e0 XL |
1482 | if disambiguator != 0 { |
1483 | debug!("Set disambiguator for expn_data={:?} expn_hash={:?}", expn_data, expn_hash); | |
1484 | ||
1485 | expn_data.disambiguator = disambiguator; | |
1486 | expn_hash = expn_data.hash_expn(&mut ctx); | |
5869c6ff XL |
1487 | |
1488 | // Verify that the new disambiguator makes the hash unique | |
1489 | #[cfg(debug_assertions)] | |
136023e0 XL |
1490 | HygieneData::with(|data| { |
1491 | assert_eq!( | |
1492 | data.expn_data_disambiguators.get(&expn_hash), | |
1493 | None, | |
1494 | "Hash collision after disambiguator update!", | |
1495 | ); | |
1496 | }); | |
1497 | } | |
1498 | ||
1499 | ExpnHash::new(ctx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(), expn_hash) | |
1500 | } | |
1501 | ||
1502 | impl<CTX: HashStableContext> HashStable<CTX> for SyntaxContext { | |
1503 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { | |
1504 | const TAG_EXPANSION: u8 = 0; | |
1505 | const TAG_NO_EXPANSION: u8 = 1; | |
1506 | ||
1507 | if *self == SyntaxContext::root() { | |
1508 | TAG_NO_EXPANSION.hash_stable(ctx, hasher); | |
1509 | } else { | |
1510 | TAG_EXPANSION.hash_stable(ctx, hasher); | |
1511 | let (expn_id, transparency) = self.outer_mark(); | |
1512 | expn_id.hash_stable(ctx, hasher); | |
1513 | transparency.hash_stable(ctx, hasher); | |
1514 | } | |
1515 | } | |
1516 | } | |
1517 | ||
1518 | impl<CTX: HashStableContext> HashStable<CTX> for ExpnId { | |
1519 | fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) { | |
5099ac24 | 1520 | assert_default_hashing_controls(ctx, "ExpnId"); |
136023e0 XL |
1521 | let hash = if *self == ExpnId::root() { |
1522 | // Avoid fetching TLS storage for a trivial often-used value. | |
1523 | Fingerprint::ZERO | |
1524 | } else { | |
1525 | self.expn_hash().0 | |
5869c6ff | 1526 | }; |
136023e0 XL |
1527 | |
1528 | hash.hash_stable(ctx, hasher); | |
5869c6ff XL |
1529 | } |
1530 | } |