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04454e1e FG |
1 | use rustc_ast::{self as ast, NodeId}; |
2 | use rustc_feature::is_builtin_attr_name; | |
3 | use rustc_hir::def::{DefKind, Namespace, NonMacroAttrKind, PartialRes, PerNS}; | |
4 | use rustc_hir::PrimTy; | |
5 | use rustc_middle::bug; | |
6 | use rustc_middle::ty; | |
7 | use rustc_session::lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK; | |
8 | use rustc_session::lint::BuiltinLintDiagnostics; | |
9 | use rustc_span::edition::Edition; | |
10 | use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext}; | |
11 | use rustc_span::symbol::{kw, Ident}; | |
12 | use rustc_span::{Span, DUMMY_SP}; | |
13 | ||
14 | use std::ptr; | |
15 | ||
16 | use crate::late::{ConstantItemKind, HasGenericParams, PathSource, Rib, RibKind}; | |
17 | use crate::macros::{sub_namespace_match, MacroRulesScope}; | |
18 | use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, Determinacy, Finalize}; | |
19 | use crate::{ImportKind, LexicalScopeBinding, Module, ModuleKind, ModuleOrUniformRoot}; | |
20 | use crate::{NameBinding, NameBindingKind, ParentScope, PathResult, PrivacyError, Res}; | |
21 | use crate::{ResolutionError, Resolver, Scope, ScopeSet, Segment, ToNameBinding, Weak}; | |
22 | ||
23 | use Determinacy::*; | |
24 | use Namespace::*; | |
25 | use RibKind::*; | |
26 | ||
27 | impl<'a> Resolver<'a> { | |
28 | /// A generic scope visitor. | |
29 | /// Visits scopes in order to resolve some identifier in them or perform other actions. | |
30 | /// If the callback returns `Some` result, we stop visiting scopes and return it. | |
923072b8 | 31 | pub(crate) fn visit_scopes<T>( |
04454e1e FG |
32 | &mut self, |
33 | scope_set: ScopeSet<'a>, | |
34 | parent_scope: &ParentScope<'a>, | |
35 | ctxt: SyntaxContext, | |
36 | mut visitor: impl FnMut( | |
37 | &mut Self, | |
38 | Scope<'a>, | |
39 | /*use_prelude*/ bool, | |
40 | SyntaxContext, | |
41 | ) -> Option<T>, | |
42 | ) -> Option<T> { | |
43 | // General principles: | |
44 | // 1. Not controlled (user-defined) names should have higher priority than controlled names | |
45 | // built into the language or standard library. This way we can add new names into the | |
46 | // language or standard library without breaking user code. | |
47 | // 2. "Closed set" below means new names cannot appear after the current resolution attempt. | |
48 | // Places to search (in order of decreasing priority): | |
49 | // (Type NS) | |
50 | // 1. FIXME: Ribs (type parameters), there's no necessary infrastructure yet | |
51 | // (open set, not controlled). | |
52 | // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents | |
53 | // (open, not controlled). | |
54 | // 3. Extern prelude (open, the open part is from macro expansions, not controlled). | |
55 | // 4. Tool modules (closed, controlled right now, but not in the future). | |
56 | // 5. Standard library prelude (de-facto closed, controlled). | |
57 | // 6. Language prelude (closed, controlled). | |
58 | // (Value NS) | |
59 | // 1. FIXME: Ribs (local variables), there's no necessary infrastructure yet | |
60 | // (open set, not controlled). | |
61 | // 2. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents | |
62 | // (open, not controlled). | |
63 | // 3. Standard library prelude (de-facto closed, controlled). | |
64 | // (Macro NS) | |
65 | // 1-3. Derive helpers (open, not controlled). All ambiguities with other names | |
66 | // are currently reported as errors. They should be higher in priority than preludes | |
67 | // and probably even names in modules according to the "general principles" above. They | |
68 | // also should be subject to restricted shadowing because are effectively produced by | |
69 | // derives (you need to resolve the derive first to add helpers into scope), but they | |
70 | // should be available before the derive is expanded for compatibility. | |
71 | // It's mess in general, so we are being conservative for now. | |
72 | // 1-3. `macro_rules` (open, not controlled), loop through `macro_rules` scopes. Have higher | |
73 | // priority than prelude macros, but create ambiguities with macros in modules. | |
74 | // 1-3. Names in modules (both normal `mod`ules and blocks), loop through hygienic parents | |
75 | // (open, not controlled). Have higher priority than prelude macros, but create | |
76 | // ambiguities with `macro_rules`. | |
77 | // 4. `macro_use` prelude (open, the open part is from macro expansions, not controlled). | |
78 | // 4a. User-defined prelude from macro-use | |
79 | // (open, the open part is from macro expansions, not controlled). | |
80 | // 4b. "Standard library prelude" part implemented through `macro-use` (closed, controlled). | |
81 | // 4c. Standard library prelude (de-facto closed, controlled). | |
82 | // 6. Language prelude: builtin attributes (closed, controlled). | |
83 | ||
84 | let rust_2015 = ctxt.edition() == Edition::Edition2015; | |
85 | let (ns, macro_kind, is_absolute_path) = match scope_set { | |
86 | ScopeSet::All(ns, _) => (ns, None, false), | |
87 | ScopeSet::AbsolutePath(ns) => (ns, None, true), | |
88 | ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false), | |
89 | ScopeSet::Late(ns, ..) => (ns, None, false), | |
90 | }; | |
91 | let module = match scope_set { | |
92 | // Start with the specified module. | |
93 | ScopeSet::Late(_, module, _) => module, | |
94 | // Jump out of trait or enum modules, they do not act as scopes. | |
95 | _ => parent_scope.module.nearest_item_scope(), | |
96 | }; | |
97 | let mut scope = match ns { | |
98 | _ if is_absolute_path => Scope::CrateRoot, | |
99 | TypeNS | ValueNS => Scope::Module(module, None), | |
100 | MacroNS => Scope::DeriveHelpers(parent_scope.expansion), | |
101 | }; | |
102 | let mut ctxt = ctxt.normalize_to_macros_2_0(); | |
103 | let mut use_prelude = !module.no_implicit_prelude; | |
104 | ||
105 | loop { | |
106 | let visit = match scope { | |
107 | // Derive helpers are not in scope when resolving derives in the same container. | |
108 | Scope::DeriveHelpers(expn_id) => { | |
109 | !(expn_id == parent_scope.expansion && macro_kind == Some(MacroKind::Derive)) | |
110 | } | |
111 | Scope::DeriveHelpersCompat => true, | |
112 | Scope::MacroRules(macro_rules_scope) => { | |
113 | // Use "path compression" on `macro_rules` scope chains. This is an optimization | |
114 | // used to avoid long scope chains, see the comments on `MacroRulesScopeRef`. | |
115 | // As another consequence of this optimization visitors never observe invocation | |
116 | // scopes for macros that were already expanded. | |
117 | while let MacroRulesScope::Invocation(invoc_id) = macro_rules_scope.get() { | |
118 | if let Some(next_scope) = self.output_macro_rules_scopes.get(&invoc_id) { | |
119 | macro_rules_scope.set(next_scope.get()); | |
120 | } else { | |
121 | break; | |
122 | } | |
123 | } | |
124 | true | |
125 | } | |
126 | Scope::CrateRoot => true, | |
127 | Scope::Module(..) => true, | |
128 | Scope::RegisteredAttrs => use_prelude, | |
129 | Scope::MacroUsePrelude => use_prelude || rust_2015, | |
130 | Scope::BuiltinAttrs => true, | |
131 | Scope::ExternPrelude => use_prelude || is_absolute_path, | |
132 | Scope::ToolPrelude => use_prelude, | |
133 | Scope::StdLibPrelude => use_prelude || ns == MacroNS, | |
134 | Scope::BuiltinTypes => true, | |
135 | }; | |
136 | ||
137 | if visit { | |
138 | if let break_result @ Some(..) = visitor(self, scope, use_prelude, ctxt) { | |
139 | return break_result; | |
140 | } | |
141 | } | |
142 | ||
143 | scope = match scope { | |
144 | Scope::DeriveHelpers(LocalExpnId::ROOT) => Scope::DeriveHelpersCompat, | |
145 | Scope::DeriveHelpers(expn_id) => { | |
146 | // Derive helpers are not visible to code generated by bang or derive macros. | |
147 | let expn_data = expn_id.expn_data(); | |
148 | match expn_data.kind { | |
149 | ExpnKind::Root | |
150 | | ExpnKind::Macro(MacroKind::Bang | MacroKind::Derive, _) => { | |
151 | Scope::DeriveHelpersCompat | |
152 | } | |
153 | _ => Scope::DeriveHelpers(expn_data.parent.expect_local()), | |
154 | } | |
155 | } | |
156 | Scope::DeriveHelpersCompat => Scope::MacroRules(parent_scope.macro_rules), | |
157 | Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() { | |
158 | MacroRulesScope::Binding(binding) => { | |
159 | Scope::MacroRules(binding.parent_macro_rules_scope) | |
160 | } | |
161 | MacroRulesScope::Invocation(invoc_id) => { | |
162 | Scope::MacroRules(self.invocation_parent_scopes[&invoc_id].macro_rules) | |
163 | } | |
164 | MacroRulesScope::Empty => Scope::Module(module, None), | |
165 | }, | |
166 | Scope::CrateRoot => match ns { | |
167 | TypeNS => { | |
168 | ctxt.adjust(ExpnId::root()); | |
169 | Scope::ExternPrelude | |
170 | } | |
171 | ValueNS | MacroNS => break, | |
172 | }, | |
173 | Scope::Module(module, prev_lint_id) => { | |
174 | use_prelude = !module.no_implicit_prelude; | |
175 | let derive_fallback_lint_id = match scope_set { | |
176 | ScopeSet::Late(.., lint_id) => lint_id, | |
177 | _ => None, | |
178 | }; | |
179 | match self.hygienic_lexical_parent(module, &mut ctxt, derive_fallback_lint_id) { | |
180 | Some((parent_module, lint_id)) => { | |
181 | Scope::Module(parent_module, lint_id.or(prev_lint_id)) | |
182 | } | |
183 | None => { | |
184 | ctxt.adjust(ExpnId::root()); | |
185 | match ns { | |
186 | TypeNS => Scope::ExternPrelude, | |
187 | ValueNS => Scope::StdLibPrelude, | |
188 | MacroNS => Scope::RegisteredAttrs, | |
189 | } | |
190 | } | |
191 | } | |
192 | } | |
193 | Scope::RegisteredAttrs => Scope::MacroUsePrelude, | |
194 | Scope::MacroUsePrelude => Scope::StdLibPrelude, | |
195 | Scope::BuiltinAttrs => break, // nowhere else to search | |
196 | Scope::ExternPrelude if is_absolute_path => break, | |
197 | Scope::ExternPrelude => Scope::ToolPrelude, | |
198 | Scope::ToolPrelude => Scope::StdLibPrelude, | |
199 | Scope::StdLibPrelude => match ns { | |
200 | TypeNS => Scope::BuiltinTypes, | |
201 | ValueNS => break, // nowhere else to search | |
202 | MacroNS => Scope::BuiltinAttrs, | |
203 | }, | |
204 | Scope::BuiltinTypes => break, // nowhere else to search | |
205 | }; | |
206 | } | |
207 | ||
208 | None | |
209 | } | |
210 | ||
211 | fn hygienic_lexical_parent( | |
212 | &mut self, | |
213 | module: Module<'a>, | |
214 | ctxt: &mut SyntaxContext, | |
215 | derive_fallback_lint_id: Option<NodeId>, | |
216 | ) -> Option<(Module<'a>, Option<NodeId>)> { | |
217 | if !module.expansion.outer_expn_is_descendant_of(*ctxt) { | |
218 | return Some((self.expn_def_scope(ctxt.remove_mark()), None)); | |
219 | } | |
220 | ||
064997fb | 221 | if let ModuleKind::Block = module.kind { |
04454e1e FG |
222 | return Some((module.parent.unwrap().nearest_item_scope(), None)); |
223 | } | |
224 | ||
225 | // We need to support the next case under a deprecation warning | |
226 | // ``` | |
227 | // struct MyStruct; | |
228 | // ---- begin: this comes from a proc macro derive | |
229 | // mod implementation_details { | |
230 | // // Note that `MyStruct` is not in scope here. | |
231 | // impl SomeTrait for MyStruct { ... } | |
232 | // } | |
233 | // ---- end | |
234 | // ``` | |
235 | // So we have to fall back to the module's parent during lexical resolution in this case. | |
236 | if derive_fallback_lint_id.is_some() { | |
237 | if let Some(parent) = module.parent { | |
238 | // Inner module is inside the macro, parent module is outside of the macro. | |
239 | if module.expansion != parent.expansion | |
240 | && module.expansion.is_descendant_of(parent.expansion) | |
241 | { | |
242 | // The macro is a proc macro derive | |
243 | if let Some(def_id) = module.expansion.expn_data().macro_def_id { | |
923072b8 | 244 | let ext = self.get_macro_by_def_id(def_id).ext; |
04454e1e FG |
245 | if ext.builtin_name.is_none() |
246 | && ext.macro_kind() == MacroKind::Derive | |
247 | && parent.expansion.outer_expn_is_descendant_of(*ctxt) | |
248 | { | |
249 | return Some((parent, derive_fallback_lint_id)); | |
250 | } | |
251 | } | |
252 | } | |
253 | } | |
254 | } | |
255 | ||
256 | None | |
257 | } | |
258 | ||
259 | /// This resolves the identifier `ident` in the namespace `ns` in the current lexical scope. | |
260 | /// More specifically, we proceed up the hierarchy of scopes and return the binding for | |
261 | /// `ident` in the first scope that defines it (or None if no scopes define it). | |
262 | /// | |
263 | /// A block's items are above its local variables in the scope hierarchy, regardless of where | |
264 | /// the items are defined in the block. For example, | |
265 | /// ```rust | |
266 | /// fn f() { | |
267 | /// g(); // Since there are no local variables in scope yet, this resolves to the item. | |
268 | /// let g = || {}; | |
269 | /// fn g() {} | |
270 | /// g(); // This resolves to the local variable `g` since it shadows the item. | |
271 | /// } | |
272 | /// ``` | |
273 | /// | |
274 | /// Invariant: This must only be called during main resolution, not during | |
275 | /// import resolution. | |
276 | #[tracing::instrument(level = "debug", skip(self, ribs))] | |
923072b8 | 277 | pub(crate) fn resolve_ident_in_lexical_scope( |
04454e1e FG |
278 | &mut self, |
279 | mut ident: Ident, | |
280 | ns: Namespace, | |
281 | parent_scope: &ParentScope<'a>, | |
282 | finalize: Option<Finalize>, | |
283 | ribs: &[Rib<'a>], | |
284 | ignore_binding: Option<&'a NameBinding<'a>>, | |
285 | ) -> Option<LexicalScopeBinding<'a>> { | |
286 | assert!(ns == TypeNS || ns == ValueNS); | |
287 | let orig_ident = ident; | |
288 | if ident.name == kw::Empty { | |
289 | return Some(LexicalScopeBinding::Res(Res::Err)); | |
290 | } | |
291 | let (general_span, normalized_span) = if ident.name == kw::SelfUpper { | |
292 | // FIXME(jseyfried) improve `Self` hygiene | |
293 | let empty_span = ident.span.with_ctxt(SyntaxContext::root()); | |
294 | (empty_span, empty_span) | |
295 | } else if ns == TypeNS { | |
296 | let normalized_span = ident.span.normalize_to_macros_2_0(); | |
297 | (normalized_span, normalized_span) | |
298 | } else { | |
299 | (ident.span.normalize_to_macro_rules(), ident.span.normalize_to_macros_2_0()) | |
300 | }; | |
301 | ident.span = general_span; | |
302 | let normalized_ident = Ident { span: normalized_span, ..ident }; | |
303 | ||
304 | // Walk backwards up the ribs in scope. | |
305 | let mut module = self.graph_root; | |
306 | for i in (0..ribs.len()).rev() { | |
307 | debug!("walk rib\n{:?}", ribs[i].bindings); | |
308 | // Use the rib kind to determine whether we are resolving parameters | |
309 | // (macro 2.0 hygiene) or local variables (`macro_rules` hygiene). | |
310 | let rib_ident = if ribs[i].kind.contains_params() { normalized_ident } else { ident }; | |
311 | if let Some((original_rib_ident_def, res)) = ribs[i].bindings.get_key_value(&rib_ident) | |
312 | { | |
313 | // The ident resolves to a type parameter or local variable. | |
314 | return Some(LexicalScopeBinding::Res(self.validate_res_from_ribs( | |
315 | i, | |
316 | rib_ident, | |
317 | *res, | |
318 | finalize.map(|finalize| finalize.path_span), | |
319 | *original_rib_ident_def, | |
320 | ribs, | |
321 | ))); | |
322 | } | |
323 | ||
324 | module = match ribs[i].kind { | |
325 | ModuleRibKind(module) => module, | |
326 | MacroDefinition(def) if def == self.macro_def(ident.span.ctxt()) => { | |
327 | // If an invocation of this macro created `ident`, give up on `ident` | |
328 | // and switch to `ident`'s source from the macro definition. | |
329 | ident.span.remove_mark(); | |
330 | continue; | |
331 | } | |
332 | _ => continue, | |
333 | }; | |
334 | ||
335 | match module.kind { | |
064997fb | 336 | ModuleKind::Block => {} // We can see through blocks |
04454e1e FG |
337 | _ => break, |
338 | } | |
339 | ||
340 | let item = self.resolve_ident_in_module_unadjusted( | |
341 | ModuleOrUniformRoot::Module(module), | |
342 | ident, | |
343 | ns, | |
344 | parent_scope, | |
345 | finalize, | |
346 | ignore_binding, | |
347 | ); | |
348 | if let Ok(binding) = item { | |
349 | // The ident resolves to an item. | |
350 | return Some(LexicalScopeBinding::Item(binding)); | |
351 | } | |
352 | } | |
353 | self.early_resolve_ident_in_lexical_scope( | |
354 | orig_ident, | |
355 | ScopeSet::Late(ns, module, finalize.map(|finalize| finalize.node_id)), | |
356 | parent_scope, | |
357 | finalize, | |
358 | finalize.is_some(), | |
359 | ignore_binding, | |
360 | ) | |
361 | .ok() | |
362 | .map(LexicalScopeBinding::Item) | |
363 | } | |
364 | ||
365 | /// Resolve an identifier in lexical scope. | |
366 | /// This is a variation of `fn resolve_ident_in_lexical_scope` that can be run during | |
367 | /// expansion and import resolution (perhaps they can be merged in the future). | |
368 | /// The function is used for resolving initial segments of macro paths (e.g., `foo` in | |
369 | /// `foo::bar!(); or `foo!();`) and also for import paths on 2018 edition. | |
370 | #[tracing::instrument(level = "debug", skip(self, scope_set))] | |
923072b8 | 371 | pub(crate) fn early_resolve_ident_in_lexical_scope( |
04454e1e FG |
372 | &mut self, |
373 | orig_ident: Ident, | |
374 | scope_set: ScopeSet<'a>, | |
375 | parent_scope: &ParentScope<'a>, | |
376 | finalize: Option<Finalize>, | |
377 | force: bool, | |
378 | ignore_binding: Option<&'a NameBinding<'a>>, | |
379 | ) -> Result<&'a NameBinding<'a>, Determinacy> { | |
380 | bitflags::bitflags! { | |
381 | struct Flags: u8 { | |
382 | const MACRO_RULES = 1 << 0; | |
383 | const MODULE = 1 << 1; | |
384 | const MISC_SUGGEST_CRATE = 1 << 2; | |
385 | const MISC_SUGGEST_SELF = 1 << 3; | |
386 | const MISC_FROM_PRELUDE = 1 << 4; | |
387 | } | |
388 | } | |
389 | ||
390 | assert!(force || !finalize.is_some()); // `finalize` implies `force` | |
391 | ||
392 | // Make sure `self`, `super` etc produce an error when passed to here. | |
393 | if orig_ident.is_path_segment_keyword() { | |
394 | return Err(Determinacy::Determined); | |
395 | } | |
396 | ||
397 | let (ns, macro_kind, is_import) = match scope_set { | |
398 | ScopeSet::All(ns, is_import) => (ns, None, is_import), | |
399 | ScopeSet::AbsolutePath(ns) => (ns, None, false), | |
400 | ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false), | |
401 | ScopeSet::Late(ns, ..) => (ns, None, false), | |
402 | }; | |
403 | ||
404 | // This is *the* result, resolution from the scope closest to the resolved identifier. | |
405 | // However, sometimes this result is "weak" because it comes from a glob import or | |
406 | // a macro expansion, and in this case it cannot shadow names from outer scopes, e.g. | |
407 | // mod m { ... } // solution in outer scope | |
408 | // { | |
409 | // use prefix::*; // imports another `m` - innermost solution | |
410 | // // weak, cannot shadow the outer `m`, need to report ambiguity error | |
411 | // m::mac!(); | |
412 | // } | |
413 | // So we have to save the innermost solution and continue searching in outer scopes | |
414 | // to detect potential ambiguities. | |
415 | let mut innermost_result: Option<(&NameBinding<'_>, Flags)> = None; | |
416 | let mut determinacy = Determinacy::Determined; | |
417 | ||
418 | // Go through all the scopes and try to resolve the name. | |
419 | let break_result = self.visit_scopes( | |
420 | scope_set, | |
421 | parent_scope, | |
422 | orig_ident.span.ctxt(), | |
423 | |this, scope, use_prelude, ctxt| { | |
424 | let ident = Ident::new(orig_ident.name, orig_ident.span.with_ctxt(ctxt)); | |
425 | let ok = |res, span, arenas| { | |
426 | Ok(( | |
427 | (res, ty::Visibility::Public, span, LocalExpnId::ROOT) | |
428 | .to_name_binding(arenas), | |
429 | Flags::empty(), | |
430 | )) | |
431 | }; | |
432 | let result = match scope { | |
433 | Scope::DeriveHelpers(expn_id) => { | |
434 | if let Some(attr) = this | |
435 | .helper_attrs | |
436 | .get(&expn_id) | |
437 | .and_then(|attrs| attrs.iter().rfind(|i| ident == **i)) | |
438 | { | |
439 | let binding = ( | |
440 | Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper), | |
441 | ty::Visibility::Public, | |
442 | attr.span, | |
443 | expn_id, | |
444 | ) | |
445 | .to_name_binding(this.arenas); | |
446 | Ok((binding, Flags::empty())) | |
447 | } else { | |
448 | Err(Determinacy::Determined) | |
449 | } | |
450 | } | |
451 | Scope::DeriveHelpersCompat => { | |
452 | let mut result = Err(Determinacy::Determined); | |
453 | for derive in parent_scope.derives { | |
454 | let parent_scope = &ParentScope { derives: &[], ..*parent_scope }; | |
455 | match this.resolve_macro_path( | |
456 | derive, | |
457 | Some(MacroKind::Derive), | |
458 | parent_scope, | |
459 | true, | |
460 | force, | |
461 | ) { | |
462 | Ok((Some(ext), _)) => { | |
463 | if ext.helper_attrs.contains(&ident.name) { | |
464 | result = ok( | |
465 | Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat), | |
466 | derive.span, | |
467 | this.arenas, | |
468 | ); | |
469 | break; | |
470 | } | |
471 | } | |
472 | Ok(_) | Err(Determinacy::Determined) => {} | |
473 | Err(Determinacy::Undetermined) => { | |
474 | result = Err(Determinacy::Undetermined) | |
475 | } | |
476 | } | |
477 | } | |
478 | result | |
479 | } | |
480 | Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() { | |
481 | MacroRulesScope::Binding(macro_rules_binding) | |
482 | if ident == macro_rules_binding.ident => | |
483 | { | |
484 | Ok((macro_rules_binding.binding, Flags::MACRO_RULES)) | |
485 | } | |
486 | MacroRulesScope::Invocation(_) => Err(Determinacy::Undetermined), | |
487 | _ => Err(Determinacy::Determined), | |
488 | }, | |
489 | Scope::CrateRoot => { | |
490 | let root_ident = Ident::new(kw::PathRoot, ident.span); | |
491 | let root_module = this.resolve_crate_root(root_ident); | |
492 | let binding = this.resolve_ident_in_module_ext( | |
493 | ModuleOrUniformRoot::Module(root_module), | |
494 | ident, | |
495 | ns, | |
496 | parent_scope, | |
497 | finalize, | |
498 | ignore_binding, | |
499 | ); | |
500 | match binding { | |
501 | Ok(binding) => Ok((binding, Flags::MODULE | Flags::MISC_SUGGEST_CRATE)), | |
502 | Err((Determinacy::Undetermined, Weak::No)) => { | |
503 | return Some(Err(Determinacy::determined(force))); | |
504 | } | |
505 | Err((Determinacy::Undetermined, Weak::Yes)) => { | |
506 | Err(Determinacy::Undetermined) | |
507 | } | |
508 | Err((Determinacy::Determined, _)) => Err(Determinacy::Determined), | |
509 | } | |
510 | } | |
511 | Scope::Module(module, derive_fallback_lint_id) => { | |
512 | let adjusted_parent_scope = &ParentScope { module, ..*parent_scope }; | |
513 | let binding = this.resolve_ident_in_module_unadjusted_ext( | |
514 | ModuleOrUniformRoot::Module(module), | |
515 | ident, | |
516 | ns, | |
517 | adjusted_parent_scope, | |
518 | !matches!(scope_set, ScopeSet::Late(..)), | |
519 | finalize, | |
520 | ignore_binding, | |
521 | ); | |
522 | match binding { | |
523 | Ok(binding) => { | |
524 | if let Some(lint_id) = derive_fallback_lint_id { | |
525 | this.lint_buffer.buffer_lint_with_diagnostic( | |
526 | PROC_MACRO_DERIVE_RESOLUTION_FALLBACK, | |
527 | lint_id, | |
528 | orig_ident.span, | |
529 | &format!( | |
530 | "cannot find {} `{}` in this scope", | |
531 | ns.descr(), | |
532 | ident | |
533 | ), | |
534 | BuiltinLintDiagnostics::ProcMacroDeriveResolutionFallback( | |
535 | orig_ident.span, | |
536 | ), | |
537 | ); | |
538 | } | |
539 | let misc_flags = if ptr::eq(module, this.graph_root) { | |
540 | Flags::MISC_SUGGEST_CRATE | |
541 | } else if module.is_normal() { | |
542 | Flags::MISC_SUGGEST_SELF | |
543 | } else { | |
544 | Flags::empty() | |
545 | }; | |
546 | Ok((binding, Flags::MODULE | misc_flags)) | |
547 | } | |
548 | Err((Determinacy::Undetermined, Weak::No)) => { | |
549 | return Some(Err(Determinacy::determined(force))); | |
550 | } | |
551 | Err((Determinacy::Undetermined, Weak::Yes)) => { | |
552 | Err(Determinacy::Undetermined) | |
553 | } | |
554 | Err((Determinacy::Determined, _)) => Err(Determinacy::Determined), | |
555 | } | |
556 | } | |
557 | Scope::RegisteredAttrs => match this.registered_attrs.get(&ident).cloned() { | |
558 | Some(ident) => ok( | |
559 | Res::NonMacroAttr(NonMacroAttrKind::Registered), | |
560 | ident.span, | |
561 | this.arenas, | |
562 | ), | |
563 | None => Err(Determinacy::Determined), | |
564 | }, | |
565 | Scope::MacroUsePrelude => { | |
566 | match this.macro_use_prelude.get(&ident.name).cloned() { | |
567 | Some(binding) => Ok((binding, Flags::MISC_FROM_PRELUDE)), | |
568 | None => Err(Determinacy::determined( | |
569 | this.graph_root.unexpanded_invocations.borrow().is_empty(), | |
570 | )), | |
571 | } | |
572 | } | |
573 | Scope::BuiltinAttrs => { | |
574 | if is_builtin_attr_name(ident.name) { | |
575 | ok( | |
576 | Res::NonMacroAttr(NonMacroAttrKind::Builtin(ident.name)), | |
577 | DUMMY_SP, | |
578 | this.arenas, | |
579 | ) | |
580 | } else { | |
581 | Err(Determinacy::Determined) | |
582 | } | |
583 | } | |
584 | Scope::ExternPrelude => { | |
585 | match this.extern_prelude_get(ident, finalize.is_some()) { | |
586 | Some(binding) => Ok((binding, Flags::empty())), | |
587 | None => Err(Determinacy::determined( | |
588 | this.graph_root.unexpanded_invocations.borrow().is_empty(), | |
589 | )), | |
590 | } | |
591 | } | |
592 | Scope::ToolPrelude => match this.registered_tools.get(&ident).cloned() { | |
593 | Some(ident) => ok(Res::ToolMod, ident.span, this.arenas), | |
594 | None => Err(Determinacy::Determined), | |
595 | }, | |
596 | Scope::StdLibPrelude => { | |
597 | let mut result = Err(Determinacy::Determined); | |
598 | if let Some(prelude) = this.prelude { | |
599 | if let Ok(binding) = this.resolve_ident_in_module_unadjusted( | |
600 | ModuleOrUniformRoot::Module(prelude), | |
601 | ident, | |
602 | ns, | |
603 | parent_scope, | |
604 | None, | |
605 | ignore_binding, | |
606 | ) { | |
607 | if use_prelude || this.is_builtin_macro(binding.res()) { | |
608 | result = Ok((binding, Flags::MISC_FROM_PRELUDE)); | |
609 | } | |
610 | } | |
611 | } | |
612 | result | |
613 | } | |
614 | Scope::BuiltinTypes => match PrimTy::from_name(ident.name) { | |
615 | Some(prim_ty) => ok(Res::PrimTy(prim_ty), DUMMY_SP, this.arenas), | |
616 | None => Err(Determinacy::Determined), | |
617 | }, | |
618 | }; | |
619 | ||
620 | match result { | |
621 | Ok((binding, flags)) | |
622 | if sub_namespace_match(binding.macro_kind(), macro_kind) => | |
623 | { | |
624 | if finalize.is_none() || matches!(scope_set, ScopeSet::Late(..)) { | |
625 | return Some(Ok(binding)); | |
626 | } | |
627 | ||
628 | if let Some((innermost_binding, innermost_flags)) = innermost_result { | |
629 | // Found another solution, if the first one was "weak", report an error. | |
630 | let (res, innermost_res) = (binding.res(), innermost_binding.res()); | |
631 | if res != innermost_res { | |
632 | let is_builtin = |res| { | |
633 | matches!(res, Res::NonMacroAttr(NonMacroAttrKind::Builtin(..))) | |
634 | }; | |
635 | let derive_helper = | |
636 | Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper); | |
637 | let derive_helper_compat = | |
638 | Res::NonMacroAttr(NonMacroAttrKind::DeriveHelperCompat); | |
639 | ||
640 | let ambiguity_error_kind = if is_import { | |
641 | Some(AmbiguityKind::Import) | |
642 | } else if is_builtin(innermost_res) || is_builtin(res) { | |
643 | Some(AmbiguityKind::BuiltinAttr) | |
644 | } else if innermost_res == derive_helper_compat | |
645 | || res == derive_helper_compat && innermost_res != derive_helper | |
646 | { | |
647 | Some(AmbiguityKind::DeriveHelper) | |
648 | } else if innermost_flags.contains(Flags::MACRO_RULES) | |
649 | && flags.contains(Flags::MODULE) | |
650 | && !this.disambiguate_macro_rules_vs_modularized( | |
651 | innermost_binding, | |
652 | binding, | |
653 | ) | |
654 | || flags.contains(Flags::MACRO_RULES) | |
655 | && innermost_flags.contains(Flags::MODULE) | |
656 | && !this.disambiguate_macro_rules_vs_modularized( | |
657 | binding, | |
658 | innermost_binding, | |
659 | ) | |
660 | { | |
661 | Some(AmbiguityKind::MacroRulesVsModularized) | |
662 | } else if innermost_binding.is_glob_import() { | |
663 | Some(AmbiguityKind::GlobVsOuter) | |
664 | } else if innermost_binding | |
665 | .may_appear_after(parent_scope.expansion, binding) | |
666 | { | |
667 | Some(AmbiguityKind::MoreExpandedVsOuter) | |
668 | } else { | |
669 | None | |
670 | }; | |
671 | if let Some(kind) = ambiguity_error_kind { | |
672 | let misc = |f: Flags| { | |
673 | if f.contains(Flags::MISC_SUGGEST_CRATE) { | |
674 | AmbiguityErrorMisc::SuggestCrate | |
675 | } else if f.contains(Flags::MISC_SUGGEST_SELF) { | |
676 | AmbiguityErrorMisc::SuggestSelf | |
677 | } else if f.contains(Flags::MISC_FROM_PRELUDE) { | |
678 | AmbiguityErrorMisc::FromPrelude | |
679 | } else { | |
680 | AmbiguityErrorMisc::None | |
681 | } | |
682 | }; | |
683 | this.ambiguity_errors.push(AmbiguityError { | |
684 | kind, | |
685 | ident: orig_ident, | |
686 | b1: innermost_binding, | |
687 | b2: binding, | |
688 | misc1: misc(innermost_flags), | |
689 | misc2: misc(flags), | |
690 | }); | |
691 | return Some(Ok(innermost_binding)); | |
692 | } | |
693 | } | |
694 | } else { | |
695 | // Found the first solution. | |
696 | innermost_result = Some((binding, flags)); | |
697 | } | |
698 | } | |
699 | Ok(..) | Err(Determinacy::Determined) => {} | |
700 | Err(Determinacy::Undetermined) => determinacy = Determinacy::Undetermined, | |
701 | } | |
702 | ||
703 | None | |
704 | }, | |
705 | ); | |
706 | ||
707 | if let Some(break_result) = break_result { | |
708 | return break_result; | |
709 | } | |
710 | ||
711 | // The first found solution was the only one, return it. | |
712 | if let Some((binding, _)) = innermost_result { | |
713 | return Ok(binding); | |
714 | } | |
715 | ||
716 | Err(Determinacy::determined(determinacy == Determinacy::Determined || force)) | |
717 | } | |
718 | ||
719 | #[tracing::instrument(level = "debug", skip(self))] | |
923072b8 | 720 | pub(crate) fn maybe_resolve_ident_in_module( |
04454e1e FG |
721 | &mut self, |
722 | module: ModuleOrUniformRoot<'a>, | |
723 | ident: Ident, | |
724 | ns: Namespace, | |
725 | parent_scope: &ParentScope<'a>, | |
726 | ) -> Result<&'a NameBinding<'a>, Determinacy> { | |
727 | self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, None, None) | |
728 | .map_err(|(determinacy, _)| determinacy) | |
729 | } | |
730 | ||
731 | #[tracing::instrument(level = "debug", skip(self))] | |
923072b8 | 732 | pub(crate) fn resolve_ident_in_module( |
04454e1e FG |
733 | &mut self, |
734 | module: ModuleOrUniformRoot<'a>, | |
735 | ident: Ident, | |
736 | ns: Namespace, | |
737 | parent_scope: &ParentScope<'a>, | |
738 | finalize: Option<Finalize>, | |
739 | ignore_binding: Option<&'a NameBinding<'a>>, | |
740 | ) -> Result<&'a NameBinding<'a>, Determinacy> { | |
741 | self.resolve_ident_in_module_ext(module, ident, ns, parent_scope, finalize, ignore_binding) | |
742 | .map_err(|(determinacy, _)| determinacy) | |
743 | } | |
744 | ||
745 | #[tracing::instrument(level = "debug", skip(self))] | |
746 | fn resolve_ident_in_module_ext( | |
747 | &mut self, | |
748 | module: ModuleOrUniformRoot<'a>, | |
749 | mut ident: Ident, | |
750 | ns: Namespace, | |
751 | parent_scope: &ParentScope<'a>, | |
752 | finalize: Option<Finalize>, | |
753 | ignore_binding: Option<&'a NameBinding<'a>>, | |
754 | ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> { | |
755 | let tmp_parent_scope; | |
756 | let mut adjusted_parent_scope = parent_scope; | |
757 | match module { | |
758 | ModuleOrUniformRoot::Module(m) => { | |
759 | if let Some(def) = ident.span.normalize_to_macros_2_0_and_adjust(m.expansion) { | |
760 | tmp_parent_scope = | |
761 | ParentScope { module: self.expn_def_scope(def), ..*parent_scope }; | |
762 | adjusted_parent_scope = &tmp_parent_scope; | |
763 | } | |
764 | } | |
765 | ModuleOrUniformRoot::ExternPrelude => { | |
766 | ident.span.normalize_to_macros_2_0_and_adjust(ExpnId::root()); | |
767 | } | |
768 | ModuleOrUniformRoot::CrateRootAndExternPrelude | ModuleOrUniformRoot::CurrentScope => { | |
769 | // No adjustments | |
770 | } | |
771 | } | |
772 | self.resolve_ident_in_module_unadjusted_ext( | |
773 | module, | |
774 | ident, | |
775 | ns, | |
776 | adjusted_parent_scope, | |
777 | false, | |
778 | finalize, | |
779 | ignore_binding, | |
780 | ) | |
781 | } | |
782 | ||
783 | #[tracing::instrument(level = "debug", skip(self))] | |
784 | fn resolve_ident_in_module_unadjusted( | |
785 | &mut self, | |
786 | module: ModuleOrUniformRoot<'a>, | |
787 | ident: Ident, | |
788 | ns: Namespace, | |
789 | parent_scope: &ParentScope<'a>, | |
790 | finalize: Option<Finalize>, | |
791 | ignore_binding: Option<&'a NameBinding<'a>>, | |
792 | ) -> Result<&'a NameBinding<'a>, Determinacy> { | |
793 | self.resolve_ident_in_module_unadjusted_ext( | |
794 | module, | |
795 | ident, | |
796 | ns, | |
797 | parent_scope, | |
798 | false, | |
799 | finalize, | |
800 | ignore_binding, | |
801 | ) | |
802 | .map_err(|(determinacy, _)| determinacy) | |
803 | } | |
804 | ||
805 | /// Attempts to resolve `ident` in namespaces `ns` of `module`. | |
806 | /// Invariant: if `finalize` is `Some`, expansion and import resolution must be complete. | |
807 | #[tracing::instrument(level = "debug", skip(self))] | |
808 | fn resolve_ident_in_module_unadjusted_ext( | |
809 | &mut self, | |
810 | module: ModuleOrUniformRoot<'a>, | |
811 | ident: Ident, | |
812 | ns: Namespace, | |
813 | parent_scope: &ParentScope<'a>, | |
814 | restricted_shadowing: bool, | |
815 | finalize: Option<Finalize>, | |
816 | // This binding should be ignored during in-module resolution, so that we don't get | |
817 | // "self-confirming" import resolutions during import validation and checking. | |
818 | ignore_binding: Option<&'a NameBinding<'a>>, | |
819 | ) -> Result<&'a NameBinding<'a>, (Determinacy, Weak)> { | |
820 | let module = match module { | |
821 | ModuleOrUniformRoot::Module(module) => module, | |
822 | ModuleOrUniformRoot::CrateRootAndExternPrelude => { | |
823 | assert!(!restricted_shadowing); | |
824 | let binding = self.early_resolve_ident_in_lexical_scope( | |
825 | ident, | |
826 | ScopeSet::AbsolutePath(ns), | |
827 | parent_scope, | |
828 | finalize, | |
829 | finalize.is_some(), | |
830 | ignore_binding, | |
831 | ); | |
832 | return binding.map_err(|determinacy| (determinacy, Weak::No)); | |
833 | } | |
834 | ModuleOrUniformRoot::ExternPrelude => { | |
835 | assert!(!restricted_shadowing); | |
836 | return if ns != TypeNS { | |
837 | Err((Determined, Weak::No)) | |
838 | } else if let Some(binding) = self.extern_prelude_get(ident, finalize.is_some()) { | |
839 | Ok(binding) | |
840 | } else if !self.graph_root.unexpanded_invocations.borrow().is_empty() { | |
841 | // Macro-expanded `extern crate` items can add names to extern prelude. | |
842 | Err((Undetermined, Weak::No)) | |
843 | } else { | |
844 | Err((Determined, Weak::No)) | |
845 | }; | |
846 | } | |
847 | ModuleOrUniformRoot::CurrentScope => { | |
848 | assert!(!restricted_shadowing); | |
849 | if ns == TypeNS { | |
850 | if ident.name == kw::Crate || ident.name == kw::DollarCrate { | |
851 | let module = self.resolve_crate_root(ident); | |
852 | let binding = | |
853 | (module, ty::Visibility::Public, module.span, LocalExpnId::ROOT) | |
854 | .to_name_binding(self.arenas); | |
855 | return Ok(binding); | |
856 | } else if ident.name == kw::Super || ident.name == kw::SelfLower { | |
857 | // FIXME: Implement these with renaming requirements so that e.g. | |
858 | // `use super;` doesn't work, but `use super as name;` does. | |
859 | // Fall through here to get an error from `early_resolve_...`. | |
860 | } | |
861 | } | |
862 | ||
863 | let scopes = ScopeSet::All(ns, true); | |
864 | let binding = self.early_resolve_ident_in_lexical_scope( | |
865 | ident, | |
866 | scopes, | |
867 | parent_scope, | |
868 | finalize, | |
869 | finalize.is_some(), | |
870 | ignore_binding, | |
871 | ); | |
872 | return binding.map_err(|determinacy| (determinacy, Weak::No)); | |
873 | } | |
874 | }; | |
875 | ||
876 | let key = self.new_key(ident, ns); | |
877 | let resolution = | |
878 | self.resolution(module, key).try_borrow_mut().map_err(|_| (Determined, Weak::No))?; // This happens when there is a cycle of imports. | |
879 | ||
880 | if let Some(Finalize { path_span, report_private, .. }) = finalize { | |
881 | // If the primary binding is unusable, search further and return the shadowed glob | |
882 | // binding if it exists. What we really want here is having two separate scopes in | |
883 | // a module - one for non-globs and one for globs, but until that's done use this | |
884 | // hack to avoid inconsistent resolution ICEs during import validation. | |
885 | let binding = [resolution.binding, resolution.shadowed_glob] | |
886 | .into_iter() | |
887 | .filter_map(|binding| match (binding, ignore_binding) { | |
888 | (Some(binding), Some(ignored)) if ptr::eq(binding, ignored) => None, | |
889 | _ => binding, | |
890 | }) | |
891 | .next(); | |
892 | let Some(binding) = binding else { | |
893 | return Err((Determined, Weak::No)); | |
894 | }; | |
895 | ||
896 | if !self.is_accessible_from(binding.vis, parent_scope.module) { | |
897 | if report_private { | |
898 | self.privacy_errors.push(PrivacyError { | |
899 | ident, | |
900 | binding, | |
901 | dedup_span: path_span, | |
902 | }); | |
903 | } else { | |
904 | return Err((Determined, Weak::No)); | |
905 | } | |
906 | } | |
907 | ||
908 | // Forbid expanded shadowing to avoid time travel. | |
909 | if let Some(shadowed_glob) = resolution.shadowed_glob | |
910 | && restricted_shadowing | |
911 | && binding.expansion != LocalExpnId::ROOT | |
912 | && binding.res() != shadowed_glob.res() | |
913 | { | |
914 | self.ambiguity_errors.push(AmbiguityError { | |
915 | kind: AmbiguityKind::GlobVsExpanded, | |
916 | ident, | |
917 | b1: binding, | |
918 | b2: shadowed_glob, | |
919 | misc1: AmbiguityErrorMisc::None, | |
920 | misc2: AmbiguityErrorMisc::None, | |
921 | }); | |
922 | } | |
923 | ||
924 | if !restricted_shadowing && binding.expansion != LocalExpnId::ROOT { | |
925 | if let NameBindingKind::Res(_, true) = binding.kind { | |
926 | self.macro_expanded_macro_export_errors.insert((path_span, binding.span)); | |
927 | } | |
928 | } | |
929 | ||
930 | self.record_use(ident, binding, restricted_shadowing); | |
931 | return Ok(binding); | |
932 | } | |
933 | ||
934 | let check_usable = |this: &mut Self, binding: &'a NameBinding<'a>| { | |
935 | if let Some(ignored) = ignore_binding && ptr::eq(binding, ignored) { | |
936 | return Err((Determined, Weak::No)); | |
937 | } | |
938 | let usable = this.is_accessible_from(binding.vis, parent_scope.module); | |
939 | if usable { Ok(binding) } else { Err((Determined, Weak::No)) } | |
940 | }; | |
941 | ||
942 | // Items and single imports are not shadowable, if we have one, then it's determined. | |
943 | if let Some(binding) = resolution.binding { | |
944 | if !binding.is_glob_import() { | |
945 | return check_usable(self, binding); | |
946 | } | |
947 | } | |
948 | ||
949 | // --- From now on we either have a glob resolution or no resolution. --- | |
950 | ||
951 | // Check if one of single imports can still define the name, | |
952 | // if it can then our result is not determined and can be invalidated. | |
953 | for single_import in &resolution.single_imports { | |
954 | if !self.is_accessible_from(single_import.vis.get(), parent_scope.module) { | |
955 | continue; | |
956 | } | |
957 | let Some(module) = single_import.imported_module.get() else { | |
958 | return Err((Undetermined, Weak::No)); | |
959 | }; | |
960 | let ImportKind::Single { source: ident, .. } = single_import.kind else { | |
961 | unreachable!(); | |
962 | }; | |
963 | match self.resolve_ident_in_module( | |
964 | module, | |
965 | ident, | |
966 | ns, | |
967 | &single_import.parent_scope, | |
968 | None, | |
969 | ignore_binding, | |
970 | ) { | |
971 | Err(Determined) => continue, | |
972 | Ok(binding) | |
973 | if !self.is_accessible_from(binding.vis, single_import.parent_scope.module) => | |
974 | { | |
975 | continue; | |
976 | } | |
977 | Ok(_) | Err(Undetermined) => return Err((Undetermined, Weak::No)), | |
978 | } | |
979 | } | |
980 | ||
981 | // So we have a resolution that's from a glob import. This resolution is determined | |
982 | // if it cannot be shadowed by some new item/import expanded from a macro. | |
983 | // This happens either if there are no unexpanded macros, or expanded names cannot | |
984 | // shadow globs (that happens in macro namespace or with restricted shadowing). | |
985 | // | |
986 | // Additionally, any macro in any module can plant names in the root module if it creates | |
987 | // `macro_export` macros, so the root module effectively has unresolved invocations if any | |
988 | // module has unresolved invocations. | |
989 | // However, it causes resolution/expansion to stuck too often (#53144), so, to make | |
990 | // progress, we have to ignore those potential unresolved invocations from other modules | |
991 | // and prohibit access to macro-expanded `macro_export` macros instead (unless restricted | |
992 | // shadowing is enabled, see `macro_expanded_macro_export_errors`). | |
993 | let unexpanded_macros = !module.unexpanded_invocations.borrow().is_empty(); | |
994 | if let Some(binding) = resolution.binding { | |
995 | if !unexpanded_macros || ns == MacroNS || restricted_shadowing { | |
996 | return check_usable(self, binding); | |
997 | } else { | |
998 | return Err((Undetermined, Weak::No)); | |
999 | } | |
1000 | } | |
1001 | ||
1002 | // --- From now on we have no resolution. --- | |
1003 | ||
1004 | // Now we are in situation when new item/import can appear only from a glob or a macro | |
1005 | // expansion. With restricted shadowing names from globs and macro expansions cannot | |
1006 | // shadow names from outer scopes, so we can freely fallback from module search to search | |
1007 | // in outer scopes. For `early_resolve_ident_in_lexical_scope` to continue search in outer | |
1008 | // scopes we return `Undetermined` with `Weak::Yes`. | |
1009 | ||
1010 | // Check if one of unexpanded macros can still define the name, | |
1011 | // if it can then our "no resolution" result is not determined and can be invalidated. | |
1012 | if unexpanded_macros { | |
1013 | return Err((Undetermined, Weak::Yes)); | |
1014 | } | |
1015 | ||
1016 | // Check if one of glob imports can still define the name, | |
1017 | // if it can then our "no resolution" result is not determined and can be invalidated. | |
1018 | for glob_import in module.globs.borrow().iter() { | |
1019 | if !self.is_accessible_from(glob_import.vis.get(), parent_scope.module) { | |
1020 | continue; | |
1021 | } | |
1022 | let module = match glob_import.imported_module.get() { | |
1023 | Some(ModuleOrUniformRoot::Module(module)) => module, | |
1024 | Some(_) => continue, | |
1025 | None => return Err((Undetermined, Weak::Yes)), | |
1026 | }; | |
1027 | let tmp_parent_scope; | |
1028 | let (mut adjusted_parent_scope, mut ident) = | |
1029 | (parent_scope, ident.normalize_to_macros_2_0()); | |
1030 | match ident.span.glob_adjust(module.expansion, glob_import.span) { | |
1031 | Some(Some(def)) => { | |
1032 | tmp_parent_scope = | |
1033 | ParentScope { module: self.expn_def_scope(def), ..*parent_scope }; | |
1034 | adjusted_parent_scope = &tmp_parent_scope; | |
1035 | } | |
1036 | Some(None) => {} | |
1037 | None => continue, | |
1038 | }; | |
1039 | let result = self.resolve_ident_in_module_unadjusted( | |
1040 | ModuleOrUniformRoot::Module(module), | |
1041 | ident, | |
1042 | ns, | |
1043 | adjusted_parent_scope, | |
1044 | None, | |
1045 | ignore_binding, | |
1046 | ); | |
1047 | ||
1048 | match result { | |
1049 | Err(Determined) => continue, | |
1050 | Ok(binding) | |
1051 | if !self.is_accessible_from(binding.vis, glob_import.parent_scope.module) => | |
1052 | { | |
1053 | continue; | |
1054 | } | |
1055 | Ok(_) | Err(Undetermined) => return Err((Undetermined, Weak::Yes)), | |
1056 | } | |
1057 | } | |
1058 | ||
1059 | // No resolution and no one else can define the name - determinate error. | |
1060 | Err((Determined, Weak::No)) | |
1061 | } | |
1062 | ||
1063 | /// Validate a local resolution (from ribs). | |
1064 | #[tracing::instrument(level = "debug", skip(self, all_ribs))] | |
1065 | fn validate_res_from_ribs( | |
1066 | &mut self, | |
1067 | rib_index: usize, | |
1068 | rib_ident: Ident, | |
1069 | mut res: Res, | |
1070 | finalize: Option<Span>, | |
1071 | original_rib_ident_def: Ident, | |
1072 | all_ribs: &[Rib<'a>], | |
1073 | ) -> Res { | |
1074 | const CG_BUG_STR: &str = "min_const_generics resolve check didn't stop compilation"; | |
1075 | debug!("validate_res_from_ribs({:?})", res); | |
1076 | let ribs = &all_ribs[rib_index + 1..]; | |
1077 | ||
1078 | // An invalid forward use of a generic parameter from a previous default. | |
1079 | if let ForwardGenericParamBanRibKind = all_ribs[rib_index].kind { | |
1080 | if let Some(span) = finalize { | |
1081 | let res_error = if rib_ident.name == kw::SelfUpper { | |
1082 | ResolutionError::SelfInGenericParamDefault | |
1083 | } else { | |
1084 | ResolutionError::ForwardDeclaredGenericParam | |
1085 | }; | |
1086 | self.report_error(span, res_error); | |
1087 | } | |
1088 | assert_eq!(res, Res::Err); | |
1089 | return Res::Err; | |
1090 | } | |
1091 | ||
1092 | match res { | |
1093 | Res::Local(_) => { | |
1094 | use ResolutionError::*; | |
1095 | let mut res_err = None; | |
1096 | ||
1097 | for rib in ribs { | |
1098 | match rib.kind { | |
1099 | NormalRibKind | |
1100 | | ClosureOrAsyncRibKind | |
1101 | | ModuleRibKind(..) | |
1102 | | MacroDefinition(..) | |
1103 | | ForwardGenericParamBanRibKind => { | |
1104 | // Nothing to do. Continue. | |
1105 | } | |
1106 | ItemRibKind(_) | FnItemRibKind | AssocItemRibKind => { | |
1107 | // This was an attempt to access an upvar inside a | |
1108 | // named function item. This is not allowed, so we | |
1109 | // report an error. | |
1110 | if let Some(span) = finalize { | |
1111 | // We don't immediately trigger a resolve error, because | |
1112 | // we want certain other resolution errors (namely those | |
1113 | // emitted for `ConstantItemRibKind` below) to take | |
1114 | // precedence. | |
1115 | res_err = Some((span, CannotCaptureDynamicEnvironmentInFnItem)); | |
1116 | } | |
1117 | } | |
1118 | ConstantItemRibKind(_, item) => { | |
1119 | // Still doesn't deal with upvars | |
1120 | if let Some(span) = finalize { | |
1121 | let (span, resolution_error) = | |
1122 | if let Some((ident, constant_item_kind)) = item { | |
1123 | let kind_str = match constant_item_kind { | |
1124 | ConstantItemKind::Const => "const", | |
1125 | ConstantItemKind::Static => "static", | |
1126 | }; | |
1127 | ( | |
1128 | span, | |
1129 | AttemptToUseNonConstantValueInConstant( | |
1130 | ident, "let", kind_str, | |
1131 | ), | |
1132 | ) | |
1133 | } else { | |
1134 | ( | |
1135 | rib_ident.span, | |
1136 | AttemptToUseNonConstantValueInConstant( | |
1137 | original_rib_ident_def, | |
1138 | "const", | |
1139 | "let", | |
1140 | ), | |
1141 | ) | |
1142 | }; | |
1143 | self.report_error(span, resolution_error); | |
1144 | } | |
1145 | return Res::Err; | |
1146 | } | |
1147 | ConstParamTyRibKind => { | |
1148 | if let Some(span) = finalize { | |
1149 | self.report_error(span, ParamInTyOfConstParam(rib_ident.name)); | |
1150 | } | |
1151 | return Res::Err; | |
1152 | } | |
1153 | InlineAsmSymRibKind => { | |
1154 | if let Some(span) = finalize { | |
1155 | self.report_error(span, InvalidAsmSym); | |
1156 | } | |
1157 | return Res::Err; | |
1158 | } | |
1159 | } | |
1160 | } | |
1161 | if let Some((span, res_err)) = res_err { | |
1162 | self.report_error(span, res_err); | |
1163 | return Res::Err; | |
1164 | } | |
1165 | } | |
1166 | Res::Def(DefKind::TyParam, _) | Res::SelfTy { .. } => { | |
1167 | for rib in ribs { | |
1168 | let has_generic_params: HasGenericParams = match rib.kind { | |
1169 | NormalRibKind | |
1170 | | ClosureOrAsyncRibKind | |
1171 | | AssocItemRibKind | |
1172 | | ModuleRibKind(..) | |
1173 | | MacroDefinition(..) | |
923072b8 | 1174 | | InlineAsmSymRibKind |
04454e1e FG |
1175 | | ForwardGenericParamBanRibKind => { |
1176 | // Nothing to do. Continue. | |
1177 | continue; | |
1178 | } | |
1179 | ||
1180 | ConstantItemRibKind(trivial, _) => { | |
1181 | let features = self.session.features_untracked(); | |
1182 | // HACK(min_const_generics): We currently only allow `N` or `{ N }`. | |
1183 | if !(trivial == HasGenericParams::Yes || features.generic_const_exprs) { | |
1184 | // HACK(min_const_generics): If we encounter `Self` in an anonymous constant | |
1185 | // we can't easily tell if it's generic at this stage, so we instead remember | |
1186 | // this and then enforce the self type to be concrete later on. | |
1187 | if let Res::SelfTy { trait_, alias_to: Some((def, _)) } = res { | |
1188 | res = Res::SelfTy { trait_, alias_to: Some((def, true)) } | |
1189 | } else { | |
1190 | if let Some(span) = finalize { | |
1191 | self.report_error( | |
1192 | span, | |
1193 | ResolutionError::ParamInNonTrivialAnonConst { | |
1194 | name: rib_ident.name, | |
1195 | is_type: true, | |
1196 | }, | |
1197 | ); | |
1198 | self.session.delay_span_bug(span, CG_BUG_STR); | |
1199 | } | |
1200 | ||
1201 | return Res::Err; | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | continue; | |
1206 | } | |
1207 | ||
1208 | // This was an attempt to use a type parameter outside its scope. | |
1209 | ItemRibKind(has_generic_params) => has_generic_params, | |
1210 | FnItemRibKind => HasGenericParams::Yes, | |
1211 | ConstParamTyRibKind => { | |
1212 | if let Some(span) = finalize { | |
1213 | self.report_error( | |
1214 | span, | |
1215 | ResolutionError::ParamInTyOfConstParam(rib_ident.name), | |
1216 | ); | |
1217 | } | |
1218 | return Res::Err; | |
1219 | } | |
04454e1e FG |
1220 | }; |
1221 | ||
1222 | if let Some(span) = finalize { | |
1223 | self.report_error( | |
1224 | span, | |
1225 | ResolutionError::GenericParamsFromOuterFunction( | |
1226 | res, | |
1227 | has_generic_params, | |
1228 | ), | |
1229 | ); | |
1230 | } | |
1231 | return Res::Err; | |
1232 | } | |
1233 | } | |
1234 | Res::Def(DefKind::ConstParam, _) => { | |
1235 | let mut ribs = ribs.iter().peekable(); | |
1236 | if let Some(Rib { kind: FnItemRibKind, .. }) = ribs.peek() { | |
1237 | // When declaring const parameters inside function signatures, the first rib | |
1238 | // is always a `FnItemRibKind`. In this case, we can skip it, to avoid it | |
1239 | // (spuriously) conflicting with the const param. | |
1240 | ribs.next(); | |
1241 | } | |
1242 | ||
1243 | for rib in ribs { | |
1244 | let has_generic_params = match rib.kind { | |
1245 | NormalRibKind | |
1246 | | ClosureOrAsyncRibKind | |
1247 | | AssocItemRibKind | |
1248 | | ModuleRibKind(..) | |
1249 | | MacroDefinition(..) | |
923072b8 | 1250 | | InlineAsmSymRibKind |
04454e1e FG |
1251 | | ForwardGenericParamBanRibKind => continue, |
1252 | ||
1253 | ConstantItemRibKind(trivial, _) => { | |
1254 | let features = self.session.features_untracked(); | |
1255 | // HACK(min_const_generics): We currently only allow `N` or `{ N }`. | |
1256 | if !(trivial == HasGenericParams::Yes || features.generic_const_exprs) { | |
1257 | if let Some(span) = finalize { | |
1258 | self.report_error( | |
1259 | span, | |
1260 | ResolutionError::ParamInNonTrivialAnonConst { | |
1261 | name: rib_ident.name, | |
1262 | is_type: false, | |
1263 | }, | |
1264 | ); | |
1265 | self.session.delay_span_bug(span, CG_BUG_STR); | |
1266 | } | |
1267 | ||
1268 | return Res::Err; | |
1269 | } | |
1270 | ||
1271 | continue; | |
1272 | } | |
1273 | ||
1274 | ItemRibKind(has_generic_params) => has_generic_params, | |
1275 | FnItemRibKind => HasGenericParams::Yes, | |
1276 | ConstParamTyRibKind => { | |
1277 | if let Some(span) = finalize { | |
1278 | self.report_error( | |
1279 | span, | |
1280 | ResolutionError::ParamInTyOfConstParam(rib_ident.name), | |
1281 | ); | |
1282 | } | |
1283 | return Res::Err; | |
1284 | } | |
04454e1e FG |
1285 | }; |
1286 | ||
1287 | // This was an attempt to use a const parameter outside its scope. | |
1288 | if let Some(span) = finalize { | |
1289 | self.report_error( | |
1290 | span, | |
1291 | ResolutionError::GenericParamsFromOuterFunction( | |
1292 | res, | |
1293 | has_generic_params, | |
1294 | ), | |
1295 | ); | |
1296 | } | |
1297 | return Res::Err; | |
1298 | } | |
1299 | } | |
1300 | _ => {} | |
1301 | } | |
1302 | res | |
1303 | } | |
1304 | ||
1305 | #[tracing::instrument(level = "debug", skip(self))] | |
923072b8 | 1306 | pub(crate) fn maybe_resolve_path( |
04454e1e FG |
1307 | &mut self, |
1308 | path: &[Segment], | |
1309 | opt_ns: Option<Namespace>, // `None` indicates a module path in import | |
1310 | parent_scope: &ParentScope<'a>, | |
1311 | ) -> PathResult<'a> { | |
1312 | self.resolve_path_with_ribs(path, opt_ns, parent_scope, None, None, None) | |
1313 | } | |
1314 | ||
1315 | #[tracing::instrument(level = "debug", skip(self))] | |
923072b8 | 1316 | pub(crate) fn resolve_path( |
04454e1e FG |
1317 | &mut self, |
1318 | path: &[Segment], | |
1319 | opt_ns: Option<Namespace>, // `None` indicates a module path in import | |
1320 | parent_scope: &ParentScope<'a>, | |
1321 | finalize: Option<Finalize>, | |
1322 | ignore_binding: Option<&'a NameBinding<'a>>, | |
1323 | ) -> PathResult<'a> { | |
1324 | self.resolve_path_with_ribs(path, opt_ns, parent_scope, finalize, None, ignore_binding) | |
1325 | } | |
1326 | ||
923072b8 | 1327 | pub(crate) fn resolve_path_with_ribs( |
04454e1e FG |
1328 | &mut self, |
1329 | path: &[Segment], | |
1330 | opt_ns: Option<Namespace>, // `None` indicates a module path in import | |
1331 | parent_scope: &ParentScope<'a>, | |
1332 | finalize: Option<Finalize>, | |
1333 | ribs: Option<&PerNS<Vec<Rib<'a>>>>, | |
1334 | ignore_binding: Option<&'a NameBinding<'a>>, | |
1335 | ) -> PathResult<'a> { | |
1336 | debug!("resolve_path(path={:?}, opt_ns={:?}, finalize={:?})", path, opt_ns, finalize); | |
1337 | ||
1338 | let mut module = None; | |
1339 | let mut allow_super = true; | |
1340 | let mut second_binding = None; | |
1341 | ||
1342 | for (i, &Segment { ident, id, .. }) in path.iter().enumerate() { | |
1343 | debug!("resolve_path ident {} {:?} {:?}", i, ident, id); | |
1344 | let record_segment_res = |this: &mut Self, res| { | |
1345 | if finalize.is_some() { | |
1346 | if let Some(id) = id { | |
1347 | if !this.partial_res_map.contains_key(&id) { | |
1348 | assert!(id != ast::DUMMY_NODE_ID, "Trying to resolve dummy id"); | |
1349 | this.record_partial_res(id, PartialRes::new(res)); | |
1350 | } | |
1351 | } | |
1352 | } | |
1353 | }; | |
1354 | ||
1355 | let is_last = i == path.len() - 1; | |
1356 | let ns = if is_last { opt_ns.unwrap_or(TypeNS) } else { TypeNS }; | |
1357 | let name = ident.name; | |
1358 | ||
1359 | allow_super &= ns == TypeNS && (name == kw::SelfLower || name == kw::Super); | |
1360 | ||
1361 | if ns == TypeNS { | |
1362 | if allow_super && name == kw::Super { | |
1363 | let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0(); | |
1364 | let self_module = match i { | |
1365 | 0 => Some(self.resolve_self(&mut ctxt, parent_scope.module)), | |
1366 | _ => match module { | |
1367 | Some(ModuleOrUniformRoot::Module(module)) => Some(module), | |
1368 | _ => None, | |
1369 | }, | |
1370 | }; | |
1371 | if let Some(self_module) = self_module { | |
1372 | if let Some(parent) = self_module.parent { | |
1373 | module = Some(ModuleOrUniformRoot::Module( | |
1374 | self.resolve_self(&mut ctxt, parent), | |
1375 | )); | |
1376 | continue; | |
1377 | } | |
1378 | } | |
1379 | return PathResult::failed(ident.span, false, finalize.is_some(), || { | |
1380 | ("there are too many leading `super` keywords".to_string(), None) | |
1381 | }); | |
1382 | } | |
1383 | if i == 0 { | |
1384 | if name == kw::SelfLower { | |
1385 | let mut ctxt = ident.span.ctxt().normalize_to_macros_2_0(); | |
1386 | module = Some(ModuleOrUniformRoot::Module( | |
1387 | self.resolve_self(&mut ctxt, parent_scope.module), | |
1388 | )); | |
1389 | continue; | |
1390 | } | |
1391 | if name == kw::PathRoot && ident.span.rust_2018() { | |
1392 | module = Some(ModuleOrUniformRoot::ExternPrelude); | |
1393 | continue; | |
1394 | } | |
1395 | if name == kw::PathRoot && ident.span.rust_2015() && self.session.rust_2018() { | |
1396 | // `::a::b` from 2015 macro on 2018 global edition | |
1397 | module = Some(ModuleOrUniformRoot::CrateRootAndExternPrelude); | |
1398 | continue; | |
1399 | } | |
1400 | if name == kw::PathRoot || name == kw::Crate || name == kw::DollarCrate { | |
1401 | // `::a::b`, `crate::a::b` or `$crate::a::b` | |
1402 | module = Some(ModuleOrUniformRoot::Module(self.resolve_crate_root(ident))); | |
1403 | continue; | |
1404 | } | |
1405 | } | |
1406 | } | |
1407 | ||
1408 | // Report special messages for path segment keywords in wrong positions. | |
1409 | if ident.is_path_segment_keyword() && i != 0 { | |
1410 | return PathResult::failed(ident.span, false, finalize.is_some(), || { | |
1411 | let name_str = if name == kw::PathRoot { | |
1412 | "crate root".to_string() | |
1413 | } else { | |
1414 | format!("`{}`", name) | |
1415 | }; | |
1416 | let label = if i == 1 && path[0].ident.name == kw::PathRoot { | |
1417 | format!("global paths cannot start with {}", name_str) | |
1418 | } else { | |
1419 | format!("{} in paths can only be used in start position", name_str) | |
1420 | }; | |
1421 | (label, None) | |
1422 | }); | |
1423 | } | |
1424 | ||
1425 | enum FindBindingResult<'a> { | |
1426 | Binding(Result<&'a NameBinding<'a>, Determinacy>), | |
1427 | Res(Res), | |
1428 | } | |
1429 | let find_binding_in_ns = |this: &mut Self, ns| { | |
1430 | let binding = if let Some(module) = module { | |
1431 | this.resolve_ident_in_module( | |
1432 | module, | |
1433 | ident, | |
1434 | ns, | |
1435 | parent_scope, | |
1436 | finalize, | |
1437 | ignore_binding, | |
1438 | ) | |
1439 | } else if let Some(ribs) = ribs | |
1440 | && let Some(TypeNS | ValueNS) = opt_ns | |
1441 | { | |
1442 | match this.resolve_ident_in_lexical_scope( | |
1443 | ident, | |
1444 | ns, | |
1445 | parent_scope, | |
1446 | finalize, | |
1447 | &ribs[ns], | |
1448 | ignore_binding, | |
1449 | ) { | |
1450 | // we found a locally-imported or available item/module | |
1451 | Some(LexicalScopeBinding::Item(binding)) => Ok(binding), | |
1452 | // we found a local variable or type param | |
1453 | Some(LexicalScopeBinding::Res(res)) => return FindBindingResult::Res(res), | |
1454 | _ => Err(Determinacy::determined(finalize.is_some())), | |
1455 | } | |
1456 | } else { | |
1457 | let scopes = ScopeSet::All(ns, opt_ns.is_none()); | |
1458 | this.early_resolve_ident_in_lexical_scope( | |
1459 | ident, | |
1460 | scopes, | |
1461 | parent_scope, | |
1462 | finalize, | |
1463 | finalize.is_some(), | |
1464 | ignore_binding, | |
1465 | ) | |
1466 | }; | |
1467 | FindBindingResult::Binding(binding) | |
1468 | }; | |
1469 | let binding = match find_binding_in_ns(self, ns) { | |
1470 | FindBindingResult::Res(res) => { | |
1471 | record_segment_res(self, res); | |
1472 | return PathResult::NonModule(PartialRes::with_unresolved_segments( | |
1473 | res, | |
1474 | path.len() - 1, | |
1475 | )); | |
1476 | } | |
1477 | FindBindingResult::Binding(binding) => binding, | |
1478 | }; | |
1479 | match binding { | |
1480 | Ok(binding) => { | |
1481 | if i == 1 { | |
1482 | second_binding = Some(binding); | |
1483 | } | |
1484 | let res = binding.res(); | |
1485 | let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res); | |
1486 | if let Some(next_module) = binding.module() { | |
1487 | module = Some(ModuleOrUniformRoot::Module(next_module)); | |
1488 | record_segment_res(self, res); | |
1489 | } else if res == Res::ToolMod && i + 1 != path.len() { | |
1490 | if binding.is_import() { | |
1491 | self.session | |
1492 | .struct_span_err( | |
1493 | ident.span, | |
1494 | "cannot use a tool module through an import", | |
1495 | ) | |
1496 | .span_note(binding.span, "the tool module imported here") | |
1497 | .emit(); | |
1498 | } | |
1499 | let res = Res::NonMacroAttr(NonMacroAttrKind::Tool); | |
1500 | return PathResult::NonModule(PartialRes::new(res)); | |
1501 | } else if res == Res::Err { | |
1502 | return PathResult::NonModule(PartialRes::new(Res::Err)); | |
1503 | } else if opt_ns.is_some() && (is_last || maybe_assoc) { | |
1504 | self.lint_if_path_starts_with_module(finalize, path, second_binding); | |
923072b8 | 1505 | record_segment_res(self, res); |
04454e1e FG |
1506 | return PathResult::NonModule(PartialRes::with_unresolved_segments( |
1507 | res, | |
1508 | path.len() - i - 1, | |
1509 | )); | |
1510 | } else { | |
1511 | return PathResult::failed(ident.span, is_last, finalize.is_some(), || { | |
1512 | let label = format!( | |
1513 | "`{ident}` is {} {}, not a module", | |
1514 | res.article(), | |
1515 | res.descr() | |
1516 | ); | |
1517 | (label, None) | |
1518 | }); | |
1519 | } | |
1520 | } | |
1521 | Err(Undetermined) => return PathResult::Indeterminate, | |
1522 | Err(Determined) => { | |
1523 | if let Some(ModuleOrUniformRoot::Module(module)) = module { | |
1524 | if opt_ns.is_some() && !module.is_normal() { | |
1525 | return PathResult::NonModule(PartialRes::with_unresolved_segments( | |
1526 | module.res().unwrap(), | |
1527 | path.len() - i, | |
1528 | )); | |
1529 | } | |
1530 | } | |
1531 | ||
1532 | return PathResult::failed(ident.span, is_last, finalize.is_some(), || { | |
1533 | self.report_path_resolution_error( | |
1534 | path, | |
1535 | opt_ns, | |
1536 | parent_scope, | |
1537 | ribs, | |
1538 | ignore_binding, | |
1539 | module, | |
1540 | i, | |
1541 | ident, | |
1542 | ) | |
1543 | }); | |
1544 | } | |
1545 | } | |
1546 | } | |
1547 | ||
1548 | self.lint_if_path_starts_with_module(finalize, path, second_binding); | |
1549 | ||
1550 | PathResult::Module(match module { | |
1551 | Some(module) => module, | |
1552 | None if path.is_empty() => ModuleOrUniformRoot::CurrentScope, | |
1553 | _ => bug!("resolve_path: non-empty path `{:?}` has no module", path), | |
1554 | }) | |
1555 | } | |
1556 | } |