aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_hir/src/nameres.rs
blob: 3d8691f535ef13626e4b18dbdc351b84525a8c50 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
//! This module implements import-resolution/macro expansion algorithm.
//!
//! The result of this module is `CrateDefMap`: a data structure which contains:
//!
//!   * a tree of modules for the crate
//!   * for each module, a set of items visible in the module (directly declared
//!     or imported)
//!
//! Note that `CrateDefMap` contains fully macro expanded code.
//!
//! Computing `CrateDefMap` can be partitioned into several logically
//! independent "phases". The phases are mutually recursive though, there's no
//! strict ordering.
//!
//! ## Collecting RawItems
//!
//!  This happens in the `raw` module, which parses a single source file into a
//!  set of top-level items. Nested imports are desugared to flat imports in
//!  this phase. Macro calls are represented as a triple of (Path, Option<Name>,
//!  TokenTree).
//!
//! ## Collecting Modules
//!
//! This happens in the `collector` module. In this phase, we recursively walk
//! tree of modules, collect raw items from submodules, populate module scopes
//! with defined items (so, we assign item ids in this phase) and record the set
//! of unresolved imports and macros.
//!
//! While we walk tree of modules, we also record macro_rules definitions and
//! expand calls to macro_rules defined macros.
//!
//! ## Resolving Imports
//!
//! We maintain a list of currently unresolved imports. On every iteration, we
//! try to resolve some imports from this list. If the import is resolved, we
//! record it, by adding an item to current module scope and, if necessary, by
//! recursively populating glob imports.
//!
//! ## Resolving Macros
//!
//! macro_rules from the same crate use a global mutable namespace. We expand
//! them immediately, when we collect modules.
//!
//! Macros from other crates (including proc-macros) can be used with
//! `foo::bar!` syntax. We handle them similarly to imports. There's a list of
//! unexpanded macros. On every iteration, we try to resolve each macro call
//! path and, upon success, we run macro expansion and "collect module" phase
//! on the result

mod per_ns;
mod raw;
mod collector;
mod mod_resolution;
#[cfg(test)]
mod tests;

use std::sync::Arc;

use once_cell::sync::Lazy;
use ra_arena::{impl_arena_id, Arena, RawId};
use ra_db::{Edition, FileId};
use ra_prof::profile;
use ra_syntax::ast;
use rustc_hash::{FxHashMap, FxHashSet};
use test_utils::tested_by;

use crate::{
    db::{AstDatabase, DefDatabase},
    diagnostics::DiagnosticSink,
    ids::MacroDefId,
    nameres::diagnostics::DefDiagnostic,
    AstId, BuiltinType, Crate, HirFileId, MacroDef, Module, ModuleDef, Name, Path, PathKind, Trait,
};

pub(crate) use self::raw::{ImportSourceMap, RawItems};

pub use self::{
    per_ns::{Namespace, PerNs},
    raw::ImportId,
};

/// Contains all top-level defs from a macro-expanded crate
#[derive(Debug, PartialEq, Eq)]
pub struct CrateDefMap {
    krate: Crate,
    edition: Edition,
    /// The prelude module for this crate. This either comes from an import
    /// marked with the `prelude_import` attribute, or (in the normal case) from
    /// a dependency (`std` or `core`).
    prelude: Option<Module>,
    extern_prelude: FxHashMap<Name, ModuleDef>,
    root: CrateModuleId,
    modules: Arena<CrateModuleId, ModuleData>,

    /// Some macros are not well-behavior, which leads to infinite loop
    /// e.g. macro_rules! foo { ($ty:ty) => { foo!($ty); } }
    /// We mark it down and skip it in collector
    ///
    /// FIXME:
    /// Right now it only handle a poison macro in a single crate,
    /// such that if other crate try to call that macro,
    /// the whole process will do again until it became poisoned in that crate.
    /// We should handle this macro set globally
    /// However, do we want to put it as a global variable?
    poison_macros: FxHashSet<MacroDefId>,

    diagnostics: Vec<DefDiagnostic>,
}

impl std::ops::Index<CrateModuleId> for CrateDefMap {
    type Output = ModuleData;
    fn index(&self, id: CrateModuleId) -> &ModuleData {
        &self.modules[id]
    }
}

/// An ID of a module, **local** to a specific crate
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub(crate) struct CrateModuleId(RawId);
impl_arena_id!(CrateModuleId);

#[derive(Default, Debug, PartialEq, Eq)]
pub(crate) struct ModuleData {
    pub(crate) parent: Option<CrateModuleId>,
    pub(crate) children: FxHashMap<Name, CrateModuleId>,
    pub(crate) scope: ModuleScope,
    /// None for root
    pub(crate) declaration: Option<AstId<ast::Module>>,
    /// None for inline modules.
    ///
    /// Note that non-inline modules, by definition, live inside non-macro file.
    pub(crate) definition: Option<FileId>,
}

#[derive(Debug, Default, PartialEq, Eq, Clone)]
pub struct ModuleScope {
    items: FxHashMap<Name, Resolution>,
    /// Macros visable in current module in legacy textual scope
    ///
    /// For macros invoked by an unquatified identifier like `bar!()`, `legacy_macros` will be searched in first.
    /// If it yields no result, then it turns to module scoped `macros`.
    /// It macros with name quatified with a path like `crate::foo::bar!()`, `legacy_macros` will be skipped,
    /// and only normal scoped `macros` will be searched in.
    ///
    /// Note that this automatically inherit macros defined textually before the definition of module itself.
    ///
    /// Module scoped macros will be inserted into `items` instead of here.
    // FIXME: Macro shadowing in one module is not properly handled. Non-item place macros will
    // be all resolved to the last one defined if shadowing happens.
    legacy_macros: FxHashMap<Name, MacroDef>,
}

static BUILTIN_SCOPE: Lazy<FxHashMap<Name, Resolution>> = Lazy::new(|| {
    BuiltinType::ALL
        .iter()
        .map(|(name, ty)| {
            (name.clone(), Resolution { def: PerNs::types(ty.clone().into()), import: None })
        })
        .collect()
});

/// Legacy macros can only be accessed through special methods like `get_legacy_macros`.
/// Other methods will only resolve values, types and module scoped macros only.
impl ModuleScope {
    pub fn entries<'a>(&'a self) -> impl Iterator<Item = (&'a Name, &'a Resolution)> + 'a {
        //FIXME: shadowing
        self.items.iter().chain(BUILTIN_SCOPE.iter())
    }

    /// Iterate over all module scoped macros
    pub fn macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDef)> + 'a {
        self.items
            .iter()
            .filter_map(|(name, res)| res.def.get_macros().map(|macro_| (name, macro_)))
    }

    /// Iterate over all legacy textual scoped macros visable at the end of the module
    pub fn legacy_macros<'a>(&'a self) -> impl Iterator<Item = (&'a Name, MacroDef)> + 'a {
        self.legacy_macros.iter().map(|(name, def)| (name, *def))
    }

    /// Get a name from current module scope, legacy macros are not included
    pub fn get(&self, name: &Name) -> Option<&Resolution> {
        self.items.get(name).or_else(|| BUILTIN_SCOPE.get(name))
    }

    pub fn traits<'a>(&'a self) -> impl Iterator<Item = Trait> + 'a {
        self.items.values().filter_map(|r| match r.def.take_types() {
            Some(ModuleDef::Trait(t)) => Some(t),
            _ => None,
        })
    }

    fn get_legacy_macro(&self, name: &Name) -> Option<MacroDef> {
        self.legacy_macros.get(name).copied()
    }
}

#[derive(Debug, Clone, PartialEq, Eq, Default)]
pub struct Resolution {
    /// None for unresolved
    pub def: PerNs<ModuleDef>,
    /// ident by which this is imported into local scope.
    pub import: Option<ImportId>,
}

impl Resolution {
    pub(crate) fn from_macro(macro_: MacroDef) -> Self {
        Resolution { def: PerNs::macros(macro_), import: None }
    }
}

#[derive(Debug, Clone)]
struct ResolvePathResult {
    resolved_def: PerNs<ModuleDef>,
    segment_index: Option<usize>,
    reached_fixedpoint: ReachedFixedPoint,
}

impl ResolvePathResult {
    fn empty(reached_fixedpoint: ReachedFixedPoint) -> ResolvePathResult {
        ResolvePathResult::with(PerNs::none(), reached_fixedpoint, None)
    }

    fn with(
        resolved_def: PerNs<ModuleDef>,
        reached_fixedpoint: ReachedFixedPoint,
        segment_index: Option<usize>,
    ) -> ResolvePathResult {
        ResolvePathResult { resolved_def, reached_fixedpoint, segment_index }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ResolveMode {
    Import,
    Other,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum ReachedFixedPoint {
    Yes,
    No,
}

impl CrateDefMap {
    pub(crate) fn crate_def_map_query(
        // Note that this doesn't have `+ AstDatabase`!
        // This gurantess that `CrateDefMap` is stable across reparses.
        db: &impl DefDatabase,
        krate: Crate,
    ) -> Arc<CrateDefMap> {
        let _p = profile("crate_def_map_query");
        let def_map = {
            let edition = krate.edition(db);
            let mut modules: Arena<CrateModuleId, ModuleData> = Arena::default();
            let root = modules.alloc(ModuleData::default());
            CrateDefMap {
                krate,
                edition,
                extern_prelude: FxHashMap::default(),
                prelude: None,
                root,
                modules,
                poison_macros: FxHashSet::default(),
                diagnostics: Vec::new(),
            }
        };
        let def_map = collector::collect_defs(db, def_map);
        Arc::new(def_map)
    }

    pub(crate) fn krate(&self) -> Crate {
        self.krate
    }

    pub(crate) fn root(&self) -> CrateModuleId {
        self.root
    }

    pub(crate) fn mk_module(&self, module_id: CrateModuleId) -> Module {
        Module { krate: self.krate, module_id }
    }

    pub(crate) fn prelude(&self) -> Option<Module> {
        self.prelude
    }

    pub(crate) fn extern_prelude(&self) -> &FxHashMap<Name, ModuleDef> {
        &self.extern_prelude
    }

    pub(crate) fn add_diagnostics(
        &self,
        db: &(impl DefDatabase + AstDatabase),
        module: CrateModuleId,
        sink: &mut DiagnosticSink,
    ) {
        self.diagnostics.iter().for_each(|it| it.add_to(db, module, sink))
    }

    pub(crate) fn find_module_by_source(
        &self,
        file_id: HirFileId,
        decl_id: Option<AstId<ast::Module>>,
    ) -> Option<CrateModuleId> {
        let (module_id, _module_data) = self.modules.iter().find(|(_module_id, module_data)| {
            if decl_id.is_some() {
                module_data.declaration == decl_id
            } else {
                module_data.definition.map(|it| it.into()) == Some(file_id)
            }
        })?;
        Some(module_id)
    }

    pub(crate) fn resolve_path(
        &self,
        db: &impl DefDatabase,
        original_module: CrateModuleId,
        path: &Path,
    ) -> (PerNs<ModuleDef>, Option<usize>) {
        let res = self.resolve_path_fp_with_macro(db, ResolveMode::Other, original_module, path);
        (res.resolved_def, res.segment_index)
    }

    // Returns Yes if we are sure that additions to `ItemMap` wouldn't change
    // the result.
    fn resolve_path_fp_with_macro(
        &self,
        db: &impl DefDatabase,
        mode: ResolveMode,
        original_module: CrateModuleId,
        path: &Path,
    ) -> ResolvePathResult {
        let mut segments = path.segments.iter().enumerate();
        let mut curr_per_ns: PerNs<ModuleDef> = match path.kind {
            PathKind::Crate => {
                PerNs::types(Module { krate: self.krate, module_id: self.root }.into())
            }
            PathKind::Self_ => {
                PerNs::types(Module { krate: self.krate, module_id: original_module }.into())
            }
            // plain import or absolute path in 2015: crate-relative with
            // fallback to extern prelude (with the simplification in
            // rust-lang/rust#57745)
            // FIXME there must be a nicer way to write this condition
            PathKind::Plain | PathKind::Abs
                if self.edition == Edition::Edition2015
                    && (path.kind == PathKind::Abs || mode == ResolveMode::Import) =>
            {
                let segment = match segments.next() {
                    Some((_, segment)) => segment,
                    None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                };
                log::debug!("resolving {:?} in crate root (+ extern prelude)", segment);
                self.resolve_name_in_crate_root_or_extern_prelude(&segment.name)
            }
            PathKind::Plain => {
                let segment = match segments.next() {
                    Some((_, segment)) => segment,
                    None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                };
                log::debug!("resolving {:?} in module", segment);
                self.resolve_name_in_module(db, original_module, &segment.name)
            }
            PathKind::Super => {
                if let Some(p) = self.modules[original_module].parent {
                    PerNs::types(Module { krate: self.krate, module_id: p }.into())
                } else {
                    log::debug!("super path in root module");
                    return ResolvePathResult::empty(ReachedFixedPoint::Yes);
                }
            }
            PathKind::Abs => {
                // 2018-style absolute path -- only extern prelude
                let segment = match segments.next() {
                    Some((_, segment)) => segment,
                    None => return ResolvePathResult::empty(ReachedFixedPoint::Yes),
                };
                if let Some(def) = self.extern_prelude.get(&segment.name) {
                    log::debug!("absolute path {:?} resolved to crate {:?}", path, def);
                    PerNs::types(*def)
                } else {
                    return ResolvePathResult::empty(ReachedFixedPoint::No); // extern crate declarations can add to the extern prelude
                }
            }
        };

        for (i, segment) in segments {
            let curr = match curr_per_ns.as_ref().take_types() {
                Some(r) => r,
                None => {
                    // we still have path segments left, but the path so far
                    // didn't resolve in the types namespace => no resolution
                    // (don't break here because `curr_per_ns` might contain
                    // something in the value namespace, and it would be wrong
                    // to return that)
                    return ResolvePathResult::empty(ReachedFixedPoint::No);
                }
            };
            // resolve segment in curr

            curr_per_ns = match curr {
                ModuleDef::Module(module) => {
                    if module.krate != self.krate {
                        let path =
                            Path { segments: path.segments[i..].to_vec(), kind: PathKind::Self_ };
                        log::debug!("resolving {:?} in other crate", path);
                        let defp_map = db.crate_def_map(module.krate);
                        let (def, s) = defp_map.resolve_path(db, module.module_id, &path);
                        return ResolvePathResult::with(
                            def,
                            ReachedFixedPoint::Yes,
                            s.map(|s| s + i),
                        );
                    }

                    // Since it is a qualified path here, it should not contains legacy macros
                    match self[module.module_id].scope.get(&segment.name) {
                        Some(res) => res.def,
                        _ => {
                            log::debug!("path segment {:?} not found", segment.name);
                            return ResolvePathResult::empty(ReachedFixedPoint::No);
                        }
                    }
                }
                ModuleDef::Enum(e) => {
                    // enum variant
                    tested_by!(can_import_enum_variant);
                    match e.variant(db, &segment.name) {
                        Some(variant) => PerNs::both(variant.into(), variant.into()),
                        None => {
                            return ResolvePathResult::with(
                                PerNs::types((*e).into()),
                                ReachedFixedPoint::Yes,
                                Some(i),
                            );
                        }
                    }
                }
                s => {
                    // could be an inherent method call in UFCS form
                    // (`Struct::method`), or some other kind of associated item
                    log::debug!(
                        "path segment {:?} resolved to non-module {:?}, but is not last",
                        segment.name,
                        curr,
                    );

                    return ResolvePathResult::with(
                        PerNs::types(*s),
                        ReachedFixedPoint::Yes,
                        Some(i),
                    );
                }
            };
        }
        ResolvePathResult::with(curr_per_ns, ReachedFixedPoint::Yes, None)
    }

    fn resolve_name_in_crate_root_or_extern_prelude(&self, name: &Name) -> PerNs<ModuleDef> {
        let from_crate_root =
            self[self.root].scope.get(name).map_or_else(PerNs::none, |res| res.def);
        let from_extern_prelude = self.resolve_name_in_extern_prelude(name);

        from_crate_root.or(from_extern_prelude)
    }

    pub(crate) fn resolve_name_in_module(
        &self,
        db: &impl DefDatabase,
        module: CrateModuleId,
        name: &Name,
    ) -> PerNs<ModuleDef> {
        // Resolve in:
        //  - legacy scope of macro
        //  - current module / scope
        //  - extern prelude
        //  - std prelude
        let from_legacy_macro =
            self[module].scope.get_legacy_macro(name).map_or_else(PerNs::none, PerNs::macros);
        let from_scope = self[module].scope.get(name).map_or_else(PerNs::none, |res| res.def);
        let from_extern_prelude =
            self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it));
        let from_prelude = self.resolve_in_prelude(db, name);

        from_legacy_macro.or(from_scope).or(from_extern_prelude).or(from_prelude)
    }

    fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs<ModuleDef> {
        self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it))
    }

    fn resolve_in_prelude(&self, db: &impl DefDatabase, name: &Name) -> PerNs<ModuleDef> {
        if let Some(prelude) = self.prelude {
            let keep;
            let def_map = if prelude.krate == self.krate {
                self
            } else {
                // Extend lifetime
                keep = db.crate_def_map(prelude.krate);
                &keep
            };
            def_map[prelude.module_id].scope.get(name).map_or_else(PerNs::none, |res| res.def)
        } else {
            PerNs::none()
        }
    }
}

mod diagnostics {
    use ra_syntax::{ast, AstPtr};
    use relative_path::RelativePathBuf;

    use crate::{
        db::{AstDatabase, DefDatabase},
        diagnostics::{DiagnosticSink, UnresolvedModule},
        nameres::CrateModuleId,
        AstId,
    };

    #[derive(Debug, PartialEq, Eq)]
    pub(super) enum DefDiagnostic {
        UnresolvedModule {
            module: CrateModuleId,
            declaration: AstId<ast::Module>,
            candidate: RelativePathBuf,
        },
    }

    impl DefDiagnostic {
        pub(super) fn add_to(
            &self,
            db: &(impl DefDatabase + AstDatabase),
            target_module: CrateModuleId,
            sink: &mut DiagnosticSink,
        ) {
            match self {
                DefDiagnostic::UnresolvedModule { module, declaration, candidate } => {
                    if *module != target_module {
                        return;
                    }
                    let decl = declaration.to_node(db);
                    sink.push(UnresolvedModule {
                        file: declaration.file_id(),
                        decl: AstPtr::new(&decl),
                        candidate: candidate.clone(),
                    })
                }
            }
        }
    }
}