aboutsummaryrefslogtreecommitdiff
path: root/crates/ra_hir/src/code_model.rs
blob: 29ace8479dc875d674dfd6c0e2fc69ab046ec483 (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
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
//! FIXME: write short doc here

pub(crate) mod src;

use std::sync::Arc;

use either::Either;
use hir_def::{
    adt::VariantData,
    body::{Body, BodySourceMap},
    builtin_type::BuiltinType,
    docs::Documentation,
    expr::{BindingAnnotation, Pat, PatId},
    nameres::ModuleSource,
    per_ns::PerNs,
    resolver::HasResolver,
    type_ref::{Mutability, TypeRef},
    AdtId, AstItemDef, ConstId, ContainerId, DefWithBodyId, EnumId, FunctionId, GenericParamId,
    HasModule, ImplId, LocalEnumVariantId, LocalImportId, LocalModuleId, LocalStructFieldId,
    Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId, UnionId,
};
use hir_expand::{
    diagnostics::DiagnosticSink,
    name::{self, AsName},
    MacroDefId,
};
use hir_ty::expr::ExprValidator;
use ra_db::{CrateId, Edition};
use ra_syntax::ast;

use crate::{
    db::{DefDatabase, HirDatabase},
    ty::display::HirFormatter,
    ty::{self, InEnvironment, InferenceResult, TraitEnvironment, Ty, TyDefId, TypeCtor, TypeWalk},
    CallableDef, HirDisplay, InFile, Name,
};

/// hir::Crate describes a single crate. It's the main interface with which
/// a crate's dependencies interact. Mostly, it should be just a proxy for the
/// root module.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Crate {
    pub(crate) crate_id: CrateId,
}

#[derive(Debug)]
pub struct CrateDependency {
    pub krate: Crate,
    pub name: Name,
}

impl Crate {
    pub fn crate_id(self) -> CrateId {
        self.crate_id
    }

    pub fn dependencies(self, db: &impl DefDatabase) -> Vec<CrateDependency> {
        db.crate_graph()
            .dependencies(self.crate_id)
            .map(|dep| {
                let krate = Crate { crate_id: dep.crate_id() };
                let name = dep.as_name();
                CrateDependency { krate, name }
            })
            .collect()
    }

    pub fn root_module(self, db: &impl DefDatabase) -> Option<Module> {
        let module_id = db.crate_def_map(self.crate_id).root;
        Some(Module::new(self, module_id))
    }

    pub fn edition(self, db: &impl DefDatabase) -> Edition {
        let crate_graph = db.crate_graph();
        crate_graph.edition(self.crate_id)
    }

    pub fn all(db: &impl DefDatabase) -> Vec<Crate> {
        db.crate_graph().iter().map(|crate_id| Crate { crate_id }).collect()
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Module {
    pub(crate) id: ModuleId,
}

/// The defs which can be visible in the module.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ModuleDef {
    Module(Module),
    Function(Function),
    Adt(Adt),
    // Can't be directly declared, but can be imported.
    EnumVariant(EnumVariant),
    Const(Const),
    Static(Static),
    Trait(Trait),
    TypeAlias(TypeAlias),
    BuiltinType(BuiltinType),
}
impl_froms!(
    ModuleDef: Module,
    Function,
    Adt(Struct, Enum, Union),
    EnumVariant,
    Const,
    Static,
    Trait,
    TypeAlias,
    BuiltinType
);

pub use hir_def::attr::Attrs;

impl Module {
    pub(crate) fn new(krate: Crate, crate_module_id: LocalModuleId) -> Module {
        Module { id: ModuleId { krate: krate.crate_id, local_id: crate_module_id } }
    }

    /// Name of this module.
    pub fn name(self, db: &impl DefDatabase) -> Option<Name> {
        let def_map = db.crate_def_map(self.id.krate);
        let parent = def_map[self.id.local_id].parent?;
        def_map[parent].children.iter().find_map(|(name, module_id)| {
            if *module_id == self.id.local_id {
                Some(name.clone())
            } else {
                None
            }
        })
    }

    /// Returns the crate this module is part of.
    pub fn krate(self) -> Crate {
        Crate { crate_id: self.id.krate }
    }

    /// Topmost parent of this module. Every module has a `crate_root`, but some
    /// might be missing `krate`. This can happen if a module's file is not included
    /// in the module tree of any target in `Cargo.toml`.
    pub fn crate_root(self, db: &impl DefDatabase) -> Module {
        let def_map = db.crate_def_map(self.id.krate);
        self.with_module_id(def_map.root)
    }

    /// Finds a child module with the specified name.
    pub fn child(self, db: &impl DefDatabase, name: &Name) -> Option<Module> {
        let def_map = db.crate_def_map(self.id.krate);
        let child_id = def_map[self.id.local_id].children.get(name)?;
        Some(self.with_module_id(*child_id))
    }

    /// Iterates over all child modules.
    pub fn children(self, db: &impl DefDatabase) -> impl Iterator<Item = Module> {
        let def_map = db.crate_def_map(self.id.krate);
        let children = def_map[self.id.local_id]
            .children
            .iter()
            .map(|(_, module_id)| self.with_module_id(*module_id))
            .collect::<Vec<_>>();
        children.into_iter()
    }

    /// Finds a parent module.
    pub fn parent(self, db: &impl DefDatabase) -> Option<Module> {
        let def_map = db.crate_def_map(self.id.krate);
        let parent_id = def_map[self.id.local_id].parent?;
        Some(self.with_module_id(parent_id))
    }

    pub fn path_to_root(self, db: &impl HirDatabase) -> Vec<Module> {
        let mut res = vec![self];
        let mut curr = self;
        while let Some(next) = curr.parent(db) {
            res.push(next);
            curr = next
        }
        res
    }

    /// Returns a `ModuleScope`: a set of items, visible in this module.
    pub fn scope(self, db: &impl HirDatabase) -> Vec<(Name, ScopeDef, Option<Import>)> {
        db.crate_def_map(self.id.krate)[self.id.local_id]
            .scope
            .entries()
            .map(|(name, res)| {
                (name.clone(), res.def.into(), res.import.map(|id| Import { parent: self, id }))
            })
            .collect()
    }

    pub fn diagnostics(self, db: &impl HirDatabase, sink: &mut DiagnosticSink) {
        db.crate_def_map(self.id.krate).add_diagnostics(db, self.id.local_id, sink);
        for decl in self.declarations(db) {
            match decl {
                crate::ModuleDef::Function(f) => f.diagnostics(db, sink),
                crate::ModuleDef::Module(m) => {
                    // Only add diagnostics from inline modules
                    if let ModuleSource::Module(_) = m.definition_source(db).value {
                        m.diagnostics(db, sink)
                    }
                }
                _ => (),
            }
        }

        for impl_block in self.impl_blocks(db) {
            for item in impl_block.items(db) {
                if let AssocItem::Function(f) = item {
                    f.diagnostics(db, sink);
                }
            }
        }
    }

    pub fn declarations(self, db: &impl DefDatabase) -> Vec<ModuleDef> {
        let def_map = db.crate_def_map(self.id.krate);
        def_map[self.id.local_id].scope.declarations().map(ModuleDef::from).collect()
    }

    pub fn impl_blocks(self, db: &impl DefDatabase) -> Vec<ImplBlock> {
        let def_map = db.crate_def_map(self.id.krate);
        def_map[self.id.local_id].impls.iter().copied().map(ImplBlock::from).collect()
    }

    fn with_module_id(self, module_id: LocalModuleId) -> Module {
        Module::new(self.krate(), module_id)
    }
}

pub struct Import {
    pub(crate) parent: Module,
    pub(crate) id: LocalImportId,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct StructField {
    pub(crate) parent: VariantDef,
    pub(crate) id: LocalStructFieldId,
}

#[derive(Debug, PartialEq, Eq)]
pub enum FieldSource {
    Named(ast::RecordFieldDef),
    Pos(ast::TupleFieldDef),
}

impl StructField {
    pub fn name(&self, db: &impl HirDatabase) -> Name {
        self.parent.variant_data(db).fields()[self.id].name.clone()
    }

    pub fn ty(&self, db: &impl HirDatabase) -> Ty {
        db.field_types(self.parent.into())[self.id].clone()
    }

    pub fn parent_def(&self, _db: &impl HirDatabase) -> VariantDef {
        self.parent
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Struct {
    pub(crate) id: StructId,
}

impl Struct {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.module(db) }
    }

    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }

    pub fn name(self, db: &impl DefDatabase) -> Name {
        db.struct_data(self.id.into()).name.clone()
    }

    pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
        db.struct_data(self.id.into())
            .variant_data
            .fields()
            .iter()
            .map(|(id, _)| StructField { parent: self.into(), id })
            .collect()
    }

    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
        db.struct_data(self.id.into())
            .variant_data
            .fields()
            .iter()
            .find(|(_id, data)| data.name == *name)
            .map(|(id, _)| StructField { parent: self.into(), id })
    }

    pub fn ty(self, db: &impl HirDatabase) -> Type {
        Type::from_def(db, self.id.module(db).krate, self.id)
    }

    pub fn constructor_ty(self, db: &impl HirDatabase) -> Ty {
        db.value_ty(self.id.into())
    }

    fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
        db.struct_data(self.id.into()).variant_data.clone()
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Union {
    pub(crate) id: UnionId,
}

impl Union {
    pub fn name(self, db: &impl DefDatabase) -> Name {
        db.union_data(self.id).name.clone()
    }

    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.module(db) }
    }

    pub fn ty(self, db: &impl HirDatabase) -> Type {
        Type::from_def(db, self.id.module(db).krate, self.id)
    }

    pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
        db.union_data(self.id)
            .variant_data
            .fields()
            .iter()
            .map(|(id, _)| StructField { parent: self.into(), id })
            .collect()
    }

    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
        db.union_data(self.id)
            .variant_data
            .fields()
            .iter()
            .find(|(_id, data)| data.name == *name)
            .map(|(id, _)| StructField { parent: self.into(), id })
    }

    fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
        db.union_data(self.id).variant_data.clone()
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Enum {
    pub(crate) id: EnumId,
}

impl Enum {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.module(db) }
    }

    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }

    pub fn name(self, db: &impl DefDatabase) -> Name {
        db.enum_data(self.id).name.clone()
    }

    pub fn variants(self, db: &impl DefDatabase) -> Vec<EnumVariant> {
        db.enum_data(self.id)
            .variants
            .iter()
            .map(|(id, _)| EnumVariant { parent: self, id })
            .collect()
    }

    pub fn variant(self, db: &impl DefDatabase, name: &Name) -> Option<EnumVariant> {
        let id = db.enum_data(self.id).variant(name)?;
        Some(EnumVariant { parent: self, id })
    }

    pub fn ty(self, db: &impl HirDatabase) -> Type {
        Type::from_def(db, self.id.module(db).krate, self.id)
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct EnumVariant {
    pub(crate) parent: Enum,
    pub(crate) id: LocalEnumVariantId,
}

impl EnumVariant {
    pub fn module(self, db: &impl HirDatabase) -> Module {
        self.parent.module(db)
    }
    pub fn parent_enum(self, _db: &impl DefDatabase) -> Enum {
        self.parent
    }

    pub fn name(self, db: &impl DefDatabase) -> Name {
        db.enum_data(self.parent.id).variants[self.id].name.clone()
    }

    pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
        self.variant_data(db)
            .fields()
            .iter()
            .map(|(id, _)| StructField { parent: self.into(), id })
            .collect()
    }

    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
        self.variant_data(db)
            .fields()
            .iter()
            .find(|(_id, data)| data.name == *name)
            .map(|(id, _)| StructField { parent: self.into(), id })
    }

    pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
        db.enum_data(self.parent.id).variants[self.id].variant_data.clone()
    }
}

/// A Data Type
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum Adt {
    Struct(Struct),
    Union(Union),
    Enum(Enum),
}
impl_froms!(Adt: Struct, Union, Enum);

impl Adt {
    pub fn has_non_default_type_params(self, db: &impl HirDatabase) -> bool {
        let subst = db.generic_defaults(self.into());
        subst.iter().any(|ty| ty == &Ty::Unknown)
    }
    pub fn ty(self, db: &impl HirDatabase) -> Type {
        let id = AdtId::from(self);
        Type::from_def(db, id.module(db).krate, id)
    }

    pub fn module(self, db: &impl DefDatabase) -> Module {
        match self {
            Adt::Struct(s) => s.module(db),
            Adt::Union(s) => s.module(db),
            Adt::Enum(e) => e.module(db),
        }
    }

    pub fn krate(self, db: &impl HirDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum VariantDef {
    Struct(Struct),
    Union(Union),
    EnumVariant(EnumVariant),
}
impl_froms!(VariantDef: Struct, Union, EnumVariant);

impl VariantDef {
    pub fn fields(self, db: &impl HirDatabase) -> Vec<StructField> {
        match self {
            VariantDef::Struct(it) => it.fields(db),
            VariantDef::Union(it) => it.fields(db),
            VariantDef::EnumVariant(it) => it.fields(db),
        }
    }

    pub fn module(self, db: &impl HirDatabase) -> Module {
        match self {
            VariantDef::Struct(it) => it.module(db),
            VariantDef::Union(it) => it.module(db),
            VariantDef::EnumVariant(it) => it.module(db),
        }
    }

    pub(crate) fn variant_data(self, db: &impl DefDatabase) -> Arc<VariantData> {
        match self {
            VariantDef::Struct(it) => it.variant_data(db),
            VariantDef::Union(it) => it.variant_data(db),
            VariantDef::EnumVariant(it) => it.variant_data(db),
        }
    }
}

/// The defs which have a body.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum DefWithBody {
    Function(Function),
    Static(Static),
    Const(Const),
}

impl_froms!(DefWithBody: Function, Const, Static);

impl DefWithBody {
    pub fn module(self, db: &impl HirDatabase) -> Module {
        match self {
            DefWithBody::Const(c) => c.module(db),
            DefWithBody::Function(f) => f.module(db),
            DefWithBody::Static(s) => s.module(db),
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Function {
    pub(crate) id: FunctionId,
}

impl Function {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        self.id.lookup(db).module(db).into()
    }

    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }

    pub fn name(self, db: &impl HirDatabase) -> Name {
        db.function_data(self.id).name.clone()
    }

    pub fn has_self_param(self, db: &impl HirDatabase) -> bool {
        db.function_data(self.id).has_self_param
    }

    pub fn params(self, db: &impl HirDatabase) -> Vec<TypeRef> {
        db.function_data(self.id).params.clone()
    }

    pub fn body_source_map(self, db: &impl HirDatabase) -> Arc<BodySourceMap> {
        db.body_with_source_map(self.id.into()).1
    }

    pub fn body(self, db: &impl HirDatabase) -> Arc<Body> {
        db.body(self.id.into())
    }

    pub fn ty(self, db: &impl HirDatabase) -> Ty {
        db.value_ty(self.id.into())
    }

    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
        db.infer(self.id.into())
    }

    /// The containing impl block, if this is a method.
    pub fn impl_block(self, db: &impl DefDatabase) -> Option<ImplBlock> {
        match self.container(db) {
            Some(Container::ImplBlock(it)) => Some(it),
            _ => None,
        }
    }

    /// The containing trait, if this is a trait method definition.
    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
        match self.container(db) {
            Some(Container::Trait(it)) => Some(it),
            _ => None,
        }
    }

    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
        match self.id.lookup(db).container {
            ContainerId::TraitId(it) => Some(Container::Trait(it.into())),
            ContainerId::ImplId(it) => Some(Container::ImplBlock(it.into())),
            ContainerId::ModuleId(_) => None,
        }
    }

    pub fn diagnostics(self, db: &impl HirDatabase, sink: &mut DiagnosticSink) {
        let infer = self.infer(db);
        infer.add_diagnostics(db, self.id, sink);
        let mut validator = ExprValidator::new(self.id, infer, sink);
        validator.validate_body(db);
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Const {
    pub(crate) id: ConstId,
}

impl Const {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.lookup(db).module(db) }
    }

    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }

    pub fn name(self, db: &impl HirDatabase) -> Option<Name> {
        db.const_data(self.id).name.clone()
    }

    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
        db.infer(self.id.into())
    }

    /// The containing impl block, if this is a type alias.
    pub fn impl_block(self, db: &impl DefDatabase) -> Option<ImplBlock> {
        match self.container(db) {
            Some(Container::ImplBlock(it)) => Some(it),
            _ => None,
        }
    }

    /// The containing trait, if this is a trait type alias definition.
    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
        match self.container(db) {
            Some(Container::Trait(it)) => Some(it),
            _ => None,
        }
    }

    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
        match self.id.lookup(db).container {
            ContainerId::TraitId(it) => Some(Container::Trait(it.into())),
            ContainerId::ImplId(it) => Some(Container::ImplBlock(it.into())),
            ContainerId::ModuleId(_) => None,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Static {
    pub(crate) id: StaticId,
}

impl Static {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.lookup(db).module(db) }
    }

    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }

    pub fn infer(self, db: &impl HirDatabase) -> Arc<InferenceResult> {
        db.infer(self.id.into())
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct Trait {
    pub(crate) id: TraitId,
}

impl Trait {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.module(db) }
    }

    pub fn name(self, db: &impl DefDatabase) -> Name {
        db.trait_data(self.id).name.clone()
    }

    pub fn items(self, db: &impl DefDatabase) -> Vec<AssocItem> {
        db.trait_data(self.id).items.iter().map(|(_name, it)| (*it).into()).collect()
    }

    pub fn is_auto(self, db: &impl DefDatabase) -> bool {
        db.trait_data(self.id).auto
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeAlias {
    pub(crate) id: TypeAliasId,
}

impl TypeAlias {
    pub fn has_non_default_type_params(self, db: &impl HirDatabase) -> bool {
        let subst = db.generic_defaults(self.id.into());
        subst.iter().any(|ty| ty == &Ty::Unknown)
    }

    pub fn module(self, db: &impl DefDatabase) -> Module {
        Module { id: self.id.lookup(db).module(db) }
    }

    pub fn krate(self, db: &impl DefDatabase) -> Option<Crate> {
        Some(self.module(db).krate())
    }

    /// The containing impl block, if this is a type alias.
    pub fn impl_block(self, db: &impl DefDatabase) -> Option<ImplBlock> {
        match self.container(db) {
            Some(Container::ImplBlock(it)) => Some(it),
            _ => None,
        }
    }

    /// The containing trait, if this is a trait type alias definition.
    pub fn parent_trait(self, db: &impl DefDatabase) -> Option<Trait> {
        match self.container(db) {
            Some(Container::Trait(it)) => Some(it),
            _ => None,
        }
    }

    pub fn container(self, db: &impl DefDatabase) -> Option<Container> {
        match self.id.lookup(db).container {
            ContainerId::TraitId(it) => Some(Container::Trait(it.into())),
            ContainerId::ImplId(it) => Some(Container::ImplBlock(it.into())),
            ContainerId::ModuleId(_) => None,
        }
    }

    pub fn type_ref(self, db: &impl DefDatabase) -> Option<TypeRef> {
        db.type_alias_data(self.id).type_ref.clone()
    }

    pub fn ty(self, db: &impl HirDatabase) -> Type {
        Type::from_def(db, self.id.lookup(db).module(db).krate, self.id)
    }

    pub fn name(self, db: &impl DefDatabase) -> Name {
        db.type_alias_data(self.id).name.clone()
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct MacroDef {
    pub(crate) id: MacroDefId,
}

impl MacroDef {}

pub enum Container {
    Trait(Trait),
    ImplBlock(ImplBlock),
}
impl_froms!(Container: Trait, ImplBlock);

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum AssocItem {
    Function(Function),
    Const(Const),
    TypeAlias(TypeAlias),
}
// FIXME: not every function, ... is actually an assoc item. maybe we should make
// sure that you can only turn actual assoc items into AssocItems. This would
// require not implementing From, and instead having some checked way of
// casting them, and somehow making the constructors private, which would be annoying.
impl_froms!(AssocItem: Function, Const, TypeAlias);

impl AssocItem {
    pub fn module(self, db: &impl DefDatabase) -> Module {
        match self {
            AssocItem::Function(f) => f.module(db),
            AssocItem::Const(c) => c.module(db),
            AssocItem::TypeAlias(t) => t.module(db),
        }
    }

    pub fn container(self, db: &impl DefDatabase) -> Container {
        match self {
            AssocItem::Function(f) => f.container(db),
            AssocItem::Const(c) => c.container(db),
            AssocItem::TypeAlias(t) => t.container(db),
        }
        .expect("AssocItem without container")
    }
}

#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
pub enum GenericDef {
    Function(Function),
    Adt(Adt),
    Trait(Trait),
    TypeAlias(TypeAlias),
    ImplBlock(ImplBlock),
    // enum variants cannot have generics themselves, but their parent enums
    // can, and this makes some code easier to write
    EnumVariant(EnumVariant),
    // consts can have type parameters from their parents (i.e. associated consts of traits)
    Const(Const),
}
impl_froms!(
    GenericDef: Function,
    Adt(Struct, Enum, Union),
    Trait,
    TypeAlias,
    ImplBlock,
    EnumVariant,
    Const
);

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub struct Local {
    pub(crate) parent: DefWithBody,
    pub(crate) pat_id: PatId,
}

impl Local {
    pub fn name(self, db: &impl HirDatabase) -> Option<Name> {
        let body = db.body(self.parent.into());
        match &body[self.pat_id] {
            Pat::Bind { name, .. } => Some(name.clone()),
            _ => None,
        }
    }

    pub fn is_self(self, db: &impl HirDatabase) -> bool {
        self.name(db) == Some(name::SELF_PARAM)
    }

    pub fn is_mut(self, db: &impl HirDatabase) -> bool {
        let body = db.body(self.parent.into());
        match &body[self.pat_id] {
            Pat::Bind { mode, .. } => match mode {
                BindingAnnotation::Mutable | BindingAnnotation::RefMut => true,
                _ => false,
            },
            _ => false,
        }
    }

    pub fn parent(self, _db: &impl HirDatabase) -> DefWithBody {
        self.parent
    }

    pub fn module(self, db: &impl HirDatabase) -> Module {
        self.parent.module(db)
    }

    pub fn ty(self, db: &impl HirDatabase) -> Type {
        let def = DefWithBodyId::from(self.parent);
        let infer = db.infer(def);
        let ty = infer[self.pat_id].clone();
        let resolver = def.resolver(db);
        let krate = def.module(db).krate;
        let environment = TraitEnvironment::lower(db, &resolver);
        Type { krate, ty: InEnvironment { value: ty, environment } }
    }

    pub fn source(self, db: &impl HirDatabase) -> InFile<Either<ast::BindPat, ast::SelfParam>> {
        let (_body, source_map) = db.body_with_source_map(self.parent.into());
        let src = source_map.pat_syntax(self.pat_id).unwrap(); // Hmm...
        let root = src.file_syntax(db);
        src.map(|ast| {
            ast.map_left(|it| it.cast().unwrap().to_node(&root)).map_right(|it| it.to_node(&root))
        })
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub struct GenericParam {
    pub(crate) id: GenericParamId,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ImplBlock {
    pub(crate) id: ImplId,
}

impl ImplBlock {
    pub fn all_in_crate(db: &impl HirDatabase, krate: Crate) -> Vec<ImplBlock> {
        let impls = db.impls_in_crate(krate.crate_id);
        impls.all_impls().map(Self::from).collect()
    }
    pub fn for_trait(db: &impl HirDatabase, krate: Crate, trait_: Trait) -> Vec<ImplBlock> {
        let impls = db.impls_in_crate(krate.crate_id);
        impls.lookup_impl_blocks_for_trait(trait_.id).map(Self::from).collect()
    }

    pub fn target_trait(&self, db: &impl DefDatabase) -> Option<TypeRef> {
        db.impl_data(self.id).target_trait.clone()
    }

    pub fn target_type(&self, db: &impl DefDatabase) -> TypeRef {
        db.impl_data(self.id).target_type.clone()
    }

    pub fn target_ty(&self, db: &impl HirDatabase) -> Type {
        let impl_data = db.impl_data(self.id);
        let resolver = self.id.resolver(db);
        let environment = TraitEnvironment::lower(db, &resolver);
        let ty = Ty::from_hir(db, &resolver, &impl_data.target_type);
        Type { krate: self.id.module(db).krate, ty: InEnvironment { value: ty, environment } }
    }

    pub fn items(&self, db: &impl DefDatabase) -> Vec<AssocItem> {
        db.impl_data(self.id).items.iter().map(|it| (*it).into()).collect()
    }

    pub fn is_negative(&self, db: &impl DefDatabase) -> bool {
        db.impl_data(self.id).is_negative
    }

    pub fn module(&self, db: &impl DefDatabase) -> Module {
        self.id.module(db).into()
    }

    pub fn krate(&self, db: &impl DefDatabase) -> Crate {
        Crate { crate_id: self.module(db).id.krate }
    }
}

#[derive(Clone, PartialEq, Eq, Debug)]
pub struct Type {
    pub(crate) krate: CrateId,
    pub(crate) ty: InEnvironment<Ty>,
}

impl Type {
    fn from_def(
        db: &impl HirDatabase,
        krate: CrateId,
        def: impl HasResolver + Into<TyDefId>,
    ) -> Type {
        let resolver = def.resolver(db);
        let environment = TraitEnvironment::lower(db, &resolver);
        let ty = db.ty(def.into());
        Type { krate, ty: InEnvironment { value: ty, environment } }
    }

    pub fn is_bool(&self) -> bool {
        match &self.ty.value {
            Ty::Apply(a_ty) => match a_ty.ctor {
                TypeCtor::Bool => true,
                _ => false,
            },
            _ => false,
        }
    }

    pub fn is_mutable_reference(&self) -> bool {
        match &self.ty.value {
            Ty::Apply(a_ty) => match a_ty.ctor {
                TypeCtor::Ref(Mutability::Mut) => true,
                _ => false,
            },
            _ => false,
        }
    }

    pub fn is_unknown(&self) -> bool {
        match &self.ty.value {
            Ty::Unknown => true,
            _ => false,
        }
    }

    // FIXME: this method is broken, as it doesn't take closures into account.
    pub fn as_callable(&self) -> Option<CallableDef> {
        Some(self.ty.value.as_callable()?.0)
    }

    pub fn contains_unknown(&self) -> bool {
        return go(&self.ty.value);

        fn go(ty: &Ty) -> bool {
            match ty {
                Ty::Unknown => true,
                Ty::Apply(a_ty) => a_ty.parameters.iter().any(go),
                _ => false,
            }
        }
    }

    pub fn fields(&self, db: &impl HirDatabase) -> Vec<(StructField, Type)> {
        if let Ty::Apply(a_ty) = &self.ty.value {
            match a_ty.ctor {
                ty::TypeCtor::Adt(AdtId::StructId(s)) => {
                    let var_def = s.into();
                    return db
                        .field_types(var_def)
                        .iter()
                        .map(|(local_id, ty)| {
                            let def = StructField { parent: var_def.into(), id: local_id };
                            let ty = ty.clone().subst(&a_ty.parameters);
                            (def, self.derived(ty))
                        })
                        .collect();
                }
                _ => {}
            }
        };
        Vec::new()
    }

    pub fn tuple_fields(&self, _db: &impl HirDatabase) -> Vec<Type> {
        let mut res = Vec::new();
        if let Ty::Apply(a_ty) = &self.ty.value {
            match a_ty.ctor {
                ty::TypeCtor::Tuple { .. } => {
                    for ty in a_ty.parameters.iter() {
                        let ty = ty.clone().subst(&a_ty.parameters);
                        res.push(self.derived(ty));
                    }
                }
                _ => {}
            }
        };
        res
    }

    pub fn variant_fields(
        &self,
        db: &impl HirDatabase,
        def: VariantDef,
    ) -> Vec<(StructField, Type)> {
        // FIXME: check that ty and def match
        match &self.ty.value {
            Ty::Apply(a_ty) => def
                .fields(db)
                .into_iter()
                .map(|it| (it, self.derived(it.ty(db).subst(&a_ty.parameters))))
                .collect(),
            _ => Vec::new(),
        }
    }

    pub fn autoderef<'a>(&'a self, db: &'a impl HirDatabase) -> impl Iterator<Item = Type> + 'a {
        // There should be no inference vars in types passed here
        // FIXME check that?
        let canonical = crate::ty::Canonical { value: self.ty.value.clone(), num_vars: 0 };
        let environment = self.ty.environment.clone();
        let ty = InEnvironment { value: canonical, environment: environment.clone() };
        ty::autoderef(db, Some(self.krate), ty)
            .map(|canonical| canonical.value)
            .map(move |ty| self.derived(ty))
    }

    // This would be nicer if it just returned an iterator, but that runs into
    // lifetime problems, because we need to borrow temp `CrateImplBlocks`.
    pub fn iterate_impl_items<T>(
        self,
        db: &impl HirDatabase,
        krate: Crate,
        mut callback: impl FnMut(AssocItem) -> Option<T>,
    ) -> Option<T> {
        for krate in self.ty.value.def_crates(db, krate.crate_id)? {
            let impls = db.impls_in_crate(krate);

            for impl_block in impls.lookup_impl_blocks(&self.ty.value) {
                for &item in db.impl_data(impl_block).items.iter() {
                    if let Some(result) = callback(item.into()) {
                        return Some(result);
                    }
                }
            }
        }
        None
    }

    // FIXME: remove
    pub fn into_ty(self) -> Ty {
        self.ty.value
    }

    pub fn as_adt(&self) -> Option<Adt> {
        let (adt, _subst) = self.ty.value.as_adt()?;
        Some(adt.into())
    }

    // FIXME: provide required accessors such that it becomes implementable from outside.
    pub fn is_equal_for_find_impls(&self, other: &Type) -> bool {
        match (&self.ty.value, &other.ty.value) {
            (Ty::Apply(a_original_ty), Ty::Apply(ty::ApplicationTy { ctor, parameters })) => {
                match ctor {
                    TypeCtor::Ref(..) => match parameters.as_single() {
                        Ty::Apply(a_ty) => a_original_ty.ctor == a_ty.ctor,
                        _ => false,
                    },
                    _ => a_original_ty.ctor == *ctor,
                }
            }
            _ => false,
        }
    }

    fn derived(&self, ty: Ty) -> Type {
        Type {
            krate: self.krate,
            ty: InEnvironment { value: ty, environment: self.ty.environment.clone() },
        }
    }
}

impl HirDisplay for Type {
    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> std::fmt::Result {
        self.ty.value.hir_fmt(f)
    }
}

/// For IDE only
pub enum ScopeDef {
    ModuleDef(ModuleDef),
    MacroDef(MacroDef),
    GenericParam(GenericParam),
    ImplSelfType(ImplBlock),
    AdtSelfType(Adt),
    Local(Local),
    Unknown,
}

impl From<PerNs> for ScopeDef {
    fn from(def: PerNs) -> Self {
        def.take_types()
            .or_else(|| def.take_values())
            .map(|module_def_id| ScopeDef::ModuleDef(module_def_id.into()))
            .or_else(|| {
                def.take_macros().map(|macro_def_id| ScopeDef::MacroDef(macro_def_id.into()))
            })
            .unwrap_or(ScopeDef::Unknown)
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum AttrDef {
    Module(Module),
    StructField(StructField),
    Adt(Adt),
    Function(Function),
    EnumVariant(EnumVariant),
    Static(Static),
    Const(Const),
    Trait(Trait),
    TypeAlias(TypeAlias),
    MacroDef(MacroDef),
}

impl_froms!(
    AttrDef: Module,
    StructField,
    Adt(Struct, Enum, Union),
    EnumVariant,
    Static,
    Const,
    Function,
    Trait,
    TypeAlias,
    MacroDef
);

pub trait HasAttrs {
    fn attrs(self, db: &impl DefDatabase) -> Attrs;
}

impl<T: Into<AttrDef>> HasAttrs for T {
    fn attrs(self, db: &impl DefDatabase) -> Attrs {
        let def: AttrDef = self.into();
        db.attrs(def.into())
    }
}

pub trait Docs {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation>;
}
impl<T: Into<AttrDef> + Copy> Docs for T {
    fn docs(&self, db: &impl HirDatabase) -> Option<Documentation> {
        let def: AttrDef = (*self).into();
        db.documentation(def.into())
    }
}