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
//! `hir_def` crate contains everything between macro expansion and type
//! inference.
//!
//! It defines various items (structs, enums, traits) which comprises Rust code,
//! as well as an algorithm for resolving paths to such entities.
//!
//! Note that `hir_def` is a work in progress, so not all of the above is
//! actually true.

#[allow(unused)]
macro_rules! eprintln {
    ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
}

pub mod db;

pub mod attr;
pub mod path;
pub mod type_ref;
pub mod builtin_type;
pub mod builtin_attr;
pub mod per_ns;
pub mod item_scope;

pub mod dyn_map;
pub mod keys;

pub mod item_tree;
pub mod intern;

pub mod adt;
pub mod data;
pub mod generics;
pub mod lang_item;

pub mod expr;
pub mod body;
pub mod resolver;

mod trace;
pub mod nameres;

pub mod src;
pub mod child_by_source;

pub mod visibility;
pub mod find_path;
pub mod import_map;

#[cfg(test)]
mod test_db;
#[cfg(test)]
mod macro_expansion_tests;

use std::{
    hash::{Hash, Hasher},
    sync::Arc,
};

use attr::Attr;
use base_db::{impl_intern_key, salsa, CrateId};
use hir_expand::{
    ast_id_map::FileAstId,
    eager::{expand_eager_macro, ErrorEmitted, ErrorSink},
    hygiene::Hygiene,
    AstId, ExpandTo, HirFileId, InFile, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
};
use la_arena::Idx;
use nameres::DefMap;
use path::ModPath;
use stdx::impl_from;
use syntax::ast;

use crate::{
    adt::VariantData,
    attr::AttrId,
    builtin_type::BuiltinType,
    item_tree::{
        Const, Enum, Function, Impl, ItemTreeId, ItemTreeNode, ModItem, Static, Struct, Trait,
        TypeAlias, Union,
    },
};

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ModuleId {
    krate: CrateId,
    /// If this `ModuleId` was derived from a `DefMap` for a block expression, this stores the
    /// `BlockId` of that block expression. If `None`, this module is part of the crate-level
    /// `DefMap` of `krate`.
    block: Option<BlockId>,
    /// The module's ID in its originating `DefMap`.
    pub local_id: LocalModuleId,
}

impl ModuleId {
    pub fn def_map(&self, db: &dyn db::DefDatabase) -> Arc<DefMap> {
        match self.block {
            Some(block) => {
                db.block_def_map(block).unwrap_or_else(|| {
                    // NOTE: This should be unreachable - all `ModuleId`s come from their `DefMap`s,
                    // so the `DefMap` here must exist.
                    unreachable!("no `block_def_map` for `ModuleId` {:?}", self);
                })
            }
            None => db.crate_def_map(self.krate),
        }
    }

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

    pub fn containing_module(&self, db: &dyn db::DefDatabase) -> Option<ModuleId> {
        self.def_map(db).containing_module(self.local_id)
    }

    pub fn containing_block(&self) -> Option<BlockId> {
        self.block
    }
}

/// An ID of a module, **local** to a specific crate
pub type LocalModuleId = Idx<nameres::ModuleData>;

#[derive(Debug)]
pub struct ItemLoc<N: ItemTreeNode> {
    pub container: ModuleId,
    pub id: ItemTreeId<N>,
}

impl<N: ItemTreeNode> Clone for ItemLoc<N> {
    fn clone(&self) -> Self {
        Self { container: self.container, id: self.id }
    }
}

impl<N: ItemTreeNode> Copy for ItemLoc<N> {}

impl<N: ItemTreeNode> PartialEq for ItemLoc<N> {
    fn eq(&self, other: &Self) -> bool {
        self.container == other.container && self.id == other.id
    }
}

impl<N: ItemTreeNode> Eq for ItemLoc<N> {}

impl<N: ItemTreeNode> Hash for ItemLoc<N> {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.container.hash(state);
        self.id.hash(state);
    }
}

#[derive(Debug)]
pub struct AssocItemLoc<N: ItemTreeNode> {
    pub container: AssocContainerId,
    pub id: ItemTreeId<N>,
}

impl<N: ItemTreeNode> Clone for AssocItemLoc<N> {
    fn clone(&self) -> Self {
        Self { container: self.container, id: self.id }
    }
}

impl<N: ItemTreeNode> Copy for AssocItemLoc<N> {}

impl<N: ItemTreeNode> PartialEq for AssocItemLoc<N> {
    fn eq(&self, other: &Self) -> bool {
        self.container == other.container && self.id == other.id
    }
}

impl<N: ItemTreeNode> Eq for AssocItemLoc<N> {}

impl<N: ItemTreeNode> Hash for AssocItemLoc<N> {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.container.hash(state);
        self.id.hash(state);
    }
}

macro_rules! impl_intern {
    ($id:ident, $loc:ident, $intern:ident, $lookup:ident) => {
        impl_intern_key!($id);

        impl Intern for $loc {
            type ID = $id;
            fn intern(self, db: &dyn db::DefDatabase) -> $id {
                db.$intern(self)
            }
        }

        impl Lookup for $id {
            type Data = $loc;
            fn lookup(&self, db: &dyn db::DefDatabase) -> $loc {
                db.$lookup(*self)
            }
        }
    };
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct FunctionId(salsa::InternId);
type FunctionLoc = AssocItemLoc<Function>;
impl_intern!(FunctionId, FunctionLoc, intern_function, lookup_intern_function);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub struct StructId(salsa::InternId);
type StructLoc = ItemLoc<Struct>;
impl_intern!(StructId, StructLoc, intern_struct, lookup_intern_struct);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub struct UnionId(salsa::InternId);
pub type UnionLoc = ItemLoc<Union>;
impl_intern!(UnionId, UnionLoc, intern_union, lookup_intern_union);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub struct EnumId(salsa::InternId);
pub type EnumLoc = ItemLoc<Enum>;
impl_intern!(EnumId, EnumLoc, intern_enum, lookup_intern_enum);

// FIXME: rename to `VariantId`, only enums can ave variants
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct EnumVariantId {
    pub parent: EnumId,
    pub local_id: LocalEnumVariantId,
}

pub type LocalEnumVariantId = Idx<adt::EnumVariantData>;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct FieldId {
    pub parent: VariantId,
    pub local_id: LocalFieldId,
}

pub type LocalFieldId = Idx<adt::FieldData>;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ConstId(salsa::InternId);
type ConstLoc = AssocItemLoc<Const>;
impl_intern!(ConstId, ConstLoc, intern_const, lookup_intern_const);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct StaticId(salsa::InternId);
pub type StaticLoc = ItemLoc<Static>;
impl_intern!(StaticId, StaticLoc, intern_static, lookup_intern_static);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TraitId(salsa::InternId);
pub type TraitLoc = ItemLoc<Trait>;
impl_intern!(TraitId, TraitLoc, intern_trait, lookup_intern_trait);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeAliasId(salsa::InternId);
type TypeAliasLoc = AssocItemLoc<TypeAlias>;
impl_intern!(TypeAliasId, TypeAliasLoc, intern_type_alias, lookup_intern_type_alias);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
pub struct ImplId(salsa::InternId);
type ImplLoc = ItemLoc<Impl>;
impl_intern!(ImplId, ImplLoc, intern_impl, lookup_intern_impl);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
pub struct BlockId(salsa::InternId);
#[derive(Debug, Hash, PartialEq, Eq, Clone)]
pub struct BlockLoc {
    ast_id: AstId<ast::BlockExpr>,
    /// The containing module.
    module: ModuleId,
}
impl_intern!(BlockId, BlockLoc, intern_block, lookup_intern_block);

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeParamId {
    pub parent: GenericDefId,
    pub local_id: LocalTypeParamId,
}

pub type LocalTypeParamId = Idx<generics::TypeParamData>;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct LifetimeParamId {
    pub parent: GenericDefId,
    pub local_id: LocalLifetimeParamId,
}
pub type LocalLifetimeParamId = Idx<generics::LifetimeParamData>;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct ConstParamId {
    pub parent: GenericDefId,
    pub local_id: LocalConstParamId,
}
pub type LocalConstParamId = Idx<generics::ConstParamData>;

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum AssocContainerId {
    ModuleId(ModuleId),
    ImplId(ImplId),
    TraitId(TraitId),
}
impl_from!(ModuleId for AssocContainerId);

/// A Data Type
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub enum AdtId {
    StructId(StructId),
    UnionId(UnionId),
    EnumId(EnumId),
}
impl_from!(StructId, UnionId, EnumId for AdtId);

/// A generic param
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum GenericParamId {
    TypeParamId(TypeParamId),
    LifetimeParamId(LifetimeParamId),
    ConstParamId(ConstParamId),
}
impl_from!(TypeParamId, LifetimeParamId, ConstParamId for GenericParamId);

/// The defs which can be visible in the module.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ModuleDefId {
    ModuleId(ModuleId),
    FunctionId(FunctionId),
    AdtId(AdtId),
    // Can't be directly declared, but can be imported.
    EnumVariantId(EnumVariantId),
    ConstId(ConstId),
    StaticId(StaticId),
    TraitId(TraitId),
    TypeAliasId(TypeAliasId),
    BuiltinType(BuiltinType),
}
impl_from!(
    ModuleId,
    FunctionId,
    AdtId(StructId, EnumId, UnionId),
    EnumVariantId,
    ConstId,
    StaticId,
    TraitId,
    TypeAliasId,
    BuiltinType
    for ModuleDefId
);

/// The defs which have a body.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum DefWithBodyId {
    FunctionId(FunctionId),
    StaticId(StaticId),
    ConstId(ConstId),
}

impl_from!(FunctionId, ConstId, StaticId for DefWithBodyId);

impl DefWithBodyId {
    pub fn as_generic_def_id(self) -> Option<GenericDefId> {
        match self {
            DefWithBodyId::FunctionId(f) => Some(f.into()),
            DefWithBodyId::StaticId(_) => None,
            DefWithBodyId::ConstId(c) => Some(c.into()),
        }
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum AssocItemId {
    FunctionId(FunctionId),
    ConstId(ConstId),
    TypeAliasId(TypeAliasId),
}
// FIXME: not every function, ... is actually an assoc item. maybe we should make
// sure that you can only turn actual assoc items into AssocItemIds. 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_from!(FunctionId, ConstId, TypeAliasId for AssocItemId);

#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
pub enum GenericDefId {
    FunctionId(FunctionId),
    AdtId(AdtId),
    TraitId(TraitId),
    TypeAliasId(TypeAliasId),
    ImplId(ImplId),
    // enum variants cannot have generics themselves, but their parent enums
    // can, and this makes some code easier to write
    EnumVariantId(EnumVariantId),
    // consts can have type parameters from their parents (i.e. associated consts of traits)
    ConstId(ConstId),
}
impl_from!(
    FunctionId,
    AdtId(StructId, EnumId, UnionId),
    TraitId,
    TypeAliasId,
    ImplId,
    EnumVariantId,
    ConstId
    for GenericDefId
);

impl From<AssocItemId> for GenericDefId {
    fn from(item: AssocItemId) -> Self {
        match item {
            AssocItemId::FunctionId(f) => f.into(),
            AssocItemId::ConstId(c) => c.into(),
            AssocItemId::TypeAliasId(t) => t.into(),
        }
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum AttrDefId {
    ModuleId(ModuleId),
    FieldId(FieldId),
    AdtId(AdtId),
    FunctionId(FunctionId),
    EnumVariantId(EnumVariantId),
    StaticId(StaticId),
    ConstId(ConstId),
    TraitId(TraitId),
    TypeAliasId(TypeAliasId),
    MacroDefId(MacroDefId),
    ImplId(ImplId),
    GenericParamId(GenericParamId),
}

impl_from!(
    ModuleId,
    FieldId,
    AdtId(StructId, EnumId, UnionId),
    EnumVariantId,
    StaticId,
    ConstId,
    FunctionId,
    TraitId,
    TypeAliasId,
    MacroDefId,
    ImplId,
    GenericParamId
    for AttrDefId
);

impl From<AssocContainerId> for AttrDefId {
    fn from(acid: AssocContainerId) -> Self {
        match acid {
            AssocContainerId::ModuleId(mid) => AttrDefId::ModuleId(mid),
            AssocContainerId::ImplId(iid) => AttrDefId::ImplId(iid),
            AssocContainerId::TraitId(tid) => AttrDefId::TraitId(tid),
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum VariantId {
    EnumVariantId(EnumVariantId),
    StructId(StructId),
    UnionId(UnionId),
}
impl_from!(EnumVariantId, StructId, UnionId for VariantId);

impl VariantId {
    pub fn variant_data(self, db: &dyn db::DefDatabase) -> Arc<VariantData> {
        match self {
            VariantId::StructId(it) => db.struct_data(it).variant_data.clone(),
            VariantId::UnionId(it) => db.union_data(it).variant_data.clone(),
            VariantId::EnumVariantId(it) => {
                db.enum_data(it.parent).variants[it.local_id].variant_data.clone()
            }
        }
    }

    pub fn file_id(self, db: &dyn db::DefDatabase) -> HirFileId {
        match self {
            VariantId::EnumVariantId(it) => it.parent.lookup(db).id.file_id(),
            VariantId::StructId(it) => it.lookup(db).id.file_id(),
            VariantId::UnionId(it) => it.lookup(db).id.file_id(),
        }
    }

    pub fn adt_id(self) -> AdtId {
        match self {
            VariantId::EnumVariantId(it) => it.parent.into(),
            VariantId::StructId(it) => it.into(),
            VariantId::UnionId(it) => it.into(),
        }
    }
}

trait Intern {
    type ID;
    fn intern(self, db: &dyn db::DefDatabase) -> Self::ID;
}

pub trait Lookup {
    type Data;
    fn lookup(&self, db: &dyn db::DefDatabase) -> Self::Data;
}

pub trait HasModule {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId;
}

impl HasModule for AssocContainerId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        match *self {
            AssocContainerId::ModuleId(it) => it,
            AssocContainerId::ImplId(it) => it.lookup(db).container,
            AssocContainerId::TraitId(it) => it.lookup(db).container,
        }
    }
}

impl<N: ItemTreeNode> HasModule for AssocItemLoc<N> {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        self.container.module(db)
    }
}

impl HasModule for AdtId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        match self {
            AdtId::StructId(it) => it.lookup(db).container,
            AdtId::UnionId(it) => it.lookup(db).container,
            AdtId::EnumId(it) => it.lookup(db).container,
        }
    }
}

impl HasModule for VariantId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        match self {
            VariantId::EnumVariantId(it) => it.parent.lookup(db).container,
            VariantId::StructId(it) => it.lookup(db).container,
            VariantId::UnionId(it) => it.lookup(db).container,
        }
    }
}

impl HasModule for DefWithBodyId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        match self {
            DefWithBodyId::FunctionId(it) => it.lookup(db).module(db),
            DefWithBodyId::StaticId(it) => it.lookup(db).module(db),
            DefWithBodyId::ConstId(it) => it.lookup(db).module(db),
        }
    }
}

impl DefWithBodyId {
    pub fn as_mod_item(self, db: &dyn db::DefDatabase) -> ModItem {
        match self {
            DefWithBodyId::FunctionId(it) => it.lookup(db).id.value.into(),
            DefWithBodyId::StaticId(it) => it.lookup(db).id.value.into(),
            DefWithBodyId::ConstId(it) => it.lookup(db).id.value.into(),
        }
    }
}

impl HasModule for GenericDefId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        match self {
            GenericDefId::FunctionId(it) => it.lookup(db).module(db),
            GenericDefId::AdtId(it) => it.module(db),
            GenericDefId::TraitId(it) => it.lookup(db).container,
            GenericDefId::TypeAliasId(it) => it.lookup(db).module(db),
            GenericDefId::ImplId(it) => it.lookup(db).container,
            GenericDefId::EnumVariantId(it) => it.parent.lookup(db).container,
            GenericDefId::ConstId(it) => it.lookup(db).module(db),
        }
    }
}

impl HasModule for TypeAliasId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        self.lookup(db).module(db)
    }
}

impl HasModule for TraitId {
    fn module(&self, db: &dyn db::DefDatabase) -> ModuleId {
        self.lookup(db).container
    }
}

impl HasModule for StaticLoc {
    fn module(&self, _db: &dyn db::DefDatabase) -> ModuleId {
        self.container
    }
}

impl ModuleDefId {
    /// Returns the module containing `self` (or `self`, if `self` is itself a module).
    ///
    /// Returns `None` if `self` refers to a primitive type.
    pub fn module(&self, db: &dyn db::DefDatabase) -> Option<ModuleId> {
        Some(match self {
            ModuleDefId::ModuleId(id) => *id,
            ModuleDefId::FunctionId(id) => id.lookup(db).module(db),
            ModuleDefId::AdtId(id) => id.module(db),
            ModuleDefId::EnumVariantId(id) => id.parent.lookup(db).container,
            ModuleDefId::ConstId(id) => id.lookup(db).container.module(db),
            ModuleDefId::StaticId(id) => id.lookup(db).container,
            ModuleDefId::TraitId(id) => id.lookup(db).container,
            ModuleDefId::TypeAliasId(id) => id.lookup(db).module(db),
            ModuleDefId::BuiltinType(_) => return None,
        })
    }
}

impl AttrDefId {
    pub fn krate(&self, db: &dyn db::DefDatabase) -> CrateId {
        match self {
            AttrDefId::ModuleId(it) => it.krate,
            AttrDefId::FieldId(it) => it.parent.module(db).krate,
            AttrDefId::AdtId(it) => it.module(db).krate,
            AttrDefId::FunctionId(it) => it.lookup(db).module(db).krate,
            AttrDefId::EnumVariantId(it) => it.parent.lookup(db).container.krate,
            AttrDefId::StaticId(it) => it.lookup(db).module(db).krate,
            AttrDefId::ConstId(it) => it.lookup(db).module(db).krate,
            AttrDefId::TraitId(it) => it.lookup(db).container.krate,
            AttrDefId::TypeAliasId(it) => it.lookup(db).module(db).krate,
            AttrDefId::ImplId(it) => it.lookup(db).container.krate,
            AttrDefId::GenericParamId(it) => {
                match it {
                    GenericParamId::TypeParamId(it) => it.parent,
                    GenericParamId::LifetimeParamId(it) => it.parent,
                    GenericParamId::ConstParamId(it) => it.parent,
                }
                .module(db)
                .krate
            }
            // FIXME: `MacroDefId` should store the defining module, then this can implement
            // `HasModule`
            AttrDefId::MacroDefId(it) => it.krate,
        }
    }
}

/// A helper trait for converting to MacroCallId
pub trait AsMacroCall {
    fn as_call_id(
        &self,
        db: &dyn db::DefDatabase,
        krate: CrateId,
        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
    ) -> Option<MacroCallId> {
        self.as_call_id_with_errors(db, krate, resolver, &mut |_| ()).ok()?.ok()
    }

    fn as_call_id_with_errors(
        &self,
        db: &dyn db::DefDatabase,
        krate: CrateId,
        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
        error_sink: &mut dyn FnMut(mbe::ExpandError),
    ) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro>;
}

impl AsMacroCall for InFile<&ast::MacroCall> {
    fn as_call_id_with_errors(
        &self,
        db: &dyn db::DefDatabase,
        krate: CrateId,
        resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
        mut error_sink: &mut dyn FnMut(mbe::ExpandError),
    ) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
        let expands_to = hir_expand::ExpandTo::from_call_site(self.value);
        let ast_id = AstId::new(self.file_id, db.ast_id_map(self.file_id).ast_id(self.value));
        let h = Hygiene::new(db.upcast(), self.file_id);
        let path = self.value.path().and_then(|path| path::ModPath::from_src(db, path, &h));

        let path = match error_sink
            .option(path, || mbe::ExpandError::Other("malformed macro invocation".into()))
        {
            Ok(path) => path,
            Err(error) => {
                return Ok(Err(error));
            }
        };

        macro_call_as_call_id(
            &AstIdWithPath::new(ast_id.file_id, ast_id.value, path),
            expands_to,
            db,
            krate,
            resolver,
            error_sink,
        )
    }
}

/// Helper wrapper for `AstId` with `ModPath`
#[derive(Clone, Debug, Eq, PartialEq)]
struct AstIdWithPath<T: ast::AstNode> {
    ast_id: AstId<T>,
    path: path::ModPath,
}

impl<T: ast::AstNode> AstIdWithPath<T> {
    fn new(file_id: HirFileId, ast_id: FileAstId<T>, path: path::ModPath) -> AstIdWithPath<T> {
        AstIdWithPath { ast_id: AstId::new(file_id, ast_id), path }
    }
}

#[derive(Debug)]
pub struct UnresolvedMacro {
    pub path: ModPath,
}

fn macro_call_as_call_id(
    call: &AstIdWithPath<ast::MacroCall>,
    expand_to: ExpandTo,
    db: &dyn db::DefDatabase,
    krate: CrateId,
    resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
    error_sink: &mut dyn FnMut(mbe::ExpandError),
) -> Result<Result<MacroCallId, ErrorEmitted>, UnresolvedMacro> {
    let def: MacroDefId =
        resolver(call.path.clone()).ok_or_else(|| UnresolvedMacro { path: call.path.clone() })?;

    let res = if let MacroDefKind::BuiltInEager(..) = def.kind {
        let macro_call = InFile::new(call.ast_id.file_id, call.ast_id.to_node(db.upcast()));
        let hygiene = Hygiene::new(db.upcast(), call.ast_id.file_id);

        expand_eager_macro(
            db.upcast(),
            krate,
            macro_call,
            def,
            &|path: ast::Path| resolver(path::ModPath::from_src(db, path, &hygiene)?),
            error_sink,
        )
    } else {
        Ok(def.as_lazy_macro(
            db.upcast(),
            krate,
            MacroCallKind::FnLike { ast_id: call.ast_id, expand_to },
        ))
    };
    Ok(res)
}

fn derive_macro_as_call_id(
    item_attr: &AstIdWithPath<ast::Item>,
    derive_attr: AttrId,
    db: &dyn db::DefDatabase,
    krate: CrateId,
    resolver: impl Fn(path::ModPath) -> Option<MacroDefId>,
) -> Result<MacroCallId, UnresolvedMacro> {
    let def: MacroDefId = resolver(item_attr.path.clone())
        .ok_or_else(|| UnresolvedMacro { path: item_attr.path.clone() })?;
    let last_segment = item_attr
        .path
        .segments()
        .last()
        .ok_or_else(|| UnresolvedMacro { path: item_attr.path.clone() })?;
    let res = def.as_lazy_macro(
        db.upcast(),
        krate,
        MacroCallKind::Derive {
            ast_id: item_attr.ast_id,
            derive_name: last_segment.to_string().into_boxed_str(),
            derive_attr_index: derive_attr.ast_index,
        },
    );
    Ok(res)
}

fn attr_macro_as_call_id(
    item_attr: &AstIdWithPath<ast::Item>,
    macro_attr: &Attr,
    db: &dyn db::DefDatabase,
    krate: CrateId,
    def: Option<MacroDefId>,
) -> Result<MacroCallId, UnresolvedMacro> {
    let attr_path = &item_attr.path;
    let def = def.ok_or_else(|| UnresolvedMacro { path: attr_path.clone() })?;
    let last_segment =
        attr_path.segments().last().ok_or_else(|| UnresolvedMacro { path: attr_path.clone() })?;
    let mut arg = match macro_attr.input.as_deref() {
        Some(attr::AttrInput::TokenTree(tt, map)) => (tt.clone(), map.clone()),
        _ => Default::default(),
    };

    // The parentheses are always disposed here.
    arg.0.delimiter = None;

    let res = def.as_lazy_macro(
        db.upcast(),
        krate,
        MacroCallKind::Attr {
            ast_id: item_attr.ast_id,
            attr_name: last_segment.to_string().into_boxed_str(),
            attr_args: arg,
            invoc_attr_index: macro_attr.id.ast_index,
        },
    );
    Ok(res)
}