hir_def/
src.rs

1//! Utilities for mapping between hir IDs and the surface syntax.
2
3use either::Either;
4use hir_expand::{AstId, InFile};
5use la_arena::{Arena, ArenaMap, Idx};
6use syntax::{AstNode, AstPtr, ast};
7
8use crate::{
9    AstIdLoc, GenericDefId, LocalFieldId, LocalLifetimeParamId, LocalTypeOrConstParamId, Lookup,
10    UseId, VariantId, attr::Attrs, db::DefDatabase,
11};
12
13pub trait HasSource {
14    type Value: AstNode;
15    fn source(&self, db: &dyn DefDatabase) -> InFile<Self::Value> {
16        let InFile { file_id, value } = self.ast_ptr(db);
17        InFile::new(file_id, value.to_node(&db.parse_or_expand(file_id)))
18    }
19    fn ast_ptr(&self, db: &dyn DefDatabase) -> InFile<AstPtr<Self::Value>>;
20}
21
22impl<T> HasSource for T
23where
24    T: AstIdLoc,
25{
26    type Value = T::Ast;
27    fn ast_ptr(&self, db: &dyn DefDatabase) -> InFile<AstPtr<Self::Value>> {
28        let id = self.ast_id();
29        let ast_id_map = db.ast_id_map(id.file_id);
30        InFile::new(id.file_id, ast_id_map.get(id.value))
31    }
32}
33
34pub trait HasChildSource<ChildId> {
35    type Value;
36    fn child_source(&self, db: &dyn DefDatabase) -> InFile<ArenaMap<ChildId, Self::Value>>;
37}
38
39/// Maps a `UseTree` contained in this import back to its AST node.
40pub fn use_tree_to_ast(
41    db: &dyn DefDatabase,
42    use_ast_id: AstId<ast::Use>,
43    index: Idx<ast::UseTree>,
44) -> ast::UseTree {
45    use_tree_source_map(db, use_ast_id)[index].clone()
46}
47
48/// Maps a `UseTree` contained in this import back to its AST node.
49fn use_tree_source_map(db: &dyn DefDatabase, use_ast_id: AstId<ast::Use>) -> Arena<ast::UseTree> {
50    // Re-lower the AST item and get the source map.
51    // Note: The AST unwraps are fine, since if they fail we should have never obtained `index`.
52    let ast = use_ast_id.to_node(db);
53    let ast_use_tree = ast.use_tree().expect("missing `use_tree`");
54    let mut span_map = None;
55    crate::item_tree::lower_use_tree(db, ast_use_tree, &mut |range| {
56        span_map.get_or_insert_with(|| db.span_map(use_ast_id.file_id)).span_for_range(range).ctx
57    })
58    .expect("failed to lower use tree")
59    .1
60}
61
62impl HasChildSource<la_arena::Idx<ast::UseTree>> for UseId {
63    type Value = ast::UseTree;
64    fn child_source(
65        &self,
66        db: &dyn DefDatabase,
67    ) -> InFile<ArenaMap<la_arena::Idx<ast::UseTree>, Self::Value>> {
68        let loc = self.lookup(db);
69        InFile::new(loc.id.file_id, use_tree_source_map(db, loc.id).into_iter().collect())
70    }
71}
72
73impl HasChildSource<LocalTypeOrConstParamId> for GenericDefId {
74    type Value = Either<ast::TypeOrConstParam, ast::Trait>;
75    fn child_source(
76        &self,
77        db: &dyn DefDatabase,
78    ) -> InFile<ArenaMap<LocalTypeOrConstParamId, Self::Value>> {
79        let generic_params = db.generic_params(*self);
80        let mut idx_iter = generic_params.iter_type_or_consts().map(|(idx, _)| idx);
81
82        let (file_id, generic_params_list) = self.file_id_and_params_of(db);
83
84        let mut params = ArenaMap::default();
85
86        // For traits and trait aliases the first type index is `Self`, we need to add it before
87        // the other params.
88        match *self {
89            GenericDefId::TraitId(id) => {
90                let trait_ref = id.lookup(db).source(db).value;
91                let idx = idx_iter.next().unwrap();
92                params.insert(idx, Either::Right(trait_ref));
93            }
94            _ => {}
95        }
96
97        if let Some(generic_params_list) = generic_params_list {
98            for (idx, ast_param) in idx_iter.zip(generic_params_list.type_or_const_params()) {
99                params.insert(idx, Either::Left(ast_param));
100            }
101        }
102
103        InFile::new(file_id, params)
104    }
105}
106
107impl HasChildSource<LocalLifetimeParamId> for GenericDefId {
108    type Value = ast::LifetimeParam;
109    fn child_source(
110        &self,
111        db: &dyn DefDatabase,
112    ) -> InFile<ArenaMap<LocalLifetimeParamId, Self::Value>> {
113        let generic_params = db.generic_params(*self);
114        let idx_iter = generic_params.iter_lt().map(|(idx, _)| idx);
115
116        let (file_id, generic_params_list) = self.file_id_and_params_of(db);
117
118        let mut params = ArenaMap::default();
119
120        if let Some(generic_params_list) = generic_params_list {
121            for (idx, ast_param) in idx_iter.zip(generic_params_list.lifetime_params()) {
122                params.insert(idx, ast_param);
123            }
124        }
125
126        InFile::new(file_id, params)
127    }
128}
129
130impl HasChildSource<LocalFieldId> for VariantId {
131    type Value = Either<ast::TupleField, ast::RecordField>;
132
133    fn child_source(&self, db: &dyn DefDatabase) -> InFile<ArenaMap<LocalFieldId, Self::Value>> {
134        let (src, container) = match *self {
135            VariantId::EnumVariantId(it) => {
136                let lookup = it.lookup(db);
137                (lookup.source(db).map(|it| it.kind()), lookup.parent.lookup(db).container)
138            }
139            VariantId::StructId(it) => {
140                let lookup = it.lookup(db);
141                (lookup.source(db).map(|it| it.kind()), lookup.container)
142            }
143            VariantId::UnionId(it) => {
144                let lookup = it.lookup(db);
145                (lookup.source(db).map(|it| it.kind()), lookup.container)
146            }
147        };
148        let span_map = db.span_map(src.file_id);
149        let mut map = ArenaMap::new();
150        match &src.value {
151            ast::StructKind::Tuple(fl) => {
152                let cfg_options = container.krate.cfg_options(db);
153                let mut idx = 0;
154                for fd in fl.fields() {
155                    let enabled =
156                        Attrs::is_cfg_enabled_for(db, &fd, span_map.as_ref(), cfg_options).is_ok();
157                    if !enabled {
158                        continue;
159                    }
160                    map.insert(
161                        LocalFieldId::from_raw(la_arena::RawIdx::from(idx)),
162                        Either::Left(fd.clone()),
163                    );
164                    idx += 1;
165                }
166            }
167            ast::StructKind::Record(fl) => {
168                let cfg_options = container.krate.cfg_options(db);
169                let mut idx = 0;
170                for fd in fl.fields() {
171                    let enabled =
172                        Attrs::is_cfg_enabled_for(db, &fd, span_map.as_ref(), cfg_options).is_ok();
173                    if !enabled {
174                        continue;
175                    }
176                    map.insert(
177                        LocalFieldId::from_raw(la_arena::RawIdx::from(idx)),
178                        Either::Right(fd.clone()),
179                    );
180                    idx += 1;
181                }
182            }
183            ast::StructKind::Unit => (),
184        }
185        InFile::new(src.file_id, map)
186    }
187}
hir_def/src.rs

hir_def/
src.rs
