hir_def/
src.rs

1//! Utilities for mapping between hir IDs and the surface syntax.
2
3use base_db::SourceDatabase;
4use either::Either;
5use hir_expand::{AstId, InFile};
6use la_arena::{Arena, ArenaMap, Idx};
7use syntax::{AstNode, AstPtr, ast};
8
9use crate::{
10    AstIdLoc, GenericDefId, LocalFieldId, LocalLifetimeParamId, LocalTypeOrConstParamId, Lookup,
11    UseId, VariantId, attrs::AttrFlags, hir::generics::GenericParams,
12};
13
14pub trait HasSource {
15    type Value: AstNode;
16    fn source(&self, db: &dyn SourceDatabase) -> InFile<Self::Value> {
17        let InFile { file_id, value } = self.ast_ptr(db);
18        InFile::new(file_id, value.to_node(&file_id.parse_or_expand(db)))
19    }
20    fn ast_ptr(&self, db: &dyn SourceDatabase) -> InFile<AstPtr<Self::Value>>;
21}
22
23impl<T> HasSource for T
24where
25    T: AstIdLoc,
26{
27    type Value = T::Ast;
28    fn ast_ptr(&self, db: &dyn SourceDatabase) -> InFile<AstPtr<Self::Value>> {
29        let id = self.ast_id();
30        let ast_id_map = id.file_id.ast_id_map(db);
31        InFile::new(id.file_id, ast_id_map.get(id.value))
32    }
33}
34
35pub trait HasChildSource<ChildId> {
36    type Value;
37    fn child_source(&self, db: &dyn SourceDatabase) -> InFile<ArenaMap<ChildId, Self::Value>>;
38}
39
40/// Maps a `UseTree` contained in this import back to its AST node.
41pub fn use_tree_to_ast(
42    db: &dyn SourceDatabase,
43    use_ast_id: AstId<ast::Use>,
44    index: Idx<ast::UseTree>,
45) -> ast::UseTree {
46    use_tree_source_map(db, use_ast_id)[index].clone()
47}
48
49/// Maps a `UseTree` contained in this import back to its AST node.
50fn use_tree_source_map(
51    db: &dyn SourceDatabase,
52    use_ast_id: AstId<ast::Use>,
53) -> Arena<ast::UseTree> {
54    // Re-lower the AST item and get the source map.
55    // Note: The AST unwraps are fine, since if they fail we should have never obtained `index`.
56    let ast = use_ast_id.to_node(db);
57    let ast_use_tree = ast.use_tree().expect("missing `use_tree`");
58    let mut span_map = None;
59    crate::item_tree::lower_use_tree(db, ast_use_tree, &mut |range| {
60        span_map.get_or_insert_with(|| use_ast_id.file_id.span_map(db)).span_for_range(range).ctx
61    })
62    .expect("failed to lower use tree")
63    .1
64}
65
66impl HasChildSource<la_arena::Idx<ast::UseTree>> for UseId {
67    type Value = ast::UseTree;
68    fn child_source(
69        &self,
70        db: &dyn SourceDatabase,
71    ) -> InFile<ArenaMap<la_arena::Idx<ast::UseTree>, Self::Value>> {
72        let loc = self.lookup(db);
73        InFile::new(loc.id.file_id, use_tree_source_map(db, loc.id).into_iter().collect())
74    }
75}
76
77impl HasChildSource<LocalTypeOrConstParamId> for GenericDefId {
78    type Value = Either<ast::TypeOrConstParam, ast::Trait>;
79    fn child_source(
80        &self,
81        db: &dyn SourceDatabase,
82    ) -> InFile<ArenaMap<LocalTypeOrConstParamId, Self::Value>> {
83        let generic_params = GenericParams::of(db, *self);
84        let mut idx_iter = generic_params.iter_type_or_consts().map(|(idx, _)| idx);
85
86        let (file_id, generic_params_list) = self.file_id_and_params_of(db);
87
88        let mut params = ArenaMap::default();
89
90        // For traits and trait aliases the first type index is `Self`, we need to add it before
91        // the other params.
92        match *self {
93            GenericDefId::TraitId(id) => {
94                let trait_ref = id.lookup(db).source(db).value;
95                let idx = idx_iter.next().unwrap();
96                params.insert(idx, Either::Right(trait_ref));
97            }
98            _ => {}
99        }
100
101        if let Some(generic_params_list) = generic_params_list {
102            for (idx, ast_param) in idx_iter.zip(generic_params_list.type_or_const_params()) {
103                params.insert(idx, Either::Left(ast_param));
104            }
105        }
106
107        InFile::new(file_id, params)
108    }
109}
110
111impl HasChildSource<LocalLifetimeParamId> for GenericDefId {
112    type Value = ast::LifetimeParam;
113    fn child_source(
114        &self,
115        db: &dyn SourceDatabase,
116    ) -> InFile<ArenaMap<LocalLifetimeParamId, Self::Value>> {
117        let generic_params = GenericParams::of(db, *self);
118        let idx_iter = generic_params.iter_lt().map(|(idx, _)| idx);
119
120        let (file_id, generic_params_list) = self.file_id_and_params_of(db);
121
122        let mut params = ArenaMap::default();
123
124        if let Some(generic_params_list) = generic_params_list {
125            for (idx, ast_param) in idx_iter.zip(generic_params_list.lifetime_params()) {
126                params.insert(idx, ast_param);
127            }
128        }
129
130        InFile::new(file_id, params)
131    }
132}
133
134impl HasChildSource<LocalFieldId> for VariantId {
135    type Value = Either<ast::TupleField, ast::RecordField>;
136
137    fn child_source(&self, db: &dyn SourceDatabase) -> InFile<ArenaMap<LocalFieldId, Self::Value>> {
138        let (src, container) = match *self {
139            VariantId::EnumVariantId(it) => {
140                let lookup = it.lookup(db);
141                (lookup.source(db).map(|it| it.kind()), lookup.parent.lookup(db).container)
142            }
143            VariantId::StructId(it) => {
144                let lookup = it.lookup(db);
145                (lookup.source(db).map(|it| it.kind()), lookup.container)
146            }
147            VariantId::UnionId(it) => {
148                let lookup = it.lookup(db);
149                (lookup.source(db).map(|it| it.kind()), lookup.container)
150            }
151        };
152        let mut map = ArenaMap::new();
153        match &src.value {
154            ast::StructKind::Tuple(fl) => {
155                let cfg_options = container.krate(db).cfg_options(db);
156                let mut idx = 0;
157                for fd in fl.fields() {
158                    let enabled = AttrFlags::is_cfg_enabled_for(&fd, cfg_options).is_ok();
159                    if !enabled {
160                        continue;
161                    }
162                    map.insert(
163                        LocalFieldId::from_raw(la_arena::RawIdx::from(idx)),
164                        Either::Left(fd.clone()),
165                    );
166                    idx += 1;
167                }
168            }
169            ast::StructKind::Record(fl) => {
170                let cfg_options = container.krate(db).cfg_options(db);
171                let mut idx = 0;
172                for fd in fl.fields() {
173                    let enabled = AttrFlags::is_cfg_enabled_for(&fd, cfg_options).is_ok();
174                    if !enabled {
175                        continue;
176                    }
177                    map.insert(
178                        LocalFieldId::from_raw(la_arena::RawIdx::from(idx)),
179                        Either::Right(fd.clone()),
180                    );
181                    idx += 1;
182                }
183            }
184            ast::StructKind::Unit => (),
185        }
186        InFile::new(src.file_id, map)
187    }
188}
hir_def/src.rs

hir_def/
src.rs
