diff options
Diffstat (limited to 'crates/ra_hir_expand/src/builtin_derive.rs')
-rw-r--r-- | crates/ra_hir_expand/src/builtin_derive.rs | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/crates/ra_hir_expand/src/builtin_derive.rs b/crates/ra_hir_expand/src/builtin_derive.rs new file mode 100644 index 000000000..0a70c63c0 --- /dev/null +++ b/crates/ra_hir_expand/src/builtin_derive.rs | |||
@@ -0,0 +1,64 @@ | |||
1 | //! Builtin derives. | ||
2 | use crate::db::AstDatabase; | ||
3 | use crate::{name, MacroCallId, MacroDefId, MacroDefKind}; | ||
4 | |||
5 | use crate::quote; | ||
6 | |||
7 | macro_rules! register_builtin { | ||
8 | ( $(($name:ident, $kind: ident) => $expand:ident),* ) => { | ||
9 | #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] | ||
10 | pub enum BuiltinDeriveExpander { | ||
11 | $($kind),* | ||
12 | } | ||
13 | |||
14 | impl BuiltinDeriveExpander { | ||
15 | pub fn expand( | ||
16 | &self, | ||
17 | db: &dyn AstDatabase, | ||
18 | id: MacroCallId, | ||
19 | tt: &tt::Subtree, | ||
20 | ) -> Result<tt::Subtree, mbe::ExpandError> { | ||
21 | let expander = match *self { | ||
22 | $( BuiltinDeriveExpander::$kind => $expand, )* | ||
23 | }; | ||
24 | expander(db, id, tt) | ||
25 | } | ||
26 | } | ||
27 | |||
28 | pub fn find_builtin_derive(ident: &name::Name) -> Option<MacroDefId> { | ||
29 | let kind = match ident { | ||
30 | $( id if id == &name::$name => BuiltinDeriveExpander::$kind, )* | ||
31 | _ => return None, | ||
32 | }; | ||
33 | |||
34 | Some(MacroDefId { krate: None, ast_id: None, kind: MacroDefKind::BuiltInDerive(kind) }) | ||
35 | } | ||
36 | }; | ||
37 | } | ||
38 | |||
39 | register_builtin! { | ||
40 | (COPY_TRAIT, Copy) => copy_expand, | ||
41 | (CLONE_TRAIT, Clone) => clone_expand | ||
42 | } | ||
43 | |||
44 | fn copy_expand( | ||
45 | _db: &dyn AstDatabase, | ||
46 | _id: MacroCallId, | ||
47 | _tt: &tt::Subtree, | ||
48 | ) -> Result<tt::Subtree, mbe::ExpandError> { | ||
49 | let expanded = quote! { | ||
50 | impl Copy for Foo {} | ||
51 | }; | ||
52 | Ok(expanded) | ||
53 | } | ||
54 | |||
55 | fn clone_expand( | ||
56 | _db: &dyn AstDatabase, | ||
57 | _id: MacroCallId, | ||
58 | _tt: &tt::Subtree, | ||
59 | ) -> Result<tt::Subtree, mbe::ExpandError> { | ||
60 | let expanded = quote! { | ||
61 | impl Clone for Foo {} | ||
62 | }; | ||
63 | Ok(expanded) | ||
64 | } | ||