bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir_expand/src/builtin_attr_macro.rs')
-rw-r--r--crates/hir_expand/src/builtin_attr_macro.rs68
1 files changed, 68 insertions, 0 deletions
diff --git a/crates/hir_expand/src/builtin_attr_macro.rs b/crates/hir_expand/src/builtin_attr_macro.rs
new file mode 100644
index 0000000000..2e461864a0
--- /dev/null
+++ b/crates/hir_expand/src/builtin_attr_macro.rs
@@ -0,0 +1,68 @@
+//! Builtin attributes.
+
+use mbe::ExpandResult;
+use syntax::ast;
+
+use crate::{db::AstDatabase, name, AstId, CrateId, MacroCallId, MacroDefId, MacroDefKind};
+
+macro_rules! register_builtin {
+ ( $(($name:ident, $variant:ident) => $expand:ident),* ) => {
+ #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+ pub enum BuiltinAttrExpander {
+ $($variant),*
+ }
+
+ impl BuiltinAttrExpander {
+ pub fn expand(
+ &self,
+ db: &dyn AstDatabase,
+ id: MacroCallId,
+ tt: &tt::Subtree,
+ ) -> ExpandResult<tt::Subtree> {
+ let expander = match *self {
+ $( BuiltinAttrExpander::$variant => $expand, )*
+ };
+ expander(db, id, tt)
+ }
+
+ fn find_by_name(name: &name::Name) -> Option<Self> {
+ match name {
+ $( id if id == &name::name![$name] => Some(BuiltinAttrExpander::$variant), )*
+ _ => None,
+ }
+ }
+ }
+
+ };
+}
+
+register_builtin! {
+ (bench, Bench) => dummy_attr_expand,
+ (cfg_accessible, CfgAccessible) => dummy_attr_expand,
+ (cfg_eval, CfgEval) => dummy_attr_expand,
+ (derive, Derive) => dummy_attr_expand,
+ (global_allocator, GlobalAllocator) => dummy_attr_expand,
+ (test, Test) => dummy_attr_expand,
+ (test_case, TestCase) => dummy_attr_expand
+}
+
+pub fn find_builtin_attr(
+ ident: &name::Name,
+ krate: CrateId,
+ ast_id: AstId<ast::Macro>,
+) -> Option<MacroDefId> {
+ let expander = BuiltinAttrExpander::find_by_name(ident)?;
+ Some(MacroDefId {
+ krate,
+ kind: MacroDefKind::BuiltInAttr(expander, ast_id),
+ local_inner: false,
+ })
+}
+
+fn dummy_attr_expand(
+ _db: &dyn AstDatabase,
+ _id: MacroCallId,
+ tt: &tt::Subtree,
+) -> ExpandResult<tt::Subtree> {
+ ExpandResult::ok(tt.clone())
+}