bendns' repos / rust-analyzer
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Diffstat
-rw-r--r--crates/hir-def/src/generics.rs53
1 files changed, 42 insertions, 11 deletions
diff --git a/crates/hir-def/src/generics.rs b/crates/hir-def/src/generics.rs
index b0fb27e81d..540fa115a0 100644
--- a/crates/hir-def/src/generics.rs
+++ b/crates/hir-def/src/generics.rs
@@ -159,17 +159,47 @@ impl GenericParams {
let krate = def.module(db).krate;
let cfg_options = db.crate_graph();
let cfg_options = &cfg_options[krate].cfg_options;
- let enabled_params = |params: &GenericParams, item_tree: &ItemTree| {
+
+ // Returns the generic parameters that are enabled under the current `#[cfg]` options
+ let enabled_params = |params: &Interned<GenericParams>, item_tree: &ItemTree| {
let enabled = |param| item_tree.attrs(db, krate, param).is_cfg_enabled(cfg_options);
- Interned::new(GenericParams {
- type_or_consts: (params.type_or_consts.iter())
- .filter_map(|(idx, param)| enabled(idx.into()).then(|| param.clone()))
- .collect(),
- lifetimes: (params.lifetimes.iter())
- .filter_map(|(idx, param)| enabled(idx.into()).then(|| param.clone()))
- .collect(),
- where_predicates: params.where_predicates.clone(),
- })
+
+ // In the common case, no parameters will by disabled by `#[cfg]` attributes.
+ // Therefore, make a first pass to check if all parameters are enabled and, if so,
+ // clone the `Interned<GenericParams>` instead of recreating an identical copy.
+ let all_type_or_consts_enabled =
+ params.type_or_consts.iter().all(|(idx, _)| enabled(idx.into()));
+ let all_lifetimes_enabled = params.lifetimes.iter().all(|(idx, _)| enabled(idx.into()));
+
+ if all_type_or_consts_enabled && all_lifetimes_enabled {
+ params.clone()
+ } else {
+ Interned::new(GenericParams {
+ type_or_consts: all_type_or_consts_enabled
+ .then(|| params.type_or_consts.clone())
+ .unwrap_or_else(|| {
+ params
+ .type_or_consts
+ .iter()
+ .filter_map(|(idx, param)| {
+ enabled(idx.into()).then(|| param.clone())
+ })
+ .collect()
+ }),
+ lifetimes: all_lifetimes_enabled
+ .then(|| params.lifetimes.clone())
+ .unwrap_or_else(|| {
+ params
+ .lifetimes
+ .iter()
+ .filter_map(|(idx, param)| {
+ enabled(idx.into()).then(|| param.clone())
+ })
+ .collect()
+ }),
+ where_predicates: params.where_predicates.clone(),
+ })
+ }
};
macro_rules! id_to_generics {
($id:ident) => {{
@@ -186,7 +216,8 @@ impl GenericParams {
let tree = loc.id.item_tree(db);
let item = &tree[loc.id.value];
- let mut generic_params = GenericParams::clone(&item.explicit_generic_params);
+ let enabled_params = enabled_params(&item.explicit_generic_params, &tree);
+ let mut generic_params = GenericParams::clone(&enabled_params);
let module = loc.container.module(db);
let func_data = db.function_data(id);