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Use `ManuallyDrop` in `RootDatabase`
| -rw-r--r-- | crates/ide_db/src/lib.rs | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/crates/ide_db/src/lib.rs b/crates/ide_db/src/lib.rs index bde8767dd6..384b66d81c 100644 --- a/crates/ide_db/src/lib.rs +++ b/crates/ide_db/src/lib.rs @@ -19,7 +19,7 @@ pub mod path_transform; pub mod search; pub mod rename; -use std::{fmt, sync::Arc}; +use std::{fmt, mem::ManuallyDrop, sync::Arc}; use base_db::{ salsa::{self, Durability}, @@ -44,7 +44,19 @@ pub use base_db; hir::db::HirDatabaseStorage )] pub struct RootDatabase { - storage: salsa::Storage<RootDatabase>, + // We use `ManuallyDrop` here because every codegen unit that contains a + // `&RootDatabase -> &dyn OtherDatabase` cast will instantiate its drop glue in the vtable, + // which duplicates `Weak::drop` and `Arc::drop` tens of thousands of times, which makes + // compile times of all `ide_*` and downstream crates suffer greatly. + storage: ManuallyDrop<salsa::Storage<RootDatabase>>, +} + +impl Drop for RootDatabase { + fn drop(&mut self) { + unsafe { + ManuallyDrop::drop(&mut self.storage); + } + } } impl fmt::Debug for RootDatabase { @@ -93,7 +105,7 @@ impl Default for RootDatabase { impl RootDatabase { pub fn new(lru_capacity: Option<usize>) -> RootDatabase { - let mut db = RootDatabase { storage: salsa::Storage::default() }; + let mut db = RootDatabase { storage: ManuallyDrop::new(salsa::Storage::default()) }; db.set_crate_graph_with_durability(Default::default(), Durability::HIGH); db.set_local_roots_with_durability(Default::default(), Durability::HIGH); db.set_library_roots_with_durability(Default::default(), Durability::HIGH); @@ -112,7 +124,7 @@ impl RootDatabase { impl salsa::ParallelDatabase for RootDatabase { fn snapshot(&self) -> salsa::Snapshot<RootDatabase> { - salsa::Snapshot::new(RootDatabase { storage: self.storage.snapshot() }) + salsa::Snapshot::new(RootDatabase { storage: ManuallyDrop::new(self.storage.snapshot()) }) } } |