From 0bbe345ad637305d84015dafe51a70fe623f72c9 Mon Sep 17 00:00:00 2001
From: Weidong Cui <wdcui@microsoft.com>
Date: Mon, 6 Apr 2026 21:19:41 -0700
Subject: [PATCH] Add trace_fs feature gate for conditional DebugLogProvider
 bound

Add trace_fs feature to litebox Cargo.toml. When enabled (without
lock_tracing), RawSyncPrimitivesProvider additionally requires
DebugLogProvider, allowing filesystem tracing code to log through
the platform's debug output.
---
 litebox/Cargo.toml      |  1 +
 litebox/src/sync/mod.rs | 22 ++++++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/litebox/Cargo.toml b/litebox/Cargo.toml
index 9a8b2e401..8d3e59eed 100644
--- a/litebox/Cargo.toml
+++ b/litebox/Cargo.toml
@@ -31,6 +31,7 @@ windows-sys = { version = "0.60.2", features = [
 
 [features]
 lock_tracing = ["dep:arrayvec", "spin/mutex"]
+trace_fs = []
 panic_on_unclosed_fd_drop = []
 enforce_singleton_litebox_instance = []
 
diff --git a/litebox/src/sync/mod.rs b/litebox/src/sync/mod.rs
index 0778d6d15..54ba89945 100644
--- a/litebox/src/sync/mod.rs
+++ b/litebox/src/sync/mod.rs
@@ -29,15 +29,33 @@ pub use rwlock::{
     MappedRwLockReadGuard, MappedRwLockWriteGuard, RwLock, RwLockReadGuard, RwLockWriteGuard,
 };
 
-#[cfg(not(feature = "lock_tracing"))]
+#[cfg(not(any(feature = "lock_tracing", feature = "trace_fs")))]
 /// A convenience name for specific requirements from the platform
 pub trait RawSyncPrimitivesProvider: platform::RawMutexProvider + Sync + 'static {}
-#[cfg(not(feature = "lock_tracing"))]
+#[cfg(not(any(feature = "lock_tracing", feature = "trace_fs")))]
 impl<Platform> RawSyncPrimitivesProvider for Platform where
     Platform: platform::RawMutexProvider + Sync + 'static
 {
 }
 
+// When `trace_fs` is enabled, filesystem tracing code logs through
+// `DebugLogProvider`. Since the platform type is threaded through
+// `RawSyncPrimitivesProvider` in fs-related contexts, the bound is added here
+// so it is available wherever the platform is used. `lock_tracing` already
+// includes `DebugLogProvider`, so this branch only applies when `trace_fs` is
+// enabled without `lock_tracing`.
+#[cfg(all(feature = "trace_fs", not(feature = "lock_tracing")))]
+/// A convenience name for specific requirements from the platform
+pub trait RawSyncPrimitivesProvider:
+    platform::RawMutexProvider + platform::DebugLogProvider + Sync + 'static
+{
+}
+#[cfg(all(feature = "trace_fs", not(feature = "lock_tracing")))]
+impl<Platform> RawSyncPrimitivesProvider for Platform where
+    Platform: platform::RawMutexProvider + platform::DebugLogProvider + Sync + 'static
+{
+}
+
 #[cfg(feature = "lock_tracing")]
 /// A convenience name for specific requirements from the platform
 pub trait RawSyncPrimitivesProvider: