From 83d320c2ead82632cb2188448242880f558278f5 Mon Sep 17 00:00:00 2001
From: Hanyu Deng <deng_hanyu@apple.com>
Date: Thu, 10 Apr 2025 12:00:52 +0800
Subject: [PATCH] Remove static initializer InTracing::trace_stack

---
 mlx/transforms.cpp    |  5 ++++-
 mlx/transforms_impl.h | 10 +++++-----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/mlx/transforms.cpp b/mlx/transforms.cpp
index b305257f0..4c462a74f 100644
--- a/mlx/transforms.cpp
+++ b/mlx/transforms.cpp
@@ -42,7 +42,10 @@ class Synchronizer : public Primitive {
 // are currently under a function transformation and the retain_graph()
 // function which returns true if we are forced to retain the graph during
 // evaluation.
-std::vector<std::pair<char, char>> detail::InTracing::trace_stack{};
+std::vector<char>& detail::InTracing::trace_stack() {
+  static std::vector<char> trace_stack_;
+  return trace_stack_;
+}
 int detail::InTracing::grad_counter{0};
 int detail::RetainGraph::tracing_counter{0};
 
diff --git a/mlx/transforms_impl.h b/mlx/transforms_impl.h
index 7f62c406b..f61b25c56 100644
--- a/mlx/transforms_impl.h
+++ b/mlx/transforms_impl.h
@@ -22,19 +22,19 @@ std::vector<array> vmap_replace(
 struct InTracing {
   explicit InTracing(bool dynamic = false, bool grad = false) {
     grad_counter += grad;
-    trace_stack.push_back({dynamic, grad});
+    trace_stack().push_back({dynamic, grad});
   }
   ~InTracing() {
-    grad_counter -= trace_stack.back().second;
+    grad_counter -= trace_stack().back().second;
     trace_stack.pop_back();
   }
 
   static bool in_tracing() {
-    return !trace_stack.empty();
+    return !trace_stack().empty();
   }
   static bool in_dynamic_tracing() {
     // compile is always and only the outer-most transform
-    return in_tracing() && trace_stack.front().first;
+    return in_tracing() && trace_stack().front().first;
   }
 
   static bool in_grad_tracing() {
@@ -43,7 +43,7 @@ struct InTracing {
 
  private:
   static int grad_counter;
-  static std::vector<std::pair<char, char>> trace_stack;
+  static std::vector<char>& trace_stack();
 };
 
 struct RetainGraph {