Let noexcept StaticSingletonManager::create be outline

Summary: [Folly] Let `noexcept` member function template `StaticSingletonManager::create` be outline to avoid pathological inline path behavior.

Reviewed By: iahs

Differential Revision: D23522488

fbshipit-source-id: 5ec9ed271b814f4496812e226e0f0929f65565a2

folly/detail/StaticSingletonManager.cpp

@@ -28,11 +28,13 @@ namespace {
 class StaticSingletonManagerWithRttiImpl {
  public:
   using Make = void*();
-  using Cache = std::atomic<void*>;
 
-  void* create(std::type_info const& key, Make& make, Cache& cache) {
-    auto const ptr = entry(key).get(make);
-    cache.store(ptr, std::memory_order_release);
+  template <typename Arg>
+  static void* create(Arg& arg) {
+    // This Leaky Meyers Singleton must always live in the .cpp file.
+    static auto& instance = *new StaticSingletonManagerWithRttiImpl();
+    auto const ptr = instance.entry(*arg.key).get(arg.make);
+    arg.cache.store(ptr, std::memory_order_release);
     return ptr;
   }
 
@@ -59,11 +61,13 @@ class StaticSingletonManagerWithRttiImpl {
 
 } // namespace
 
-void* StaticSingletonManagerWithRtti::create_(Arg& arg) {
-  // This Leaky Meyers Singleton must always live in the .cpp file.
-  static auto& instance = *new StaticSingletonManagerWithRttiImpl();
-  return instance.create(*arg.key, arg.make, arg.cache);
+template <bool Noexcept>
+void* StaticSingletonManagerWithRtti::create_(Arg& arg) noexcept(Noexcept) {
+  return StaticSingletonManagerWithRttiImpl::create(arg);
 }
 
+template void* StaticSingletonManagerWithRtti::create_<false>(Arg& arg);
+template void* StaticSingletonManagerWithRtti::create_<true>(Arg& arg);
+
 } // namespace detail
 } // namespace folly

folly/detail/StaticSingletonManager.h

@@ -81,10 +81,7 @@ class StaticSingletonManagerWithRtti {
   }
 
   template <bool Noexcept>
-  FOLLY_ERASE static void* create_(Arg& arg) noexcept(Noexcept) {
-    return create_(arg);
-  }
-  FOLLY_NOINLINE static void* create_(Arg& arg);
+  FOLLY_NOINLINE static void* create_(Arg& arg) noexcept(Noexcept);
 };
 
 using StaticSingletonManager = std::conditional_t<