Use weak_ptr instead

Author: augusto2112

lldb/include/lldb/Core/ModuleList.h

@@ -489,7 +489,7 @@ class ModuleList {
 
   static size_t RemoveOrphanSharedModules(bool mandatory);
 
-  static bool RemoveSharedModuleIfOrphaned(const Module *module_ptr);
+  static bool RemoveSharedModuleIfOrphaned(const lldb::ModuleWP module_ptr);
 
   /// Applies 'callback' to each module in this ModuleList.
   /// If 'callback' returns false, iteration terminates.

lldb/source/Core/ModuleList.cpp

@@ -1278,7 +1278,16 @@ bool ModuleList::RemoveSharedModule(lldb::ModuleSP &module_sp) {
   return GetSharedModuleList().Remove(module_sp);
 }
 
-bool ModuleList::RemoveSharedModuleIfOrphaned(const Module *module_ptr) {
+bool ModuleList::RemoveSharedModuleIfOrphaned(const ModuleWP module_wp) {
+  // Get the module pointer if the shared pointer is still valid,
+  // but be careful to call RemoveIfOrphaned after the shared pointer
+  // is out of scope, otherwise the use count would be incremented by one and
+  // RemoveIfOrphaned would never identify the module as an orphan.
+  Module *module_ptr = nullptr;
+  if (ModuleSP module_sp = module_wp.lock())
+    module_ptr = module_sp.get();
+  else
+    return false;
   return GetSharedModuleList().RemoveIfOrphaned(module_ptr);
 }
 

lldb/source/Target/Target.cpp

@@ -2564,12 +2564,9 @@ ModuleSP Target::GetOrCreateModule(const ModuleSpec &orig_module_spec,
           m_images.Append(module_sp, notify);
 
         for (ModuleSP &old_module_sp : replaced_modules) {
-          auto use_count = old_module_sp.use_count();
-          Module *old_module_ptr = old_module_sp.get();
+          auto old_module_wp =  old_module_sp->weak_from_this();
           old_module_sp.reset();
-          // If the use count was one, this was not in the shared module list.
-          if (use_count > 1)
-            ModuleList::RemoveSharedModuleIfOrphaned(old_module_ptr);
+          ModuleList::RemoveSharedModuleIfOrphaned(old_module_wp);
         }
       } else
         module_sp.reset();