more to fixing memory leaks

1. reorder destruction order of several key classes to avoid using deleted IR objects when destroying Types
2. remove Session::canonicalTypes and make each Type own a RefPtr to the canonicalType, to allow types to be destroyed along with each IRModule it belongs to.

1 files changed, 14 insertions, 0 deletions

diff --git a/source/core/smart-pointer.h b/source/core/smart-pointer.h
index 17d6caaa4..bc1683a5b 100644
--- a/source/core/smart-pointer.h
+++ b/source/core/smart-pointer.h
@@ -35,6 +35,11 @@ namespace Slang
             referenceCount++;
         }
 
+        void decreaseReference()
+        {
+            --referenceCount;
+        }
+
         void releaseReference()
         {
             SLANG_ASSERT(referenceCount != 0);
@@ -192,6 +197,15 @@ namespace Slang
             return pointer;
         }
 
+        T* detach()
+        {
+            if (pointer)
+                dynamic_cast<RefObject*>(pointer)->decreaseReference();
+            auto rs = pointer;
+            pointer = nullptr;
+            return rs;
+        }
+
     private:
         T* pointer;