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, 13 insertions, 0 deletions

diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index 0f5d8e17a..b65ec5615 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -734,6 +734,19 @@ void Session::addBuiltinSource(
     loadedModuleCode.Add(syntax);
 }
 
+Session::~Session()
+{
+    // free all built-in types first
+    errorType = nullptr;
+    initializerListType = nullptr;
+    overloadedType = nullptr;
+    irBasicBlockType = nullptr;
+
+    builtinTypes = decltype(builtinTypes)();
+    // destroy modules next
+    loadedModuleCode = decltype(loadedModuleCode)();
+}
+
 }
 
 // implementation of C interface