How to forcibly insert placement_new after malloc?

Hi, all.

I want to insert “placement_new” after “malloc” to call the constructor (to initialize vtable ptr) when the allocated object is a polymorphic object.

Could I forcibly insert “placement_new” after “malloc” in the clang level (e.g., modify clang to use “CXXNewEXpr::Create()”) without modifying AST tree?

If not, could you please tell me the way?

Best Regards,

Y. Jeon.