What is the __NULL_IMPORT_DESCRIPTOR good for (MSVC map file)?

Question

I have a map file generated with microsoft visual studio. It contains a relatively big area named __NULL_IMPORT_DESCRIPTOR. What is this good for? It has something to do with linked dlls but I cannot figure out the exact purpose of it.

Answer 1

__NULL_IMPORT_DESCRIPTOR is the IMAGE_IMPORT_DESCRIPTOR structure. With all its fields set to null it indicates the end of the IMAGE_IMPORT_DESCRIPTOR array in the imports section. It takes only 20 bytes.