What does USE_CTRLDLL=1 in SOURCES file do?

Question

I am in the process of updating an older windows driver. I am using Build.exe and the associated tool set included in the WinDDK (7600.16385.1). Reviewing the SOURCES file I came across the following macro: USE_CTRLDLL=1. I cannot find any documentation related to this on MSDN (https://msdn.microsoft.com/en-us/library/ms910176.aspx) or third party sites. Any idea as to what this macro actually tells the tool set to do?

Answer 1

The following answer was provided by Don Burn in the Windows Dev Center Forums (What does USE_CTRLDLL=1 in SOURCES file do?):

I suspect someone typo'd meaning to put in USE_CRTDLL which is obsolete and instead should be USE_MSVCRT.

Removing this MACRO has no apparent effect on the compilation, linking, or execution of the driver. As Don implies, it is likely the result of a typo made during a maintenance update.