Geoff Chappell - Software Analyst
This is a listen-to attribute for ATLPROV. It is handled first by the compiler as a built-in attribute and then by such other attribute providers that “listen to” it. The following notes assume familiarity with the syntax and behaviour of the event_source attribute as built in to the compiler. The only case of interest to ATLPROV is when the type argument has the value com.
ATLPROV ordinarily adds IProvideClassInfoImpl as a base class to the target of a coclass attribute. This addition is skipped if the target also has the event_source attribute with com as the type.