use DUChainUtils::getArgumentContext

you can use auto

a context for the return parameter? is that really required? just asking out of curiosity, afaik the other language plugins don't do that (or?)

are you sure that this always creates a context? i.e. even if the user typed somewhat broken code into the editor? I suggest you better rewrite this like the below, to be on the safe side:

if (block) {
    visitBlock(block);
    DUChainWriteLocker lock;
    bodyContext = lastContext();
    if (bodyContext) {
        bodyContext->setType(DUContext::Other);
    }
}

better yet, could you set this type directly wherever you are creating the context itself? from a cursory glance, I don't even see where this is done

nitpicks here and below: please try to follow our coding style and add spaces around operators (such as the = here

also, you can use = {} to reduce some typing repetition here for the comment

dito, see above