Class Make::DataFlowIntegration::SsaInputNode

A node that represents an input to an SSA phi (read) definition.

This allows for barrier guards to filter input to phi nodes. For example, in

x = taint
if x != "safe" then
    x = "safe"
end
sink x

the false edge out of x != "safe" guards the input from x = taint into the phi node after the condition.

It is also relevant to filter input into phi read nodes:

x = taint
if b then
    if x != "safe1" then
        return
    end
else
    if x != "safe2" then
        return
    end
end

sink x

both inputs into the phi read node after the outer condition are guarded.