expose rule's meta data to other rule

[virusdefender]

private rule Rule1
{
    meta:
        score = 20
    strings:
        $a = "dummy1"
    condition:
        $a
}

private rule Rule2
{
    meta:
        score = 70
    strings:
        $a = "dummy2"
    condition:
        $a
}

private rule Rule3
{
    meta:
        score = 60
    strings:
        $a = "dummy3"
    condition:
        $a
}

rule Rule
{
    condition:
        math.tonumber(Rule1) *Rule1.score + math.tonumber(Rule2) *Rule2.score + math.tonumber(Rule3) *Rule3.score > 85
}

we can avoid hard coding the score value in the final rule if the meta value can be used here, or it should be math.tonumber(Rule1) * 20 + math.tonumber(Rule2) * 70 + math.tonumber(Rule3) * 60 > 85

• it equals to (Rule1 and Rule2) or (Rule2 or Rule3)
• however the semantics of RuleX is a little strange, it can be a bool or struct.
• math.tonumber(RuleX) can be defined as rule_matched ? 1 : 0 add math.tonumber function to convert bool to number #1450
• the score can be defined in variables if Internal variables for rules #1353 is merged

[virusdefender]

the semantics of RuleX is a little strange, it can be a bool or struct, i will re-open this issue if i have a better idea