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/**

* @name Inconsistent method resolution order

* @description Class definition will raise a type error at runtime due to inconsistent method resolution order(MRO)

* @kind problem

* @tags quality

* reliability

* correctness

* @problem.severity error

* @sub-severity high

* @precision very-high

* @id py/inconsistent-mro

import python

private import LegacyPointsTo

ClassObject left_base(ClassObject type, ClassObject base) {

exists(int i | i > 0 and type.getBaseType(i) = base and result = type.getBaseType(i - 1))

}

predicate invalid_mro(ClassObject t, ClassObject left, ClassObject right) {

t.isNewStyle() and

left = left_base(t, right) and

left = right.getAnImproperSuperType()

}

from ClassObject t, ClassObject left, ClassObject right

where invalid_mro(t, left, right)

select t,

"Construction of class " + t.getName() +

" can fail due to invalid method resolution order(MRO) for bases $@ and $@.", left,

left.getName(), right, right.getName()