BuildCHG(){
for each vtable(v) created in a file do {
create a node (n) for v if nonexistent ;
add the virtual functions (f) accessible via v to n;
let t = typeid of v;
for each baseclass (b) of t do {
find the CHG node(nb) corresponding to b ;
add nb as a baseclass of n ;
add n as a subclass of nb ;
}
}
}