mx-print-call-graph.md

mx-print-call-graph

This tool takes in an --entity_id <entity_id>, typically the ID of a function, and prints a DOT digraph of all transitive callers of the function. For example:

% mx-list-functions --db /tmp/curl.db | grep freecookie
1152921504606847273 2305843009214753862 9281918843895152640 freecookie  def

% mx-print-call-graph --db /tmp/curl.db --entity_id 9281918843895152640 >/tmp/test.dot
% xdot /tmp/test.dot

This can produce giant graphs.

Sometimes, you want to know how to get from point A to point B. There is an option for this, --reachable_from_entity_id <from_entity_id>. This finds the call graph leading to --entity_id <to_entity_id> that is transitively reachable from the entity with ID <from_entity_id>. Here’s an example:

% mx-list-functions --db /tmp/curl.db | grep cf_setup_connect
1152921504606847266 2305843009214753742 9281918843769323520 cf_setup_connect  def

% mx-print-call-graph --db /tmp/curl.db --entity_id 9281918843895152640 --reachable_from_entity_id 9281918843769323520 >/tmp/test.dot
% xdot /tmp/test.dot

This produces a marginally more manageable graph: