call graph helper interface to depth limited search

Gets all functions reachable within n steps, by calling depth limited search

Author: polgreen

src/analyses/call_graph_helpers.cpp

@@ -70,3 +70,21 @@ std::set<irep_idt> get_reaching_functions(
 {
   return get_connected_functions(graph, function, false);
 }
+
+std::set<irep_idt> get_functions_reachable_within_n_steps(
+  const call_grapht::directed_grapht &graph,
+  const irep_idt &start_function,
+  std::size_t n)
+{
+  std::set<irep_idt> result;
+
+  if(auto start_idx = graph.get_node_index(start_function))
+  {
+    for(const auto &index : graph.depth_limited_search(*start_idx, n))
+      result.insert(graph[index].function);
+  }
+  else
+    throw "unknown start function";
+
+  return result;
+}

src/analyses/call_graph_helpers.h

@@ -40,13 +40,26 @@ std::set<irep_idt> get_callers(
 /// \param function: function to query
 /// \return set of reachable functions, including `function`
 std::set<irep_idt> get_reachable_functions(
-  const call_grapht::directed_grapht &graph, const irep_idt &function);
+  const call_grapht::directed_grapht &graph,
+  const irep_idt &function);
 
-/// Get functions that can reach a given function
 /// \param graph: call graph
 /// \param function: function to query
 /// \return set of functions that can reach the target, including `function`
 std::set<irep_idt> get_reaching_functions(
-  const call_grapht::directed_grapht &graph, const irep_idt &function);
+  const call_grapht::directed_grapht &graph,
+  const irep_idt &function);
+
+/// Get either callers or callees reachable from a given
+/// start function within N steps
+/// \param graph: call graph
+/// \param start_function: single start function
+/// \param n: number of steps to consider
+/// \return set of functions that can be reached from the start function
+/// including the start function
+std::set<irep_idt> get_functions_reachable_within_n_steps(
+  const call_grapht::directed_grapht &graph,
+  const irep_idt &start_function,
+  std::size_t n);
 
 #endif