Make directed callgraph include uncalled functions

Author: Owen Jones

src/analyses/call_graph.cpp

@@ -192,11 +192,17 @@ class function_indicest
 /// was set when this call-graph was constructed the edge will be annotated
 /// with the call-site set.
 /// \return grapht representation of this call_grapht
-call_grapht::directed_grapht call_grapht::get_directed_graph() const
+call_grapht::directed_grapht
+call_grapht::get_directed_graph(const goto_modelt &goto_model) const
 {
   call_grapht::directed_grapht ret;
   function_indicest function_indices(ret);
 
+  // To make sure we include unreachable functions we first create indices
+  // for all functions in the function map
+  for(const auto &f : goto_model.goto_functions.function_map)
+    function_indices[f.first];
+
   for(const auto &edge : graph)
   {
     auto a_index=function_indices[edge.first];

src/analyses/call_graph.h

@@ -135,7 +135,7 @@ class call_grapht
     }
   };
 
-  directed_grapht get_directed_graph() const;
+  directed_grapht get_directed_graph(const goto_modelt &goto_model) const;
 
 protected:
   void add(const irep_idt &function,

src/goto-programs/slice_global_inits.cpp

@@ -39,7 +39,7 @@ void slice_global_inits(goto_modelt &goto_model)
   // the entry point:
   call_grapht call_graph =
     call_grapht::create_from_root_function(goto_model, entry_point, false);
-  const auto directed_graph = call_graph.get_directed_graph();
+  const auto directed_graph = call_graph.get_directed_graph(goto_model);
   INVARIANT(
     !directed_graph.empty(), "At least __CPROVER_start should be reachable");
 

unit/analyses/call_graph.cpp

@@ -176,7 +176,7 @@ SCENARIO("call_graph",
     WHEN("The call graph is exported as a grapht")
     {
       call_grapht::directed_grapht exported=
-        call_graph_from_goto_functions.get_directed_graph();
+        call_graph_from_goto_functions.get_directed_graph(goto_model);
 
       typedef call_grapht::directed_grapht::node_indext node_indext;
       std::map<irep_idt, node_indext> nodes_by_name;
@@ -234,7 +234,7 @@ SCENARIO("call_graph",
     {
       call_grapht call_graph_from_goto_functions(goto_model, true);
       call_grapht::directed_grapht exported=
-        call_graph_from_goto_functions.get_directed_graph();
+        call_graph_from_goto_functions.get_directed_graph(goto_model);
 
       typedef call_grapht::directed_grapht::node_indext node_indext;
       std::map<irep_idt, node_indext> nodes_by_name;