Dependence graph: ensure grapht representation is consistent with domain

Previously the grapht representation was incrementally populated at the same
time as the domain representation was computed, but at least one case (control
dependencies crossing function callsites) was missing, leading to inconsistency,
and doing it this way invites future similar mistakes. Instead, this commit switches
to generating the grapht representation in one go after the AI fixedpoint has been
computed.

Author: smowton

src/analyses/dependence_graph.cpp

@@ -120,10 +120,6 @@ void dep_graph_domaint::control_dependencies(
 
     it=next;
   }
-
-  // add edges to the graph
-  for(const auto &c_dep : control_deps)
-    dep_graph.add_dep(dep_edget::kindt::CTRL, c_dep, to);
 }
 
 static bool may_be_def_use_pair(
@@ -185,15 +181,6 @@ void dep_graph_domaint::data_dependencies(
 
     dep_graph.reaching_definitions()[to].clear_cache(it->first);
   }
-
-  // add edges to the graph
-  for(const auto &d_dep : data_deps)
-  {
-    // *it might be handled in a future call call to visit only,
-    // depending on the sequence of successors; make sure it exists
-    dep_graph.get_state(d_dep);
-    dep_graph.add_dep(dep_edget::kindt::DATA, d_dep, to);
-  }
 }
 
 void dep_graph_domaint::transform(
@@ -326,3 +313,13 @@ void dependence_grapht::add_dep(
   nodes[n_from].out[n_to].add(kind);
   nodes[n_to].in[n_from].add(kind);
 }
+
+void dep_graph_domaint::populate_dep_graph(
+  dependence_grapht &dep_graph, goto_programt::const_targett this_loc) const
+{
+  for(const auto &c_dep : control_deps)
+    dep_graph.add_dep(dep_edget::kindt::CTRL, c_dep, this_loc);
+
+  for(const auto &d_dep : data_deps)
+    dep_graph.add_dep(dep_edget::kindt::DATA, d_dep, this_loc);
+}

src/analyses/dependence_graph.h

@@ -154,6 +154,9 @@ class dep_graph_domaint:public ai_domain_baset
     return node_id;
   }
 
+  void populate_dep_graph(
+    dependence_grapht &, goto_programt::const_targett) const;
+
 private:
   tvt has_values;
   node_indext node_id;
@@ -207,6 +210,14 @@ class dependence_grapht:
     }
   }
 
+  void finalize()
+  {
+    for(const auto &location_state : state_map)
+    {
+      location_state.second.populate_dep_graph(*this, location_state.first);
+    }
+  }
+
   void add_dep(
     dep_edget::kindt kind,
     goto_programt::const_targett from,