Merge pull request diffblue#276 from danpoe/fixes/dependence-graph-remove-precondition

Fix dependence graph precondition failure

Author: chrisr-diffblue

regression/goto-analyzer/dependence-graph15/main.c

@@ -6,7 +6,7 @@ int g_out2;
 
 extern int g_in;
 
-void main(void)
+int main(void)
 {
   int t1;
   int t2;
@@ -20,4 +20,6 @@ void main(void)
     g_out1 = 0;
 
   g_out2 = t1;
+
+  return 0;
 }

src/analyses/dependence_graph.cpp

@@ -72,8 +72,6 @@ void dep_graph_domaint::control_dependencies(
 
   // Add new candidates
 
-  PRECONDITION(!control_dep_call_candidates.empty());
-
   if(from->is_goto() || from->is_assume())
     control_dep_candidates.insert(from);
   else if(from->is_end_function())