added constructor for goto_symex_statet::framet

This enables removing the default constructor for sourcet.

Author: Daniel Kroening

src/goto-symex/goto_symex_state.h

@@ -196,6 +196,11 @@ class goto_symex_statet final
       bool is_recursion = false;
     };
     std::unordered_map<irep_idt, loop_infot> loop_iterations;
+
+    explicit framet(const symex_targett::sourcet &_calling_location)
+      : calling_location(_calling_location)
+    {
+    }
   };
 
   typedef std::vector<framet> call_stackt;
@@ -224,8 +229,14 @@ class goto_symex_statet final
     return call_stack().back();
   }
 
-  framet &new_frame() { call_stack().push_back(framet()); return top(); }
+  framet &new_frame()
+  {
+    call_stack().emplace_back(source);
+    return top();
+  }
+
   void pop_frame() { call_stack().pop_back(); }
+
   const framet &previous_frame() { return *(--(--call_stack().end())); }
 
   void print_backtrace(std::ostream &) const;

src/goto-symex/symex_function_call.cpp

@@ -311,7 +311,6 @@ void goto_symext::symex_function_call_code(
 
   frame.end_of_function=--goto_function.body.instructions.end();
   frame.return_value=call.lhs();
-  frame.calling_location=state.source;
   frame.function_identifier=identifier;
   frame.hidden_function=goto_function.is_hidden();