Fixed CEGIS control benchmark 2

CEGIS control benchmark 2 was not working anymore due to a bug introduced
in the meta variable detection with the new control back-end. Fixed this
bug.

Author: pkesseli

src/cegis/cegis-util/program_helper.cpp

@@ -348,8 +348,10 @@ goto_programt::targett insert_after_preserving_source_location(
 goto_programt::targett insert_before_preserving_source_location(
     goto_programt &body, goto_programt::targett pos)
 {
-  typedef goto_programt::targett(goto_programt::*ftype)(goto_programt::targett);
-  const auto op=std::bind1st(std::mem_fun(static_cast<ftype>(&goto_programt::insert_before)), &body);
+  typedef goto_programt::targett (goto_programt::*ftype)(
+      goto_programt::targett);
+  const auto op=std::bind1st(
+      std::mem_fun(static_cast<ftype>(&goto_programt::insert_before)), &body);
   return insert_preserving_source_location(pos, op);
 }
 

src/cegis/control/learn/rational_solution_configuration.cpp

@@ -30,9 +30,8 @@ const struct_exprt &find_solution(const goto_tracet &trace)
 }
 }
 
-void rational_solution_configurationt::convert(
-    solutiont &current_candidate, const goto_tracet &trace,
-    const symbol_tablet &st)
+void rational_solution_configurationt::convert(solutiont &current_candidate,
+    const goto_tracet &trace, const symbol_tablet &st)
 {
   const struct_exprt &solution=find_solution(trace);
   const namespacet ns(st);

src/cegis/control/preprocessing/control_preprocessing.cpp

@@ -11,12 +11,12 @@
 #include <cegis/control/preprocessing/control_preprocessing.h>
 #include <goto-programs/remove_returns.h>
 
+#define TMP_MARKER "$tmp"
+
 // XXX: Debug
 #include <iostream>
 // XXX: Debug
 
-#define TMP_MARKER "$tmp"
-
 control_preprocessingt::control_preprocessingt(const symbol_tablet &st,
     const goto_functionst &gf) :
     control_program(st, gf)
@@ -39,8 +39,11 @@ bool is_meta(const goto_programt::const_targett pos)
   const std::string &func=id2string(loc.get_function());
   for (const char * const excluded : excluded_functions)
     if (contains(func, excluded)) return true;
-  if (goto_program_instruction_typet::ASSIGN != pos->type
-      && goto_program_instruction_typet::DECL != pos->type) return false;
+  if ((goto_program_instruction_typet::ASSIGN != pos->type
+      && goto_program_instruction_typet::DECL != pos->type)
+      || !pos->code.has_operands()
+      || (pos->code.has_operands() && ID_symbol != pos->code.op0().id()))
+    return false;
   const std::string &var=id2string(get_affected_variable(*pos));
   if (contains(var, TMP_MARKER) || contains(var, RETURN_VALUE_SUFFIX)
       || contains(var, CPROVER_PREFIX)) return true;