Parse debug-level at symex_config construction

No functional change

Author: romainbrenguier

src/goto-symex/goto_symex.h

@@ -59,7 +59,7 @@ struct symex_configt final
   bool simplify_opt;
   bool unwinding_assertions;
   bool partial_loops;
-  std::string debug_level;
+  mp_integer debug_level;
 
   explicit symex_configt(const optionst &options);
 };

src/goto-symex/symex_builtin_functions.cpp

@@ -458,8 +458,6 @@ void goto_symext::symex_trace(
 {
   PRECONDITION(code.arguments().size() >= 2);
 
-  int debug_thresh = unsafe_string2int(symex_config.debug_level);
-
   mp_integer debug_lvl;
   optionalt<mp_integer> maybe_debug =
     numeric_cast<mp_integer>(code.arguments()[0]);
@@ -473,7 +471,7 @@ void goto_symext::symex_trace(
       code.arguments()[1].op0().id() == ID_string_constant,
     "CBMC_trace expects string constant as second argument");
 
-  if(mp_integer(debug_thresh)>=debug_lvl)
+  if(symex_config.debug_level >= debug_lvl)
   {
     std::list<exprt> vars;
 

src/goto-symex/symex_main.cpp

@@ -18,6 +18,7 @@ Author: Daniel Kroening, kroening@kroening.com
 #include <util/make_unique.h>
 #include <util/replace_symbol.h>
 #include <util/std_expr.h>
+#include <util/string2int.h>
 #include <util/symbol_table.h>
 
 #include <analyses/dirty.h>
@@ -33,7 +34,7 @@ symex_configt::symex_configt(const optionst &options)
     simplify_opt(options.get_bool_option("simplify")),
     unwinding_assertions(options.get_bool_option("unwinding-assertions")),
     partial_loops(options.get_bool_option("partial-loops")),
-    debug_level(options.get_option("debug-level"))
+    debug_level(unsafe_string2int(options.get_option("debug-level")))
 {
 }