Remove unnecessary uses of ""

Appending "" to a string has no effect.

Author: tautschnig

src/ansi-c/expr2c.cpp

@@ -479,9 +479,7 @@ std::string expr2ct::convert_rec(
 
     if(parameters.empty())
     {
-      if(code_type.has_ellipsis())
-        dest+=""; // empty!
-      else
+      if(!code_type.has_ellipsis())
         dest+="void"; // means 'no parameters'
     }
     else

src/cpp/parse.cpp

@@ -839,9 +839,8 @@ bool Parser::rNamespaceSpec(cpp_namespace_spect &namespace_spec)
 
   irep_idt name;
 
-  if(lex.LookAhead(0)=='{')
-    name=""; // an anonymous namespace
-  else
+  // namespace might be anonymous
+  if(lex.LookAhead(0) != '{')
   {
     if(lex.get_token(tk2)==TOK_IDENTIFIER)
       name=tk2.data.get(ID_C_base_name);

src/goto-instrument/dot.cpp

@@ -192,12 +192,12 @@ void dott::write_dot_subgraph(
       std::set<goto_programt::const_targett> fres;
       find_next(instructions, it, tres, fres);
 
-      std::string tlabel="true";
-      std::string flabel="false";
-      if(fres.empty() || tres.empty())
+      std::string tlabel;
+      std::string flabel;
+      if(!fres.empty() && !tres.empty())
       {
-        tlabel="";
-        flabel="";
+        tlabel = "true";
+        flabel = "false";
       }
 
       typedef std::set<goto_programt::const_targett> t;

src/goto-programs/property_checker.cpp

@@ -21,7 +21,7 @@ std::string property_checkert::as_string(resultt result)
   case property_checkert::resultt::UNKNOWN: return "UNKNOWN";
   }
 
-  return "";
+  UNREACHABLE;
 }
 
 property_checkert::property_checkert(

src/goto-symex/partial_order_concurrency.cpp

@@ -133,8 +133,6 @@ irep_idt partial_order_concurrencyt::rw_clock_id(
     return id2string(id(event))+"$rclk$"+std::to_string(axiom);
   else
     UNREACHABLE;
-
-  return "";
 }
 
 symbol_exprt partial_order_concurrencyt::clock(

src/pointer-analysis/value_set.cpp

@@ -181,7 +181,7 @@ void value_sett::output(const namespacet &ns, std::ostream &out) const
         result = "<" + from_expr(ns, identifier, o) + ", ";
 
         if(o_it->second)
-          result += integer2string(*o_it->second) + "";
+          result += integer2string(*o_it->second);
         else
           result += '*';
 

src/pointer-analysis/value_set_fi.cpp

@@ -102,7 +102,7 @@ void value_set_fit::output(
         result="<"+from_expr(ns, identifier, o)+", ";
 
         if(o_it->second)
-          result += integer2string(*o_it->second) + "";
+          result += integer2string(*o_it->second);
         else
           result+='*';
 

src/pointer-analysis/value_set_fivr.cpp

@@ -143,7 +143,7 @@ void value_set_fivrt::output(
         result+=from_expr(ns, identifier, o)+", ";
 
         if(o_it->second)
-          result += integer2string(*o_it->second) + "";
+          result += integer2string(*o_it->second);
         else
           result+='*';
 

src/pointer-analysis/value_set_fivrns.cpp

@@ -134,7 +134,7 @@ void value_set_fivrnst::output_entry(
       result+=from_expr(ns, identifier, o)+", ";
 
       if(o_it->second)
-        result += integer2string(*o_it->second) + "";
+        result += integer2string(*o_it->second);
       else
         result+='*';
 

src/solvers/smt2/smt2_conv.cpp

@@ -832,7 +832,6 @@ std::string smt2_convt::type2id(const typet &type) const
   else
   {
     UNREACHABLE;
-    return "";
   }
 }