Remove useless temporaries

Construct an exprt of the appropriate type directly, and move the object where
possible or just construct it inline. This avoids unnecessary copies and reduces
the amount of code.

Author: tautschnig

src/analyses/flow_insensitive_analysis.cpp

@@ -210,11 +210,9 @@ bool flow_insensitive_analysis_baset::do_function_call(
 
     goto_programt temp;
 
-    exprt rhs =
-      side_effect_expr_nondett(code.lhs().type(), l_call->source_location);
+    goto_programt::targett r = temp.add(goto_programt::make_return(code_returnt(
+      side_effect_expr_nondett(code.lhs().type(), l_call->source_location))));
 
-    goto_programt::targett r =
-      temp.add(goto_programt::make_return(code_returnt(rhs)));
     r->function=f_it->first;
     r->location_number=0;
 

src/analyses/goto_check.cpp

@@ -1834,18 +1834,16 @@ void goto_checkt::goto_check(
         if(local_bitvector_analysis->dirty(variable))
         {
           // need to mark the dead variable as dead
-          exprt address_of_expr=address_of_exprt(variable);
           exprt lhs=ns.lookup(CPROVER_PREFIX "dead_object").symbol_expr();
-          address_of_expr =
-            typecast_exprt::conditional_cast(address_of_expr, lhs.type());
-          const if_exprt rhs(
+          exprt address_of_expr = typecast_exprt::conditional_cast(
+            address_of_exprt(variable), lhs.type());
+          if_exprt rhs(
             side_effect_expr_nondett(bool_typet(), i.source_location),
-            address_of_expr,
-            lhs,
-            lhs.type());
+            std::move(address_of_expr),
+            lhs);
           goto_programt::targett t =
             new_code.add(goto_programt::make_assignment(
-              code_assignt(lhs, rhs), i.source_location));
+              code_assignt(std::move(lhs), std::move(rhs)), i.source_location));
           t->code.add_source_location()=i.source_location;
         }
       }

src/goto-instrument/loop_utils.cpp

@@ -45,11 +45,11 @@ void build_havoc_code(
       m_it++)
   {
     exprt lhs=*m_it;
-    exprt rhs =
-      side_effect_expr_nondett(lhs.type(), loop_head->source_location);
+    side_effect_expr_nondett rhs(lhs.type(), loop_head->source_location);
 
     goto_programt::targett t = dest.add(goto_programt::make_assignment(
-      code_assignt(lhs, rhs), loop_head->source_location));
+      code_assignt(std::move(lhs), std::move(rhs)),
+      loop_head->source_location));
     t->function=loop_head->function;
     t->code.add_source_location()=loop_head->source_location;
   }