keep typedefs when dumping c with --use-system-headers

Author: thk123

src/ansi-c/ansi_c_declaration.cpp

@@ -146,6 +146,10 @@ typet ansi_c_declarationt::full_type(
 
   *p=type();
 
+  // retain typedef for dump-c
+  if(get_is_typedef())
+    result.set(ID_typedef,declarator.get_name());
+
   return result;
 }
 

src/ansi-c/c_typecheck_type.cpp

@@ -52,6 +52,7 @@ void c_typecheck_baset::typecheck_type(typet &type)
     c_qualifiers+=c_qualifierst(type.subtype());
     bool packed=type.get_bool(ID_C_packed);
     exprt alignment=static_cast<const exprt &>(type.find(ID_C_alignment));
+    irept _typedef=type.find(ID_typedef);
 
     type.swap(type.subtype());
 
@@ -60,6 +61,8 @@ void c_typecheck_baset::typecheck_type(typet &type)
       type.set(ID_C_packed, true);
     if(alignment.is_not_nil())
       type.add(ID_C_alignment, alignment);
+    if(_typedef.is_not_nil())
+      type.add(ID_typedef, _typedef);
 
     return; // done
   }