code: def update_unnamed_class(decls):
      
  
      for decl in decls:
          if isinstance(decl, declarations.typedef_t):
              referent = decl.decl_type
              if isinstance(referent, declarations.elaborated_t):
                  referent = referent.base
              if not isinstance(referent, declarations.declarated_t):
                  continue
              referent = referent.declaration
              if referent.name or not isinstance(referent, declarations.class_t):
                  continue
              referent.name = decl.name
docs: Adds name to class_t declarations.
  
      If CastXML is being used, the type definitions with an unnamed
      class/struct are split across two nodes in the XML tree. For example,
  
          typedef struct {} cls;
  
      produces
  
          <Struct id="_7" name="" context="_1" .../>
          <Typedef id="_8" name="cls" type="_7" context="_1" .../>
  
      For each typedef, we look at which class it refers to, and update the name
      accordingly. This helps the matcher classes finding these declarations.
      This was the behaviour with gccxml too, so this is important for
      backward compatibility.
  
      If the castxml epic version 1 is used, there is even an elaborated type
      declaration between the typedef and the struct/class, that also needs to be
      taken care of.
  
      Args:
          decls (list[declaration_t]): a list of declarations to be patched.
      Returns:
          None