G++ question

[Gabriel Dos Reis]

Hi,

While working on a project involing checking the internal (logic)
consistency of the C++ front-end, I came across the following code in
cp/parser.c:cp_parser_translation_unit():

  while (true)
    {
      cp_parser_declaration_seq_opt (parser);

      /* If there are no tokens left then all went well.  */
      if (cp_lexer_next_token_is (parser->lexer, CPP_EOF))
	{
	  /* Get rid of the token array; we don't need it any more.  */
	  cp_lexer_destroy (parser->lexer);
	  parser->lexer = NULL;

	  /* This file might have been a context that's implicitly extern
	     "C".  If so, pop the lang context.  (Only relevant for PCH.) */
	  if (parser->implicit_extern_c)
	    {
	      pop_lang_context ();
	      parser->implicit_extern_c = false;
	    }

	  /* Finish up.  */
	  finish_translation_unit ();

	  success = true;
	  break;
	}
      else
	{
	  cp_parser_error (parser, "expected declaration");
	  success = false;
	  break;
	}
    }


Both branches of the if-statement contain an unconditional "break",
which implies that the apparant unbounded while-loop is executed only
once.  If that reasoning is correct, why do we have the while-loop in
the first place? 

-- Gaby