+ char *file_name; /* Name of file containing error, or NULL. */
+ int first_line; /* 1-based line number, or 0 if none. */
+ int last_line; /* 1-based exclusive last line (0=none). */
+ int first_column; /* 1-based first column, or 0 if none. */
+ int last_column; /* 1-based exclusive last column (0=none). */