2011-05-02  Steven G. Kargl  <kargl@gcc.gnu.org>

    PR fortran/48720
    * gfortran.texi: Document the 'Q' exponent-letter extension.
    * invoke.texi: Document -Wreal-q-constant.
    * lang.opt: Add -Wreal-q-constant option.
    * gfortran.h: Add warn_real_q_constant to option struct.
    * primary.c (match_real_constant):  Use it.  Accept 'Q' as
    exponent-letter for REAL(16) real-literal-constant with a
    fallback to REAL(10) or error if REAL(10) is not available.
    * options.c (gfc_init_options, set_Wall) Set it.
    (gfc_handle_option): Handle new option.

From-SVN: r173285