[Bug middle-end/82798] Inconsistent descriptions for warning options in documentation

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82798

Eric Gallager <egallager at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |egallager at gcc dot gnu.org
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=71283

--- Comment #1 from Eric Gallager <egallager at gcc dot gnu.org> ---
(In reply to Julien ÉLIE from comment #0)
> In GCC 7 documentation:
> 
> 1/ One can read "Some options, such as -Wall and -Wextra, turn on other
> options, such as -Wunused" and later in the description of -Wunused:  "note
> that -Wall implies -Wunused".
> 
> However, "-Wunused" is not listed in the list of warning flags turned on by
> -Wall.
> 4 warning flags are instead listed in the -Wall list: -Wunused-function,
> -Wunused-label, -Wunused-value and -Wunused-variable.
> And 2 warning flags are listed in the -Werror list: -Wunused-parameter,
> -Wunused-but-set-parameter.
> 
> It seems a bit confusing, and I believe there is something to fix.
> Maybe in fact -Wunused is not turned on by -Wall?
> 
> 
> 2/ -Wuninitialized is listed in both -Wall and -Werror list.
> And the description of -Wuninitialized does not mention either of them.
> I believe there is something to fix for that.
> 
> 
> 3/ -Wall should list "-Walloc-size-larger-than=PTRDIFF_MAX" in the warning
> flags turned on (according to GCC 7 changes).  The description should
> mention that at the same time.
> 
> 
> 4/ The description of -Wexpansion-to-defined mentions that it is enabled by
> -Wextra and -Wpedantic.  The list of warning flags turned on by them should
> mention that.
> 
> 
> 5/ -Wall mentions two warnings that are not described in the documentation:
> -Wmultistatement-macros and -Wreorder.  Can they be described please?
> 

-Wreorder at least is listed in the "C++ Dialect Options" section, which is bug
71283

> 
> Thanks beforehand for fixing these issues.
> 
> Julien ÉLIE