Re: Documentation style for options with optional levels

[Nathan Sidwell <nathan@acm.org>]

On 4/10/19 7:13 AM, Jonathan Wakely wrote:
> For options that can be used as -foo or -foo=level we have a variety
> of different styels for documenting what the default level is. See
> below for several examples. I find this a bit confusing when try to
> see what it means to use the option without a level.
> 
> Do we want to pick a style and try to be consistent?

yes?

All the examples you give leave something to be desired.

> For -Wformat-overflow we show the option with and without the level:
> 
>   @item -Wformat-overflow
>   @itemx -Wformat-overflow=1
>   @opindex Wformat-overflow
>   @opindex Wno-format-overflow
>   Level @var{1} of @option{-Wformat-overflow} enabled by @option{-Wformat}

The @item is the clearest to read, and also the most accurate as it 
shows you can provide it without a level.  But from that snippet there's 
no indication what not giving a level gets you.  There needs to be some 
words somewhere to say what it maps to.

> For -Wshift-overflow we use prose to say what omitting the level
> means:
> 
>   @item -Wshift-overflow=1
>   This is the warning level of @option{-Wshift-overflow} and is enabled
>   by default in C99 and C++11 modes (and newer).

.. for example that, I can't tell if I can say just -Wshift-overflow and 
get level 1, or if I'll get level 1 whatever unless I say 
-Wno-shift-overflow

> For -Warray-bounds we list both options separately, and then also list
> the forms with levels and say what no level means:
> 
>   @item -Warray-bounds
>   @itemx -Warray-bounds=@var{n}
>   @opindex Wno-array-bounds
>   @opindex Warray-bounds
>   This option is only active when @option{-ftree-vrp} is active
>   (default for @option{-O2} and above). It warns about subscripts to arrays
>   that are always out of bounds. This warning is enabled by @option{-Wall}.
> 
>   @table @gcctabopt
>   @item -Warray-bounds=1
>   This is the warning level of @option{-Warray-bounds} and is enabled
>   by @option{-Wall}; higher levels are not, and must be explicitly 
> requested.

In context with the other levels, I see that is trying to tell you that 
1 is the default, but it's unclear.  My first reading was that 1 gets 
you a warning level, (with the implication that 2 got you an error level 
or something?)

nathan


-- 
Nathan Sidwell