Re: [PATCH v4 7/8] GDB: Add a character string limiting option

["Maciej W. Rozycki" <macro@embecosm.com>]

On Wed, 9 Mar 2022, Eli Zaretskii wrote:

> > --- src.orig/gdb/NEWS
> > +++ src/gdb/NEWS
> > @@ -119,6 +119,17 @@ show ada source-charset
> >    values for this follow the values that can be passed to the GNAT
> >    compiler via the '-gnati' option.  The default is ISO-8859-1.
> >  
> > +set print characters LIMIT
> > +show print characters
> > +print -characters LIMIT
> > +  This new setting is like 'set print elements', but controls how many
> 
> "This new setting" is okay for "set print characters", but not for
> "print -characters".  I suggest to move "print -characters" to after
> the description, and then to say that its effect is the same as a
> temporary use of "set print characters".

 OK.  I will update it in v5.

> > +@item -characters @var{number-of-characters}|@code{elements}|@code{unlimited}
> > +Set limit on string characters to print.  The value @code{elements}
> > +causes the limit on array elements to print to be used.  The value
>                        ^^^^^^^^^^^^^^
> "characters", not "array elements", right?

 No, this is as intended.  With a character string `foo' and this command:

(gdb) print -characters elements foo

the limit previously set by `set print elements' will be used (which is 
usually the setting for array elements).  Likewise:

(gdb) print -characters elements -elements 5 foo

will print up to 5 characters regardless of the current limit set by `set 
print characters', and the `-elements' option usually applies to array 
elements.

> And, btw, we actually count bytes, not characters, right?  If the
> string contains multibyte sequences, we don't count characters.  I
> think this should be mentioned.

 We do count characters not bytes, as previously discussed; cf.: 
<https://sourceware.org/pipermail/gdb-patches/2021-December/184466.html>. 
Multibyte sequences comprising a single character are treated as such.  
This change does not affect it.

> > +@item -elements @var{number-of-elements}|@code{unlimited}
> > +Set limit on array elements and optionally string characters to print.
> > +See @ref{set print characters} and the @code{-characters} option above
>                                  ^
> Please insert a comma after the closing brace.  Some relatively old
> versions of makeinfo require that.

 OK.  I will update it in v5.  (Now that you mention it I remember it from 
the old days.)

> > +for when this option applies to strings.  The value @code{unlimited}
> > +causes there to be no limit.  Related setting: @ref{set print elements}.
>                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> This is not a very good idea.  Texinfo is not HTML, so the results
> produced for this in some formats will look awkward or even downright
> incorrect English.  It is better to use something like:
> 
>   @xref{set print elements}, for a related CLI command.

 Likewise.  Thank you for your review.

  Maciej