Re: [PATCH v8 5/6] GDB: Add a character string limiting option

[Simon Marchi <simon.marchi@polymtl.ca>]

On 11/24/22 06:22, Maciej W. Rozycki wrote:
> From: Andrew Burgess <andrew.burgess@embecosm.com>
> 
> This commit splits the `set/show print elements' option into two.  We 
> retain `set/show print elements' for controlling how many elements of an 
> array we print, but a new `set/show print characters' setting is added 
> which is used for controlling how many characters of a string are 
> printed.
> 
> The motivation behind this change is to allow users a finer level of 
> control over how data is printed, reflecting that, although strings can 
> be thought of as arrays of characters, users often want to treat these 
> two things differently.
> 
> For compatibility reasons by default the `set/show print characters' 
> option is set to `elements', which makes the limit for character strings 
> follow the setting of the `set/show print elements' option, as it used 
> to.  Using `set print characters' with any other value makes the limit 
> independent from the `set/show print elements' setting, however it can 
> be restored to the default with the `set print characters elements' 
> command at any time.
> 
> A corresponding `-characters' option for the `print' command is added, 
> with the same semantics, i.e. one can use `elements' to make a given 
> `print' invocation follow the limit of elements, be it set with the 
> `-elements' option also given with the same invocation or taken from the 
> `set/show print elements' setting, for characters as well regardless of 
> the current setting of the `set/show print characters' option.
> 
> The GDB changes are all pretty straightforward, just changing references 
> to the old 'print_max' to use a new `get_print_max_chars' helper which 
> figures out which of the two of `print_max' and `print_max_chars' values 
> to use.
> 
> Likewise, the documentation is just updated to reference the new setting 
> where appropriate.
> 
> To make people's life easier the message shown by `show print elements' 
> now indicates if the setting also applies to character strings:
> 
> (gdb) set print characters elements
> (gdb) show print elements
> Limit on string chars or array elements to print is 200.
> (gdb) set print characters unlimited
> (gdb) show print elements
> Limit on array elements to print is 200.
> (gdb) 
> 
> which keeps it the same as it used to be, although in other contexts the 
> setting is described as applying to array elements only, e.g.:
> 
> (gdb) help set print elements
> Set limit on array elements to print.
> "unlimited" causes there to be no limit.

I think it would be helpful to say here that if this value influences
"set print characters", if "set print characters" is set to "elements".

Otherwise, the patch LGTM:

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon