[PATCH v2] preprocessor: -Wbidi-chars and UCNs [PR104030]

[Marek Polacek]

On Fri, Jan 28, 2022 at 04:08:18PM +0100, Martin Liška wrote:
> On 1/28/22 15:59, Marek Polacek wrote:
> > On Fri, Jan 28, 2022 at 02:53:16PM +0100, Martin Liška wrote:
> > > On 1/24/22 23:36, Marek Polacek via Gcc-patches wrote:
> > > > |@@ -7820,6 +7820,10 @@ bidi contexts. @option{-Wbidi-chars=none} turns the warning off. @option{-Wbidi-chars=any} warns about any use of bidirectional control characters. +By default, this warning does not warn about UCNs. It is, however, possible +to turn on such checking by using @option{-Wbidi-chars=unpaired,ucn} or +@option{-Wbidi-chars=any,ucn}.|
> > > 
> > > Hello.
> > > 
> > > Can you please extend the documentation entry and explain what 'ucn' actually means?
> > > 
> > > '''
> > > There are three levels of warning supported by GCC@.  The default is
> > > @option{-Wbidi-chars=unpaired}, which warns about improperly terminated
> > > bidi contexts.  @option{-Wbidi-chars=none} turns the warning off.
> > > @option{-Wbidi-chars=any} warns about any use of bidirectional control
> > > characters.
> > > '''
> > > 
> > > Right now we have 4 levels and 'ucn' is not defined the paragraph.
> > 
> > The following paragraph says
> > 
> > By default, this warning does not warn about UCNs.  It is, however, possible
> > to turn on such checking by using @option{-Wbidi-chars=unpaired,ucn} or
> > @option{-Wbidi-chars=any,ucn}.
> > 
> > Is that not enough?
> 
> Yeah, makes sense. Do I understand it correctly that one can't use -Wbidi-chars=ucn?

You could, it just means use the default (=unpaired) with UCN checking enabled.
Do you want me to make a note about that in the manual?

Marek