On Mon, Aug 16, 2021 at 07:45:55PM -0400, Jason Merrill wrote:
> On 8/16/21 4:51 PM, Jakub Jelinek wrote:
> > On Mon, Aug 16, 2021 at 04:21:00PM -0400, Jason Merrill wrote:
> > > > I see for the UTF-8 chars we have:
> > > > switch (ucn_valid_in_identifier (pfile, *cp, nst))
> > > > {
> > > > case 0:
> > > > /* In C++, this is an error for invalid character in an
> > > > identifier
> > > > because logically, the UTF-8 was converted to a UCN
> > > > during
> > > > translation phase 1 (even though we don't physically do
> > > > it that
> > > > way). In C, this byte rather becomes grammatically a
> > > > separate
> > > > token. */
> > > > if (CPP_OPTION (pfile, cplusplus))
> > > > cpp_error (pfile, CPP_DL_ERROR,
> > > > "extended character %.*s is not valid in an
> > > > identifier",
> > > > (int) (*pstr - base), base);
> > > > else
> > > > {
> > > > *pstr = base;
> > > > return false;
> > > > }
> > > > So, shall we behave the same as C for cxx23_identifiers here? And
> > > > shall we
> > > > do something similar for the UCNs in \uxxxx and \Uxxxxxxxx forms?
> > > > Confused...
> > >
> > > I tend to agree with Joseph's comment on your followup patch about this
> > > issue; do you?
> >
> > It isn't clear to me if it is ok that it is an error even with just -E,
> > i.e. whether
> > "If a single universal-character-name does not match any of the other
> > preprocessing token categories, the program is ill-formed."
> > applies already in translation phase 4 which is what -E emits (or some other
> > one?), or only in phase 7 when converting preprocessing tokens to tokens.
>
> I read it as applying in phase 3.
Ok, follow-up patch withdrawn.
Jakub
