Re: double inclusion of '-p' flex flag - Mailing list pgsql-hackers

From Ashutosh Sharma
Subject Re: double inclusion of '-p' flex flag
Date
Msg-id CAE9k0PmrADcayHJ74RL+v8z2zbjz0CppJikv4zy8L5cMUB2bTQ@mail.gmail.com
Whole thread Raw
In response to Re: double inclusion of '-p' flex flag  (John Naylor <john.naylor@enterprisedb.com>)
List pgsql-hackers
On Tue, Apr 26, 2022 at 5:55 PM John Naylor
<john.naylor@enterprisedb.com> wrote:
>
> On Tue, Apr 26, 2022 at 7:16 PM Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
> >
> > Hi,
> >
> > I see that we have included '-p' flex flag twice in the commands used
> > to generate the scanner files. See below:
> >
> > src/backend/parser/Makefile:60:        scan.c: FLEXFLAGS = -CF -p -p
> > src/backend/utils/adt/Makefile:122:    jsonpath_scan.c: FLEXFLAGS = -CF -p -p
> > src/bin/psql/Makefile:61:       psqlscanslash.c: FLEXFLAGS = -Cfe -p -p
> > src/fe_utils/Makefile:43:        psqlscan.c: FLEXFLAGS = -Cfe -p -p
> > src/backend/utils/adt/Makefile:122:    jsonpath_scan.c: FLEXFLAGS = -CF -p -p
> > src/bin/psql/Makefile:61:        psqlscanslash.c: FLEXFLAGS = -Cfe -p -p
> >
> > Do we need this or can the extra -p flag be removed?
>
> From the Flex manual:
>
> "generates a performance report to stderr. The report consists of
> comments regarding features of the flex input file which will cause a
> serious loss of performance in the resulting scanner. If you give the
> flag twice, you will also get comments regarding features that lead to
> minor performance losses."
>

Ahh. I see. This information is missing in the man page. thanks.!

--
With Regards,
Ashutosh Sharma.



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