Re: double inclusion of '-p' flex flag

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."

-- 
John Naylor
EDB: http://www.enterprisedb.com