Re: Re: [PATCHES] Select parser at runtime

Ian Lance Taylor <ian@airs.com>

From: Ian Lance Taylor <ian@airs.com>
To: Jan Wieck <JanWieck@Yahoo.com>
Cc: Vince Vielhaber <vev@michvhf.com>, Justin Clift <justin@postgresql.org>, Peter Eisentraut <peter_e@gmx.net>, PostgreSQL Development <pgsql-hackers@postgresql.org>
Date: 2001-08-13T17:08:46Z
Lists: pgsql-hackers
Jan Wieck <JanWieck@Yahoo.com> writes:

>     If we want to have both parsers available at runtime we  need
>     to  replace the YY (case-insensitive) prefix in the generated
>     files per parser and call the right one from tcop.   Now  for
>     some flex/bison combo's at least the prefix switches (to have
>     something different than YY) don't work reliable. There  will
>     be  some  global  YY-objects  left, causing linkage problems.
>     That's why PL/pgSQL's scanner/parser's C-code is run  through
>     sed(1).

This is a solved problem.  gdb, for example, links together four
different Yacc-based parsers, without even using bison's -p option.

Ian