Re: [PATCH] Revert 'Fix logic error in _AC_PROG_LEX_YYTEXT_DECL (#109320)'

[Ross Burton]

Building bc:

checking for flex... flex
checking for lex output file root... lex.yy
checking for lex library... not found
configure: WARNING: required lex library not found; giving up on flex
...
configure: error: readline works only with flex.

Again, bc's scanner has its own yywrap implementation, so it doesn't
need to link to libfl.

Ross

On Thu, 16 Jul 2020 at 19:52, Zack Weinberg <zackw@panix.com> wrote:
>
> On Thu, Jul 16, 2020 at 2:47 PM Ross Burton <ross@burtonini.com> wrote:
> > On Thu, 16 Jul 2020 at 19:41, Zack Weinberg <zackw@panix.com> wrote:
> > > Can we slow down a bit please?  I had written out a patch (basically
> > > equivalent to what's now in trunk) and I am in the process of setting
> > > up a cross-compilation environment to validate the fix for certain,
> > > but this is going to take several hours.
> > >
> > > I believe that what's in trunk now should work fine for
> > > cross-compilation of programs that don't require yywrap, even if there
> > > is no target libfl, even for source tarballs that don't ship lex.yy.c,
> > > as long as the flex program is available in the build environment.  If
> > > that's not the scenario you're talking about, Ross, please clarify,
> > > but I don't see how a tarball that doesn't ship the generated scanner
> > > could ever have worked with no flex at all.
> >
> > Build-testing current master now. Will report back later: I love Yocto
> > but it is annoying to work on something like autoconf as that causes a
> > toolchain rebuild...
>
> Thanks for testing.  I will proceed with my own tests in parallel.
>
> I pushed another change but it just revises the manual section for
> AC_PROG_LEX some more.
>
> zw