Re: [MinGW-dvlpr] [Flex-devel] flex 2.5.33 under MSYS

[Keith M. <kei...@us...>]

On Sunday 22 April 2007 07:21, Julien Lecomte wrote:
> > Based on your comments, it looks like you could set an LDFLAGS
> > variable to include -lregex, and then you wouldn't have to re-run
> > the link command when building flex. Is that correct?
>
> That was my first reaction to link libregex. Awkwardly, it doesn't
> work: $ ./configure --prefix=3D/usr
> $ make LDFLAGS=3D'-lregex' flex.exe
> gcc -g -O2 -lregex -o flex.exe =C2=A0ccl.o dfa.o ecs.o gen.o main.o misc.o
> nfa.o parse.o scan.o skel.o sym.o tblcmp.o yylex.o options.o
> scanopt.o buf.o tables.o tables_shared.o filter.o regex.o -lm
>
> Note where the LDFLAGS where inserted!

Which is correct; AIUI, you are not supposed to add actual *libraries*
to LDFLAGS; it is intended for *flags* affecting the behaviour of the
linker, or specifying supplementary linker search paths.

> It would 'work' with the LIBS flag though, but I'm pretty sure it's
> not standard procedure to mess with LIBS:

On the contrary, that's exactly where you should specify libraries that=20
you know will be required.  If the configure script is generated by=20
autoconf >=3D 2.50, the best way to do it is

  ./configure --prefix=3D/usr LDFLAGS=3D-L/lib/search/path LIBS=3D-lregex

so that configure can *add* any extra libraries it needs to.  As you=20
point out, it is not wise to mess with LIBS, nor even with LDFLAGS, in=20
the make command line, as that will override any other requirements=20
discovered by the configure script.

If the configure script is generated by an older autoconf, then you=20
can't add these definitions as configure arguments; you should pass=20
them to configure via the environment instead:

  LDFLAGS=3D-L/lib/search/path LIBS=3D-lregex ./configure --prefix=3D/usr

(and respectfully suggest to the package maintainers, that it's time
 they upgraded their build tools).

Oh, and if the package maintainers think they can write the configure=20
script without using a tool like autoconf, then you really are in=20
trouble, for I've yet to see one of those that actually works properly,=20
on any platform the maintainer himself hasn't encountered.

Regards,
Keith.