[Spice-devel] [PATCH spice-common] spice-deps: Make LZ4 check depending on function

[Pavel Grunt]

On Thu, 2016-11-24 at 06:25 -0500, Frediano Ziglio wrote:
> > 
> > On Thu, 2016-11-24 at 05:18 -0500, Frediano Ziglio wrote:
> > > > LZ4 changed versioning scheme from r131 to v1.7.3 making our
> > > > configure
> > > > fail with (1.7.3 < 129).
> > > > 
> > > > Switch from version checking to checking that the necessary
> > > > function
> > > > is available.
> > > > ---
> > > >  m4/spice-deps.m4 | 6 ++++--
> > > >  1 file changed, 4 insertions(+), 2 deletions(-)
> > > > 
> > > > diff --git a/m4/spice-deps.m4 b/m4/spice-deps.m4
> > > > index adedec4..43a7d4a 100644
> > > > --- a/m4/spice-deps.m4
> > > > +++ b/m4/spice-deps.m4
> > > > @@ -185,12 +185,14 @@ AC_DEFUN([SPICE_CHECK_LZ4], [
> > > >  
> > > >      have_lz4="no"
> > > >      if test "x$enable_lz4" != "xno"; then
> > > > -      PKG_CHECK_MODULES([LZ4], [liblz4 >= 129],
> > > > [have_lz4="yes"],
> > > > [have_lz4="no"])
> > > > +      PKG_CHECK_MODULES([LZ4], [liblz4], [
> > > > +          AC_SEARCH_LIBS([LZ4_compress_default], [lz4],
> > > > [have_lz4="yes"],
> > > > [have_lz4="no"])],
> > > > +          [have_lz4="no"])
> > > >  
> > > 
> > > have_lz4 by default is defined no so you could remove the
> > > assignment
> > > to "no", but that's not a problem.
> > 
> > ok
> > 
> > > 
> > > Using AC_SEARCH_LIBS and [lz4] as library you are assuming you
> > > can
> > > link lz4 library with -llz4 (more or less) but this can be a
> > > problem
> > > if you are using MingW or another cross compiler that needs
> > > other
> > > options. Maybe this is hidden by the fact that we just require a
> > > library path and is already included by another library.
> > > Did you try to cross compile the client for Windows?
> > 
> > lz4 is not available for mingw so I haven't tried it
> > 
> 
> Mumble... but probably is worth adding in the future.
> As far as I know the code should be something like
> https://cgit.freedesktop.org/spice/spice-gtk/commit/?id=f697933524b1
> 9186cb078b5fca43f748fd68cf9f
> replacing LIBS and CFLAGS temporarily before doing the function
> check but it's quite ugly (well, lot of configure code looks ugly
> to me...)
>  
not a bad idea, i will do it

> > > 
> > > >        if test "x$have_lz4" = "xyes"; then
> > > >          AC_DEFINE(USE_LZ4, [1], [Define to build with lz4
> > > > support])
> > > >        elif test "x$enable_lz4" = "xyes"; then
> > > > -        AC_MSG_ERROR([lz4 support requested but liblz4 could
> > > > not
> > > > be found])
> > > > +        AC_MSG_ERROR([lz4 support requested but liblz4 >= 129
> > > > could not be
> > > > found])
> > > >        fi
> > > >      fi
> > > >      AM_CONDITIONAL(HAVE_LZ4, test "x$have_lz4" = "xyes")
> > > 
> > > Beside the cross compilation issue patch works for me.
> > > 
> 
> Frediano