[postgis-devel] GDALFPolygonize... none required ?

[Sandro Santilli]

On Mon, Jun 11, 2012 at 10:02:47AM -0700, dustymugs wrote:
> On 06/11/2012 09:38 AM, Sandro Santilli wrote:
> > I see this has been already asked:
> > http://postgis.refractions.net/pipermail/postgis-devel/2012-March/020024.html
> > 
> > But I'm not sure I'm convinced by the explanation there.
> > The message seems to suggest that it's not even being checked
> > if or not GDALAllRegister / GDALFPolygonize is available, but
> > we do account for two different variables for it.
> > 
> > What does "none required" mean ?
> > Is it because the check result was already cached ?
> > Is presence of GDALAllRegister precluding GDALFPolygonize from being checked ?
> > 
> 
> "None required" means that the configure doesn't need user involvement
> to resolve the dependency.  Actually, the "None required" is straight
> from autoconf's AC_SEARCH_LIBS()
> 
> http://www.gnu.org/software/autoconf/manual/autoconf.html#Libraries

Thanks for the pointer. So it looks like "none required" means that
all the required libraries for the searched symbol are already in the
LIBS variable, not needing to add any more.

Not surprising if -lgdal was already added by the first check (for
GDALAllRegister). But confirms GDALFPolygonize is _also_ checked.

> GDALAllRegister is also checked using AC_SEARCH_LIBS prior to
> GDALFPolygonize.
> 
> The problem with AC_CHECK_LIB() is that we aren't assured of the various
> names of the GDAL library as provided by a distro package.  This is
> particularly true in debian.

But we're calling it with a single library name (gdal) so how is that
going to fix different naming ?

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