[gdal-dev] Fwd: GPKG Driver

[Even Rouault]

Selon Pepijn Van Eeckhoudt <pepijn at vaneeckhoudt.net>:

> > Regarding cmake, I guess that adding the names of the .c files in a
> GNUmakefile
> > / makefile.vc should do it. One worry I have is the minimum MSVC version to
> > build it. In libgpkg history I see a mention of Visual Studio Express 2012.
> > Don't know if it works with older versions but I can see some use of C99
> > (int64_t) extensions that will likely not please older compiler versions.
> It's indeed a C99 library. Seems silly to still not be able to use a language
> revision from more than a decade ago.
>
> For msvc I'm using the 'compile as c++' flag to work around lack of c99
> support. From the 2013 release notes it looks like there's now sufficient
> support for c99 that this will no longer be necessary, but I haven't tested
> that yet. 2012 is what I tested with so far. Might work on older versions but
> never tried.

> Are people still using old msvc compilers these days ?

Yes, people are sometimes a few versions behind the latest one. There are
sometimes good (or bad) reasons to do that. For example for a software
distribution like OSGeo4W, you want to make sure as much as possible that all
components are built with the same compiler version to avoid issues with
different and incompatible C runtime. And migrating a full stack of software can
take some time. You may also have to deal with binary SDKs (FileGDB, ECW SDK,
etc...) that are provided only for a few versions of the compiler, and not
necessarily the latest one.

As an example of how antique compilers can be used, Tamas Szekeres maintains
builds of GDAL and MapServer from MSVC 1310 (VS 2003) to MSVC 1600 :
http://gisinternals.com/sdk/ . VS 2003 and 2005 is admitedly a bit extreme now.

> Why would you if the recent ones are available for free?

This has maybe changed in latest releases, but the Express editions in the past
didn't include Win64 support for example. I also believe they didn't have OpenMP
support, but I don't think it is widely used in OSGeo4W stack.

Even