On Thu, May 08 2014, David Bremner <david at tethera.net> wrote: > Tomi Ollila <tomi.ollila at iki.fi> writes: > >> >> But, I'd like suggest alternate option to create a test c program >> and test whether it compiles (analogous to what there is already >> done with many other checks) -- this same would apply to fdatasync() >> case too. >> > > I agree in principle, but I'm not sure it's detectable at compile time, > since the option we need is passed as a string (boo!). > > I guess the ZLIB_VERNUM hack would be preferable to adding platform > specific checks to configure. But note you'd need somehow to find > zlib.h.
Actually my suggestion would be that if that pkg-config line for zlib does not work (btw why does it not work) try an option where zlib_cflags is expected to be empty and and zlib_ldflags -lz -- and try compile and run test program with those options then the test program is something like int main(void) { return(ZLIB_VERNUM >= 0x1252); } (perhaps we could manage the same value in slightly different formats in 2 tests and remember to update those in sync .. or we could try: zv1=1 zv2=2 zv3=5 zv4= if pkg-config --atleast-version=$zv1.$zv2.$zv3.$zv4 zlib; then and return(ZLIB_VERNUM >= 0x$zv1$zv2$zv3$zv4); > > d Tomi