[Paraview] Re: cmake is making bad decisions on our compiler

[Joel Welling]

Joel Welling wrote:
> Hi folks;
>   We're trying to compile ParaView on our Compaq Alpha Tru64 platform using 
> Compaq's cxx and cc compilers rather than GNU, and I've noticed that the cmake 
> process seems to be making some incorrect inferences.  So far, I have found 
> that it is incorrectly setting VTK_OSTREAM_SUPPORTS_LONG_LONG and 
> VTK_ISTREAM_SUPPORTS_LONG_LONG to false, even though the tests in HDF5Tests.c 
> seem to produce the correct result.  Also, H5_HAVE_ATTRIBUTE in H5pubconf.h is 
> being inappropriately set to 1, even though the test for that in HDF5Tests.c 
> seems to fail appropriately.

The root cause of this problem seems to be that I was trying to use ccmake to 
change my choice of compiler.  Apparently some configuration options get 
frozen in the first time cmake does a 'configure', and that must happen before 
ccmake can change the compiler.  The result is that those options are always 
frozen in based on the default compiler, which in our case is gnu.  If the 
options are different from those required with the desired compiler, well, 
tough noogies on you.

One solution is to always specify the compilers by setting the CXX and CC 
environment variables before starting up ccmake for the first time.  I was 
able to solve my problem by deleting everything back down to an empty binary 
tree, setting those environment variables, and then doing ccmake.  (Thanks, 
Bill!)

-Joel