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[netCDF #QVV-651237]: NetCDF 3.6.3: build warning for f90 library

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  • Subject: [netCDF #QVV-651237]: NetCDF 3.6.3: build warning for f90 library
  • Date: Mon, 20 Jun 2011 10:34:09 -0600
Hi Reto

> I've upgraded to both NetCDF 3.6.3 and the fink install of gcc/gfortran
> 4.5.2 on OSX 10.6 x86_64. NetCDF 3.6.3 builds fine and runs with both
> the C and F90 interfaces. So far so good.
> 
> What worries me is the following warning during build-time, that was
> never there before in earlier NetCDF or gcc/gfortran versions. This may
> be a hint that the array is initialized with 0 dimension size and may
> cause problem under certain circumstances?
> 
> libtool: compile:  gfortran -I../libsrc -I. -g -O2 -c netcdf.f90 -o netcdf.o
> netcdf_text_variables.f90:284.93:
> Included at netcdf.f90:51:
> 
> localMap(:numDims  ) = (/ 1, (product(localCount(:counter)), counter = 1, 
> numDims - 1) /)
> 1
> Warning: DO loop at (1) will be executed zero times
> netcdf_text_variables.f90:60.93:
> Included at netcdf.f90:51:
> 
> localMap(:numDims  ) = (/ 1, (product(localCount(:counter)), counter = 1, 
> numDims - 1) /)
> 1
> Warning: DO loop at (1) will be executed zero times
> 
> 
> Please let me know what you think. numDims is initialized earlier on in
> netcdf_text_variables.f90 with the value of 1, so numDims - 1 is 0,
> which means that the localMap(:numDims) will be of size 0. Is that ok or
> not?

It's OK, and has never caused any reported problems other than this
harmless warning that gfortran added in an upgrade.  Getting rid of
the warning actually makes the code less maintainable, but it's
probably worth it for reassuring users who look at the compiler
warnings that it's not a symptom of a bug.

By the way, we just released netCDF-4.1.3 and it can be built with the
--disable-netcdf-4 configure option that results in a netCDF-3 library
completely compatible with the old netCDF-3.6.3 library, but with some
bug fixes and enhancements that haven't been incorporated in the 3.6.3
release.

--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                      http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: QVV-651237
Department: Support netCDF
Priority: Normal
Status: Closed