Fix fseek test

[islas]

TYPE: bug fix

KEYWORDS: fseek, compilation, cmake

SOURCE: internal

DESCRIPTION OF CHANGES:
Problem:
The fseek test lacks correct syntax causing false negative reports of feature not existing when newer compiler standards disallow this.

Solution:
Add int to the main program in the fseek test. Also to add further robustness in detecting this feature, use the -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE=1 generally *nix standard defines.

LIST OF MODIFIED FILES:
M CMakeLists.txt
M confcheck/CMakeLists.txt
M tools/fseek_test.c

RELEASE NOTE: Fix fseek test

[Plantain]

This seems to break the build in an odd way, or at least my build:

#11 21.86 -- WRF_CONFIG           : /home/wrf/WRF/_build/wrf_config.cmake
#11 21.86 -- CMAKE_BUILD_TYPE     : Release
#11 21.86 -- WRF_CORE             : ARW
#11 21.86 -- WRF_NESTING          : BASIC
#11 21.86 -- WRF_CASE             : EM_REAL
#11 21.86 -- USE_DOUBLE           : OFF
#11 21.86 -- USE_MPI              : ON
#11 21.86 -- USE_OPENMP           : OFF
#11 21.86 -- USE_IPO              : OFF
#11 21.86 -- ENABLE_CHEM          : OFF
#11 21.86 -- ENABLE_CLM           :
#11 21.86 -- ENABLE_CMAQ          : OFF
#11 21.86 -- ENABLE_DFI_RADAR     : OFF
#11 21.86 -- ENABLE_HYDRO         : OFF
#11 21.86 -- ENABLE_KPP           : OFF
#11 21.86 -- ENABLE_MARS          : OFF
#11 21.86 -- ENABLE_TERRAIN       : OFF
#11 21.86 -- ENABLE_TITAN         : OFF
#11 21.86 -- ENABLE_VENUS         : OFF
#11 21.86 -- USE_ALLOCATABLES     : ON
#11 21.86 -- wrfmodel             : ON
#11 21.86 -- GRIB1                : ON
#11 21.86 -- INTIO                : ON
#11 21.86 -- KEEP_INT_AROUND      : ON
#11 21.86 -- LIMIT_ARGS           : ON
#11 21.86 -- FORCE_NETCDF_CLASSIC  : ON
#11 21.86 -- BUILD_RRTMG_FAST     : ON
#11 21.86 -- BUILD_RRTMK          : OFF
#11 21.86 -- BUILD_SBM_FAST       : ON
#11 21.86 -- SHOW_ALL_VARS_USED   : OFF
#11 21.86 -- WRFIO_NCD_NO_LARGE_FILE_SUPPORT      : OFF
#11 21.86 -- Performing Test Fortran_2003_IEEE
#11 22.14 -- Performing Test Fortran_2003_IEEE - Success
#11 22.14 -- Performing Test Fortran_2003_ISO_C
#11 22.42 -- Performing Test Fortran_2003_ISO_C - Success
#11 22.43 -- Performing Test Fortran_2003_FLUSH
#11 22.70 -- Performing Test Fortran_2003_FLUSH - Success
#11 22.70 -- Performing Test Fortran_2003_GAMMA
#11 22.97 -- Performing Test Fortran_2003_GAMMA - Success
#11 22.97 -- Performing Test FSEEKO64
#11 23.09 -- Performing Test FSEEKO64 - Failed
#11 23.09 -- fseeko64 not supported, checking alternate fseeko
#11 23.09 -- Performing Test FSEEKO
#11 23.34 -- Performing Test FSEEKO - Success
#11 23.35 -- Adding [io_pnetcdf] to configuration
#11 23.36 -- Setting gen_comms to RSL_LITE
#11 23.40 -- Setting module_dm to RSL_LITE
#11 23.40 -- Configuring done (5.9s)
#11 23.58 -- Generating done (0.1s)
#11 23.59 -- Build files have been written to: /home/wrf/WRF/_build
#11 23.61 Using default build directory : /home/wrf/WRF/_build
#11 23.74 [  0%] Preprocessing md_calls
#11 23.75 [  0%] Building C object external/io_grib_share/CMakeFiles/io_grib_share.dir/gridnav.c.o
#11 23.75 [  0%] Building C object external/io_grib_share/CMakeFiles/io_grib_share.dir/open_file.c.o
#11 23.75 [  0%] Building Fortran object external/io_int/CMakeFiles/io_int.dir/__/__/frame/module_internal_header_util.F.o
#11 23.75 [  0%] Building Fortran object external/io_grib_share/CMakeFiles/io_grib_share.dir/io_grib_share.F.o
#11 23.75 [  0%] Building C object external/io_grib_share/CMakeFiles/io_grib_share.dir/get_region_center.c.o
#11 23.75 [  0%] Preprocessing io_netcdf_c_preproc_wrf_io
#11 23.75 [  0%] Building Fortran object external/RSL_LITE/CMakeFiles/RSL_LITE.dir/f_pack.F90.o
#11 23.75 [  0%] Building C object tools/CMakeFiles/registry.dir/registry.c.o
#11 23.75 [  0%] Building C object external/io_grib1/MEL_grib1/CMakeFiles/MEL_grib1.dir/FTP_getfile.c.o
#11 23.75 [  0%] Preprocessing io_pnetcdf_c_preproc_wrf_io
#11 23.75 [  0%] Building C object external/io_grib1/grib1_util/CMakeFiles/grib1_util.dir/alloc_2d.c.o
#11 23.76 [  0%] Building Fortran object external/io_grib1/CMakeFiles/io_grib1.dir/io_grib1.F.o
#11 23.76 [  0%] Building C object external/io_grib1/WGRIB/CMakeFiles/WGRIB.dir/seekgrib.c.o
#11 23.76 [  0%] Building Fortran object external/esmf_time_f90/CMakeFiles/esmf_time_f90.dir/ESMF_Base.F90.o
#11 23.76 [  0%] Building Fortran object external/fftpack/fftpack5/CMakeFiles/fftpack5.dir/c1f2kb.F.o
#11 23.78 cpp: fatal error: too many input files

[islas]

@Plantain Thanks for the catch! The issue was some assumptions made in the use of cmake generator expressions. PR #2056 should fix that issue so that this will build properly.

[islas]

Requires #2056 and #2053

[amstokely]

I’ll approve these changes, but I noticed that the use of void main() in fseek_test.c is not ISO C compliant. Is there any reason why the contents of main() can’t be moved to a new function, which can then be called from an int main()? This wouldn't alter the current code's behavior and would make it ISO C compliant.

[islas]

the use of void main() in fseek_test.c is not ISO C compliant

I didn't actually know that void return on main wasn't ISO C. I think we don't even need to move it to a function if instead of the exit( retval ) call we replace that with return retval

[mgduda]

@islas Can you update the PR description to note that main returns an int rather than void?

[islas]

Rebased to v4.6.1 to resolve conflicts from duplicate changes