compilation fails when simmetrix is enabled and sim_discrete is disabled

[cwsmith]

Disabling SimDiscrete results in a linking error (details below).

The cmake option is here:

omega_h/cmake/FindSimModSuite.cmake

Lines 157 to 160 in a730c78

	option(SIM_DISCRETE "Use Simmetrix discrete modeling" ON)
	if (SIM_DISCRETE)
	set(SIM_CAD_LIB_NAMES SimDiscrete ${SIM_CAD_LIB_NAMES})
	endif()

Is SimDiscrete required? If so, what functionality needs it?

environment

module use /opt/scorec/spack/rhel9/v0201_4/lmod/linux-rhel9-x86_64/Core/
module load gcc/12.3.0-iil3lno mpich/4.1.1-xpoyz4t cuda/12.1.1-zxa4msk
module load cmake
module load simmetrix-simmodsuite/2025.0-241025dev-rirnzju

cmake config

build error

[ 49%] Linking CXX executable describe
cd /space/cwsmith/omegahSimDebug/buildOmegahHostSim_discreteoff/src && /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/cmake-3.26.3-2duxfcdiykykfynkadpp2m2y6zrmuvz4/bin/cmake -E cmake_link_script CMakeFiles/describe.dir/link.txt --verbose=1
/opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-7.4.0/gcc-12.3.0-iil3lnovyknyxf7pec36wljem3fntjd5/bin/g++ -g -Wl,-rpath -Wl,/opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/mpich-4.1.1-xpoyz4tqgfxtrm6m7qq67q4ccp5pnlre/lib CMakeFiles/describe.dir/describe.cpp.o -o describe  -Wl,-rpath,/space/cwsmith/omegahSimDebug/buildOmegahHostSim_discreteoff/src:/opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/libtirpc-1.2.6-k2lf3byep5phz3y6ei7xm4pdbw5jwusn/lib:/opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/zlib-1.2.13-mjocrm2cwyth6kvpmj3yrg52ulwd64ow/lib:/opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/mpich-4.1.1-xpoyz4tqgfxtrm6m7qq67q4ccp5pnlre/lib:::::::: libomega_h.so /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimField.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimAdvMeshing.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimPartitionedMesh-mpi.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimMeshing.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimMeshTools.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimModel.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/simmetrix-simmodsuite-2023.1-230907dev-jquex4zn5d7xd2ohri3xzbsrvubonoex/lib/x64_rhel8_gcc83/libSimPartitionWrapper-mpich4.1.1.a /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/libtirpc-1.2.6-k2lf3byep5phz3y6ei7xm4pdbw5jwusn/lib/libtirpc.so /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/zlib-1.2.13-mjocrm2cwyth6kvpmj3yrg52ulwd64ow/lib/libz.so /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/mpich-4.1.1-xpoyz4tqgfxtrm6m7qq67q4ccp5pnlre/lib/libmpicxx.so /opt/scorec/spack/rhel9/v0201_4/install/linux-rhel9-x86_64/gcc-12.3.0/mpich-4.1.1-xpoyz4tqgfxtrm6m7qq67q4ccp5pnlre/lib/libmpi.so 
/usr/bin/ld: libomega_h.so: undefined reference to `SimDiscrete_start(int)'
/usr/bin/ld: libomega_h.so: undefined reference to `SimDiscrete_stop(int)'
collect2: error: ld returned 1 exit status

[cwsmith]

With commit ad94723 a new cmake argument is supported Omega_h_USE_SimDiscrete. It is off by default.

When it is disabled only Simmetrix GeomSim models can be loaded. When it is enabled Simmetrix discrete models can also be loaded. Note, both GeomSim and discrete models have the .smd extension.

The mixed mesh tests here:

omega_h/src/CMakeLists.txt

Lines 432 to 442 in ad94723

	if(Omega_h_USE_SimDiscrete)
	osh_add_exe(mixed_writeMesh)
	set(TEST_EXES ${TEST_EXES} mixed_writeMesh)
	test_func(run_mixed_writeMesh 1 ./mixed_writeMesh
	${CMAKE_SOURCE_DIR}/meshes)
	osh_add_exe(mixed_test)
	set(TEST_EXES ${TEST_EXES} mixed_test)
	test_func(run_mixed_test 1 ./mixed_test
	${CMAKE_SOURCE_DIR}/meshes)
	endif()

create and load discrete models so they are now conditional on Omega_h_USE_SimDiscrete.