Remove unused Google benchmark dependency

Closes #419

See merge request gysela-developpers/gyselalibxx!827

--------------------------------------------

.gitmodules

@@ -2,9 +2,6 @@
 	path = vendor/googletest
 	url = https://github.com/google/googletest.git
 	branch = master
-[submodule "vendor/benchmark"]
-	path = vendor/benchmark
-	url = https://github.com/google/benchmark.git
 [submodule "vendor/kokkos"]
 	path = vendor/kokkos
 	url = https://github.com/kokkos/kokkos.git

CMakeLists.txt

@@ -15,7 +15,6 @@ list(INSERT CMAKE_MODULE_PATH 0 "${CMAKE_SOURCE_DIR}/cmake")
 set(CMAKE_CXX_STANDARD 17 CACHE INTERNAL "The C++ standard whose features are requested to build this project.")
 
 ## List of options
-option(GYSELALIBXX_BUILD_BENCHMARKS "Build the benchmarks." OFF)
 option(GYSELALIBXX_BUILD_DOCUMENTATION "Build the documentation." OFF)
 option(GYSELALIBXX_BUILD_SIMULATIONS "Build the simulations." ON)
 option(GYSELALIBXX_BUILD_TESTING "Build the tests." ON)
@@ -91,29 +90,6 @@ if("${GYSELALIBXX_INCLUDE_TESTING_DEPENDENCIES}")
   endif()
 endif()
 
-## if benchmarks are enabled, use (google) benchmark from `vendor/`
-### we use it to write our micro-benchmarks
-### this must come after googletest
-if("${GYSELALIBXX_BUILD_BENCHMARKS}")
-    set(GYSELALIBXX_benchmark_DEPENDENCY_POLICY "AUTO" CACHE STRING "Policy to find the `benchmark` package. Options: ${GYSELALIBXX_DEPENDENCY_POLICIES}")
-    set_property(CACHE GYSELALIBXX_benchmark_DEPENDENCY_POLICY PROPERTY STRINGS ${GYSELALIBXX_DEPENDENCY_POLICIES})
-
-    if("${GYSELALIBXX_benchmark_DEPENDENCY_POLICY}" STREQUAL "AUTO")
-      find_package(benchmark "1.6" QUIET)
-      if(NOT "${benchmark_FOUND}")
-        option(BENCHMARK_ENABLE_TESTING "Enable testing of the benchmark library." OFF)
-        option(BENCHMARK_ENABLE_INSTALL "Enable installation of benchmark. (Projects embedding benchmark may want to turn this OFF.)" OFF)
-        add_subdirectory("vendor/benchmark/" "benchmark") # SYSTEM)
-      endif()
-    elseif("${GYSELALIBXX_benchmark_DEPENDENCY_POLICY}" STREQUAL "EMBEDDED")
-      option(BENCHMARK_ENABLE_TESTING "Enable testing of the benchmark library." OFF)
-      option(BENCHMARK_ENABLE_INSTALL "Enable installation of benchmark. (Projects embedding benchmark may want to turn this OFF.)" OFF)
-      add_subdirectory("vendor/benchmark/" "benchmark") # SYSTEM)
-    elseif("${GYSELALIBXX_benchmark_DEPENDENCY_POLICY}" STREQUAL "INSTALLED")
-      find_package(benchmark "1.6" REQUIRED)
-    endif()
-endif()
-
 ## Use Kokkos from `vendor/`
 if("${Kokkos_ENABLE_CUDA}")
   option(Kokkos_ENABLE_CUDA_CONSTEXPR "Whether to activate experimental relaxed constexpr functions" ON)

spack.yaml

@@ -3,7 +3,6 @@ spack:
     unify: when_possible
   specs:
   - '[email protected]:'
-  - 'benchmark'
   - 'googletest +gmock'
   - 'fftw ~mpi precision=double'
   - 'lapack'

toolchains/a100.leonardo.spack/spack.yaml

@@ -5,7 +5,6 @@ spack:
   - compilers:
     - gcc@12
   - packages:
-    - benchmark
     - [email protected]:3
     - cuda
     - eigen