Move FetchContent for benchmark to extern

CMakeLists.txt

@@ -154,6 +154,8 @@ option(RECASTNAVIGATION_STATIC "Build recastnavigation static libraries" ${_reca
 
 option(OPENMW_USE_SYSTEM_SQLITE3 "Use system provided SQLite3 library" ON)
 
+option(OPENMW_USE_SYSTEM_BENCHMARK "Use system Google Benchmark library." OFF)
+
 option(OPENMW_UNITY_BUILD "Use fewer compilation units to speed up compile time" FALSE)
 option(OPENMW_LTO_BUILD "Build OpenMW with Link-Time Optimization (Needs ~2GB of RAM)" OFF)
 

apps/benchmarks/CMakeLists.txt

@@ -1,27 +1,5 @@
-option(OPENMW_USE_SYSTEM_BENCHMARK "Use system Google Benchmark library." OFF)
-
 if(OPENMW_USE_SYSTEM_BENCHMARK)
     find_package(benchmark REQUIRED)
-else()
-    cmake_minimum_required(VERSION 3.11)
-
-    set(BENCHMARK_ENABLE_TESTING OFF)
-    set(BENCHMARK_ENABLE_INSTALL OFF)
-    set(BENCHMARK_ENABLE_GTEST_TESTS OFF)
-
-    set(SAVED_CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-
-    string(REPLACE "-Wsuggest-override" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-    string(REPLACE "-Wundef" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-    include(FetchContent)
-    FetchContent_Declare(benchmark
-        URL https://github.com/google/benchmark/archive/refs/tags/v1.5.2.zip
-        URL_HASH MD5=49395b757a7c4656d70f1328d93efd00
-        SOURCE_DIR fetched/benchmark
-    )
-    FetchContent_MakeAvailableExcludeFromAll(benchmark)
-
-    set(CMAKE_CXX_FLAGS "${SAVED_CMAKE_CXX_FLAGS}")
 endif()
 
 openmw_add_executable(openmw_detournavigator_navmeshtilescache_benchmark detournavigator/navmeshtilescache.cpp)

extern/CMakeLists.txt

@@ -210,3 +210,19 @@ if (NOT OPENMW_USE_SYSTEM_SQLITE3)
 endif()
 
 add_subdirectory(smhasher)
+
+if (NOT OPENMW_USE_SYSTEM_BENCHMARK)
+    cmake_minimum_required(VERSION 3.11)
+
+    set(BENCHMARK_ENABLE_TESTING OFF)
+    set(BENCHMARK_ENABLE_INSTALL OFF)
+    set(BENCHMARK_ENABLE_GTEST_TESTS OFF)
+
+    include(FetchContent)
+    FetchContent_Declare(benchmark
+        URL https://github.com/google/benchmark/archive/refs/tags/v1.5.2.zip
+        URL_HASH MD5=49395b757a7c4656d70f1328d93efd00
+        SOURCE_DIR fetched/benchmark
+    )
+    FetchContent_MakeAvailableExcludeFromAll(benchmark)
+endif()