cmake: Fix inconsistent thrust detection across the backends

CMakeLists.txt

@@ -20,7 +20,7 @@ string(REGEX REPLACE "^STDGPU_BACKEND_" "" STDGPU_BACKEND_DIRECTORY ${STDGPU_BAC
 string(TOLOWER ${STDGPU_BACKEND_DIRECTORY} STDGPU_BACKEND_DIRECTORY)
 
 
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake/${STDGPU_BACKEND_DIRECTORY}")
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
 
 
 if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)

src/stdgpu/CMakeLists.txt

@@ -1,4 +1,7 @@
 
+find_package(thrust 1.9.3 REQUIRED)
+
+
 if(${CMAKE_BUILD_TYPE} MATCHES "Release" OR ${CMAKE_BUILD_TYPE} MATCHES "MinSizeRel")
     set(STDGPU_ENABLE_CONTRACT_CHECKS_DEFAULT OFF)
 else()
@@ -12,13 +15,13 @@ option(STDGPU_USE_32_BIT_INDEX "Use 32-bit instead of 64-bit signed integer for
 option(STDGPU_USE_FAST_DESTROY "Use fast destruction of allocated arrays (filled with a default value) by omitting destructor calls in memory API, default: OFF" OFF)
 option(STDGPU_USE_FIBONACCI_HASHING "Use Fibonacci Hashing instead of Modulo to compute hash bucket indices, default: ON" ON)
 
-
 set(STDGPU_INCLUDE_LOCAL_DIR "${CMAKE_CURRENT_LIST_DIR}/..")
 set(STDGPU_CONFIG_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/include")
 
 configure_file("${STDGPU_INCLUDE_LOCAL_DIR}/stdgpu/config.h.in"
                "${STDGPU_CONFIG_BUILD_DIR}/stdgpu/config.h")
 
+
 if(STDGPU_BUILD_SHARED_LIBS)
     add_library(stdgpu SHARED)
 else()
@@ -29,17 +32,21 @@ target_sources(stdgpu PRIVATE impl/iterator.cpp
                               impl/memory.cpp
                               impl/limits.cpp)
 
-add_subdirectory(${STDGPU_BACKEND_DIRECTORY})
-
 target_include_directories(stdgpu PUBLIC
                                   $<BUILD_INTERFACE:${STDGPU_INCLUDE_LOCAL_DIR}>
                                   $<BUILD_INTERFACE:${STDGPU_CONFIG_BUILD_DIR}>
                                   $<INSTALL_INTERFACE:${STDGPU_INCLUDE_INSTALL_DIR}>)
 
 target_compile_features(stdgpu PUBLIC cxx_std_14)
 
+target_link_libraries(stdgpu PUBLIC thrust::thrust)
+
 add_library(stdgpu::stdgpu ALIAS stdgpu)
 
+
+add_subdirectory(${STDGPU_BACKEND_DIRECTORY})
+
+
 # Export targets and install header files
 install(TARGETS stdgpu
         EXPORT stdgpu-targets

src/stdgpu/cuda/CMakeLists.txt

@@ -3,5 +3,7 @@ target_sources(stdgpu PRIVATE impl/memory.cpp
                               impl/bitset.cu
                               impl/mutex.cu)
 
+target_compile_definitions(stdgpu PUBLIC THRUST_DEVICE_SYSTEM=THRUST_DEVICE_SYSTEM_CUDA)
+
 target_include_directories(stdgpu PUBLIC
                                   ${CMAKE_CUDA_TOOLKIT_INCLUDE_DIRECTORIES})

src/stdgpu/openmp/CMakeLists.txt

@@ -1,5 +1,4 @@
 
-find_package(thrust 1.9.3 REQUIRED)
 find_package(OpenMP 2.0 REQUIRED)
 
 target_sources(stdgpu PRIVATE impl/memory.cpp
@@ -8,5 +7,4 @@ target_sources(stdgpu PRIVATE impl/memory.cpp
 
 target_compile_definitions(stdgpu PUBLIC THRUST_DEVICE_SYSTEM=THRUST_DEVICE_SYSTEM_OMP)
 
-target_link_libraries(stdgpu PUBLIC OpenMP::OpenMP_CXX
-                                    thrust::thrust)
+target_link_libraries(stdgpu PUBLIC OpenMP::OpenMP_CXX)