cmake: use IMPORTED target for the threads library (#1991)

CMakeLists.txt

@@ -51,6 +51,7 @@ project(migraphx LANGUAGES C CXX)
 include(CTest)
 
 find_package(ROCM REQUIRED)
+find_package(Threads REQUIRED)
 
 find_path(HALF_INCLUDE_DIR half.hpp PATH_SUFFIXES half)
 if (NOT HALF_INCLUDE_DIR)

src/CMakeLists.txt

@@ -248,8 +248,6 @@ endif()
 target_link_libraries(migraphx PRIVATE -ldl)
 
 target_include_directories(migraphx SYSTEM PUBLIC $<BUILD_INTERFACE:${HALF_INCLUDE_DIR}>)
-
-find_package(Threads)
 target_link_libraries(migraphx PUBLIC Threads::Threads)
 
 find_package(nlohmann_json 3.8.0 REQUIRED)

test/CMakeLists.txt

@@ -98,17 +98,11 @@ endfunction()
 
 function(add_test_executable TEST_NAME)
     add_executable(${TEST_NAME} EXCLUDE_FROM_ALL ${ARGN})
-    target_link_libraries(${TEST_NAME} ${CMAKE_THREAD_LIBS_INIT})
-
-    # Cmake does not add flags correctly for gcc
-    if(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
-        set_target_properties(${TEST_NAME} PROPERTIES COMPILE_FLAGS -pthread LINK_FLAGS -pthread)
-    endif()
     set(TEST_COMMAND ${TEST_NAME})
     add_test_command(${TEST_NAME} ${TEST_COMMAND})
     add_dependencies(tests ${TEST_NAME})
     add_dependencies(check ${TEST_NAME})
-    target_link_libraries(${TEST_NAME} migraphx migraphx_onnx migraphx_ref)
+    target_link_libraries(${TEST_NAME} Threads::Threads migraphx migraphx_onnx migraphx_ref)
     target_include_directories(${TEST_NAME} PUBLIC include)
 endfunction(add_test_executable)