Fix windows build for gflags for time_tests (#3504)

GFlags builds multiple targets, require aligning build
options on windows builds.

FetchModule offloads project configuration to cmake. This also allows
to align build configurations and targets across projects:
https://crascit.com/2015/07/25/cmake-gtest/

tests/time_tests/CMakeLists.txt

@@ -4,14 +4,17 @@
 
 cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
 
-if (CMAKE_BUILD_TYPE STREQUAL "")
-    message(STATUS "CMAKE_BUILD_TYPE not defined, 'Release' will be used")
-    set(CMAKE_BUILD_TYPE "Release")
-endif()
+set (CMAKE_BUILD_TYPE "Release" CACHE STRING "Choose the build type")
 
-find_package(InferenceEngineDeveloperPackage QUIET)
-if (NOT InferenceEngineDeveloperPackage_FOUND)
-    find_package(InferenceEngine REQUIRED)
+project(time_tests)
+
+
+find_package(InferenceEngine)
+if (NOT InferenceEngine_FOUND)
+    set (HAVE_SYS_STAT_H 1)
+    set (HAVE_INTTYPES_H 1)
+    set (INTTYPES_FORMAT C99)
+    find_package(InferenceEngineDeveloperPackage REQUIRED)
 endif()
 
 add_subdirectory(src)

tests/time_tests/src/timetests_helper/CMakeLists.txt

@@ -8,36 +8,16 @@ file (GLOB SRC *.cpp)
 add_library(${TARGET_NAME} STATIC ${SRC})
 target_include_directories(${TARGET_NAME} PUBLIC "${CMAKE_SOURCE_DIR}/include")
 
-find_package(gflags QUIET)
-if (gflags_FOUND)
-    set(GFLAGS_LIBRARIES gflags)  # use gflags from developer package
-else()
-    include(ExternalProject)
-    find_package(Threads)
-    set(gflags_PREFIX ${CMAKE_BINARY_DIR}/external/gflags-prefix)
-    set(gflags_INSTALL ${CMAKE_BINARY_DIR}/external/gflags-install)
-    set(gflags_LIB ${gflags_INSTALL}/lib/libgflags.a)
-
-    ExternalProject_Add(
-        gflags
-        PREFIX ${gflags_PREFIX}
-        GIT_REPOSITORY "https://github.com/gflags/gflags.git"
-        GIT_TAG "v2.2.2"
-        UPDATE_COMMAND ""
-        INSTALL_DIR ${gflags_INSTALL}
-        CMAKE_BUILD_TYPE ${CMAKE_BUILD_TYPE}
-        CMAKE_GENERATOR ${CMAKE_GENERATOR}
-        CMAKE_GENERATOR_PLATFORM ${CMAKE_GENERATOR_PLATFORM}
-        CMAKE_GENERATOR_TOOLSET ${CMAKE_GENERATOR_TOOLSET}
-        CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${gflags_INSTALL}
-        EXCLUDE_FROM_ALL TRUE
-        BUILD_BYPRODUCTS ${gflags_LIB}
-        LOG_DOWNLOAD 1
-        LOG_INSTALL 1
-    )
-    set(GFLAGS_LIBRARIES ${gflags_LIB} ${CMAKE_THREAD_LIBS_INIT})
-    add_dependencies(${TARGET_NAME} gflags)
-    target_include_directories(${TARGET_NAME} PRIVATE "${gflags_INSTALL}/include")
+include(FetchContent)
+FetchContent_Declare(
+    gflags
+    GIT_REPOSITORY "https://github.com/gflags/gflags.git"
+    GIT_TAG "v2.2.2"
+)
+FetchContent_GetProperties(gflags)
+if(NOT gflags_POPULATED)
+    FetchContent_Populate(gflags)
+    add_subdirectory(${gflags_SOURCE_DIR} ${gflags_BINARY_DIR})
 endif()
 
-target_link_libraries(${TARGET_NAME} ${GFLAGS_LIBRARIES})
+target_link_libraries(${TARGET_NAME} gflags)