support optional gitee gtest download (#1793)

* support gitee gtest download

* put the download address in googletest.cmake.in

Author: denghuilu

source/cmake/googletest.cmake.in

@@ -2,9 +2,15 @@ cmake_minimum_required(VERSION 2.8.2)
 
 project(googletest-download NONE)
 
+if (USE_GITEE_GTEST)
+  set(GTEST_REPO_ADDRESS "https://gitee.com/mirrors/googletest.git")
+else ()
+  set(GTEST_REPO_ADDRESS "https://github.com/google/googletest.git")
+endif()
+
 include(ExternalProject)
 ExternalProject_Add(googletest
-  GIT_REPOSITORY    https://github.com/google/googletest.git
+  GIT_REPOSITORY    ${GTEST_REPO_ADDRESS}
   GIT_TAG           main
   SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
   BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"