gtest: add submodule

.gitmodules

@@ -11,3 +11,6 @@
 	path = external/supercop
 	url = https://github.com/monero-project/supercop
 	branch = monero
+[submodule "external/gtest"]
+	path = external/gtest
+	url = https://github.com/google/googletest.git

README.md

@@ -195,12 +195,12 @@ sudo apt update && sudo apt install build-essential cmake pkg-config libssl-dev
 
 Install all dependencies at once on Arch:
 ```
-sudo pacman -Syu --needed base-devel cmake boost openssl zeromq unbound libsodium libunwind xz readline expat gtest python3 ccache doxygen graphviz qt5-tools hidapi libusb protobuf systemd
+sudo pacman -Syu --needed base-devel cmake boost openssl zeromq unbound libsodium libunwind xz readline expat python3 ccache doxygen graphviz qt5-tools hidapi libusb protobuf systemd
 ```
 
 Install all dependencies at once on Fedora:
 ```
-sudo dnf install gcc gcc-c++ cmake pkgconf boost-devel openssl-devel zeromq-devel unbound-devel libsodium-devel libunwind-devel xz-devel readline-devel expat-devel gtest-devel ccache doxygen graphviz qt5-linguist hidapi-devel libusbx-devel protobuf-devel protobuf-compiler systemd-devel
+sudo dnf install gcc gcc-c++ cmake pkgconf boost-devel openssl-devel zeromq-devel unbound-devel libsodium-devel libunwind-devel xz-devel readline-devel expat-devel ccache doxygen graphviz qt5-linguist hidapi-devel libusbx-devel protobuf-devel protobuf-compiler systemd-devel
 ```
 
 Install all dependencies at once on openSUSE:

contrib/depends/packages/packages.mk

@@ -15,10 +15,6 @@ ifneq ($(host_os),mingw32)
 packages += ncurses readline
 endif
 
-ifeq ($(build_tests),ON)
-packages += gtest
-endif
-
 linux_native_packages :=
 linux_packages := eudev
 

tests/CMakeLists.txt

@@ -40,37 +40,11 @@ if (WIN32 AND STATIC)
   add_definitions(-DMINIUPNP_STATICLIB)
 endif ()
 
-find_package(GTest)
-
-if (GTest_FOUND)
-  include_directories(SYSTEM ${GTEST_INCLUDE_DIRS})
-else ()
-  message(STATUS "GTest not found on the system: will use GTest bundled with this source")
-
-  include(ExternalProject)
-  ExternalProject_Add(googletest
-    SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/gtest
-    BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/gtest
-    DOWNLOAD_COMMAND ""
-    UPDATE_COMMAND ""
-    INSTALL_COMMAND ""
-  )
-  add_library(gtest      UNKNOWN IMPORTED)
-  add_library(gtest_main UNKNOWN IMPORTED)
-  set_target_properties(gtest PROPERTIES
-    IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/gtest/${CMAKE_STATIC_LIBRARY_PREFIX}gtest${CMAKE_STATIC_LIBRARY_SUFFIX}"
-  )
-  set_target_properties(gtest_main PROPERTIES
-    IMPORTED_LOCATION "${CMAKE_CURRENT_BINARY_DIR}/gtest/${CMAKE_STATIC_LIBRARY_PREFIX}gtest_main${CMAKE_STATIC_LIBRARY_SUFFIX}"
-  )
-  add_dependencies(gtest      googletest)
-  add_dependencies(gtest_main googletest)
-
-  # Emulate the FindGTest module's variable.
-  set(GTEST_LIBRARIES gtest gtest_main)
-  set(GTEST_BOTH_LIBRARIES gtest gtest_main)
-  include_directories(SYSTEM "${CMAKE_CURRENT_SOURCE_DIR}/gtest/include")
-endif (GTest_FOUND)
+set(BUILD_GMOCK OFF CACHE BOOL "Don't build GMock" FORCE)
+set(INSTALL_GTEST OFF CACHE BOOL "Don't install GTest" FORCE)
+add_subdirectory("${CMAKE_SOURCE_DIR}/external/gtest" ${CMAKE_BINARY_DIR}/googletest)
+include_directories(SYSTEM "${CMAKE_SOURCE_DIR}/external/gtest/googletest/include")
+set(GTEST_LIBRARIES gtest gtest_main)
 
 message(STATUS "Copying test data directory...")
 file(COPY data DESTINATION .) # Copy data directory from source root to build root