Install gtest from distro

Allows us to remove the custom install scripts from CMake.

Author: TheAssassin

.gitmodules

@@ -46,7 +46,6 @@ endif()
 # used by e.g., Debian packaging infrastructure
 include(GNUInstallDirs)
 
-add_subdirectory(lib)
 add_subdirectory(src)
 
 if(BUILD_TESTING)

CMakeLists.txt

@@ -34,6 +34,7 @@ packages=(
     lcov
     gcovr
     libboost-dev
+    libgtest-dev
 )
 
 # make sure installation won't hang on GitHub actions

ci/install-deps.sh

@@ -1,5 +1,6 @@
 # >= 3.2 required for ExternalProject_Add_StepDependencies
-cmake_minimum_required(VERSION 3.2)
+# >= 3.20 for FindGTest IMPORTED target
+cmake_minimum_required(VERSION 3.20)
 
 include(${CMAKE_CURRENT_LIST_DIR}/scripts.cmake)
 
@@ -33,6 +34,10 @@ set(CFLAGS ${DEPENDENCIES_CFLAGS})
 set(CPPFLAGS ${DEPENDENCIES_CPPFLAGS})
 set(LDFLAGS ${DEPENDENCIES_LDFLAGS})
 
+if(BUILD_TESTING)
+    find_package(GTest REQUIRED)
+endif()
+
 if (NOT LIBAPPIMAGE_SHARED_ONLY)
     import_pkgconfig_target(TARGET_NAME liblzma PKGCONFIG_TARGET liblzma)
 

cmake/dependencies.cmake

@@ -25,7 +25,7 @@ if (NOT LIBAPPIMAGE_SHARED_ONLY)
     )
 
     target_include_directories(test_libappimage++ PRIVATE "${PROJECT_SOURCE_DIR}/src/libappimage")
-    target_link_libraries(test_libappimage++ temporarydirectory libappimage libarchive libsquashfuse XdgUtils::DesktopEntry XdgUtils::BaseDir gtest gtest_main)
+    target_link_libraries(test_libappimage++ temporarydirectory libappimage libarchive libsquashfuse XdgUtils::DesktopEntry XdgUtils::BaseDir GTest::gtest GTest::gtest_main)
 
     add_test(test_libappimage++ test_libappimage++)
 endif()

lib/CMakeLists.txt

@@ -36,8 +36,8 @@ target_link_libraries(TestDesktopIntegration
     # statically once glib is loaded.
     PRIVATE libglib
     PUBLIC dl
-    PRIVATE gtest
-    PRIVATE gtest_main
+    PRIVATE GTest::gtest
+    PRIVATE GTest::gtest_main
     PRIVATE librsvg
     PRIVATE libcairo
 )

lib/gtest

@@ -4,7 +4,7 @@ set_property(TARGET fixtures PROPERTY INTERFACE_LINK_LIBRARIES xdg-basedir gtest
 
 if (NOT LIBAPPIMAGE_SHARED_ONLY)
     add_executable(test_libappimage test_libappimage.cpp)
-    target_link_libraries(test_libappimage fixtures libappimage libsquashfuse libglib libgobject gtest gtest_main)
+    target_link_libraries(test_libappimage fixtures libappimage libsquashfuse libglib libgobject GTest::gtest GTest::gtest_main)
 
     add_executable(test-xdg-basedir test-xdg-basedir.cpp)
     target_link_libraries(test-xdg-basedir fixtures xdg-basedir)