Bye bye Catch2, hello Google Test

.github/workflows/main.yml

@@ -20,9 +20,10 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - run: |
-          gcc --version
-          clang --version
-          clang-tidy --version
+          # TODO BEGIN https://github.com/OpenCyphal/docker_toolchains/issues/36
+          dpkg --add-architecture i386
+          apt-get update
+          apt-get install -y libgtest-dev libgtest-dev:i386
       - run: >
           cmake
           -B ${{ github.workspace }}/build
@@ -60,6 +61,11 @@ jobs:
             cxx-compiler: clang++
     steps:
       - uses: actions/checkout@v3
+      - run: |
+          # TODO BEGIN https://github.com/OpenCyphal/docker_toolchains/issues/36
+          dpkg --add-architecture i386
+          apt-get update
+          apt-get install -y libgtest-dev libgtest-dev:i386
       - run: >
           cmake
           -B ${{ github.workspace }}/build

tests/CMakeLists.txt

@@ -44,15 +44,15 @@ add_compile_options(
 )
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Woverloaded-virtual -Wnon-virtual-dtor -Wsign-promo")
 
-include_directories(${library_dir})
-include_directories(SYSTEM catch)
-
-set(common_sources ${CMAKE_SOURCE_DIR}/main.cpp ${library_dir}/udpard.c)
-
 function(gen_test name files compile_definitions compile_flags link_flags c_standard)
-    add_executable(${name} ${common_sources} ${files})
+    add_executable(${name} ${library_dir}/udpard.c ${files})
+    target_include_directories(${name} PUBLIC ${library_dir})
     target_compile_definitions(${name} PUBLIC ${compile_definitions})
-    target_link_libraries(${name} pthread)
+    # We're not using find_package(GTest) because this method can only find the package for one specific architecture,
+    # which is not what we want. We build tests for AMD64 and x86 separately, which requires linking against different
+    # GTest libraries located in different directories. Instead of doing it the hard way via find_package separately
+    # per architecture, we just pass the library names directly and let the linker figure out where to find them.
+    target_link_libraries(${name} pthread gtest gtest_main)
     set_target_properties(
             ${name}
             PROPERTIES
@@ -67,10 +67,8 @@ endfunction()
 function(gen_test_matrix name files compile_definitions compile_flags link_flags)
     gen_test("${name}_x64_c99" "${files}" "${compile_definitions}" "${compile_flags} -m64" "-m64 ${link_flags}" "99")
     gen_test("${name}_x32_c99" "${files}" "${compile_definitions}" "${compile_flags} -m32" "-m32 ${link_flags}" "99")
-    target_link_libraries("${name}_x32_c99" ${ADDITIONAL_LIBS_32})
     gen_test("${name}_x64_c11" "${files}" "${compile_definitions}" "${compile_flags} -m64" "-m64 ${link_flags}" "11")
     gen_test("${name}_x32_c11" "${files}" "${compile_definitions}" "${compile_flags} -m32" "-m32 ${link_flags}" "11")
-    target_link_libraries("${name}_x32_c11" ${ADDITIONAL_LIBS_32})
     # Coverage is only available for GCC builds.
     if ((CMAKE_CXX_COMPILER_ID STREQUAL "GNU") AND (CMAKE_BUILD_TYPE STREQUAL "Debug"))
         gen_test("${name}_cov"