Switch to Catch2 v3

.github/workflows/coverity.yml

@@ -13,7 +13,7 @@ jobs:
     - uses: cvmfs-contrib/github-action-cvmfs@v2
     - uses: aidasoft/run-lcg-view@v2
       with:
-        coverity-cmake-command: 'cmake -DCMAKE_CXX_STANDARD=17  -DENABLE_SIO=ON ..'
+        coverity-cmake-command: 'cmake -DCMAKE_CXX_STANDARD=17  -DENABLE_SIO=ON -DUSE_EXTERNAL_CATCH2=OFF ..'
         coverity-project: 'AIDASoft%2Fpodio'
         coverity-project-token: ${{ secrets.PODIO_COVERITY_TOKEN }}
         github-pat: ${{ secrets.READ_COVERITY_IMAGE }}

.github/workflows/key4hep.yml

@@ -20,6 +20,7 @@ jobs:
             -DCMAKE_INSTALL_PREFIX=../install \
             -DCMAKE_CXX_STANDARD=17 \
             -DCMAKE_CXX_FLAGS=" -fdiagnostics-color=always -Werror " \
+            -DUSE_EXTERNAL_CATCH2=OFF \
             -G Ninja ..
           ninja -k0
           ctest --output-on-failure

.github/workflows/mac.yml

@@ -29,6 +29,7 @@ jobs:
             -DCMAKE_INSTALL_PREFIX=../install \
             -DCMAKE_CXX_STANDARD=17 \
             -DCMAKE_CXX_FLAGS=" -fdiagnostics-color=always -Werror " \
+            -DUSE_EXTERNAL_CATCH2=OFF \
             -G Ninja ..
           ninja -k0
           ctest --output-on-failure

.github/workflows/test.yml

@@ -27,6 +27,7 @@ jobs:
             -DCMAKE_INSTALL_PREFIX=../install \
             -DCMAKE_CXX_STANDARD=17 \
             -DCMAKE_CXX_FLAGS=" -fdiagnostics-color=always -Werror " \
+            -DUSE_EXTERNAL_CATCH2=OFF \
             -G Ninja ..
           ninja -k0
           ctest --output-on-failure

.github/workflows/ubuntu.yml

@@ -25,6 +25,7 @@ jobs:
             -DCMAKE_INSTALL_PREFIX=../install \
             -DCMAKE_CXX_STANDARD=17 \
             -DCMAKE_CXX_FLAGS=" -fdiagnostics-color=always -Werror " \
+            -DUSE_EXTERNAL_CATCH2=OFF \
             -G Ninja ..
           ninja -k0
           ctest --output-on-failure

.gitignore

@@ -51,3 +51,7 @@ spack*
 *.exe
 *.out
 *.app
+
+# Tooling
+/.clangd/
+/compile_commands.json

CMakeLists.txt

@@ -121,6 +121,7 @@ endif()
 
 #--- enable unit testing capabilities ------------------------------------------
 include(CTest)
+option(USE_EXTERNAL_CATCH2 "Link against an external Catch2 v3 static library, otherwise build it locally" ON)
 
 #--- enable CPack --------------------------------------------------------------
 

cmake/podioBuild.cmake

@@ -42,6 +42,10 @@ endmacro(podio_set_rpath)
 macro(podio_set_compiler_flags)
   include(CheckCXXCompilerFlag)
 
+  # Store the default flags here, before we add all the warning, so that we can
+  # build Catch2 locally without them
+  SET(CXX_FLAGS_CMAKE_DEFAULTS "${CMAKE_CXX_FLAGS}")
+
   SET(COMPILER_FLAGS -Wshadow -Wformat-security -Wno-long-long -Wdeprecated -fdiagnostics-color=auto -Wall -Wextra -pedantic -Weffc++)
 
   # AppleClang/Clang specific warning flags

tests/CMakeLists.txt

@@ -31,11 +31,40 @@ foreach( sourcefile ${root_dependent_tests} )
   CREATE_PODIO_TEST(${sourcefile} "${root_libs}")
 endforeach()
 
+CREATE_PODIO_TEST(ostream_operator.cpp "")
+CREATE_PODIO_TEST(write_ascii.cpp "")
+
+if(USE_EXTERNAL_CATCH2)
+  find_package(Catch2 REQUIRED)
+else()
+  message(STATUS "Fetching local copy of Catch2 library for unit-tests...")
+  # Build Catch2 with the default flags, to avoid generating warnings when we
+  # build it
+  set(CXX_FLAGS_CMAKE_USED ${CMAKE_CXX_FLAGS})
+  set(CMAKE_CXX_FLAGS ${CXX_FLAGS_CMAKE_DEFAULTS})
+  Include(FetchContent)
+  FetchContent_Declare(
+    Catch2
+    GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+    GIT_TAG        037ddbc75cc5e58b93cf5a010a94b32333ad824d
+    )
+  FetchContent_MakeAvailable(Catch2)
+  set(CMAKE_MODULE_PATH ${Catch2_SOURCE_DIR}/extras ${CMAKE_MODULE_PATH})
 
-set(independent_tests ostream_operator.cpp unittest.cpp write_ascii.cpp)
-foreach( sourcefile ${independent_tests} )
-  CREATE_PODIO_TEST(${sourcefile} "")
-endforeach()
+
+  # Hack around the fact, that the include directories are not declared as
+  # SYSTEM for the targets defined this way. Otherwise warnings can still occur
+  # in Catch2 code when templates are evaluated (which happens quite a bit)
+  get_target_property(CATCH2_IF_INC_DIRS Catch2 INTERFACE_INCLUDE_DIRECTORIES)
+  set_target_properties(Catch2 PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES "${CATCH2_IF_INC_DIRS}")
+
+  # Reset the flags
+  set(CMAKE_CXX_FLAGS ${CXX_FLAGS_CMAKE_USED})
+endif()
+
+CREATE_PODIO_TEST(unittest.cpp "Catch2::Catch2;Catch2::Catch2WithMain")
+include(Catch)
+catch_discover_tests(unittest WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR})
 
 
 if (TARGET TestDataModelSioBlocks)