I'm trying to build a coverage report for an extension using the

gcovr

tool (on which I have very little knowledge).

.gcno

and

.gcda

files are generated but test coverage is always 0% in all the sources. At the moment I'm blocked, all the guides I've read say it should work. Maybe someone can point me in the right direction? I think it is related to the way extensions are built because sources are in a different folder than binaries. However,

gcovr

has a

--root

option on which source files can be specified so it might not be the problem. This are the steps I'm performing on Ubuntu

cd osquery
ln -s /home/danielbreton/workspace/osquery-extension-hello/ external/extension_hello
cd build
cmake -DOSQUERY_TOOLCHAIN_SYSROOT=/usr/local/osquery-toolchain -DOSQUERY_BUILD_TESTS=ON -DENABLE_COVERAGE=true ..
cmake --build . -j$(nproc) --target hello_my_friend_extension_test
./external/extension_hello/hello_my_friend_extension_test
gcovr --xml-pretty --exclude-unreachable-branches --print-summary -o coverage.xml --root /home/danielbreton/workspace/osquery-extension-hello/

And this is the complete

CMakeLists.txt

for the extension

project("hello_my_friend_extension")

addOsqueryExtension(
  "${PROJECT_NAME}"
  hello.cpp
  main.cpp
)

set(common_test_files
  hello.cpp
)

add_executable(
  "${PROJECT_NAME}_test"
  EXCLUDE_FROM_ALL
  ${common_test_files}
  test.cpp
)

if(ENABLE_COVERAGE)
  message("Enabling coverage")
  # set compiler flags
  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O0 -fprofile-arcs -ftest-coverage")
  set(CMAKE_CXX_FLAGS " ${CMAKE_CXX_FLAGS} -O0 -fprofile-arcs -ftest-coverage")
  # find required tools
  find_program(GCOVR gcovr REQUIRED)
endif()

target_link_libraries("${PROJECT_NAME}_test" PRIVATE
  thirdparty_googletest
  osquery_sdk_pluginsdk
  osquery_extensions_implthrift
)

if(ENABLE_COVERAGE)
  add_link_options("--coverage")
endif()

Project tree

danielbreton@2022-EMEA-0022 ~/workspace/osquery-extension-hello (feature/UA-1101)$ tree
.
├── CMakeLists.txt
├── hello.cpp
├── hello.h
├── main.cpp
├── README.md
└── test.cpp

Can you elaborate more on the --root option? I think that from the CMake standpoint the extension is still in the osquery source tree, so those paths should not be too different from the core files (but I may have misunderstood)

`--root`option is used to chose the folder which contains all the sources, each source should have associated a `.gcda`and `.gcno`file (with the same name) to build the coverage report. I'm worried about having the source files on the extension folder (outside osquery) and those `gcda`and

gcno

files under `osquery/build/external/extension_hello/CMakeFiles/hello_my_friend_extension_test.dir`so the util is not able to "link" the files

I see; I think the link we create is to be considered just a workaround, and we should consider the build process as compiling osquery & the extension together

I agree with you, osquery is not responsible for third-party extensions

I wonder how many users rely on this, maybe we do have to provide a migration plan

Well, if i'm able to generate the coverage reports, I will explain how. Also, I have a guide for beginners and a very basic extension I've done for myself based on the docs and TOB public repository. Maybe it helps others

That would definitely help! But I was thinking about redistribution