My experiences setting up a C++ project using VAMP as a third party directory

[claytonwramsey]

I've been trying to see if I can use VAMP as a library, so I had to set up VAMP as a third-party directory. I eventually managed to get a simple test binary (which currently includes, but does not call upon, VAMP as a dependency) running.

The biggest issue is that VAMP doesn't seem to forward its own dependencies when used as a dependency itself. I worked around that by manually editing VAMP's own internal include directories / link targets and also by overwriting the dependency as needed.

For starters, here's my project structure:

project
├── CMakeLists.txt
├── external
│   ├─── vamp
│   │    ├── external
│   │    └── CMakeLists.txt
│   └── CMakeLists.txt
└── src
    └── test.cpp

(I use external as a subfolder for all vendored dependencies, and vamp is a Git submodule of this repository at the latest version).

There are 3 CMakeLists files of relevance:

• /external/vamp/CMakeLists.txt
• /external/CMakeLists.txt
• /CMakeLists.txt

/external/vamp/CMakeLists.txt is largely the same, except I made the value of VAMP_EXT_INCLUDES public to make the include directories visbile to my project:

@@ -69,6 +69,8 @@ list(APPEND VAMP_EXT_INCLUDES
   src/impl
 )

+set(VAMP_EXT_INCLUDES ${VAMP_EXT_INCLUDES} PARENT_SCOPE)
+
 nanobind_add_module(_core_ext
     NB_STATIC
     STABLE_ABI

Inside of /external/CMakeLists.txt I added the path to the source headers for vamp to the publicly available list of includes and forwarded it as one variable:

add_subdirectory(vamp)

list(APPEND VAMP_INCLUDE_DIRS ${VAMP_EXT_INCLUDES} ${CMAKE_CURRENT_SOURCE_DIR}/vamp/src/impl)

set(VAMP_INCLUDE_DIRS
    ${VAMP_INCLUDE_DIRS}

    PARENT_SCOPE
)

Finally, I had to manually include the Eigen on top of requiring the above include directories in my top-level /CMakeLists.txt.

cmake_minimum_required(VERSION 3.16...3.22)

project(
    navvy
    VERSION 0.1
    LANGUAGES CXX
)

add_subdirectory(external)

find_package(Eigen3 REQUIRED NO_MODULE)

add_executable(test src/test.cpp)
target_include_directories(test SYSTEM PRIVATE ${VAMP_INCLUDE_DIRS})
target_link_libraries(test PUBLIC Eigen3::Eigen)

I am not particularly good at CMake, so there may be a far less painful way to do all this; if not, maybe we should make some effort to make it easier to use VAMP as a submodule.

[claytonwramsey]

turns out this is actually not enough - some headers for VAMP also require pdqsort (and maybe other libraries; I haven't run up against them yet). Still debugging...

[wbthomason]

#31 will resolve this, though it is still WIP.