CMake FetchContent

[myzinsky]

Im using the lib via FetchContent in my project.

message(STATUS "Fetching libad9361-iio from github")
FetchContent_Declare(
    libad9361-iio
    GIT_REPOSITORY https://github.com/analogdevicesinc/libad9361-iio
    GIT_TAG main
)
FetchContent_MakeAvailable(libad9361-iio)

However, there is a naming clash with another library that also has a target uninstall:

[cmake] CMake Error at out/build/Debug/_deps/libad9361-iio-src/CMakeLists.txt:217 (add_custom_target):
[cmake]   add_custom_target cannot create target "uninstall" because another target
[cmake]   with the same name already exists.  The existing target is a custom target
[cmake]   created in source directory
[cmake]   "/Users/myzinsky/Programming/qluto4/out/build/Debug/_deps/sdl2-src".  See
[cmake]   documentation for policy CMP0002 for more details.

One workaround would be to change the cmake a bit, in this way:

if(NOT TARGET uninstall) 

endif()

Any thoughts?

[tfcollins]

My understanding is FetchContent is normally used to include things like header only projects or general source you want to use. Do you not want to simply link against libiio? What is your end goal here?

[myzinsky]

I will setup a project, where cmake will automatically download all dependencies. iio and ad9361 are just 2 of 10 dependencies that I have.

[tfcollins]

Are you building all the dependencies from source (even libiio's)? Or can you use prebuilt binaries? What is the target OS?

[myzinsky]

So it's even the problem when both, iio and this library are combined. It would be already enough to rename the targets to uninstall_iio and uninstall_ad9361-iio.

I want to have a full independence from pebuild libraries. Such that my program can be just build everywhere.

[myzinsky]

Seems that this would be a solution that works around this:

cmake_minimum_required(VERSION 3.30)
project(pluto17)
include(FetchContent)
include(ExternalProject)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_INCLUDE_CURRENT_DIR ON)

ExternalProject_Add(
    libiio
    GIT_REPOSITORY https://github.com/analogdevicesinc/libiio
    GIT_TAG v0.26
    INSTALL_COMMAND   ""
)

ExternalProject_Add(
    libad9361-iio
    GIT_REPOSITORY https://github.com/analogdevicesinc/libad9361-iio
    GIT_TAG v0.3
    INSTALL_COMMAND   ""
    CMAKE_ARGS
        -DLIBIIO_INCLUDEDIR=${CMAKE_BINARY_DIR}/libiio-prefix/src/libiio/
        -DLIBIIO_LIBRARIES=${CMAKE_BINARY_DIR}/libiio-prefix/src/libiio-build/iio.framework/
)

add_executable(pluto17
    src/main.cpp
)

add_dependencies(pluto17 libiio libad9361-iio)

target_include_directories(pluto17
    PRIVATE ${CMAKE_BINARY_DIR}/libiio-prefix/src/libiio/
)

target_link_libraries(pluto17 PRIVATE ${CMAKE_DL_LIBS})