cmake-transitive-linking

README.md

This shows off transitive linking

CMakeLists.txt

cmake_minimum_required(VERSION 3.14)

project(asdf LANGUAGES CXX)

find_package(Boost REQUIRED COMPONENTS thread)


add_library(low SHARED low.cpp)
target_link_libraries(low PRIVATE Boost::thread)

add_library(high SHARED high.cpp)
target_link_libraries(high PRIVATE low)

add_executable(exe exe.cpp)
target_link_libraries(exe PRIVATE high)


install(TARGETS low high exe)

default.nix

with import <nixpkgs> {};

pkgs.stdenv.mkDerivation {
  name = "transitive-cmake";
  src = builtins.fetchGit ./.;
  nativeBuildInputs = with pkgs; [
    cmake
  ];
  buildInputs = with pkgs; [
    boost
  ];
  cmakeFlags = [
    "-DCMAKE_VERBOSE_MAKEFILE=ON"
  ];
}

exe.cpp

void f();
int main(int argc, char* argv[]){
    f();
}

high.cpp

#include <string>

void low(const std::string&);

void f(){
    low("/tmp/asdf");
}

low.cpp

#include <boost/chrono.hpp>
#include <boost/thread.hpp>

#include <iostream>
#include <string>

void work() {
  try {
    for (int i = 0; i < 5; ++i) {
      sleep(1);
      std::cout << i << '\n';
    }
  } catch (boost::thread_interrupted &) {
  }
}

void low(const std::string &f) {
  boost::thread t{work};
  sleep(3);
  t.interrupt();
  t.join();
}