How to make Boost DLLs accessible to an executable built with CMake?

Question

I'm using CMake on Windows to build test suite based on Boost.Test. As I'm linking to Boost.Test dynamically, my executable needs to be able to find the DLL (which is under ../../../boost/boost_1_47/lib or something like that relative to the executable).

So I need to either copy the DLL into the folder where the executable is, or make it findable in some other way. What's the best way to achieve this with CMake?

-- Additional info --

My CMakeLists.txt has this Boost related configuration at the moment:

set(Boost_ADDITIONAL_VERSIONS "1.47" "1.47.0")
set(BOOST_ROOT "../boost")

find_package(Boost 1.47 COMPONENTS unit_test_framework REQUIRED)
include_directories(${Boost_INCLUDE_DIR})
link_directories(${Boost_LIBRARY_DIR})

add_executable(test-suite test-suite.cpp)
target_link_libraries(test-suite ${Boost_LIBRARIES})

Answer 1

Assuming you are running your tests by building the RUN_TESTS target in Visual Studio:

1. I always add .../boost/boost_1_47/lib to my command PATH environment variable, so the boost unit_test_framework dlls can be found at run time. That's what I recommend.

2. If for some reason changing your PATH is not possible, you could copy the files with cmake.

(untested)

get_filename_component(LIBNAME "${Boost_UNIT_TEST_FRAMEWORK_LIBRARY_RELEASE}" NAME)
add_custom_command(TARGET test-suite POST_BUILD
    COMMAND ${CMAKE_COMMAND} -E copy "${Boost_UNIT_TEST_FRAMEWORK_LIBRARY_RELEASE}" "${CMAKE_CURRENT_BINARY_DIR}/${LIBNAME}"
)

3. If you are NOT only running the tests at build time (as I was assuming above), then you need a series of INSTALL commands, like Hans Passant suggested. In your snippet you don't have an INSTALL command for your executable; so even your executable won't end up "in the executable folder". First add a cmake INSTALL command to put your executable someplace in response to the cmake INSTALL target. Once you have that working, we can work on figuring out how to add another INSTALL command to put the boost unit_test_framework library into the same location. After that, if you want to make an installer using CPACK, the library will automatically be installed with the executable.