CMake/C++ library to get the installation prefix of a shared library in a relocatable way.

In a nutshell, it permits to avoid the need to hardcode the location of CMAKE_INSTALL_PREFIX in a shared library if you need it to localize other resources installed with the package. This permits to easily move the installation prefix in a location different from CMAKE_INSTALL_PREFIX after the installation (i.e. making it a relocatable installation), as long as the library is compiled as shared. This is useful when the C++ shared library is packaged in package managers that create the package with a given CMAKE_INSTALL_PREFIX and install it with a different prefix, such as conda, vcpkg or conan.

In the case that the library is compiled as static, reloc-cpp will fall back to hardcode CMAKE_INSTALL_PREFIX in the library.

reloc-cpp requires the use of C++ 17 or any later version.

include(FetchContent)
FetchContent_Declare(
  reloc-cpp
  GIT_REPOSITORY https://github.com/ami-iit/reloc-cpp.git
  GIT_TAG        v0.1.0
)

FetchContent_MakeAvailable(reloc-cpp)

In your CMake build system you can use reloc-cpp as:

add_library(yourLibrary)

# ...

reloc_cpp_generate(yourLibrary
                   GENERATED_HEADER ${CMAKE_CURRENT_BINARY_DIR}/yourLibrary_getInstallPrefix.h
                   GENERATED_FUNCTION yourLibrary::getInstallPrefix)

then, you can use it in C++ as:

#include <yourLibrary_getInstallationPrefix.h>

// This return the value corresponding to CMAKE_INSTALL_PREFIX
std::string installPrefix = yourLibrary::getInstallPrefix().value();

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

References that were useful as inspiration when developing reloc-cpp:

• "Helping C/C++ Packages be Relocatable" presentation
• Resourceful: Techniques for installing and accessing resource files using C++ and Python.
• "Qt is relocatable" blog post
• binreloc: Library for creating relocatable software

Resources that could be useful as an alternative to reloc-cpp:

• cmrc: A Resource Compiler in a Single CMake Script

BSD-3-Clause