Unveiling the Mystery: Finding CMAKE Runtime Libraries
CMake, a powerful build system, often leaves developers scratching their heads when it comes to locating runtime libraries. These libraries, essential for your application's execution, are sometimes hidden, leading to confusion and frustration. This article delves into the secrets of CMake's runtime library handling, equipping you with the knowledge to confidently find and manage them.
The Mystery: Why are runtime libraries hidden?
Let's imagine you've built your application with CMake. You've run your executable, and everything seems to work perfectly. But, where are the runtime libraries that your application depends on? They don't appear in your project's build directory, leaving you with a sense of unease.
The Solution: CMake's Magic
CMake, by default, strives to simplify your workflow. It doesn't directly place runtime libraries in your build directory. Instead, it utilizes a clever strategy:
- System Libraries: For libraries pre-installed on your system, CMake often uses symbolic links. These links point to the actual library files on your system, streamlining the build process and avoiding redundancy.
- Project Libraries: For libraries built as part of your project, CMake places them within a specific directory within your build output, usually
liborlib64. This ensures efficient organization and avoids cluttering your project's root directory.
Where to find the libraries:
- System Libraries: If the library is a system library, it's likely located within your system's library directory. On Linux-based systems, this could be
/usr/lib,/lib, or similar paths. You can usually find these paths by running the commandldconfig -p. - Project Libraries: Check the
liborlib64directory within your build output. This is the default location for CMake to place libraries built for your project.
Example:
Let's say you've built an application using a library called my_lib. In your CMakeLists.txt file, you've added:
find_package(my_lib REQUIRED)
target_link_libraries(my_app my_lib)
After building your application, you'll find libmy_lib.so (or a similar name) in the lib or lib64 directory within your build output.
Unveiling the Secrets:
- CMAKE_INSTALL_PREFIX: This variable controls the installation location of your project's components. If you want to customize the placement of runtime libraries, you can modify this variable in your CMakeLists.txt.
- CMAKE_INSTALL_LIBDIR: This variable specifically controls the installation directory for libraries. You can set this to a custom location if needed.
Conclusion:
CMake's handling of runtime libraries is designed to simplify the build process and enhance portability. While it may seem like a mystery at first, understanding CMake's approach allows you to efficiently find and manage your project's dependencies. By leveraging the knowledge gained in this article, you can confidently navigate the world of CMake and build powerful applications with ease.
Further Resources:
- CMake Documentation: https://cmake.org/
- CMake Tutorial: https://cmake.org/cmake-tutorial/
- CMake Wiki: https://cmake.org/Wiki/
