If you’ve been working on a project that uses CMake for build configuration and you’re considering migrating to a Makefile-based build system, this guide will help you make a smooth transition. While CMake is widely used and offers various advantages, you may have specific reasons for preferring Makefile, such as simplicity or integration with existing Makefile-based projects.

Understanding the Differences

Before diving into the migration process, it’s important to understand the key differences between CMake and Makefile.

CMake is a meta-build system that generates platform-specific build files, such as Makefiles or Visual Studio project files. It provides a high-level abstraction for managing build configuration and dependencies, making it easier to write cross-platform build scripts.

On the other hand, Makefile is a build script written in the Make language. It is traditionally used on UNIX-like systems and provides a more low-level and manual approach to building projects.

Steps for Migration

1. Identify Your Build Targets: Start by identifying the build targets defined in your CMakeLists.txt file. This could include executable binaries, library targets, or custom targets.

2. Create a Makefile: Define a new Makefile in your project directory or a centralized location. The Makefile will contain instructions for building your project. You can use a text editor or a Makefile generator tool to simplify the process.

3. Translate CMake Build Configurations: Review your CMakeLists.txt file and translate the build configurations, such as compiler flags, libraries, and include directories, into the corresponding Makefile rules or variables.

4. Handle Dependency Tracking: CMake automatically handles dependency tracking, but with Makefile, you will need to manually handle dependencies and ensure that targets are built in the correct order. Use the appropriate Makefile rules, such as .PHONY targets and dependencies using the $(DEPENDS) variable.

5. Integrate External Tools: If your CMake build system relies on external tools or processes, ensure that they are integrated into your Makefile. This could include code generators, preprocessor steps, or additional build tasks.

6. Test the Makefile Build: Test your new Makefile build system to ensure that it produces the expected results. Build your project and check if the binaries or artifacts are generated correctly.

7. Iterate and Refine: In case any issues or discrepancies arise during the migration process, iterate and refine your Makefile. Pay attention to edge cases and corner scenarios specific to your project configuration.

Conclusion

Migrating from CMake to Makefile requires careful consideration and understanding of the differences between the two build systems. By following the steps outlined in this guide, you can successfully transition your project to a Makefile-based build system. Remember to validate the build results and make necessary refinements as required.

Tags: #Makefile #CMake