Building an optimized build pipeline with C++ Modules and continuous integration

15 Sep 2023

In today’s software development world, building efficient and optimized code is essential. One of the recent advancements in the C++ world is the introduction of C++ Modules, which aim to improve the build times and overall performance of C++ applications.

What are C++ Modules?

C++ Modules are a new way of organizing and managing the code in C++ applications. They allow developers to separate the declaration and implementation of code, resulting in faster compilation times. Instead of relying on header files, C++ Modules store precompiled versions of the code, which can be reused by the compiler.

By using C++ Modules, developers can eliminate unnecessary recompilation of headers, reduce build times, and improve the overall performance of their applications.

Implementing C++ Modules in a build pipeline

To take advantage of C++ Modules, you need to ensure that your build pipeline is properly configured to support them. Here are some key steps to follow:

Use a modern C++ compiler: Ensure that you are using a compiler that supports C++20, as Modules were introduced in this version of the language.
Apply C++ Module syntax: Modify your code to use the C++ Module syntax, which includes using the module keyword and explicitly declaring the module’s dependencies.
```
import mymodule;
   
int main() {
    // Use functions and classes from the imported module
    mymodule::foo();
    return 0;
}
```
Update your build system: Configure your build system (e.g., CMake, Makefile) to handle C++ Modules properly. Make sure it includes the necessary flags to enable Module support during compilation.
Use precompiled Modules: To ensure optimal build times, precompile your Modules and distribute them as artifacts. This allows your build pipeline to reuse the precompiled Modules instead of recompiling them from scratch.

Continuous Integration for C++ Modules

In a continuous integration (CI) environment, it is crucial to ensure that your build pipeline is optimized for efficiency. Here are some steps you can take to incorporate C++ Modules into your CI pipeline:

Automate Module precompilation: Configure your CI pipeline to precompile Modules during the initial build step. This ensures that subsequent builds can reuse the precompiled Modules, reducing build times.
Cache precompiled Modules: Utilize a caching mechanism in your CI system to store and retrieve precompiled Modules. This prevents unnecessary recompilation of Modules on each CI build, further reducing build times.
Parallelize builds: Take advantage of parallel computing capabilities in your CI system to distribute the build workload across multiple machines or cores. This can significantly speed up the build process, especially when handling large-scale projects.
Monitor build performance: Continuously monitor and analyze the build performance of your CI pipeline. Identify any bottlenecks or areas for improvement and make necessary adjustments to optimize the overall build process further.

With an optimized build pipeline that supports C++ Modules and leverages continuous integration, you can significantly improve the build times and overall performance of your C++ applications.

#cpp #buildpipeline #CIModules