An introduction to the build pipeline, and how we can orchestrate it manually

Before working with CMake, it's useful to understand the tools it orchestrates. This lesson guides you through setting up a C++ toolchain.

Building C++ Programs

Walking through the steps of the C++ compilation process, from source code to machine code.

The Compilation Pipeline

The linker's role in the build process, how it resolves symbols to combine object files, and how to troubleshoot common errors.

Object Files and the Linking Process

The difference between static and dynamic libraries, how to create them, and the trade-offs between them.

Static and Shared Libraries

The C++ Build Process

Recommended approaches for managing large projects and the libraries that they depend on

Learn how to structure your C++ projects for scalability and maintainability, from basic directory layouts to managing multiple modules.

Organizing a C++ Project

Learn to manage third-party libraries in C++, covering include/library paths, static vs. shared libraries, versioning, and platform differences.

Managing Libraries and Dependencies

An introduction to traditional build tools like Makefiles and IDE projects, highlighting the maintenance, scalability, and cross-platform challenges that result

Automated Build Systems and Their Limitations

Project Structure and Dependency Management

Setting up CMake and creating your first project

An introduction to CMake, the cross-platform, open-source meta-build system that solves the core challenges of C++ project management.

Why CMake?

A step-by-step guide to installing CMake. We'll explore command-line, GUI, and IDE workflows, and how to configure your compiler.

Setting Up a CMake Environment

Creating the bare minimum `CMakeLists.txt` file and build up to a project with an executable and a library, learning the fundamental commands along the way.

Writing a CMakeLists File

Learn the two-stage process of building a CMake project. This lesson covers configuring, generating, building, running, and troubleshooting common errors.

Building and Running CMake Projects

Learn how to organize large C++ projects in CMake using subdirectories and the `add_subdirectory()` command to create modular, maintainable builds.

CMake Project Structure and Subdirectories

Introducing CMake

Exploring CMake's programming features, caching mechanisms, and interactions with the file system

A primer on the fundamental building blocks of the CMake language: variables, string interpolation, and logging messages.

CMake Variables and Logging

Discover the CMake Cache, the mechanism for storing persistent user-configurable options, and learn how to create and manage cached variables.

The CMake Cache

Exploring CMake's command syntax and its list data type, including how to create, manipulate, and use lists in your projects.

CMake Commands, Arguments, and Lists

Transform your static build descriptions into dynamic scripts with CMake's control flow commands, if() and foreach().

CMake Conditionals and Loops

Exploring CMake's `file()` command, covering how to read, write, copy, and glob files, and how to manipulate paths.

Working with the File System

Learn to create reusable logic with CMake functions and macros, and how to organize them into modules for clean, scalable build systems.

Modularizing CMake Code

CMake Language and Fundamentals

Learn more about targets, and how their properties and links are the foundation of modern CMake

Learn to work with target properties - understanding their purpose, setting and updating them, and retrieving them when your build requires it

Target Properties

Learn about target types, and how the `PUBLIC`, `PRIVATE`, and `INTERFACE` keywords control how properties are shared.

Relationships Between Targets

Discover how CMake's `target_link_libraries()` command builds a dependency graph, and how it uses this graph to automatically manage transitive dependencies and link order.

Indirect Relationships and the Dependency Graph

Learn to use abstract target types like `INTERFACE`, `ALIAS`, and `IMPORTED` to model complex project needs, organize build properties, and integrate pre-compiled binaries.

Using `INTERFACE`, `ALIAS`, and `IMPORTED` Libraries

Adding support for user-configurable library types and an initial introduction to target installation.

Using Shared Libraries

Targets and Dependencies

Learn how to manage multiple build configurations within the same project, and how to create scripts that adapt to the environment

Learn how CMake manages different build configurations like Debug and Release, the difference between generator types, and how to apply settings conditionally using modern techniques.

Build Configurations (Debug, Release, etc.)

Learn the tools and patterns needed to write portable CMakeLists.txt files that work seamlessly across platforms and compilers

Cross-Platform Configurations

Learn to write architecture-aware CMake scripts for 32/64-bit systems and Apple's Universal Binaries (Intel/ARM).

Handling Different Architectures

Learn to build for different operating systems and architectures using CMake's cross-compilation support and toolchain files.

Cross-Compilation and Toolchain Files

Platforms and Build Configurations

Learn how to add external libraries to our build, and how to create our own packages for others to use

Learn to find and use pre-installed libraries with `find_package()`, understanding Module vs. Config mode and the power of imported targets

Finding Dependencies using `find_package()`

Learn how to make your libraries consumable by other projects using CMake by turning your build-tree into a distributable install-tree.

Creating a Consumable Package

Learn how to consume a CMake package you've installed, completing the producer-consumer cycle. We'll cover using `find_package()` and how to point CMake to your library's location

Using Installed Packages

Learn how to create self-contained, reproducible builds by fetching dependencies from source using `FetchContent()` and `ExternalProject_Add()`.

Fetching External Dependencies

Creating and Consuming Packages

Integrating the vcpkg and Conan package managers to handle external dependencies

Learn to manage C++ dependencies effortlessly with the vcpkg package manager and its seamless CMake integration using toolchain files and manifests.

Integrating CMake and vcpkg

Learn the day-to-day commands for managing dependencies with vcpkg and how to guarantee reproducible builds using baselines and version overrides

vcpkg Commands and Versioning

Combine vcpkg with CMake's cross-compilation capabilities. Learn to use triplets to target different architectures and chain-load toolchain files

Cross-Compiling with vcpkg

Discover Conan, the binary-first C++ package manager, and learn how to integrate it with CMake using profiles and lockfiles for fast, reproducible builds.

Using Conan with CMake

Learn to cross-compile C++ projects with Conan, using build and host profiles to manage dependencies for different platforms.

Cross-Compilation with Conan

Package Managers

Introducing presets, allowing us to simplify our workflow and share common configurations across our team

Learn the fundamentals of CMake Presets. This lesson introduces `CMakePresets.json` to simplify complex build commands.

CMake Presets

Learn to structure your CMake presets with inheritance and customize them for your local environment using `CMakeUserPresets.json`.

User Presets and Inheritance

Learn to make your CMake presets portable by using environment variables and conditional logic to adapt to different machine configurations.

Environment Variables and Conditional Presets

Learn how to extend the build process beyond simple compilation by integrating external tools and custom commands

Learn how to use generator expressions `$<...>` for build-time conditional logic.

Generator Expressions and Conditional Logic

Learn how to attach commands to specific points in a target's build lifecycle using `add_custom_command(TARGET)` for tasks like post-build file copying.

Integrating Tools with `add_custom_command()`

Learn to integrate code generators like Protobuf into your build process using `add_custom_command()`, creating automated file-level dependencies in CMake.

Generating Files with Protobuf and `add_custom_command()`

Custom Commands

An introduction to automating common workflow chores by creating custom targets

Learn to create standalone, non-code targets using add_custom_target() for utility tasks like code formatting and documentation generation.

Custom Targets and Build Utilities

Using the Clang-Format tool to automatically enforce a consistent coding style, and integrating it into our build using a custom CMake target

Using Clang-Format

An introduction to file sets and the `target_sources()` command, allowing us to manage our header files in a more controlled way

Using File Sets

A step-by-step guide to integrating Doxygen into your CMake build process for automated C++ documentation.

Generating Documentation with Doxygen

Custom Targets

Integrate automated tests into a CMake project using CTest, GoogleTest, and GoogleMock

Learn the fundamentals of automated testing in C++ with CTest. Create your first test suite, register tests with `add_test()`, and run them with the `ctest` command.

Automated Testing and CTest

Learn to refactor manual C++ tests into a professional test suite using the GoogleTest framework, managed by vcpkg and integrated with CTest.

Integrating GoogleTest with CMake

Learn to use a wide range of assertions, write data-driven parameterized tests, and isolate dependencies with Google Mock.

Assertions and Parameterized Tests

Learn how to isolate dependencies that our project uses, and then how to replace those dependencies at test time using Google Mock.

Dependency Injection and Mocking

Learn the standard pattern for testing application logic by refactoring it into a linkable library

Testing Executables

Move beyond individual tests to manage a full test suite. Learn to organize tests, run tests in parallel, filter by labels, and measure our code coverage

Managing a Test Suite

Automated Testing

Using static and dynamic analysis in CMake projects to automatically detect memory bugs, performance issues, and problematic code

Learn to find memory bugs at runtime by integrating AddressSanitizer (ASan) into a CMake project

Using AddressSanitizer (ASan)

Adding benchmarks to our build to measure the performance of our code, and track how it changes over time

Using Google Benchmark

Integrating Clang-Tidy to enforce good practices and find bugs before we even compile

Using Clang-Tidy

Automated Analysis

Automating the entire development lifecycle using Git for souce control, GitHub Actions for cloud builds, and CPack to create distributable packages and installers.

An introduction to Git, the version control system that underpins modern collaborative software development and automated build pipelines.

Source Control with Git

Learn how to automate your build and test process with Continuous Integration (CI) and a build server. This lesson provides a guide to creating a GitHub Actions workflow for a CMake project.

Build Servers and Continuous Integration

Learn to package your C++ projects using CMake's CPack. This lesson covers creating developer ZIP archives and professional Windows MSI installers with components.

Packaging with CPack

Learn to automate the packaging process by integrating CPack with a multi-platform GitHub Actions workflow

Packaging with GitHub Actions

Learn to automate the creation of a professional Windows installer by integrating CPack, the WiX Toolset, and a multi-platform GitHub Actions workflow.

Creating Installers with CPack and GitHub Actions

Learn to automate the release process using a GitHub Actions workflow that builds, packages, and publishes artifacts to a GitHub Release

Deployment with GitHub Releases

Continuous Integration and Packaging

If you have a basic grasp of C++ but find the build process intimidating, this course is for you. We assume you know the language, but not how to manage large projects.

Manage complex, cross-platform builds using industry-standard tools. Create scalable build systems that automate the entire development lifecycle.

This course is a comprehensive deep-dive into the entire C++ build ecosystem, centered around the power and flexibility of modern CMake. We leave no stone unturned.

Start with a foundational understanding of compilers, linkers, static vs. shared libraries, and object files.

The Full Build Pipeline

Learn every aspect of the CMake language, from variables and control flow to functions, modules, and generator expressions.

Complete CMake Language Mastery

Master the modern target-centric paradigm, including properties, usage requirements, and abstract targets.

Advanced Target Management

Explore every method for handling dependencies, from `find_package` and `FetchContent` to vcpkg and Conan, including versioning and cross-compilation.

In-Depth Dependency Management

Integrate a full suite of professional tools for testing (CTest, GoogleTest), analysis (ASan, Clang-Tidy), and packaging (CPack).

Total Workflow Automation

Build a fully automated deployment pipeline that takes your code from a Git push to a published GitHub Release with multi-platform installers.

End-to-End CI/CD and Deployment

What You'll Learn

Become a software engineer with C++.  Starting from the basics, we guide you step by step along the way

Intro to C++ Programming

If you're completely new to programming or want a thorough introduction, consider starting with our free introductory course:

New to Programming?

Managing C++ Projects Using CMake

In the last two lessons, we've wrestled with the command line. We've compiled, linked, and managed dependencies using a flurry of flags like `-I`, `-L`, and `-l`. We've seen that while this is possible for a tiny project, it's a completely untenable way to build real software. No sane developer types out a 20-file `g++` command every time they want to build.


To escape this tedium, we turn to build systems. A build system is a tool that automates the process of compiling and linking. You tell it _**what**_ to build, and it figures out _**how**_ to call the compiler and linker with the correct commands and flags.


Before we crown CMake as our champion, it's useful to understand the tools it was designed to replace. In this lesson, we'll take a tour of the "old ways": manual build tools like Makefiles and the project files generated by IDEs.


These tools are still widely used in industry, particularly in projects that have been around for a long time, so this knowledge is directly useful.  Additionally, by understanding their limitations, you'll gain a much deeper understanding of the problems CMake solves.


## Build Automation


The most basic form of build automation involves writing a script that contains the exact compiler commands you want to run. The two most common approaches are using `make` and relying on an IDE's native project format.


### Using `make` and Makefiles


The `make` utility is a classic build automation tool that has been a cornerstone of Unix development for decades. It reads its instructions from a file, by default named `Makefile`.


We won't cover `make` in detail in this course, but have included an example below.  A simple project with two source files, and a minimalist `Makefile` to automate the build process, would look something like this:


<CodeViewer>


<CodeFile path="Makefile" defaultOpen>


```makefile
CXX = g++                    # Compiler
CXXFLAGS = -std=c++20        # Additional Flags
TARGET = my_app              # Output Name
SOURCES = main.cpp math.cpp  # Source Files

all: $(TARGET)

$(TARGET): $(SOURCES)
	$(CXX) $(CXXFLAGS) $^ -o $@
```


</CodeFile>


<CodeFile path="main.cpp">


```c++
#include <iostream>

int add(int a, int b);

int main() {
  std::cout << "3 + 4 = " << add(3, 4);
  return 0;
}
```


</CodeFile>


<CodeFile path="math.cpp">


```c++
int add(int a, int b) {
  return a + b;
}
```


</CodeFile>


</CodeViewer>


To build our project, we just run `make`:


```c++
//<ti>
make
```


Now, `make` will handle the compiler interaction for us:


```c++
//<o>
g++ -std=c++20 main.cpp math.cpp -o my_app
```


This is a huge improvement, and scales much better to larger projects - no more huge terminal commands filled with `-l`, `-L`, `-i`, and other cryptic flags.


Even better, if we run it again without changing anything, it's smart enough to not recompile anything unnecessarily:


```c++
//<ti>
make
```


```c++
//<o>
make: 'my_app' is up to date.
```


In more complex projects involving multiple targets, such as a collection of libraries and a main executable, `make` is smart enough to only recompile the libraries whose source files we changed since the last build.


<Pw>


### IDE Project Files (`.sln`, `.xcodeproj`)


The other common approach is to let an IDE handle everything. When you create a project in Visual Studio, it creates a Solution file (`.sln`) and one or more Project files (`.vcxproj`). Xcode does the same with `.xcodeproj` bundles.


These files are the IDE's internal "Makefile." They store all the information about your source files, compiler settings, linker flags, and dependencies.


For example, when you add a new file to the project in the IDE's Solution Explorer or update the include directories within your project settings, the IDE updates the `.vcxproj` file to keep track of these configurations.


When it comes time to compile our project, Microsoft's compiler, `msbuild.exe`, reads the contents of these `.vcxproj` files and behaves accordingly.


<Img hasTransparency file="cmake-vcxproj.png" alt="Diagram showing the role of vcxproj files" width="1400" height="323" blurHash="L95;|0Rx-tIk%ORhxwRiIkn;Rgs@" />


This is incredibly convenient, especially for beginners. The maintenance of the build script is handled automatically by the IDE's user interface. However, this convenience comes at a cost:

- **Opacity**: The project files are complex, verbose XML files not meant for human editing. All your build settings are hidden behind layers of GUI property pages.
- **Vendor Lock-in**: The project is now tied to that specific IDE and platform.  Everyone working on your project needs to use this same IDE, and you can't easily take a Visual Studio project and build it on Linux.
- **Command-Line Hostility**: Building an IDE project from a script requires using platform-specific command-line tools like `msbuild.exe` on Windows or `xcodebuild` on macOS, each with its own unique and complex command-line syntax.

## Scalability Issues in Large Codebases


As projects grow from a handful of files to hundreds or thousands, the limitations of these manual approaches become critical bottlenecks.


### The Unscalable Makefile


In a large codebase, a single Makefile becomes a monolithic, unreadable monster. To cope, developers invent complex systems of recursive `make` calls, where subdirectories have their own Makefiles. This sounds modular, but is widely considered harmful because it makes it very difficult to get a global view of the dependency tree, leading to incorrect and inefficient builds.


The Makefile itself becomes a piece of arcane software that only one or two "build gurus" on the team understand. Adding a new library or changing a fundamental build setting becomes a high-risk operation that can break the build for everyone. Duplication runs rampant, with similar rules for building different executables or libraries copied and pasted across multiple Makefiles.


### The Unscalable IDE Project


Managing a large system with dozens of interdependent libraries within a single IDE solution also becomes unwieldy.

- **Merge Conflicts**: IDE project files are a nightmare for version control. If two developers add a file in different branches, the resulting merge conflict in the giant XML file is often impossible to resolve manually. The only safe option is often to accept one version and have the other developer re-add their file in the IDE.
- **Scattered Settings**: The build configuration is scattered across countless property dialogs for each of the dozens of projects in the solution. Want to change a compiler flag across the entire codebase? Get ready for a lot of clicking. There's no single, text-based source of truth for the build.
- **Inter-Project Dependencies**: Managing dependencies between projects in the solution is done through the GUI. This creates implicit links that are not easily visible or editable in a text format, making it hard to reason about the overall dependency graph.

## Multiple Build Configurations


The final challenge is managing different build configurations.  Most projects need to manage at least two different build configurations:

- A `Debug` build should compile with debugging information (using the `g` flag in GCC/Clang) and no optimizations (using the `O0` flag), making it easy to step through with a debugger.
- A `Release` build should be compiled with full optimizations (using the `O3` flag) and no debug symbols, making it fast and small for shipping to users.

Most projects need to control many more configurations than this, which introduces further complexity that we need to manage.


### Configurations in Makefiles


In a Makefile, you might handle this with variables and conditional logic:


```makefile
# Default to release
CONFIG ?= Release

CXXFLAGS = -std=c++20

ifeq ($(CONFIG),Debug)
	CXXFLAGS += -g -O0
else
	CXXFLAGS += -O3 -DNDEBUG
endif

# ... rest of the Makefile
```


A developer would then build by specifying the configuration on the command line: `make CONFIG=Debug`.


This works, but it's clunky. The logic for different configurations is mixed in with the logic for building targets. Furthermore, you can't easily have a debug build and a release build co-exist.


The object files and executables for each configuration will overwrite each other unless you add even more complex logic to the Makefile to put them in separate directories (e.g., `build/debug/` and `build/release/`).


### Configurations in IDEs


IDEs handle this much more gracefully. Visual Studio and Xcode have a built-in concept of configurations:


<Img file="cmake-configuration-manager.png" alt="Visual Studio configuration manager" width="806" height="592" blurHash="L0RC[70000oe0X004?IU00~1-iD%" />


We can then customize each configuration with the set of options we want to be applied when that configuration is selected:


<Img file="vs-cpp-language-standard.png" alt="Screenshot showing C++ language standard configuration in Visual Studio" width="986" height="687" blurHash="L2R:HH00DgRN9I9FROIT00~po%tS" />


This is a significant advantage over simple Makefiles. However, the configuration settings themselves are still locked away in the GUI and stored in the opaque project files, making them difficult to script, version control, or share consistently across a team.


<Preview>


### The CMake Solution


We have now painted a rather bleak picture of the challenges in C++ build automation. We are trapped between two undesirable extremes:

1. **Manual Scripts (Makefiles)**: Text-based and scriptable, but brittle, hard to maintain, and fundamentally not portable.
2. **IDE Projects**: User-friendly and great for single-platform development, but opaque, not portable, and hostile to command-line automation.

This is the problem that CMake was created to solve. It provides a third way. With CMake, you don't write a `Makefile` or a `.vcxproj` file. You write a single, high-level, platform-agnostic file called `CMakeLists.txt`. This file _describes_ your project: its targets, its source files, and its dependencies.


Then, you run CMake, telling it what you want to generate.

- **On Linux**: `cmake -G "Unix Makefiles"` will read your `CMakeLists.txt` and generate a `Makefile`.
- **On Windows**: `cmake -G "Visual Studio 17 2022"` will generate a full `.sln` and `.vcxproj` solution.

You get the best of both worlds: a single, readable, portable, and version-controllable source of truth for your build, combined with the power and convenience of the best native build tools on each platform.


In the next chapter, we will finally leave these limitations behind and write our first `CMakeLists.txt` file.


</Preview>


</Pw>

Managing Libraries and External Dependencies

Why CMake? Addressing Build Complexity

Preprocessor Directives and the Build Process

GNU `make` Manual

Use the Microsoft C++ toolset from the command line

Building from the Command Line with Xcode FAQ

Managing Projects with GNU Make

Make (software)

Introduction to Makefiles

Explore the limitations of traditional C++ build systems. This lesson covers the maintenance overhead of Makefiles, scalability issues in large codebases, cross-platform challenges, and why IDE projects fall short, setting the stage for CMake.

Automated Build Systems and Their Limitations

Understanding the Basics

Practical Applications

Common Mistakes

Next Steps

Additional Resources

Assessment Preparation

Managing C++ Projects Using CMake