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 learned about variables in CMake. We saw how normal variables let us store and reuse information within a single configuration run, and how cached variables let us create persistent, user-configurable options.


This lesson will explore the fundamental syntax of CMake commands in a bit more depth, and introduce the idea of a list, which is how we represent collections of values.


## CMake Commands and Arguments


The basic syntax of any CMake script is a series of commands. Every command follows the same pattern:


```c++
#<cmake>
command_name(argument1 argument2 ...)
```


Here are the key rules to remember:

- **Case-Insensitive Commands**: Command names are case-insensitive. `project()`, `PROJECT()`, and `Project()` are all treated as the same command. However, the strong convention is to _**always use lowercase**_ for command names. This makes your scripts consistent and easier to read.
- **Case-Sensitive Arguments**: In contrast, arguments - including variable names, target names, and file paths - are almost always case-sensitive. `GreeterApp` is a different target from `greeterapp`.
- **Whitespace Separation**: Arguments are separated by one or more spaces or newlines.

### Quoted vs. Unquoted Arguments


This brings us to an important point about how CMake parses arguments. Let's look at two `set()` commands:


```c++
#<cmake>
# 1. An unquoted argument
set(UNQUOTED_VAR Hello World)

# 2. A quoted argument
set(QUOTED_VAR "Hello World")
```


These two commands do very different things.

- `QUOTED_VAR` becomes a single string: `"Hello World"`.
- `UNQUOTED_VAR` becomes a _**list**_ of two strings: `"Hello"` and `"World"`.

When you provide multiple unquoted arguments, CMake treats them as a collection of separate items. This implicit list creation is a core feature of the language and is the most common way lists are formed.


<Aside>


### When to Quote


The rule of thumb is simple:

- If you want to pass a value that contains spaces as a _**single argument**_, you must enclose it in double quotes.
- If you want to pass multiple arguments, you can list them without quotes.

This applies to all commands, not just `set()`. For example, `message("Hello World")` prints one line, whereas `message(Hello World)` prints "HelloWorld" with no space, as `message()` concatenates all its arguments.


</Aside>


## Understanding Lists


So, what exactly is a CMake list?  It is simply a single string where the elements are separated by semicolons.


When we wrote `set(UNQUOTED_VAR Hello World)`, CMake created the string `"Hello;World"`. The `set()` command automatically joined the unquoted arguments with semicolons for us.


We can also create lists explicitly:


```c++
#<cmake>
# This creates a list with three elements.
set(MY_SOURCES "main.cpp;utils.cpp;logger.cpp")
```


This is exactly equivalent to:


```c++
#<cmake>
# This also creates a list with three elements.
set(MY_SOURCES main.cpp utils.cpp logger.cpp)
```


The semicolon-separated string is the "true" form of a list. The space-separated `set()` command is just convenient syntax for creating one, and is the preferred approach.


### Passing Lists to Commands


When you pass a list variable to a command, you typically do it _without quotes_.


```c++
#<cmake>
set(MY_SOURCES main.cpp utils.cpp)

# Correct: Pass unquoted to expand the list
add_executable(MyApp ${MY_SOURCES})
```


When CMake sees `${MY_SOURCES}`, it substitutes the variable's value (`"main.cpp;utils.cpp"`) and then expands it. The semicolons act like spaces, breaking the string into multiple arguments for the `add_executable()` command. 


The command effectively becomes:


```c++
#<cmake>
add_executable(MyApp main.cpp utils.cpp)
```


This is what you almost always want. If you were to quote the variable (`add_executable(MyApp "${MY_SOURCES}")`), you would be passing a single string `"main.cpp;utils.cpp"` as the only source file.  This would almost certainly fail because no file with that name likely exists.


<Pw>


## Manipulating Lists


CMake provides a `list()` command for performing a wide range of operations on these semicolon-separated strings. The `list()` command always takes the list variable name as its first argument, followed by a subcommand that specifies the action to take.


Let's explore the most common `list()` subcommands.


### Adding Elements


This is the most common list operation. It adds one or more elements to the end of a list.


```c++
#<cmake>
set(FILES file1.cpp file2.cpp)
message("Original list: ${FILES}")

list(APPEND FILES file3.cpp file4.cpp)
message("Appended list: ${FILES}")
```


```c++
//<o>
Original list: file1.cpp;file2.cpp
Appended list: file1.cpp;file2.cpp;file3.cpp;file4.cpp
```


### Getting the Size


To find out how many elements are in a list, use `list(LENGTH)`. It stores the result in an output variable.


```c++
#<cmake>
set(FILES file1.cpp file2.cpp file3.cpp)
list(LENGTH FILES NUM_FILES)

message("The list has ${NUM_FILES} elements.")
```


```c++
//<o>
The list has 3 elements.
```


### Accessing by Index


Lists are 0-indexed. You can retrieve an element at a specific index with `list(GET)` or remove one with `list(REMOVE_AT)`.


```c++
#<cmake>
set(COLORS red green blue)

list(GET COLORS 1 MIDDLE_COLOR)
message("The middle color is: ${MIDDLE_COLOR}")

list(REMOVE_AT COLORS 0)
message("After removing first element: ${COLORS}")
```


```c++
//<o>
The middle color is: green
After removing first element: green;blue
```


### Ordering


These commands modify the list in-place to change its order.


```c++
#<cmake>
set(LETTERS c a d b)
message("Original: ${LETTERS}")

list(SORT LETTERS)
message("Sorted:   ${LETTERS}")

list(REVERSE LETTERS)
message("Reversed: ${LETTERS}")
```


```c++
//<o>
Original: c;a;d;b
Sorted:   a;b;c;d
Reversed: d;c;b;a
```


### Searching


To check if an element exists in a list, use `list(FIND)`. It returns the index of the first match, or `-1` if the element is not found.


```c++
#<cmake>
set(TOOLS hammer saw screwdriver)
list(FIND TOOLS "saw" INDEX_OF_SAW)

message("Index of 'saw' is: ${INDEX_OF_SAW}")
```


```c++
//<o>
Index of 'saw' is: 1
```


This is particularly useful when combined with `if()` statements, which we'll cover in the next lesson.


## A Practical Example


A common practice is to define your source files in a list variable before passing them to commands like `add_library()` or `add_executable()`. This is highly recommended if your list is long, as the intermediate variable then keeps your target definitions clean.


There is also a practical reason to introduce this list variable, as it allows our script to use the `list()` commands we covered to modify our list of files before providing them to our target.


Let's refactor our `GreeterApp`'s `CMakeLists.txt` in `/app` to use this pattern:


<CodeFile path="app/CMakeLists.txt" status="Updated">


```c++
#<cmake>
cmake_minimum_required(VERSION 3.16)

option(
  SAY_GOODBYE
  "Should the program say goodbye before exiting"
  OFF
)

set(GREETER_SOURCES #<h>
  src/main.cpp #<h>
  # Add more source files here as needed #<h>
  # src/some-other-file.cpp #<h>
) #<h>

add_executable(GreeterApp src/main.cpp)#<d>
add_executable(GreeterApp ${GREETER_SOURCES})#<h>

target_compile_features(GreeterApp PUBLIC cxx_std_20)
target_link_libraries(GreeterApp GreeterLib)

if(SAY_GOODBYE)
  message(STATUS "Defining SAY_GOODBYE")
  target_compile_definitions(GreeterLib PUBLIC SAY_GOODBYE)
endif()
```


</CodeFile>


So far, the behavior is identical.


However, let's imagine the `SAY_GOODBYE` cache variable we defined in the previous lesson is set to `ON`, and our `GreeterApp` needs some additional source files to implement that behaviour.


We can now conditionally `APPEND` those source files to our list before forwarding it to our target:


<CodeViewer>


<CodeFile path="app/CMakeLists.txt" status="Updated" defaultOpen>


```c++
#<cmake>
cmake_minimum_required(VERSION 3.16)

option(
  SAY_GOODBYE
  "Should the program say goodbye before exiting"
  OFF
)

set(GREETER_SOURCES
  src/main.cpp
)

if(SAY_GOODBYE)#<h>
  message(STATUS "Adding goodbye.cpp to GREETER_SOURCES")#<h>
  list(APPEND GREETER_SOURCES src/goodbye.cpp)#<h>
#<h>
  list(LENGTH GREETER_SOURCES GREETER_SOURCE_COUNT)#<h>
  message(STATUS "GREETER_SOURCES now has ${GREETER_SOURCE_COUNT} files")#<h>
endif()#<h>

add_executable(GreeterApp ${GREETER_SOURCES})

target_compile_features(GreeterApp PUBLIC cxx_std_20)
target_link_libraries(GreeterApp GreeterLib)

if(SAY_GOODBYE)
  message(STATUS "Defining SAY_GOODBYE")
  target_compile_definitions(GreeterApp PUBLIC SAY_GOODBYE)
endif()
```


</CodeFile>


<CodeFile path="app/main.cpp" status="Updated">


```c++
#include <iostream>
#include <greeter/Greeter.h>

// Forward Declaration
void SayGoodbye();//<h>

int main() {
  std::cout << get_greeting();
#ifdef SAY_GOODBYE
  std::cout << "\nGoodbye";//<d>
  SayGoodbye();//<h>
#endif
  return 0;
}
```


</CodeFile>


<CodeFile path="app/goodbye.cpp" status="New">


```c++
#include <iostream>

void SayGoodbye() {
  std::cout << "\nGoodbye";
}
```


</CodeFile>


</CodeViewer>


Let's test everything works.  From the `/build` folder as usual, we'll run the configure step:


```c++
//<ti>
cmake -DSAY_GOODBYE=ON ..
```


```c++
//<o>
-- Configuring Greeter Version: 1.0
-- Adding goodbye.cpp to GREETER_SOURCES
-- GREETER_SOURCES now has 2 files
-- Defining SAY_GOODBYE
-- Configuring done (0.1s)
-- Generating done (0.1s)
-- Build files have been written to: D:/Projects/cmake/build
```


We'll then build our project:


```c++
//<ti>
cmake --build .
```


And run it in the usual way, remembering to add `.exe` if on Windows:


```c++
//<ti>
./app/GreeterApp
```


```c++
//<o>
Hello from the modular Greeter library!
Goodbye
```


## Summary


In this lesson, we dug into the grammar of the CMake language and learned about its collection type - lists.

- **Command Syntax**: Commands are case-insensitive, but their arguments are not. `command(arg1 arg2)` is the basic structure.
- **Quoted vs. Unquoted Arguments**: Unquoted arguments are treated as separate items, implicitly forming a list. Quoted arguments are treated as a single string.
- **Lists as Semicolon-Separated Strings**: A CMake list is just a string with semicolons as delimiters (e.g., `"a;b;c"`).
- **List Expansion**: Passing a list variable unquoted (e.g., `${MY_LIST}`) to a command expands it into multiple arguments. This is the standard way to use lists.
- **The** **`list()`** **Command**: This is your primary tool for list manipulation, with subcommands like `APPEND`, `LENGTH`, `GET`, `SORT`, and `FIND`.
- **Best Practice**: Group your source files into list variables before passing them to commands like `add_library()` or `add_executable()` to keep your scripts clean and maintainable.

You now have a solid understanding of how CMake handles commands, arguments, and collections of data.


<Preview>


### Conditionals and Loops


We've learned to create and manipulate lists, but we haven't yet seen how to iterate over them or make decisions based on their contents.


In the next lesson, we will explore CMake's control flow structures: `if()`/`elseif()`/`else()` for conditional logic, and `foreach()` for looping over the elements of a list. These commands are important for writing more dynamic and intelligent build scripts.


</Preview>


</Pw>

`list()` Command Documentation

Command-Line Interface

cmake-language(7) Manual

How do I manipulate CMake lists as sets?

CMake Lists

CMake list and option commands

Master the CMake language with this detailed guide on commands, arguments, and lists. Learn how to create and manipulate lists of strings using the set() and list() commands, and see a practical example of managing source files.

CMake Commands, Arguments, and Lists

Understanding the Basics

Practical Applications

Common Mistakes

Next Steps

Additional Resources

Assessment Preparation

Managing C++ Projects Using CMake