CMake Basics

Given a directory structure like:

.
+-- CMakeLists.txt
+-- src
|   +-- main.cpp
|   +-- ...etc

Add the following a CMakeLists.txt:

cmake_minimum_required (VERSION 3.5)
project (MyProjectName)

# Allows us to to use MSVC
if(MSVC)
    add_compile_options("/W4" "$<$<CONFIG:RELEASE>:/O2>")
else()
    add_compile_options("-Wall" "-Wextra" "-Werror" "$<$<CONFIG:RELEASE>:-O3>")
endif()

set(CMAKE_CXX_STANDARD 11)

set(source_dir  "${PROJECT_SOURCE_DIR}/src/")
file(GLOB source_files "${source_dir}*.cpp")
add_executable(MyApp ${source_files})

Building

When building from the command line:

$ mkdir build
$ cd build
$ cmake ../
$ cmake --build .

This will build MyApp (or MyApp.exe in Windows) in Debug mode by default. Depending on your distro it may place the binary either in the build directory or a build/Debug directory.

Compile Options

We configure global options using add_compile_options(...).

The $<$<CONFIG:RELEASE>:OPTION> can be used to add options based on whether you are building for debug or release.

By default we build in Debug mode. To build a Release binary:

$ cmake --build . --config Release

Note: add_compile_options should only be used at the top of the root CMakeLists.txt for compile options which are appropriate for the entire project. For all target specific options, use target_compile_options or target_compile_definitions to limit flags to thier specific modules.

Setting C++ Version

set(CMAKE_CXX_STANDARD 11)

Defining output binaries

add_executable(MyApp ${source_files})

When multiple binaries are added, then all binaries will be built when running:

$ cmake --build .

To build a specific binary (for example, Test), we can run:

$ cmake --build . --target Test