CMake force use of presets

Readme.md

CMake force use of presets

This approach uses a sentinel environment variable to effectively force the users to use CMake Presets for configure and build steps.

This approach uses a small auxiliary CMake script as a PRE_BUILD step for a target to check a sentinel environment variable and fail the configure or build step if it is not set.

Tested with CMake generators: MinGW Makefiles, Ninja, Unix Makefiles, Visual Studio 17 2022

Reference question

These non-preset command sequences all fail intentionally as they don't use presets:

cmake -Bbuild

# or

cmake --preset default
cmake --build build

These preset commands succeed

cmake --preset default

cmake --build --preset default

CheckSentinel.cmake

if(NOT DEFINED ENV{sentinel})
  message(FATAL_ERROR "sentinel not set--cmake presets must be used")
endif()

CMakeLists.txt

# force use of presets via sentinel environment variable set in presets only
cmake_minimum_required(VERSION 3.21)

project(envpre LANGUAGES C)

message(STATUS "sentinel: $ENV{sentinel}")

include(CheckSentinel.cmake)

add_executable(main main.c)
add_custom_command(
    TARGET main
    PRE_BUILD
    COMMAND ${CMAKE_COMMAND} -P ${CMAKE_CURRENT_SOURCE_DIR}/CheckSentinel.cmake
)

CMakePresets.json

{
    "version": 3,
    "configurePresets": [
      {
        "name": "default",
        "displayName": "Default Config",
        "binaryDir": "${sourceDir}/build",
        "environment": {
          "sentinel": "MyConfigure"
        }
      }
    ],
    "buildPresets": [
      {
        "name": "default",
        "configurePreset": "default",
        "environment": {
          "sentinel": "MyBuild"
        }
      }
    ]
}

main.c

int main() { return 0; }