CMakeJSON

CMakeJSON provides a way to declare CMake projects and targets via *.json files. Furthermore, it also automatically export your targets and keeps track of your dependencies to generate correct <PackageName>Config.cmake files for find_package to simply work for your project/package.
CMake is the defactor standard for a cross platform (meta) buildsystem but some people do not like it due to its syntax and/or complexity. CMakeJSON gives those people another (maybe simpler&cleaner) approach to CMake.
In the current state, CMakeJSON is mainly targeted at smaller projects which have a not too complicated CMakeLists.txt. Bigger projects are also possible due to the possibility to mix normal CMake with CMakeJSON but further functionallity might be needed to ease the usage with CMakeJSON.

Usage

The recommended way to use CMakeJSON is to include it as a submodule in your project and use include(<submodulepath>/CMakeJSON/CMakeJSON.cmake). CMakeJSON is based on the experince with CMakeCS and the newly added JSON parser to CMake. Due to that a CMake version of at least 3.19 is required.

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Documentation

List of json members allowed for:

• project
• target
• To implement: Find<PackageName>.cmake

Other questions might be answered in the FAQ Parsing logic

Note: Currently no validation is done on the passed in *.json files. So make sure your field/members names are correctly spelled and have the correct type.

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Quickstart

Examples for using CMakeJSON can be found in examples. The simplest CMakeJSON project looks like this:

1. CMakeLists.txt:

   cmake_minimum_required(VERSION 3.19)
   set(CMakeJSON_ENABLE_PROJECT_OVERRIDE ON) # defines a macro called project() to silence a CMake Warning
   include("${CMAKE_CURRENT_SOURCE_DIR}/CMakeJSON/CMakeJSON.cmake")
   project("<projectname>.json")
   # alternativly: if you don't want to use CMakeJSON_ENABLE_PROJECT_OVERRIDE
   # project(something) # this project call is mandatory since CMake throws a dev warning otherwise
   # cmakejson_project_file("<projectname>.json")
   

2. <projectname>.json read via cmakejson_project_file(<filename>):

   {
       "homepage" : "<someurl>",
       "description" : "<somedescription>",
       "version" : "0.1.0",
       "languages" : ["CXX"],
       "list" : [
           "<libname>.target.json"
       ]
   }
   

3. <libname>.target.json read via cmakejson_target_file(<filename>):

   {
       "target_type" : "library",
       "sources" : [
           "src/somesource.cpp"
       ]
   }
   

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Key features

• JSON based project/target definitions
• CMake variable expansion in JSON members
• Getting target/project name from JSON file.
• Mixing of JSON files and normal CMake.
• Automatic target export for library targets (except OBJECT libraries).
• Automatic <PackageName>Config(Version).cmake generation
• Automatic FOLDER property according to filesystem structure
• Automatic source_group(TREE) setting according to filesystem structure
• Support for feature_summary()
• Automatic namespaced ALIAS targets and deactivation of find_package for CMakeJSON defined targets/packages for easier superbuild setups using add_subdirectory of projects

In the future:

• Automatic pc file generation. (Difficult since this a target based not package based. Needs some extra introspection from where an imported target originated)
• CTest/CDash/CPack stuff (missing experience for proper setup)
• More awesome stuff
• Things from the ToDo List
• Automatic VS_DEBUGGER_ENVIRONMENT for VS Generator + VCPKG toolchain?
• Automatic vcpkg.json generation? (The way the code is executed probably doesn't allow this. Since the manifest must be created before the first project() call. Probably can only create a vcpkg.json.new after everything has run)
• automatic Conan stuff? (don't know enough about conan to generate something)
• Installation of runtime deps.

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Examples

Different Examples for using CMakeJSON can be found in examples.

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Internals