Settings in CMakeLists.txt that populate CMakeSettings.json

In CMake, the CMakeLists.txt file is used to define the build configuration and settings for your project, while the CMakeSettings.json file is used to manage user-specific configuration for CMake projects in Visual Studio.

Here's how you can set up settings in your CMakeLists.txt file that will populate the CMakeSettings.json file:

1. CMakeLists.txt Configuration:

   In your CMakeLists.txt file, you can define variables that will be used to configure your project. These variables can be used to populate the CMakeSettings.json file later. For example:

   cmakeCopy code
   set(MY_VARIABLE "my_value" CACHE STRING "My description")
   
   

   You can also use target_compile_definitions to define compile-time constants that can be used in your code:

   cmakeCopy code
   target_compile_definitions(my_target PRIVATE MY_DEFINE)
   
   

2. CMakeSettings.json Configuration:

   In the CMakeSettings.json file, you can use the variables section to define and set the values for the variables defined in your CMakeLists.txt file. For example:

   jsonCopy code
   {
   
       "configurations": [
   
           {
   
               "name": "MyConfiguration",
   
               "variables": [
   
                   {
   
                       "name": "MY_VARIABLE",
   
                       "value": "new_value"
   
                   }
   
               ]
   
           }
   
       ]
   
   }
   
   

   You can also use the definitions section to define and set compile-time constants:

   jsonCopy code
   {
   
       "configurations": [
   
           {
   
               "name": "MyConfiguration",
   
               "definitions": [
   
                   "MY_DEFINE"
   
               ]
   
           }
   
       ]
   
   }
   
   

Remember that the CMakeLists.txt file defines project-wide settings, while the CMakeSettings.json file is used for user-specific configuration in Visual Studio. Make sure to use consistent naming and values between the two files to ensure that the correct settings are applied.

When you open your CMake project in Visual Studio, it will use the settings defined in the CMakeSettings.json file to configure the project build. These settings can be adjusted on a per-configuration basis in the Visual Studio user interface.