Specify shared/'common' values for configurations in CppProperties.json or CMakeSettings.json - json

Question

When using the "Open Folder" functionality of Visual Studio, the IDE searches for project settings and configurations in a special json file. For CPP projects, this could be CppProperties.json. For CMake projects, this could be CMakeSettings.json.
This json file contains a collection of one or more "configurations," such as "Debug" or "Release". I will use a recent CMake project as an example:
"configurations": [
{
"name": "ARM-Debug",
"generator": "Ninja",
"configurationType": "Debug",
"inheritEnvironments": [
"gcc-arm"
],
"buildRoot": "${env.USERPROFILE}\\CMakeBuilds\\${workspaceHash}\\build\\${name}",
"installRoot": "${env.USERPROFILE}\\CMakeBuilds\\${workspaceHash}\\install\\${name}",
"cmakeCommandArgs": "",
"buildCommandArgs": "-v",
"ctestCommandArgs": "",
"intelliSenseMode": "linux-gcc-arm",
"variables": [
{
"name": "CMAKE_TOOLCHAIN_FILE",
"value": "${workspaceRoot}/cmake/arm-none-eabi-toolchain.cmake"
}
]
},
{
"name": "ARM-Release",
"generator": "Ninja",
"configurationType": "Release",
"inheritEnvironments": [
"gcc-arm"
],
"buildRoot": "${env.USERPROFILE}\\CMakeBuilds\\${workspaceHash}\\build\\${name}",
"installRoot": "${env.USERPROFILE}\\CMakeBuilds\\${workspaceHash}\\install\\${name}",
"cmakeCommandArgs": "",
"buildCommandArgs": "-v",
"ctestCommandArgs": "",
"intelliSenseMode": "linux-gcc-arm",
"variables": [
{
"name": "CMAKE_TOOLCHAIN_FILE",
"value": "${workspaceRoot}/cmake/arm-none-eabi-toolchain.cmake"
}
]
}
As you can see, I have two configurations with nearly identical properties.
My question: is it possible to define these common/shared properties once, in such a way as to allow the configurations to inherit them and avoid repeating myself?

Answer 1

The easier way is to define an environment at global level (outside of any configuration), such as:
{
"environments": [
{
"namespace" : "env",
"varName": "varValue"
}
],
Then you can reuse that wherever you need to, e.g.:
"cmakeCommandArgs": "${env.varName}",
You can also have multiple environments, and reuse them, like this:
{
"environments": [
{
"environment": "env1",
"namespace": "env",
"varName": "varValueEnv1"
},
{
"environment": "env2",
"namespace": "env",
"varName": "varValueEnv2"
}
],
"configurations": [
{
"name": "x64-Release",
"inheritEnvironments": [
"msvc_x64_x64", "env2"
],
"cmakeCommandArgs": "${env.varName}",
.....
}
]
the 'x64-Release' will inherit the variables's value in the environment called "env2" (namespace 'env')