Reference a variabled in tasks.json that was defined in launch.json - json

Question

I'm trying to configure my project in Visual Studio Code.
I am using CMake+make to build my project. CMake needs to know the project configuration (Debug/Release) and architecture (x64/x86) before it can generate the make files.
I could define 4 tasks and 4 launch configurations to achieve this (each hardcoding both options), but that is a lot of duplication.
Instead, I would like to use environment variables to basically "pass down" the parameters from the launch configuration to a single task.
However, VScode doesn't seem to forward what I define in the launch configuration to the task.
Here is what I have:
// launch.json
{
"version": "0.2.0",
"configurations": [
{
"name": "Debug (x64)",
"type": "cppdbg",
"request": "launch",
"program": "${workspaceFolder}/bin/debug/x64/executable",
"args": [],
"stopAtEntry": false,
"cwd": "${workspaceFolder}",
"environment": [
{
"name": "proj_configuration",
"value": "Debug"
},
{
"name": "proj_platform",
"value": "x64"
}
],
// "variables": {
// "proj_configuration": "Debug",
// "proj_platform": "x64"
// },
"externalConsole": true,
"MIMode": "gdb",
"miDebuggerPath": "/usr/bin/gdb",
"setupCommands": [
{
"description": "Enable pretty-printing for gdb",
"text": "-enable-pretty-printing",
"ignoreFailures": true
}
],
"preLaunchTask": "Make Project",
}
]
}
// tasks.json
{
"version": "2.0.0",
"tasks": [
{
"label": "Build Project",
"type": "shell",
"command": "cmake",
"args": [
"-B${workspaceFolder}/build",
"-H${workspaceFolder}",
"-DCMAKE_BUILD_TYPE=${proj_configuration}",
"-DCMAKE_GENERATOR_PLATFORM=${proj_platform}"
],
"group": {
"kind": "build",
"isDefault": false
}
},
{
"label": "Make Project",
"type": "shell",
"command": "make",
"group": {
"kind": "build",
"isDefault": true
},
"dependsOn": ["Build Project"],
}
]
}
When I try to run my project, I get
Executing task: cmake -B/home/user/project/build -H/home/user/project/ -DCMAKE_BUILD_TYPE=${proj_configuration} -DCMAKE_GENERATOR_PLATFORM=${proj_platform}
As you can see, the 2 variables are not replaced.
I've also tried using the property "variables", but no luck using that either.
So, is it possible to do what I described, or do I have to define multiple tasks instead?

Answer 1

with the extension Command Variable you can save a number of strings in a store and use these in launch.json and task.json. See example in the link