functions.ps1

# copy pasted from https://gist.github.com/cloudhan/97db3c1e57895a09a80ec1f30c471cb3
function Set-EnvFromCmdSet {
    [CmdletBinding()]
    param(
        [Parameter(ValueFromPipeline)]
        [string]$CmdSetResult
    )
    process {
        if ($CmdSetResult -Match "=") {
            $i = $CmdSetResult.IndexOf("=")
            $k = $CmdSetResult.Substring(0, $i)
            $v = $CmdSetResult.Substring($i + 1)
            Set-Item -Force -Path "Env:\$k" -Value "$v"
        }
    }
}

function Set-VSEnv {
    param (
        [parameter(Mandatory = $false)]
        [ValidateSet(2022, 2019, 2017)]
        [int]$Version = 2022,

        [parameter(Mandatory = $false)]
        [ValidateSet("all", "x86", "x64")]
        [String]$Arch = "x64"
    )

    $vs_where = 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\vswhere.exe'

    $version_range = switch ($Version) {
        2022 { '[17,18)' }
        2019 { '[16,17)' }
        2017 { '[15,16)' }
    }
    $info = &$vs_where -version $version_range -format json | ConvertFrom-Json
    $vs_env = @{
        install_path = if ($null -ne $info) { $info[0].installationPath } else { $null }
        all          = 'Common7\Tools\VsDevCmd.bat'
        x64          = 'VC\Auxiliary\Build\vcvars64.bat'
        x86          = 'VC\Auxiliary\Build\vcvars32.bat'
    }
    if ( $null -eq $vs_env.install_path) {
        Write-Host -ForegroundColor Red "Visual Studio $Version is not installed."
        return
    }

    $path = Join-Path $vs_env.install_path $vs_env.$Arch

    C:/Windows/System32/cmd.exe /c "`"$path`" & set" | Set-EnvFromCmdSet
    Set-Item -Force -Path "Env:\BAZEL_VC" -Value "$env:VCINSTALLDIR"
    Write-Host -ForegroundColor Green "Visual Studio $Version $Arch Command Prompt variables set."
}


class EnvironmentStack {
    static [System.Collections.Stack] $stack = [System.Collections.Stack]::new()
}

function Push-Environment {
    [EnvironmentStack]::stack.push([Environment]::GetEnvironmentVariables())
}

function Pop-Environment {
    [EnvironmentStack]::stack.pop().GetEnumerator() |
    ForEach-Object {
        Set-Item -Force -Path ("Env:\" + $_.Key) -Value $_.Value
    }
}