Update detection of OS Architecture to include ARM

Tasks/UseDotNetV2/externals/get-os-platform.ps1

@@ -1,16 +1,35 @@
-function Get-Machine-Architecture()
-{
-    # possible values: AMD64, IA64, x86
+function Get-Machine-Architecture() {
+    # On PS x86, PROCESSOR_ARCHITECTURE reports x86 even on x64 systems.
+    # To get the correct architecture, we need to use PROCESSOR_ARCHITEW6432.
+    # PS x64 doesn't define this, so we fall back to PROCESSOR_ARCHITECTURE.
+    # Possible values: amd64, x64, x86, arm64, arm
+    if( $ENV:PROCESSOR_ARCHITEW6432 -ne $null ) {
+        return $ENV:PROCESSOR_ARCHITEW6432
+    }
+
+    try {        
+        if( ((Get-CimInstance -ClassName CIM_OperatingSystem -OperationTimeoutSec 30).OSArchitecture) -like "ARM*") {
+            if( [Environment]::Is64BitOperatingSystem )
+            {
+                return "arm64"
+            }  
+            return "arm"
+        }
+    }
+    catch {
+        # Machine doesn't support Get-CimInstance
+    }
+
     return $ENV:PROCESSOR_ARCHITECTURE
 }
 
-function Get-CLIArchitecture-From-Architecture([string]$Architecture)
-{
-    switch ($Architecture.ToLower())
-    {
+function Get-CLIArchitecture-From-Architecture([string]$Architecture) {
+    switch ($Architecture.ToLowerInvariant()) {
         { ($_ -eq "amd64") -or ($_ -eq "x64") } { return "x64" }
         { $_ -eq "x86" } { return "x86" }
-        default { throw "Architecture not supported. If you think this is a bug, please report it at https://github.com/dotnet/cli/issues" }
+        { $_ -eq "arm" } { return "arm" }
+        { $_ -eq "arm64" } { return "arm64" }
+        default { throw "Architecture '$Architecture' not supported. If you think this is a bug, report it at https://github.com/microsoft/azure-pipelines-tasks/issues" }
     }
 }
 

Tasks/UseDotNetV2/task.json

@@ -13,7 +13,7 @@
   "author": "Microsoft Corporation",
   "version": {
     "Major": 2,
-    "Minor": 248,
+    "Minor": 249,
     "Patch": 0
   },
   "satisfies": [

Tasks/UseDotNetV2/task.loc.json

@@ -13,7 +13,7 @@
   "author": "Microsoft Corporation",
   "version": {
     "Major": 2,
-    "Minor": 248,
+    "Minor": 249,
     "Patch": 0
   },
   "satisfies": [