[Azure.Identity] Change DAC to use reflection behavior analyzable by ILLinker (Azure#49427)

* attempt fix

* fix GetType syntax

* trying something

* undo packages fixes and fix ci

* forgot to add the filepath to ci.yml

Author: m-redding

eng/scripts/compatibility/Check-AOT-Compatibility.ps1

@@ -80,7 +80,7 @@ $actualWarningCount = 0
 
 foreach ($line in $($publishOutput -split "`r`n"))
 {
-    if ($line -like "*analysis warning IL*")
+    if ($line -like "*warning IL*")
     {
         $actualWarningCount += 1
     }

sdk/identity/Azure.Identity.Broker/src/DevelopmentBrokerOptions.cs

@@ -12,7 +12,6 @@ namespace Azure.Identity.Broker
     /// Options to configure the <see cref="InteractiveBrowserCredential"/> to use the system authentication broker in lieu of an embedded web view or the system browser.
     /// For more information, see <see href="https://aka.ms/azsdk/net/identity/interactive-brokered-auth">Interactive brokered authentication</see>.
     /// </summary>
-    [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)]
     internal class DevelopmentBrokerOptions : InteractiveBrowserCredentialOptions, IMsalSettablePublicClientInitializerOptions, IMsalPublicClientInitializerOptions
     {
         private Action<PublicClientApplicationBuilder> _beforeBuildClient;

sdk/identity/Azure.Identity.Broker/tests/compatibility/ExpectedWarnings.txt

@@ -0,0 +1 @@
+ILC : warning IL3000: Microsoft\.Identity\.Client\.NativeInterop\.Platform\.GetExecutingAssemblyDirectory\(\): 'System\.Reflection\.Assembly\.Location\.get' always returns an empty string for assemblies embedded in a single-file app\. If the path to the app directory is needed, consider calling 'System\.AppContext\.BaseDirectory'

sdk/identity/Azure.Identity/src/DefaultAzureCredentialFactory.cs

@@ -262,30 +262,19 @@ public virtual TokenCredential CreateAzurePowerShellCredential()
         /// This is used to enable broker authentication for development purposes.
         /// </summary>
         /// <param name="options"></param>
-        /// <returns></returns>
-        [UnconditionalSuppressMessage("Trimming", "IL2026",
-    Justification = "Assembly.Load is used for optional functionality. If the assembly is trimmed, the catch block handles it gracefully.")]
-        [UnconditionalSuppressMessage("Trimming", "IL2072",
-    Justification = "Loading Azure.Identity.Broker assembly is optional, method handles missing assembly gracefully")]
         internal static bool TryCreateDevelopmentBrokerOptions(out InteractiveBrowserCredentialOptions options)
         {
             options = null;
             try
             {
-                // Check if the Azure.Identity.Broker assembly is loaded
-                Assembly brokerAssembly;
-                brokerAssembly = Assembly.Load("Azure.Identity.Broker");
-
-                if (brokerAssembly != null)
-                {
-                    // Get the DevelopmentBrokerOptions type
-                    var optionsType = brokerAssembly.GetType("Azure.Identity.Broker.DevelopmentBrokerOptions");
-                    if (optionsType != null)
-                    {
-                        // Create an instance using the parameterless constructor
-                        options = (InteractiveBrowserCredentialOptions)Activator.CreateInstance(optionsType);
-                    }
-                }
+                // Use Type.GetType and ConstructorInfo because they can be analyzed by the ILLinker and are
+                // AOT friendly.
+
+                // Try to get the options type
+                Type optionsType = Type.GetType("Azure.Identity.Broker.DevelopmentBrokerOptions, Azure.Identity.Broker", throwOnError: false);
+                ConstructorInfo optionsCtor = optionsType?.GetConstructor(Type.EmptyTypes);
+                object optionsInstance = optionsCtor?.Invoke(null);
+                options = optionsInstance as InteractiveBrowserCredentialOptions;
 
                 return options != null;
             }

sdk/identity/ci.yml

@@ -35,3 +35,5 @@ extends:
     AOTTestInputs:
     - ArtifactName: Azure.Identity
       ExpectedWarningsFilepath: None
+    - ArtifactName: Azure.Identity.Broker
+      ExpectedWarningsFilepath: "Azure.Identity.Broker/tests/compatibility/ExpectedWarnings.txt"