Don't assume assemblies exist

Author: grendello

src/Xamarin.Android.Build.Tasks/Mono.Android/ApplicationAttribute.Partial.cs

@@ -57,6 +57,12 @@ static partial void AddManualMapping ()
 
 		public static ApplicationAttribute FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				return null;
+			}
+
 			CustomAttribute attr = provider.GetCustomAttributes ("Android.App.ApplicationAttribute")
 				.SingleOrDefault ();
 			if (attr == null)

src/Xamarin.Android.Build.Tasks/Mono.Android/InstrumentationAttribute.Partial.cs

@@ -11,11 +11,17 @@
 namespace Android.App {
 
 	partial class InstrumentationAttribute {
-		
+
 		ICollection<string> specified;
 
 		public static IEnumerable<InstrumentationAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			foreach (CustomAttribute attr in provider.GetCustomAttributes ("Android.App.InstrumentationAttribute")) {
 				InstrumentationAttribute self = new InstrumentationAttribute ();
 				self.specified = mapping.Load (self, attr, cache);

src/Xamarin.Android.Build.Tasks/Mono.Android/PermissionAttribute.Partial.cs

@@ -16,11 +16,17 @@
 namespace Android.App {
 
 	partial class PermissionAttribute {
-		
+
 		ICollection<string> specified;
 
 		public static IEnumerable<PermissionAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			var attrs = provider.GetCustomAttributes ("Android.App.PermissionAttribute");
 			foreach (var attr in attrs) {
 				PermissionAttribute self = new PermissionAttribute ();

src/Xamarin.Android.Build.Tasks/Mono.Android/PermissionGroupAttribute.Partial.cs

@@ -16,11 +16,17 @@
 namespace Android.App {
 
 	partial class PermissionGroupAttribute {
-		
+
 		ICollection<string> specified;
 
 		public static IEnumerable<PermissionGroupAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			var attrs = provider.GetCustomAttributes ("Android.App.PermissionGroupAttribute");
 			foreach (var attr in attrs) {
 				PermissionGroupAttribute self = new PermissionGroupAttribute ();

src/Xamarin.Android.Build.Tasks/Mono.Android/PermissionTreeAttribute.Partial.cs

@@ -16,11 +16,17 @@
 namespace Android.App {
 
 	partial class PermissionTreeAttribute {
-		
+
 		ICollection<string> specified;
 
 		public static IEnumerable<PermissionTreeAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			var attrs = provider.GetCustomAttributes ("Android.App.PermissionTreeAttribute");
 			foreach (var attr in attrs) {
 				PermissionTreeAttribute self = new PermissionTreeAttribute ();

src/Xamarin.Android.Build.Tasks/Mono.Android/SupportsGLTextureAttribute.Partial.cs

@@ -29,16 +29,21 @@ internal XElement ToElement (string packageName, TypeDefinitionCache cache)
 
 		public static IEnumerable<SupportsGLTextureAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			var attrs = provider.GetCustomAttributes ("Android.App.SupportsGLTextureAttribute");
 			foreach (var attr in attrs) {
 				if (attr.HasConstructorArguments && attr.ConstructorArguments.Count == 1) {
 					SupportsGLTextureAttribute self = new SupportsGLTextureAttribute((string)attr.ConstructorArguments[0].Value);
 					self.specified = mapping.Load (self, attr, cache);
 					self.specified.Add("Name");
-					yield return self;					 
+					yield return self;
 				}
 			}
 		}
 	}
 }
-

src/Xamarin.Android.Build.Tasks/Mono.Android/UsesFeatureAttribute.Partial.cs

@@ -35,12 +35,18 @@ internal XElement ToElement (string packageName, TypeDefinitionCache cache)
 
 		public static IEnumerable<UsesFeatureAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			var attrs = provider.GetCustomAttributes ("Android.App.UsesFeatureAttribute");
 			foreach (var attr in attrs) {
 
 				UsesFeatureAttribute self = new UsesFeatureAttribute ();
 
-				if (attr.HasProperties) {	
+				if (attr.HasProperties) {
 					// handle the case where the user sets additional properties
 					self.specified = mapping.Load (self, attr, cache);
 					if (self.specified.Contains("GLESVersion") && self.GLESVersion==0) {
@@ -64,4 +70,3 @@ public static IEnumerable<UsesFeatureAttribute> FromCustomAttributeProvider (ICu
 		}
 	}
 }
-

src/Xamarin.Android.Build.Tasks/Mono.Android/UsesPermissionAttribute.Partial.cs

@@ -16,6 +16,12 @@ partial class UsesPermissionAttribute {
 
 		public static IEnumerable<UsesPermissionAttribute> FromCustomAttributeProvider (ICustomAttributeProvider provider, TypeDefinitionCache cache)
 		{
+			// `provider` might be null in situations when application configuration is broken, and it surfaces in a number of
+			// tests which check these situations.
+			if (provider == null) {
+				yield break;
+			}
+
 			var attrs = provider.GetCustomAttributes ("Android.App.UsesPermissionAttribute");
 			foreach (var attr in attrs) {
 				UsesPermissionAttribute self;

src/Xamarin.Android.Build.Tasks/Tasks/GeneratePackageManagerJava.cs

@@ -468,8 +468,15 @@ bool ShouldIgnoreSplitConfigs ()
 
 		void GetRequiredTokens (string assemblyFilePath, out int android_runtime_jnienv_class_token, out int jnienv_initialize_method_token, out int jnienv_registerjninatives_method_token)
 		{
-			using (var pe = new PEReader (File.OpenRead (assemblyFilePath))) {
+			if (File.Exists (assemblyFilePath)) {
+				using var pe = new PEReader (File.OpenRead (assemblyFilePath));
 				GetRequiredTokens (pe.GetMetadataReader (), out android_runtime_jnienv_class_token, out jnienv_initialize_method_token, out jnienv_registerjninatives_method_token);
+			} else {
+				android_runtime_jnienv_class_token = -1;
+				jnienv_initialize_method_token = -1;
+				jnienv_registerjninatives_method_token = -1;
+				Log.LogDebugMessage ($"Assembly '{assemblyFilePath}' does not exist, unable to read required tokens from it");
+				return;
 			}
 
 			if (android_runtime_jnienv_class_token == -1 || jnienv_initialize_method_token == -1 || jnienv_registerjninatives_method_token == -1) {

src/Xamarin.Android.Build.Tasks/Utilities/ManifestDocument.cs

@@ -578,6 +578,10 @@ XElement CreateApplicationElement (XElement manifest, string applicationClass, L
 			List<UsesConfigurationAttribute> usesConfigurationAttr = [];
 			foreach (var assemblyPath in Assemblies) {
 				var assembly = Resolver.GetAssembly (assemblyPath);
+				if (assembly == null) {
+					continue;
+				}
+
 				if (ApplicationAttribute.FromCustomAttributeProvider (assembly, cache) is ApplicationAttribute a) {
 					assemblyAttr.Add (a);
 				}