[dotnet] Parse --dlsym and pass it to the dotnet-linker tasks.

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -359,6 +359,7 @@
 				AssemblyName=$(AssemblyName).dll
 				AOTOutputDirectory=$(_AOTOutputDirectory)
 				CacheDirectory=$(_LinkerCacheDirectory)
+				@(_BundlerDlsym -> 'Dlsym=%(Identity)')
 				Debug=$(_BundlerDebug)
 				DeploymentTarget=$(_MinimumOSVersion)
 				@(_BundlerEnvironmentVariables -> 'EnvironmentVariable=%(Identity)=%(Value)')

msbuild/Xamarin.MacDev.Tasks.Core/Tasks/ParseBundlerArgumentsTaskBase.cs

@@ -7,6 +7,9 @@ namespace Xamarin.MacDev.Tasks {
 	public abstract class ParseBundlerArgumentsTaskBase : XamarinTask {
 		public string ExtraArgs { get; set; }
 
+		[Output]
+		public ITaskItem [] DlSym { get; set; }
+
 		[Output]
 		public ITaskItem[] EnvironmentVariables { get; set; }
 
@@ -49,6 +52,7 @@ namespace Xamarin.MacDev.Tasks {
 				var args = CommandLineArgumentBuilder.Parse (ExtraArgs);
 				List<string> xml = null;
 				var envVariables = new List<ITaskItem> ();
+				var dlsyms = new List<ITaskItem> ();
 
 				for (int i = 0; i < args.Length; i++) {
 					var arg = args [i];
@@ -84,6 +88,9 @@ namespace Xamarin.MacDev.Tasks {
 						// do not set the MtouchNoSymbolStrip property to 'true' in that case.
 						NoSymbolStrip = string.IsNullOrEmpty (value) ? "true" : "false";
 						break;
+					case "dlsym":
+						dlsyms.Add (new TaskItem (string.IsNullOrEmpty (value) ? "true" : value));
+						break;
 					case "dsym":
 						NoDSymUtil = ParseBool (value) ? "false" : "true";
 						break;
@@ -143,6 +150,11 @@ namespace Xamarin.MacDev.Tasks {
 					EnvironmentVariables = envVariables.ToArray ();
 				}
 
+				if (dlsyms.Count > 0) {
+					if (DlSym != null)
+						dlsyms.AddRange (DlSym);
+					DlSym = dlsyms.ToArray ();
+				}
 			}
 
 			return !Log.HasLoggedErrors;

msbuild/Xamarin.Shared/Xamarin.Shared.targets

@@ -1016,6 +1016,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			NoDSymUtil="$(_NoDSymUtil)"
 			>
 			<Output TaskParameter="CustomBundleName" PropertyName="_CustomBundleName" />
+			<Output TaskParameter="DlSym" ItemName="_BundlerDlsym" />
 			<Output TaskParameter="EnvironmentVariables" ItemName="_BundlerEnvironmentVariables" />
 			<Output TaskParameter="MarshalManagedExceptionMode" PropertyName="_MarshalManagedExceptionMode" />
 			<Output TaskParameter="MarshalObjectiveCExceptionMode" PropertyName="_MarshalObjectiveCExceptionMode" />

tools/dotnet-linker/LinkerConfiguration.cs

@@ -121,6 +121,9 @@ namespace Xamarin.Linker {
 						throw new InvalidOperationException ($"Unable to parse the {key} value: {value} in {linker_file}");
 					DeploymentTarget = deployment_target;
 					break;
+				case "Dlsym":
+					Application.ParseDlsymOptions (value);
+					break;
 				case "EnvironmentVariable":
 					var separators = new char [] { ':', '=' };
 					var equals = value.IndexOfAny (separators);
@@ -314,6 +317,7 @@ namespace Xamarin.Linker {
 				Console.WriteLine ($"    AssemblyName: {Application.AssemblyName}");
 				Console.WriteLine ($"    CacheDirectory: {CacheDirectory}");
 				Console.WriteLine ($"    Debug: {Application.EnableDebug}");
+				Console.WriteLine ($"    Dlsym: {Application.DlsymOptions} {(Application.DlsymAssemblies != null ? string.Join (" ", Application.DlsymAssemblies.Select (v => (v.Item2 ? "+" : "-") + v.Item1)) : string.Empty)}");
 				Console.WriteLine ($"    DeploymentTarget: {DeploymentTarget}");
 				Console.WriteLine ($"    IntermediateLinkDir: {IntermediateLinkDir}");
 				Console.WriteLine ($"    InterpretedAssemblies: {string.Join (", ", Application.InterpretedAssemblies)}");