[dotnet] Parse the -gcc_flags and -link_flags mtouch/mmp arguments and pass them to the native linker. (#13521)

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -1058,7 +1058,7 @@
 			EntitlementsInExecutable="$(_CompiledEntitlements)"
 			FrameworkRPath="$(_EmbeddedFrameworksRPath)"
 			Frameworks="@(_NativeExecutableFrameworks);@(_BindingLibraryFrameworks)"
-			LinkerFlags="@(_AssemblyLinkerFlags);@(_ReferencesLinkerFlags);@(_MainLinkerFlags)"
+			LinkerFlags="@(_AssemblyLinkerFlags);@(_ReferencesLinkerFlags);@(_MainLinkerFlags);@(_CustomLinkFlags)"
 			LinkWithLibraries="@(_XamarinMainLibraries);@(_BindingLibraryLinkWith);@(_MainLinkWith)"
 			MinimumOSVersion="$(_MinimumOSVersion)"
 			NativeReferences="@(_FileNativeReference);@(_FrameworkNativeReference)"

msbuild/Xamarin.Localization.MSBuild/MSBStrings.Designer.cs

@@ -1106,6 +1106,15 @@ namespace Xamarin.Localization.MSBuild {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Could not parse the custom linker argument(s) &apos;-{0}&apos;: {1}.
+        /// </summary>
+        public static string E0189 {
+            get {
+                return ResourceManager.GetString("E0189", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Could not resolve host IPs for WiFi debugger settings.
         ///        .

msbuild/Xamarin.Localization.MSBuild/MSBStrings.resx

@@ -888,6 +888,10 @@
         <value>Could not map the Mac Catalyst version {0} to a corresponding macOS version. Valid Mac Catalyst versions are: {1}</value>
     </data>
 
+    <data name="E0189" xml:space="preserve">
+        <value>Could not parse the custom linker argument(s) '-{0}': {1}</value>
+    </data>
+
     <data name="E7001" xml:space="preserve">
         <value>Could not resolve host IPs for WiFi debugger settings.
         </value>

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

@@ -3,6 +3,9 @@ using System.Collections.Generic;
 using Microsoft.Build.Utilities;
 using Microsoft.Build.Framework;
 
+using Xamarin.Localization.MSBuild;
+using Xamarin.Utils;
+
 namespace Xamarin.MacDev.Tasks {
 	public abstract class ParseBundlerArgumentsTaskBase : XamarinTask {
 		public string ExtraArgs { get; set; }
@@ -22,6 +25,9 @@ namespace Xamarin.MacDev.Tasks {
 		[Output]
 		public string CustomBundleName { get; set; }
 
+		[Output]
+		public ITaskItem[] CustomLinkFlags { get; set; }
+
 		[Output]
 		public string NoSymbolStrip { get; set; }
 
@@ -55,6 +61,7 @@ namespace Xamarin.MacDev.Tasks {
 			if (!string.IsNullOrEmpty (ExtraArgs)) {
 				var args = CommandLineArgumentBuilder.Parse (ExtraArgs);
 				List<string> xml = null;
+				List<string> customLinkFlags = null;
 				var envVariables = new List<ITaskItem> ();
 				var dlsyms = new List<ITaskItem> ();
 
@@ -149,6 +156,16 @@ namespace Xamarin.MacDev.Tasks {
 						// Output is EnableAssemblyILStripping so we enable if --nostrip=false and disable if true
 						NoStrip = ParseBool (value) ? "false" : "true";
 						break;
+					case "gcc_flags": // mtouch uses gcc_flags
+					case "link_flags": // mmp uses link_flags
+						if (!StringUtils.TryParseArguments (value, out var lf, out var ex)) {
+							Log.LogError (MSBStrings.E0189 /* Could not parse the custom linker argument(s) '-{0}': {1} */, $"-{name}={value}", ex.Message);
+							continue;
+						}
+						if (customLinkFlags is null)
+							customLinkFlags = new List<string> ();
+						customLinkFlags.AddRange (lf);
+						break;
 					default:
 						Log.LogMessage (MessageImportance.Low, "Skipping unknown argument '{0}' with value '{1}'", name, value);
 						break;
@@ -164,6 +181,15 @@ namespace Xamarin.MacDev.Tasks {
 					XmlDefinitions = defs.ToArray ();
 				}
 
+				if (customLinkFlags is not null) {
+					var defs = new List<ITaskItem> ();
+					if (CustomLinkFlags is not null)
+						defs.AddRange (CustomLinkFlags);
+					foreach (var lf in customLinkFlags)
+						defs.Add (new TaskItem (lf));
+					CustomLinkFlags = defs.ToArray ();
+				}
+
 				if (envVariables.Count > 0) {
 					if (EnvironmentVariables != null)
 						envVariables.AddRange (EnvironmentVariables);

msbuild/Xamarin.Shared/Xamarin.Shared.targets

@@ -1658,6 +1658,7 @@ Copyright (C) 2018 Microsoft. All rights reserved.
 			Verbosity="$(_BundlerVerbosity)"
 			>
 			<Output TaskParameter="CustomBundleName" PropertyName="_CustomBundleName" />
+			<Output TaskParameter="CustomLinkFlags" ItemName="_CustomLinkFlags" />
 			<Output TaskParameter="DlSym" ItemName="_BundlerDlsym" />
 			<Output TaskParameter="EnvironmentVariables" ItemName="_BundlerEnvironmentVariables" />
 			<Output TaskParameter="MarshalManagedExceptionMode" PropertyName="_MarshalManagedExceptionMode" />