[api-compat] Provide API diffs around API breakage

.gitignore

@@ -24,4 +24,5 @@ src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.props
 external/monodroid/
 external/mono/
 tests/api-compatibility/reference/*.dll
+tests/api-compatibility/reference/*.cs
 Novell

Before.Xamarin.Android.sln.targets

@@ -3,4 +3,5 @@
   <Import Project="$(MSBuildThisFileDirectory)build-tools\scripts\ImportExportDocs.targets" />
   <Import Project="$(MSBuildThisFileDirectory)build-tools\scripts\PrepareWindows.targets" Condition=" '$(OS)' == 'Windows_NT' " />
   <Import Project="$(MSBuildThisFileDirectory)build-tools\scripts\RunTests.targets" />
+  <Import Project="$(MSBuildThisFileDirectory)tests\api-compatibility\api-compatibility.targets" />
 </Project>

build-tools/Xamarin.Android.Tools.BootstrapTasks/Xamarin.Android.Tools.BootstrapTasks/Zip.cs

@@ -57,7 +57,13 @@ public override bool Execute ()
 					if (prefix != null && entryDir.StartsWith (prefix, StringComparison.OrdinalIgnoreCase)) {
 						zipDir = entryDir.Substring (prefix.Length);
 					}
-					zip.AddFileToDirectory (entryPath, zipDir, useFileDirectory: false);
+					if (string.IsNullOrEmpty (zipDir)) {
+						// JonP can't figure out how to actually clear the archive directory name
+						// using AddFileToDirectory().  This works as desired.
+						zip.AddFile (entryPath, Path.GetFileName (entryPath));
+					} else {
+						zip.AddFileToDirectory (entryPath, zipDir, useFileDirectory: false);
+					}
 				}
 			}
 			return !Log.HasLoggedErrors;

build-tools/xa-prep-tasks/Xamarin.Android.BuildTools.PrepTasks/Git.cs

@@ -26,6 +26,10 @@ protected   virtual     bool            LogTaskMessages {
 			get { return true; }
 		}
 
+		protected   virtual      bool           PreserveOutput {
+			get { return true; }
+		}
+
 		protected   override    string          ToolBaseName {
 			get { return "git"; }
 		}
@@ -68,7 +72,9 @@ protected override string GetWorkingDirectory ()
 		protected override void LogEventsFromTextOutput (string singleLine, MessageImportance messageImportance)
 		{
 			base.LogEventsFromTextOutput (singleLine, messageImportance);
-			Lines.Add (singleLine);
+			if (PreserveOutput) {
+				Lines.Add (singleLine);
+			}
 		}
 	}
 }

src/Mono.Android/Mono.Android.targets

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <UsingTask AssemblyFile="$(PrepTasksAssembly)" TaskName="Xamarin.Android.BuildTools.PrepTasks.GitDiff" />
   <UsingTask AssemblyFile="$(PrepTasksAssembly)" TaskName="Xamarin.Android.BuildTools.PrepTasks.ReplaceFileContents" />
   <UsingTask AssemblyFile="$(BootstrapTasksAssembly)" TaskName="Xamarin.Android.Tools.BootstrapTasks.CheckApiCompatibility" />
   <Import Project="..\..\build-tools\scripts\XAVersionInfo.targets" />
@@ -174,23 +175,41 @@
     <ApiCompatibilityFiles Include="$(ApiCompatibilityDir)/reference/*.*" />
   </ItemGroup>
   <Target
-      Name="AfterBuild"
+      Name="_CheckApiCompatibility"
       Condition=" '$(DisableApiCompatibilityCheck)' != 'True' "
+      AfterTargets="Build"
       Inputs="$(TargetPath);@(ApiCompatibilityFiles)"
       Outputs="$(IntermediateOutputPath)CheckApiCompatibility.stamp">
     <CheckApiCompatibility
+        ContinueOnError="ErrorAndContinue"
         ApiCompatPath="$(XAPackagesDir)\microsoft.dotnet.apicompat\5.0.0-beta.20078.1\tools\net472\"
         ApiLevel="$(AndroidFrameworkVersion)"
         LastStableApiLevel="$(AndroidLatestStableFrameworkVersion)"
         TargetImplementationPath="$(OutputPath)"
         ApiCompatibilityPath="$(ApiCompatibilityDir)"
     />
-    <Touch
-      Files="$(IntermediateOutputPath)CheckApiCompatibility.stamp"
-      AlwaysCreate="True"
+    <PropertyGroup>
+      <_RunApiDiff Condition=" '$(MSBuildLastTaskResult)' == 'False' ">True</_RunApiDiff>
+      <_GenAPI>"$(XAPackagesDir)\microsoft.dotnet.genapi\5.0.0-beta.20078.1\tools\net472\Microsoft.DotNet.GenAPI.exe"</_GenAPI>
+      <_ContractRefSrc>"$(ApiCompatibilityDir)\reference\Mono.Android.dll.cs"</_ContractRefSrc>
+      <_TargetRefSrc>"$(TargetPath).cs"</_TargetRefSrc>
+    </PropertyGroup>
+    <Exec
+        Condition=" '$(_RunApiDiff)' == 'True' "
+        Command="$(ManagedRuntime) $(ManagedRuntimeArgs) $(_GenAPI) &quot;$(TargetPath)&quot; > $(_TargetRefSrc)"
+    />
+    <GitDiff
+        Condition=" '$(_RunApiDiff)' == 'True' "
+        ContinueOnError="ErrorAndContinue"
+        Arguments="--no-index $(_ContractRefSrc) $(_TargetRefSrc)"
+        WorkingDirectory="$(MSBuildThisFileDirectory)"
     />
     <ItemGroup>
       <FileWrites Include="$(IntermediateOutputPath)CheckApiCompatibility.stamp" />
     </ItemGroup>
+    <Touch
+        Files="$(IntermediateOutputPath)CheckApiCompatibility.stamp"
+        AlwaysCreate="True"
+    />
   </Target>
 </Project>

tests/api-compatibility/README.md

@@ -16,6 +16,15 @@ current version of an assembly.  We could also called it the V2 assembly.
 [mdac]: https://github.com/dotnet/arcade/tree/master/src/Microsoft.DotNet.ApiCompat
 
 
+## Update Contract Assembly
+
+To update the contract assembly, run the `UpdateMonoAndroidContract` target
+and provide the `$(ContractAssembly)` MSBuild property.  `$(ContractAssembly)`
+should be the path to the new contract assembly to use:
+
+	msbuild Xamarin.Android.sln /t:UpdateMonoAndroidContract '/p:ContractAssembly=/Users/example/Downloads/\$ReferenceAssemblies/Microsoft/Framework/MonoAndroid/v10.0/Mono.Android.dll'
+
+
 ## Build Task
 
 We have developed a build task that will wrap *Microsoft.DotNet.ApiCompat.exe*

tests/api-compatibility/api-compatibility.targets

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="..\..\Configuration.props" />
+  <UsingTask AssemblyFile="$(BootstrapTasksAssembly)" TaskName="Xamarin.Android.Tools.BootstrapTasks.Zip" />
+  <Target Name="UpdateMonoAndroidContract">
+    <Error
+        Condition=" '$(ContractAssembly)' == '' "
+        Text="Please set the %24(ContractAssembly) property!"
+    />
+    <PropertyGroup>
+      <_GenAPI>"$(XAPackagesDir)\microsoft.dotnet.genapi\5.0.0-beta.20078.1\tools\net472\Microsoft.DotNet.GenAPI.exe"</_GenAPI>
+      <_CilStrip>"$(XAInstallPrefix)\xbuild\Xamarin\Android\cil-strip.exe"</_CilStrip>
+      <_ContractRefDll>$(MSBuildThisFileDirectory)\reference\Mono.Android.dll</_ContractRefDll>
+      <_ContractRefSrc>$(MSBuildThisFileDirectory)\reference\Mono.Android.dll.cs</_ContractRefSrc>
+    </PropertyGroup>
+    <Copy
+        SourceFiles="$(ContractAssembly)"
+        DestinationFiles="$(_ContractRefDll)"
+    />
+    <Exec
+        Command="$(ManagedRuntime) $(ManagedRuntimeArgs) $(_GenAPI) &quot;$(_ContractRefDll)&quot; > &quot;$(_ContractRefSrc)&quot;"
+    />
+    <Exec
+        Command="$(ManagedRuntime) $(ManagedRuntimeArgs) $(_CilStrip) &quot;$(_ContractRefDll)&quot;"
+    />
+    <ItemGroup>
+      <_ZipEntry Include="$(_ContractRefDll)" />
+      <_ZipEntry Include="$(_ContractRefSrc)" />
+    </ItemGroup>
+    <Zip
+        File="$(MSBuildThisFileDirectory)\reference\Mono.Android.zip"
+        Entries="@(_ZipEntry)"
+        Prefix="$(MSBuildThisFileDirectory)\reference\"
+        Overwrite="True"
+    />
+    <!--
+    <Exec
+        Command="zip Mono.Android.zip Mono.Android.dll Mono.Android.dll.cs"
+        WorkingDirectory="$(MSBuildThisFileDirectory)\reference"
+    />
+    -->
+  </Target>
+</Project>