Declare internal source attributes in consuming projects

IDisposableAnalyzers/IDisposableAnalyzers.csproj

@@ -66,7 +66,10 @@
   </ItemGroup>
 
   <ItemGroup>
-    <None Update="tools\*" Pack="true" PackagePath="" />
+    <None Update="tools\*;build\*" Pack="true" PackagePath="" />
+    <Compile Remove="build\*.cs" />
+    <None Include="build\*.cs" Pack="true" PackagePath="build" />
+
     <None Include="$(OutputPath)\$(AssemblyName).dll;$(OutputPath)\Gu.Roslyn.Extensions.dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
   </ItemGroup>
 </Project>

IDisposableAnalyzers/build/IDisposableAnalyzers.targets

@@ -0,0 +1,13 @@
+<Project>
+
+  <PropertyGroup>
+    <OwnershipAttributesPath Condition="'$(OwnershipAttributesPath)' == ''">$(MSBuildThisFileDirectory)OwnershipAttributes$(DefaultLanguageSourceExtension)</OwnershipAttributesPath>
+
+    <IncludeOwnershipAttributes Condition="'$(IncludeOwnershipAttributes)' == '' and Exists($(OwnershipAttributesPath))">true</IncludeOwnershipAttributes>
+  </PropertyGroup>
+
+  <ItemGroup Condition="'$(IncludeOwnershipAttributes)' == 'true'">
+    <Compile Include="$(OwnershipAttributesPath)" Visible="false" />
+  </ItemGroup>
+
+</Project>

IDisposableAnalyzers/build/OwnershipAttributes.cs

@@ -0,0 +1,28 @@
+namespace IDisposableAnnotations
+{
+    using System;
+
+    /// <summary>
+    /// The return value must be disposed by the caller.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.ReturnValue | AttributeTargets.Parameter, AllowMultiple = false, Inherited = true)]
+    internal sealed class GivesOwnershipAttribute : Attribute
+    {
+    }
+
+    /// <summary>
+    /// The return value must not be disposed by the caller.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.ReturnValue | AttributeTargets.Parameter, AllowMultiple = false, Inherited = true)]
+    internal sealed class KeepsOwnershipAttribute : Attribute
+    {
+    }
+
+    /// <summary>
+    /// The ownership of instance is transferred and the receiver is responsible for disposing.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false, Inherited = true)]
+    internal sealed class TakesOwnershipAttribute : Attribute
+    {
+    }
+}