[AOT] Added publishAOT test app to ensure OpenTelemetry SDK is AOT safe.

OpenTelemetry.sln

@@ -255,9 +255,13 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "tail-based-sampling-example
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "stratified-sampling-example", "docs\trace\stratified-sampling-example\stratified-sampling-example.csproj", "{9C99621C-343E-479C-A943-332DB6129B71}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "links-sampler", "docs\trace\links-based-sampler\links-sampler.csproj", "{62AF4BD3-DCAE-4D44-AA5B-991C1071166B}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "OpenTelemetry.Api.Tests", "test\OpenTelemetry.Api.Tests\OpenTelemetry.Api.Tests.csproj", "{FD8433F4-EDCF-475C-9B4A-625D3DE11671}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "OpenTelemetry.AotCompatibility.TestApp", "test\OpenTelemetry.AotCompatibility.TestApp\OpenTelemetry.AotCompatibility.TestApp.csproj", "{13A59BD9-9475-4991-B74D-7C20F1C63409}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OpenTelemetry.Api.Tests", "test\OpenTelemetry.Api.Tests\OpenTelemetry.Api.Tests.csproj", "{FD8433F4-EDCF-475C-9B4A-625D3DE11671}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "OpenTelemetry.AotCompatibility.Tests", "test\OpenTelemetry.AotCompatibility.Tests\OpenTelemetry.AotCompatibility.Tests.csproj", "{D438EF9C-7959-47A0-B2A2-DEBFCDC2A8DC}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "links-sampler", "docs\trace\links-based-sampler\links-sampler.csproj", "{62AF4BD3-DCAE-4D44-AA5B-991C1071166B}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -553,6 +557,14 @@ Global
 		{FD8433F4-EDCF-475C-9B4A-625D3DE11671}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{FD8433F4-EDCF-475C-9B4A-625D3DE11671}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{FD8433F4-EDCF-475C-9B4A-625D3DE11671}.Release|Any CPU.Build.0 = Release|Any CPU
+		{13A59BD9-9475-4991-B74D-7C20F1C63409}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{13A59BD9-9475-4991-B74D-7C20F1C63409}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{13A59BD9-9475-4991-B74D-7C20F1C63409}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{13A59BD9-9475-4991-B74D-7C20F1C63409}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D438EF9C-7959-47A0-B2A2-DEBFCDC2A8DC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D438EF9C-7959-47A0-B2A2-DEBFCDC2A8DC}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D438EF9C-7959-47A0-B2A2-DEBFCDC2A8DC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D438EF9C-7959-47A0-B2A2-DEBFCDC2A8DC}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

test/OpenTelemetry.AotCompatibility.TestApp/OpenTelemetry.AotCompatibility.TestApp.csproj

@@ -0,0 +1,34 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <PublishAot>true</PublishAot>
+    <TrimmerSingleWarn>false</TrimmerSingleWarn>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <TrimmerRootAssembly Include="OpenTelemetry.Api.ProviderBuilderExtensions" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Api" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.Console" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.InMemory" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.Jaeger" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.Prometheus.AspNetCore" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.Prometheus.HttpListener" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.Zipkin" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Exporter.ZPages" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Extensions.Hosting" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Extensions.Propagators" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Instrumentation.AspNetCore" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Instrumentation.GrpcNetClient" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Instrumentation.Http" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Instrumentation.SqlClient" />
+    <TrimmerRootAssembly Include="OpenTelemetry.SemanticConventions" />
+    <TrimmerRootAssembly Include="OpenTelemetry.Shims.OpenTracing" />
+    <TrimmerRootAssembly Include="OpenTelemetry" />
+
+    <TrimmerRootAssembly Update="@(TrimmerRootAssembly)" Path="$(RepoRoot)\src\%(Identity)\%(Identity).csproj" />
+    <ProjectReference Include="@(TrimmerRootAssembly->'%(Path)')" />
+  </ItemGroup>
+
+</Project>

test/OpenTelemetry.AotCompatibility.TestApp/Program.cs

@@ -0,0 +1,17 @@
+// <copyright file="Program.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+Console.WriteLine("Hello, World!");

test/OpenTelemetry.AotCompatibility.Tests/AotCompatibilityTests.cs

@@ -0,0 +1,91 @@
+// <copyright file="AotCompatibilityTests.cs" company="OpenTelemetry Authors">
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// </copyright>
+
+using System.Diagnostics;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace OpenTelemetry.AotCompatibility.Tests
+{
+    public class AotCompatibilityTests
+    {
+        private readonly ITestOutputHelper testOutputHelper;
+
+        public AotCompatibilityTests(ITestOutputHelper testOutputHelper)
+        {
+            this.testOutputHelper = testOutputHelper;
+        }
+
+        /// <summary>
+        /// This test ensures that the intended APIs of the OpenTelemetry.AotCompatibility.TestApp libraries are
+        /// trimming and NativeAOT compatible.
+        ///
+        /// This test follows the instructions in https://learn.microsoft.com/dotnet/core/deploying/trimming/prepare-libraries-for-trimming#show-all-warnings-with-sample-application
+        ///
+        /// If this test fails, it is due to adding trimming and/or AOT incompatible changes
+        /// to code that is supposed to be compatible.
+        ///
+        /// To diagnose the problem, inspect the test output which will contain the trimming and AOT errors. For example:
+        ///
+        /// error IL2091: 'T' generic argument does not satisfy 'DynamicallyAccessedMemberTypes.PublicConstructors'.
+        /// </summary>
+        [Fact]
+        public void EnsureAotCompatibility()
+        {
+            string[] paths = { @"..", "..", "..", "..", "OpenTelemetry.AotCompatibility.TestApp" };
+            string testAppPath = Path.Combine(paths);
+            string testAppProject = "OpenTelemetry.AotCompatibility.TestApp.csproj";
+
+            // ensure we run a clean publish every time
+            DirectoryInfo testObjDir = new DirectoryInfo(Path.Combine(testAppPath, "obj"));
+            if (testObjDir.Exists)
+            {
+                testObjDir.Delete(recursive: true);
+            }
+
+            var process = new Process
+            {
+                // set '-nodereuse:false /p:UseSharedCompilation=false' so the MSBuild and Roslyn server processes don't hang around, which may hang the test in CI
+                StartInfo = new ProcessStartInfo("dotnet", $"publish {testAppProject} --self-contained -nodereuse:false /p:UseSharedCompilation=false")
+                {
+                    RedirectStandardOutput = true,
+                    UseShellExecute = false,
+                    CreateNoWindow = true,
+                    WorkingDirectory = testAppPath,
+                },
+            };
+
+            var expectedOutput = new System.Text.StringBuilder();
+            process.OutputDataReceived += (sender, e) =>
+            {
+                if (!string.IsNullOrEmpty(e.Data))
+                {
+                    this.testOutputHelper.WriteLine(e.Data);
+                    expectedOutput.AppendLine(e.Data);
+                }
+            };
+
+            process.Start();
+            process.BeginOutputReadLine();
+
+            Assert.True(process.WaitForExit(milliseconds: 180_000), "dotnet publish command timed out after 180 seconds.");
+            Assert.True(process.ExitCode == 0, "Publishing the AotCompatibility app failed. See test output for more details.");
+
+            var warnings = expectedOutput.ToString().Split('\n', '\r').Where(line => line.Contains("warning IL"));
+            Assert.Equal(77, warnings.Count());
+        }
+    }
+}

test/OpenTelemetry.AotCompatibility.Tests/OpenTelemetry.AotCompatibility.Tests.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <Description>Test to ensure AOT compatilibity.</Description>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkPkgVer)" />
+    <PackageReference Include="xunit" Version="$(XUnitPkgVer)" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="$(XUnitRunnerVisualStudioPkgVer)">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+    </PackageReference>
+    <DotNetCliToolReference Include="dotnet-xunit" Version="$(DotNetXUnitCliVer)" />
+  </ItemGroup>
+
+</Project>