Add AmbientMetadata.Build component

eng/MSBuild/Generators.props

@@ -10,4 +10,8 @@
   <ItemGroup Condition="'$(UseContextualOptionsGenerator)' == 'true' and '$(BuildingSlnForDocs)' != 'true'">
     <ProjectReference Include="$(MSBuildThisFileDirectory)\..\..\src\Generators\Microsoft.Gen.ContextualOptions\Microsoft.Gen.ContextualOptions.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" Private="false" IncludeAssets="runtime; build; native; contentfiles; analyzers; buildtransitive" />
   </ItemGroup>
+
+  <ItemGroup Condition="'$(UseBuildMetadataGenerator)' == 'true' and '$(BuildingSlnForDocs)' != 'true'">
+    <ProjectReference Include="$(MSBuildThisFileDirectory)\..\..\src\Generators\Microsoft.Gen.BuildMetadata\Microsoft.Gen.BuildMetadata.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" Private="false" IncludeAssets="runtime; build; native; contentfiles; analyzers; buildtransitive" />
+  </ItemGroup>
 </Project>

src/Generators/Microsoft.Gen.BuildMetadata/AnalyzerConfigOptionsExtensions.cs

@@ -0,0 +1,40 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.CodeAnalysis.Diagnostics;
+
+namespace Microsoft.Gen.BuildMetadata;
+
+/// <summary>
+/// Extension methods for <see cref="AnalyzerConfigOptions"/> to simplify MSBuild property access.
+/// </summary>
+internal static class AnalyzerConfigOptionsExtensions
+{
+    private const string PropertyPrefix = "build_property.";
+
+    /// <summary>
+    /// Gets a boolean property value from MSBuild properties.
+    /// Supports "true"/"false" values (case-insensitive).
+    /// </summary>
+    /// <param name="options">The analyzer configuration options.</param>
+    /// <param name="propertyName">The property name (without "build_property." prefix).</param>
+    /// <returns>True if the property value is "true", false otherwise.</returns>
+    public static bool GetBooleanProperty(this AnalyzerConfigOptions options, string propertyName)
+    {
+        var value = GetProperty(options, propertyName);
+        return !string.IsNullOrEmpty(value) &&
+               string.Equals(value, "true", System.StringComparison.OrdinalIgnoreCase);
+    }
+
+    /// <summary>
+    /// Gets a string property value from MSBuild properties.
+    /// </summary>
+    /// <param name="options">The analyzer configuration options.</param>
+    /// <param name="propertyName">The property name (without "build_property." prefix).</param>
+    /// <returns>The property value, or null if not found.</returns>
+    public static string? GetProperty(this AnalyzerConfigOptions options, string propertyName)
+    {
+        var key = string.Concat(PropertyPrefix, propertyName);
+        return options.TryGetValue(key, out var value) ? value : null;
+    }
+}

src/Generators/Microsoft.Gen.BuildMetadata/BuildMetadataGenerator.cs

@@ -0,0 +1,59 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Text;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Text;
+
+namespace Microsoft.Gen.BuildMetadata;
+
+/// <summary>
+/// Source generator that creates build metadata extensions from MSBuild properties.
+/// Supports both Azure DevOps and GitHub Actions build environments.
+/// </summary>
+[Generator]
+public class BuildMetadataGenerator : IIncrementalGenerator
+{
+    /// <inheritdoc/>
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        var buildPropertiesPipeline = context.AnalyzerConfigOptionsProvider.Select((provider, ct) =>
+        {
+            return CreateBuildMetadata(provider.GlobalOptions);
+        });
+
+        context.RegisterSourceOutput(buildPropertiesPipeline, Execute);
+    }
+
+    private static BuildMetadata CreateBuildMetadata(AnalyzerConfigOptions globalOptions)
+    {
+        // Azure DevOps properties
+        var azureBuildId = globalOptions.GetProperty("BuildMetadataAzureBuildId");
+        var azureBuildNumber = globalOptions.GetProperty("BuildMetadataAzureBuildNumber");
+        var azureSourceBranchName = globalOptions.GetProperty("BuildMetadataAzureSourceBranchName");
+        var azureSourceVersion = globalOptions.GetProperty("BuildMetadataAzureSourceVersion");
+        var isAzureDevOps = globalOptions.GetBooleanProperty("BuildMetadataIsAzureDevOps");
+
+        // GitHub Actions properties
+        var gitHubRunId = globalOptions.GetProperty("BuildMetadataGitHubRunId");
+        var gitHubRunNumber = globalOptions.GetProperty("BuildMetadataGitHubRunNumber");
+        var gitHubRefName = globalOptions.GetProperty("BuildMetadataGitHubRefName");
+        var gitHubSha = globalOptions.GetProperty("BuildMetadataGitHubSha");
+
+        return new BuildMetadata(
+            isAzureDevOps ? azureBuildId : gitHubRunId,
+            isAzureDevOps ? azureBuildNumber : gitHubRunNumber,
+            isAzureDevOps ? azureSourceBranchName : gitHubRefName,
+            isAzureDevOps ? azureSourceVersion : gitHubSha);
+    }
+
+    private static void Execute(SourceProductionContext context, BuildMetadata buildMetadata)
+    {
+        var emitter = new Emitter(buildMetadata.BuildId, buildMetadata.BuildNumber, buildMetadata.SourceBranchName, buildMetadata.SourceVersion);
+        var result = emitter.Emit(context.CancellationToken);
+        context.AddSource("BuildMetadataExtensions.g.cs", SourceText.From(result, Encoding.UTF8));
+    }
+
+    private readonly record struct BuildMetadata(string? BuildId, string? BuildNumber, string? SourceBranchName, string? SourceVersion);
+}

src/Generators/Microsoft.Gen.BuildMetadata/Emitter.cs

@@ -0,0 +1,186 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Diagnostics.CodeAnalysis;
+using System.Threading;
+using Microsoft.Gen.Shared;
+
+namespace Microsoft.Gen.BuildMetadata;
+
+[SuppressMessage("Format", "S1199", Justification = "For better visualization of how the generated code will look like.")]
+internal sealed class Emitter : EmitterBase
+{
+    private const string DependencyInjectionNamespace = "global::Microsoft.Extensions.DependencyInjection.";
+    private const string ConfigurationNamespace = "global::Microsoft.Extensions.Configuration.";
+    private const string HostingNamespace = "global::Microsoft.Extensions.Hosting.";
+    private readonly string? _buildId;
+    private readonly string? _buildNumber;
+    private readonly string? _sourceBranchName;
+    private readonly string? _sourceVersion;
+
+    public Emitter(string? buildId, string? buildNumber, string? sourceBranchName, string? sourceVersion)
+    {
+        _buildId = buildId;
+        _buildNumber = buildNumber;
+        _sourceBranchName = sourceBranchName;
+        _sourceVersion = sourceVersion;
+    }
+
+    public string Emit(CancellationToken cancellationToken)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+        GenerateBuildMetadataExtensions();
+        return Capture();
+    }
+
+    private void GenerateBuildMetadataSource()
+    {
+        OutGeneratedCodeAttribute();
+        OutLn("[global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]");
+        OutLn($"private sealed class BuildMetadataSource : {ConfigurationNamespace}IConfigurationSource");
+        OutOpenBrace();
+        {
+            OutLn("public string SectionName { get; }");
+            OutLn();
+
+            OutLn("public BuildMetadataSource(string sectionName)");
+            OutOpenBrace();
+            {
+                OutNullGuards(checkBuilder: false);
+                OutLn("SectionName = sectionName;");
+            }
+
+            OutCloseBrace();
+            OutLn();
+            OutLn($"public {ConfigurationNamespace}IConfigurationProvider Build({ConfigurationNamespace}IConfigurationBuilder builder)");
+            OutOpenBrace();
+            {
+                OutLn($"return new {ConfigurationNamespace}Memory.MemoryConfigurationProvider(new {ConfigurationNamespace}Memory.MemoryConfigurationSource())");
+                OutOpenBrace();
+                {
+                    OutLn($$"""{ $"{SectionName}:buildid", "{{_buildId}}" },""");
+                    OutLn($$"""{ $"{SectionName}:buildnumber", "{{_buildNumber}}" },""");
+                    OutLn($$"""{ $"{SectionName}:sourcebranchname", "{{_sourceBranchName}}" },""");
+                    OutLn($$"""{ $"{SectionName}:sourceversion", "{{_sourceVersion}}" },""");
+                }
+
+                OutCloseBraceWithExtra(";");
+            }
+
+            OutCloseBrace();
+        }
+
+        OutCloseBrace();
+    }
+
+    private void GenerateBuildMetadataExtensions()
+    {
+        OutLn("namespace Microsoft.Extensions.AmbientMetadata");
+        OutOpenBrace();
+        {
+            OutGeneratedCodeAttribute();
+            OutLn("internal static class BuildMetadataGeneratedExtensions");
+            OutOpenBrace();
+            {
+                OutLn("private const string DefaultSectionName = \"ambientmetadata:build\";");
+                OutLn();
+
+                GenerateBuildMetadataSource();
+                OutLn();
+
+                OutLn($"public static {HostingNamespace}IHostBuilder UseBuildMetadata(this {HostingNamespace}IHostBuilder builder, string sectionName = DefaultSectionName)");
+                OutOpenBrace();
+                {
+                    OutNullGuards();
+                    OutLn("_ = builder.ConfigureHostConfiguration(configBuilder => configBuilder.AddBuildMetadata(sectionName))");
+                    Indent();
+                    OutLn(".ConfigureServices((hostBuilderContext, serviceCollection) =>");
+                    Indent();
+                    OutLn($"{DependencyInjectionNamespace}BuildMetadataServiceCollectionExtensions.AddBuildMetadata(serviceCollection, hostBuilderContext.Configuration.GetSection(sectionName)));");
+                    Unindent();
+                    Unindent();
+                    OutLn();
+
+                    OutLn("return builder;");
+                }
+
+                OutCloseBrace();
+                OutLn();
+
+                OutLn("public static TBuilder UseBuildMetadata<TBuilder>(this TBuilder builder, string sectionName = DefaultSectionName)");
+                Indent();
+                OutLn($"where TBuilder : {HostingNamespace}IHostApplicationBuilder");
+                Unindent();
+                OutOpenBrace();
+                {
+                    OutNullGuards();
+                    OutLn("_ = builder.Configuration.AddBuildMetadata(sectionName);");
+                    OutLn($"{DependencyInjectionNamespace}BuildMetadataServiceCollectionExtensions.AddBuildMetadata(builder.Services, builder.Configuration.GetSection(sectionName));");
+                    OutLn();
+
+                    OutLn("return builder;");
+                }
+
+                OutCloseBrace();
+                OutLn();
+
+#pragma warning disable S103 // Lines should not be too long
+                OutLn($"public static {ConfigurationNamespace}IConfigurationBuilder AddBuildMetadata(this {ConfigurationNamespace}IConfigurationBuilder builder, string sectionName = DefaultSectionName)");
+#pragma warning restore S103 // Lines should not be too long
+                OutOpenBrace();
+                {
+                    OutNullGuards();
+                    OutLn("return builder.Add(new BuildMetadataSource(sectionName));");
+                }
+
+                OutCloseBrace();
+            }
+
+            OutCloseBrace();
+        }
+
+        OutCloseBrace();
+    }
+
+    private void OutNullGuards(bool checkBuilder = true)
+    {
+        OutPP("#if !NET");
+
+        if (checkBuilder)
+        {
+            OutLn("if (builder is null)");
+            OutOpenBrace();
+            OutLn("throw new global::System.ArgumentNullException(nameof(builder));");
+            OutCloseBrace();
+            OutLn();
+        }
+
+        OutLn("if (global::System.string.IsNullOrWhiteSpace(sectionName))");
+        OutOpenBrace();
+        {
+            OutLn("if (sectionName is null)");
+            OutOpenBrace();
+            {
+                OutLn("throw new global::System.ArgumentNullException(nameof(sectionName));");
+            }
+
+            OutCloseBrace();
+            OutLn();
+            OutLn("throw new global::System.ArgumentException(\"The value cannot be an empty string or composed entirely of whitespace.\", nameof(sectionName));");
+        }
+
+        OutCloseBrace();
+
+        OutPP("#else");
+
+        if (checkBuilder)
+        {
+            OutLn("global::System.ArgumentNullException.ThrowIfNull(builder);");
+        }
+
+        OutLn("global::System.ArgumentException.ThrowIfNullOrWhiteSpace(sectionName);");
+
+        OutPP("#endif");
+        OutLn();
+    }
+}

src/Generators/Microsoft.Gen.BuildMetadata/Microsoft.Gen.BuildMetadata.csproj

@@ -0,0 +1,37 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <RootNamespace>Microsoft.Gen.BuildMetadata</RootNamespace>
+    <Description>Code generator to support Microsoft.Extensions.AmbientMetadata.Build</Description>
+    <Workstream>Fundamentals</Workstream>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <AnalyzerLanguage>cs</AnalyzerLanguage>
+    <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
+    <InjectExperimentalAttributeOnLegacy>true</InjectExperimentalAttributeOnLegacy>
+    <InjectSharedDiagnosticIds>true</InjectSharedDiagnosticIds>
+    <InjectIsExternalInitOnLegacy>true</InjectIsExternalInitOnLegacy>
+    <!-- CA1852 is for the internal shared type DiagDescriptorsBase. It can't be sealed because there are child classes in other components-->
+    <NoWarn>$(NoWarn);EA0002;CA1852</NoWarn>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <Stage>normal</Stage>
+    <MinCodeCoverage>100</MinCodeCoverage>
+    <MinMutationScore>75</MinMutationScore>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" PrivateAssets="all" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="Parsing\Resources.Designer.cs" DesignTime="True" AutoGen="True" DependentUpon="Resources.resx" />
+    <Compile Include="..\Shared\*.cs" LinkBase="Shared" />
+  </ItemGroup>
+  <ItemGroup>
+    <InternalsVisibleToTest Include="Microsoft.Gen.BuildMetadata.Generated.Tests" />
+    <InternalsVisibleToTest Include="Microsoft.Gen.BuildMetadata.Unit.Tests" />
+  </ItemGroup>
+
+</Project>

src/Libraries/Microsoft.Extensions.AmbientMetadata.Build/BuildMetadata.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.Extensions.AmbientMetadata;
+
+/// <summary>
+/// Data model for the Build metadata.
+/// </summary>
+/// <remarks>
+/// The values are automatically grabbed from environment variables at build time in CI pipeline and saved in generated code.
+/// At startup time, the class properties will be initialized from the generated code.
+/// Currently supported CI pipelines:
+/// <list type="bullet">
+/// <item><see href="https://learn.microsoft.com/azure/devops/pipelines/build/variables#build-variables-devops-services">Azure DevOps</see></item>
+/// <item><see href="https://docs.github.com/en/actions/reference/variables-reference#default-environment-variables">GitHub Actions</see></item>
+/// </list>
+/// </remarks>
+public class BuildMetadata
+{
+    /// <summary>
+    /// Gets or sets the ID of the record for the build, also known as the run ID.
+    /// </summary>
+    public string? BuildId { get; set; }
+
+    /// <summary>
+    /// Gets or sets the name of the completed build, also known as the run number.
+    /// </summary>
+    public string? BuildNumber { get; set; }
+
+    /// <summary>
+    /// Gets or sets the name of the branch in the triggering repo the build was queued for, also known as the ref name.
+    /// </summary>
+    public string? SourceBranchName { get; set; }
+
+    /// <summary>
+    /// Gets or sets the latest version control change that is included in this build, also known as the commit SHA.
+    /// </summary>
+    public string? SourceVersion { get; set; }
+}