feat(generator): opt out of WebApplicationBuilder.Build() interception

src/Qyl.OpenTelemetry.AutoInstrumentation.SourceGenerators/QylAutoInstrumentationGenerator.cs

@@ -5,6 +5,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
 using Microsoft.CodeAnalysis.Text;
 
 namespace Qyl.OpenTelemetry.AutoInstrumentation.SourceGenerators;
@@ -80,9 +81,29 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             .Where(static invocation => invocation is not null)
             .Collect();
 
-        context.RegisterSourceOutput(interceptedInvocations, EmitInterceptors);
+        // A consumer can hand WebApplicationBuilder.Build() interception to another generator
+        // (e.g. qyl's ServiceDefaults generator, which composes our QylInterceptedAspNetCore.Build)
+        // by setting <QylAutoInstrumentationInterceptWebApplicationBuilderBuild>false</...>. C#
+        // forbids two interceptors on one call site, so this opt-out is how the package boundary
+        // stays clean instead of colliding (CS9153). Default keeps full auto-instrumentation.
+        var interceptWebApplicationBuilderBuild = context.AnalyzerConfigOptionsProvider
+            .Select(static (provider, _) => ReadInterceptWebApplicationBuilderBuild(provider));
+
+        context.RegisterSourceOutput(
+            interceptedInvocations.Combine(interceptWebApplicationBuilderBuild),
+            static (productionContext, input) =>
+                EmitInterceptors(productionContext, input.Left, input.Right));
     }
 
+    private const string InterceptWebApplicationBuilderBuildProperty =
+        "build_property.QylAutoInstrumentationInterceptWebApplicationBuilderBuild";
+
+    // Default (property absent or any value other than "false") keeps intercepting Build(). Only an
+    // explicit "false" yields the call site so a cooperating generator can own it.
+    private static bool ReadInterceptWebApplicationBuilderBuild(AnalyzerConfigOptionsProvider provider) =>
+        !provider.GlobalOptions.TryGetValue(InterceptWebApplicationBuilderBuildProperty, out var value)
+        || !string.Equals(value, "false", System.StringComparison.OrdinalIgnoreCase);
+
     private static InterceptedInvocation? TryCreateInterceptedInvocation(
         GeneratorSyntaxContext context,
         CancellationToken cancellationToken)
@@ -198,14 +219,18 @@ private static void EnsureContractDeclaredByMatcher(
 
     private static void EmitInterceptors(
         SourceProductionContext context,
-        ImmutableArray<InterceptedInvocation?> nullableInvocations)
+        ImmutableArray<InterceptedInvocation?> nullableInvocations,
+        bool interceptWebApplicationBuilderBuild)
     {
         if (nullableInvocations.IsDefaultOrEmpty)
             return;
 
         var invocations = nullableInvocations
             .Where(static invocation => invocation is not null)
             .Select(static invocation => invocation!.Value)
+            .Where(invocation =>
+                interceptWebApplicationBuilderBuild ||
+                invocation.Target.Kind != InterceptorKind.AspNetCoreWebApplicationBuilderBuild)
             .Distinct()
             // Stable, content-based ordering so the emission order and the _N interceptor-name indices
             // are a pure function of the matched call sites — independent of Roslyn's cross-tree syntax

src/Qyl.OpenTelemetry.AutoInstrumentation/build/Qyl.OpenTelemetry.AutoInstrumentation.targets

@@ -7,4 +7,11 @@
   <PropertyGroup Condition="'$(_QylAutoInstrumentationCoreBuildAssetsAlreadyImported)' != 'true'">
     <InterceptorsNamespaces>$(InterceptorsNamespaces);Qyl.OpenTelemetry.AutoInstrumentation.Generated</InterceptorsNamespaces>
   </PropertyGroup>
+
+  <!-- Lets a consumer hand WebApplicationBuilder.Build() interception to a cooperating generator by
+       setting <QylAutoInstrumentationInterceptWebApplicationBuilderBuild>false</...>; the qyl source
+       generator reads this as build_property.* to avoid a CS9153 interceptor collision. -->
+  <ItemGroup Condition="'$(_QylAutoInstrumentationCoreBuildAssetsAlreadyImported)' != 'true'">
+    <CompilerVisibleProperty Include="QylAutoInstrumentationInterceptWebApplicationBuilderBuild" />
+  </ItemGroup>
 </Project>

src/Qyl.OpenTelemetry.AutoInstrumentation/buildTransitive/Qyl.OpenTelemetry.AutoInstrumentation.targets

@@ -7,4 +7,11 @@
   <PropertyGroup Condition="'$(_QylAutoInstrumentationCoreBuildAssetsAlreadyImported)' != 'true'">
     <InterceptorsNamespaces>$(InterceptorsNamespaces);Qyl.OpenTelemetry.AutoInstrumentation.Generated</InterceptorsNamespaces>
   </PropertyGroup>
+
+  <!-- Lets a consumer hand WebApplicationBuilder.Build() interception to a cooperating generator by
+       setting <QylAutoInstrumentationInterceptWebApplicationBuilderBuild>false</...>; the qyl source
+       generator reads this as build_property.* to avoid a CS9153 interceptor collision. -->
+  <ItemGroup Condition="'$(_QylAutoInstrumentationCoreBuildAssetsAlreadyImported)' != 'true'">
+    <CompilerVisibleProperty Include="QylAutoInstrumentationInterceptWebApplicationBuilderBuild" />
+  </ItemGroup>
 </Project>

tools/verify-aot-autoinstrumentation-goal.py

@@ -23,6 +23,7 @@
     ("instrumentation disabled behavior", [sys.executable, "tools/verify-instrumentation-disabled-behavior.py"]),
     ("conformance opt-in", [sys.executable, "tools/verify-conformance-opt-in.py"]),
     ("generator snapshots", [sys.executable, "tools/verify-generator-snapshots.py"]),
+    ("build interceptor opt-out", [sys.executable, "tools/verify-build-interceptor-optout.py"]),
     ("source interceptor consumer", [sys.executable, "tools/verify-source-interceptor-consumer.py"]),
     ("real adonet demo", [sys.executable, "tools/verify-real-adonet-demo.py"]),
     ("real aspnetcore demo", [sys.executable, "tools/verify-real-aspnetcore-demo.py"]),

tools/verify-build-interceptor-optout.py

@@ -0,0 +1,125 @@
+#!/usr/bin/env python3
+"""Verifies the WebApplicationBuilder.Build() interceptor opt-out.
+
+A consumer can hand WebApplicationBuilder.Build() interception to a cooperating generator
+(for example qyl's ServiceDefaults generator, which composes QylInterceptedAspNetCore.Build)
+by setting <QylAutoInstrumentationInterceptWebApplicationBuilderBuild>false</...>. C# forbids
+two interceptors on one call site, so without this opt-out the two generators collide (CS9153).
+
+  default build  -> the Build() interceptor IS emitted (full auto-instrumentation).
+  opt-out build  -> the Build() interceptor is NOT emitted, and the build still succeeds.
+
+The opt-out is surgical: only the WebApplicationBuilder.Build() interceptor is withheld; every
+other interceptor in the same consumer is unaffected.
+"""
+from __future__ import annotations
+
+import tempfile
+from pathlib import Path
+
+from verify_helpers import clean_env, run_checked
+
+
+ROOT = Path(__file__).resolve().parents[1]
+CORE_PROJECT = ROOT / "src" / "Qyl.OpenTelemetry.AutoInstrumentation" / "Qyl.OpenTelemetry.AutoInstrumentation.csproj"
+GENERATOR_PROJECT = (
+    ROOT
+    / "src"
+    / "Qyl.OpenTelemetry.AutoInstrumentation.SourceGenerators"
+    / "Qyl.OpenTelemetry.AutoInstrumentation.SourceGenerators.csproj"
+)
+TARGETS = ROOT / "src" / "Qyl.OpenTelemetry.AutoInstrumentation" / "buildTransitive" / "Qyl.OpenTelemetry.AutoInstrumentation.targets"
+TARGET_FRAMEWORK = "net10.0"
+OPT_OUT_PROPERTY = "QylAutoInstrumentationInterceptWebApplicationBuilderBuild"
+BUILD_INTERCEPTOR_TOKEN = "global::Qyl.OpenTelemetry.AutoInstrumentation.QylInterceptedAspNetCore.Build("
+OTHER_INTERCEPTOR_TOKEN = "global::Qyl.OpenTelemetry.AutoInstrumentation.QylInterceptedHttpClient.GetStringAsync("
+
+# A WebApplicationBuilder.Build() call (intercepted by AspNetCoreWebApplicationBuilderBuild) plus a
+# never-executed HttpClient call (intercepted by HttpClient) so the opt-out build still emits at
+# least one interceptor — proving the opt-out drops only Build(), not every interceptor.
+PROGRAM = """using System.Net.Http;
+
+var builder = WebApplication.CreateSlimBuilder(args);
+var app = builder.Build();
+app.MapGet("/", () => "ok");
+app.Run();
+
+static async System.Threading.Tasks.Task Probe(HttpClient client)
+    => _ = await client.GetStringAsync("https://qyl-build-optout.invalid");
+"""
+
+
+def fail(message: str) -> None:
+    raise SystemExit(message)
+
+
+def write_project(directory: Path) -> Path:
+    directory.mkdir(parents=True)
+    project = directory / "BuildOptOutConsumer.csproj"
+    project.write_text(
+        f"""<Project Sdk="Microsoft.NET.Sdk.Web">
+  <PropertyGroup>
+    <TargetFramework>{TARGET_FRAMEWORK}</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+    <CompilerGeneratedFilesOutputPath>Generated</CompilerGeneratedFilesOutputPath>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="{CORE_PROJECT}" />
+    <ProjectReference Include="{GENERATOR_PROJECT}"
+                      OutputItemType="Analyzer"
+                      ReferenceOutputAssembly="false" />
+    <Compile Remove="Generated/**/*.cs" />
+  </ItemGroup>
+
+  <Import Project="{TARGETS}" />
+</Project>
+""",
+        encoding="utf-8",
+    )
+    (directory / "Program.cs").write_text(PROGRAM, encoding="utf-8")
+    return project
+
+
+def generated_interceptor_text(directory: Path) -> str:
+    files = sorted((directory / "Generated").rglob("QylAutoInstrumentation.Interceptors.g.cs"))
+    if not files:
+        return ""
+    if len(files) != 1:
+        fail(f"expected at most one generated interceptor source file, found {len(files)}")
+    return files[0].read_text(encoding="utf-8")
+
+
+def build(project: Path, env: dict[str, str], opt_out: bool) -> None:
+    command = ["dotnet", "build", str(project), "-c", "Release", "-v", "quiet"]
+    if opt_out:
+        command.append(f"-p:{OPT_OUT_PROPERTY}=false")
+    run_checked(command, project.parent, env)
+
+
+def main() -> None:
+    env = clean_env()
+    with tempfile.TemporaryDirectory(prefix="qyl-build-optout-") as temp:
+        default_dir = Path(temp) / "default"
+        build(write_project(default_dir), env, opt_out=False)
+        default_text = generated_interceptor_text(default_dir)
+        if BUILD_INTERCEPTOR_TOKEN not in default_text:
+            fail("default build did not emit the WebApplicationBuilder.Build() interceptor")
+        if OTHER_INTERCEPTOR_TOKEN not in default_text:
+            fail("default build did not emit the control HttpClient interceptor")
+
+        optout_dir = Path(temp) / "optout"
+        build(write_project(optout_dir), env, opt_out=True)
+        optout_text = generated_interceptor_text(optout_dir)
+        if BUILD_INTERCEPTOR_TOKEN in optout_text:
+            fail("opt-out build still emitted the WebApplicationBuilder.Build() interceptor")
+        if OTHER_INTERCEPTOR_TOKEN not in optout_text:
+            fail("opt-out build dropped more than Build() — the control HttpClient interceptor is gone")
+
+    print("build-interceptor-optout-ok")
+
+
+if __name__ == "__main__":
+    main()