Migrate to source-generated logging across Stack, Libraries and Applications (#3908) (#4003)

# Description

Migrates the entire code base (Stack, Libraries and Applications) from
direct

`ILogger.LogInformation/LogError/LogWarning/LogDebug/LogTrace/LogCritical(...)`
calls to **source-generated `[LoggerMessage]` logging**, as tracked in
#3908.
Source-generated logging avoids boxing of value-type arguments, caches
the
message formatter, and emits an efficient `IsEnabled` check so a
disabled log
level costs nothing.

This is a behavior-preserving refactor: message text, levels and
structured
placeholders are unchanged; only the call shape changes.

## What changed

- **36 projects migrated.** Every static log call now goes through a
per-file
  `internal static partial class <Class>Log` holding `[LoggerMessage]`
  extension methods on `ILogger`, so call sites keep the natural
`logger.SomeEvent(...)` shape. Closely-related files that emit the same
messages share one log class (e.g. the encoders/decoders in
`Opc.Ua.Types`
  share `EncodingLog`) to avoid duplication and CS0121 ambiguity.
- **Per-assembly event-id classes.** Each project has one
  `internal static class <AssemblyToken>EventIds` (e.g. `CoreEventIds`,
  `ClientEventIds`, `PubSubEventIds`) with a reserved `public const int`
  offset block per log class. The assembly-token prefix avoids CS0436
  collisions across `InternalsVisibleTo` boundaries.
- **`CA1873` enabled solution-wide** in `.editorconfig` now that the
whole
code base (including test, sample and tooling projects) is migrated, so
any
regression back to a direct `ILogger.Log*` call with an expensive
argument is
flagged. Every occurrence has been guarded with an `IsEnabled` check (or
the
check merged into an existing condition where the log was the sole body
of an
`if`/`else`, preserving side effects); the only suppressions are two Moq
  `Verify` expression-tree sites, which are not executed log calls.
- **Dynamic log levels stay hand-written.** A handful of calls whose
level is
only known at runtime keep the structured `logger.Log(logLevel, ...)`
form
under an `if (logger.IsEnabled(logLevel))` guard — `[LoggerMessage]`
requires
  a compile-time level.
- **netstandard duplicate-generator fix.** Projects that also pull in an
R9
package (`Microsoft.Extensions.Http.Resilience`, `.Compliance`,
`.Telemetry`)
get the `Microsoft.Gen.Logging` generator in addition to the in-box one;
on
  `netstandard` both implement every partial method (CS0757). A single
`Directory.Build.targets` target removes the R9 analyzer on
`netstandard`
  only (no-op elsewhere and where it is not referenced).
- **Shared/linked source files** that are compiled into more than one
project
(e.g. sample files linked into test projects) use self-contained literal
event ids instead of a per-assembly class the consumer does not compile.
- **Docs.** The authoring recipe (event-id convention, log-class
convention,
  parameter rules, the `IsEnabled` guard, shared/linked files, and the
  netstandard generator interaction) lives in the new

[`Docs/DeveloperGuide.md`](Docs/DeveloperGuide.md#add-a-log-message-source-generated);
`Docs/Diagnostics.md` keeps the runtime/observability side and links to
it.
- **Redaction preserved.** Log calls that previously wrapped sensitive
values
with `Redact.Create(...)` keep passing the `RedactionWrapper<T>`
(instead of
an eager `.ToString()`), so format-time redaction still applies — this
also
  clears the CodeQL clear-text alerts introduced during the migration.

## Validation

- Full `UA.slnx` build passes with **0 errors / 0 warnings**; the
multi-target
  test projects force every referenced library to build on
  net472/net48/netstandard2.1/net8.0/net9.0/net10.0.
- No unguarded static `ILogger.Log*` calls remain anywhere (only the
guarded
dynamic-level calls); `CA1873` is clean across the full solution on
net10.0.

## Related Issues

- Fixes #3908

## Checklist

_Put an `x` in the boxes that apply. You can complete these step by step
after opening the PR._

- [ ] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [ ] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

Author: marcschier

.editorconfig

@@ -481,8 +481,11 @@ dotnet_diagnostic.CA1724.severity                                             =
 
 # CA1848: Use the LoggerMessage delegates
 dotnet_diagnostic.CA1848.severity = none
-# CA1873: Avoid potentially expensive logging
-dotnet_diagnostic.CA1873.severity = none
+# CA1873: Avoid potentially expensive logging. Enabled solution-wide (issue
+# #3908) now that the entire code base uses source-generated [LoggerMessage]
+# logging; any regression back to direct ILogger.Log* calls with expensive
+# arguments is flagged.
+dotnet_diagnostic.CA1873.severity = warning
 # CA1000: Do not declare static members on generic types
 dotnet_diagnostic.CA1000.severity = none
 # CA1031: Do not catch general exception types

.github/copilot-instructions.md

@@ -20,6 +20,7 @@ This is the official OPC UA .NET Standard Stack from the OPC Foundation. It prov
 - **Build**: Use Visual Studio 2026 or `dotnet build`
 - **Key solutions**:
   - `UA.slnx` - Contains all projects
+- **Contributor guide**: see [`Docs/DeveloperGuide.md`](../Docs/DeveloperGuide.md) for prerequisites, building (including per-TFM), testing, coding standards, and how-to recipes.
 
 ### Project Structure
 - `Libraries/` - Core OPC UA libraries (Client, Server, Configuration, etc.)
@@ -76,7 +77,7 @@ This is the official OPC UA .NET Standard Stack from the OPC Foundation. It prov
   - All source generated code, in particular ObjectType proxies should be used over manually calling service calls inside new clients.
   - Consider using the source generators to implement emitting "boilerplate", especially if it is related to the OPC UA standard (e.g. information model).
   - Base services: File System, Certificate manager, Secret store, State machine, Alarms and conditions Streaming subscription, Sessions, etc. in new code. (Documented in docs/*).
-  - Observability is plumbed through via `ITelemetryContext`. Use it to create a `ILogger` for logging.
+  - Observability is plumbed through via `ITelemetryContext`. Use it to create an `ILogger` for logging; follow the source-generated logging conventions in [`Docs/DeveloperGuide.md`](../Docs/DeveloperGuide.md#add-a-log-message-source-generated).
 - If reuse is not possible, ASK whether to extend an existing feature so it becomes reuseable.
 
 ### Code Style
@@ -102,6 +103,7 @@ This is the official OPC UA .NET Standard Stack from the OPC Foundation. It prov
 - Assembly prefix: `Opc.Ua` (Except applications, or if otherwise requested)
 - Package prefix: `OPCFoundation.NetStandard`
 - Always use a line break after `<summary>` and before `</summary>` for all members (except for documentation of fields). This applies to **every** XML-doc summary, including in sample/application code — never write a single-line `/// <summary> ... </summary>`; always put the text on its own line between the opening and closing tags.
+- Use source-generated `[LoggerMessage]` logging; never call `ILogger.LogInformation/LogError/...` directly. Follow the per-file `<Class>Log` and per-assembly `<AssemblyToken>EventIds` conventions in [`Docs/DeveloperGuide.md`](../Docs/DeveloperGuide.md#add-a-log-message-source-generated).
 
 ### Security Requirements
 - **Never hardcode credentials, certificates, or secrets** in source code
@@ -139,6 +141,7 @@ This is the official OPC UA .NET Standard Stack from the OPC Foundation. It prov
 - Update `/README.md` for significant changes
 - Keep `NugetREADME.md` updated for package-related changes
 - Document breaking changes prominently
+- Keep [`Docs/DeveloperGuide.md`](../Docs/DeveloperGuide.md) (the contributor onboarding guide) current when build, test, or coding-convention changes affect contributors.
 
 #### Documentation Style
 - Use clear, technical language

Applications/ConsoleLdsServer/EventIds.cs

@@ -0,0 +1,45 @@
+/* ========================================================================
+ * Copyright (c) 2005-2026 The OPC Foundation, Inc. All rights reserved.
+ *
+ * OPC Foundation MIT License 1.00
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The complete license agreement can be found here:
+ * http://opcfoundation.org/License/MIT/1.00/
+ * ======================================================================*/
+
+namespace Opc.Ua.Lds.Server.Console
+{
+    /// <summary>
+    /// Centrally managed event id offsets for source-generated log messages in this assembly.
+    /// </summary>
+    /// <remarks>
+    /// Each per-file <c>&lt;ClassName&gt;Log</c> class allocates its event ids relative to the
+    /// offset constant below, using <c>offset + &lt;zero-based message index&gt;</c>. Every block
+    /// reserves at least five spare slots for future messages and is rounded up to the next
+    /// multiple of ten so that ids can be documented and managed from this single location.
+    /// </remarks>
+    internal static class ConsoleLdsServerEventIds
+    {
+        public const int Program = 0;
+    }
+}

Applications/ConsoleLdsServer/Program.cs

@@ -181,7 +181,7 @@ await application
                 }
                 catch (Exception ex)
                 {
-                    logger?.LogError(ex, "Fatal error starting LDS.");
+                    logger?.FatalErrorStartingLds(ex);
                     System.Console.Error.WriteLine(ex);
                     return 2;
                 }
@@ -194,4 +194,12 @@ await application
             return rootCommand.Parse(args).InvokeAsync();
         }
     }
+
+    internal static partial class ProgramLog
+    {
+        [LoggerMessage(EventId = ConsoleLdsServerEventIds.Program + 0, Level = LogLevel.Error,
+            Message = "Fatal error starting LDS.")]
+        public static partial void FatalErrorStartingLds(
+    this Microsoft.Extensions.Logging.ILogger logger, Exception exception);
+    }
 }

Applications/ConsoleReferenceClient/AlarmClientSample.cs

@@ -35,6 +35,7 @@
 using Opc.Ua.Client;
 using Opc.Ua.Client.Alarms;
 using Opc.Ua.Client.Subscriptions.Streaming;
+using Quickstarts.ConsoleReferenceClient;
 
 namespace Quickstarts
 {
@@ -141,7 +142,7 @@ await alarms.AcknowledgeAsync(
                     }
                     catch (Exception ex)
                     {
-                        m_logger.LogError(ex, "Acknowledge failed");
+                        m_logger.AcknowledgeFailed(ex);
                     }
                 }
             }
@@ -195,4 +196,12 @@ private static void PrintAlarm(ConditionTypeRecord record)
             }
         }
     }
+
+    internal static partial class AlarmClientSampleLog
+    {
+        [LoggerMessage(EventId = ConsoleReferenceClientEventIds.AlarmClientSample + 0, Level = LogLevel.Error,
+            Message = "Acknowledge failed")]
+        public static partial void AcknowledgeFailed(this ILogger logger, Exception ex);
+    }
+
 }