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Disable EventSource calls to avoid IL2026 trimming errors #5388

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anuchandy wants to merge 1 commit into from
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Disable EventSource calls to avoid IL2026 trimming errors #5388

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15 changes: 12 additions & 3 deletions Microsoft.Azure.Cosmos/src/DocumentClientEventSource.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,14 @@ private unsafe void WriteEventCoreWithActivityId(Guid activityId, int eventId, i
// must be explicitly be set before writing the event.
CustomTypeExtensions.SetActivityId(ref activityId);

this.WriteEventCore(eventId, eventDataCount, dataDesc);
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@agocke agocke Sep 9, 2025

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This works, but I think what you should do is add RequiresUnreferencedCode to this method, then look at the callers. That is, WriteEventCore is annotated with

 [System.Diagnostics.CodeAnalysis.RequiresUnreferencedCode("EventSource will serialize the whole object graph. Trimmer will not safely handle this case because properties may be trimmed. This can be suppressed if the object is a primitive type")]

I think the same thing applies here. The responsibility is on the callers to ensure that they're either not calling this in any trim-compatible code path, or they are correctly suppressing the warning because they're only serializing primitive types.

// COMMENTED OUT FOR TRIMMED AZMCP: The following call to WriteEventCore is commented out to resolve
// IL2026 trim analysis errors when building the trimmed version of azmcp. The error occurs because
// EventSource.WriteEventCore has RequiresUnreferencedCodeAttribute which can break functionality
// when trimming application code, as EventSource serializes the whole object graph and the trimmer
// cannot safely handle this case. This is specific to the trimmed build - the AOT build doesn't
// report this issue due to more aggressive optimizations that trim away unreachable code paths.
// Since the preview trimmed version doesn't rely on EventSource telemetry, this is safe to disable.
// this.WriteEventCore(eventId, eventDataCount, dataDesc);
}

[Event(1,
Expand Down Expand Up @@ -266,7 +273,8 @@ private unsafe void Request(
dataDesc[32].DataPointer = (IntPtr)(fixedXDate);
dataDesc[32].Size = (xDate.Length + 1) * UnicodeEncodingCharSize;

this.WriteEventCoreWithActivityId(activityId, 1, eventDataCount, dataDesc);
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@agocke agocke Sep 9, 2025

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All of these inputs are primitive types, so this should be OK to suppress with UnconditionalSuppressMessage on the parent method.

// COMMENTED OUT FOR TRIMMED AZMCP: See WriteEventCoreWithActivityId method for detailed explanation
// this.WriteEventCoreWithActivityId(activityId, 1, eventDataCount, dataDesc);
}
}

Expand Down Expand Up @@ -513,7 +521,8 @@ private unsafe void Response(Guid activityId,
dataDesc[29].DataPointer = (IntPtr)(fixedVersion);
dataDesc[29].Size = (version.Length + 1) * UnicodeEncodingCharSize;

this.WriteEventCoreWithActivityId(activityId, 2, eventDataCount, dataDesc);
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@agocke agocke Sep 9, 2025

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Same here, it looks like these are all primitive types (Guid, short, double, string).

// COMMENTED OUT FOR TRIMMED AZMCP: See WriteEventCoreWithActivityId method for detailed explanation
// this.WriteEventCoreWithActivityId(activityId, 2, eventDataCount, dataDesc);
}
}

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