.NET Native AOT warnings from System.Net.Http

[JamesNK]

Description

Publishing an app with .NET Native AOT results in analysis warnings. Devs have confidence that their app works when no errors remain, so System.Net.Http shouldn't report warnings unless an AOT incompatible API is used from the assembly.

Reproduction Steps

1. Create a console app
2. Write code to create an HTTP request with HttpClient
3. Publish with <PublishAot>true</PublishAot>

Expected behavior

No warning from System.Net.Http.

Actual behavior

I think it might be one error. I enabled this setting to get details: https://learn.microsoft.com/en-us/dotnet/core/deploying/trimming/trimming-options?pivots=dotnet-7-0#show-detailed-warnings

/_/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs(333): AOT analysis warning IL3050: System.Net.Http.DiagnosticsHandler.Write<T>(DiagnosticSource,St
ring,!!0): Using member 'System.Diagnostics.DiagnosticSource.Write(String,Object)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. Diagn
osticSource may require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling. [C:\Development\Source\grpc-dot
net\examples\Transcoder\Server\Server.csproj]

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

[ghost]

Tagging subscribers to this area: @dotnet/ncl
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Issue Details

---

Description

Publishing an app with .NET Native AOT results in analysis warnings. Devs have confidence that their app works when no errors remain, so System.Net.Http shouldn't report warnings unless an AOT incompatible API is used from the assembly.

Reproduction Steps

1. Create a console app
2. Write code to create an HTTP request with HttpClient
3. Publish with <PublishAot>true</PublishAot>

Expected behavior

No warning from System.Net.Http.

Actual behavior

/_/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs(333): AOT analysis warning IL3050: System.Net.Http.DiagnosticsHandler.Write<T>(DiagnosticSource,St
ring,!!0): Using member 'System.Diagnostics.DiagnosticSource.Write(String,Object)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. Diagn
osticSource may require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling. [C:\Development\Source\grpc-dot
net\examples\Transcoder\Server\Server.csproj]

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

Author:	JamesNK
Assignees:	-
Labels:	area-System.Net.Http
Milestone:	-

[ghost]

Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Description

Publishing an app with .NET Native AOT results in analysis warnings. Devs have confidence that their app works when no errors remain, so System.Net.Http shouldn't report warnings unless an AOT incompatible API is used from the assembly.

Reproduction Steps

1. Create a console app
2. Write code to create an HTTP request with HttpClient
3. Publish with <PublishAot>true</PublishAot>

Expected behavior

No warning from System.Net.Http.

Actual behavior

I think it might be one error. I enabled this setting to get details: https://learn.microsoft.com/en-us/dotnet/core/deploying/trimming/trimming-options?pivots=dotnet-7-0#show-detailed-warnings

/_/src/libraries/System.Net.Http/src/System/Net/Http/DiagnosticsHandler.cs(333): AOT analysis warning IL3050: System.Net.Http.DiagnosticsHandler.Write<T>(DiagnosticSource,St
ring,!!0): Using member 'System.Diagnostics.DiagnosticSource.Write(String,Object)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling. Diagn
osticSource may require creating new generic types or methods, which requires creating code at runtime. This may not work when AOT compiling. [C:\Development\Source\grpc-dot
net\examples\Transcoder\Server\Server.csproj]

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

Author:	JamesNK
Assignees:	-
Labels:	untriaged, area-NativeAOT-coreclr
Milestone:	-

[MichalStrehovsky]

The warning is potentially real if one enables EventSource (that we disabled by default in 7.0 for NativeAOT). But without opting in, it's just noise, because this won't throw.

@eerhardt made DiagnosticSource AOT-safe in #76109 and that would make the warning disappear (it shouldn't be warning in 8.0 anymore).

I know I said it probably doesn't meet the 7.0 bar in #76109 (comment) but I didn't consider the warning. The warning is annoying.

I triggered a backport on the PR to see if we can still slam it into the December update.

[MichalStrehovsky]

Ok, cool the backport failed because the bot cannot comment on the old PR. Fix in arcade: dotnet/arcade#11637

Meanwhile, I submitted #78372 with a cherry-pick to get a headstart on the CI. It's end of the day for me so I'll let the US time zone chase this if it's at all possible to get this in.

[MichalStrehovsky]

This will be fixed in 7.0.3 (#78532).