Logging source generator reruns code generation phase on keypress.

[ericstj]

Description

See more detail in #92914.

Reproduction Steps

Create a project that uses Logging source generator. Observe it's execution pattern - either in the debugger or through ETW.

Expected behavior

Changes unrelated to the logging code and it's type closure should not trigger regeneration of the logging source.

Actual behavior

Every change causes the entire pipeline to rerun.

Regression?

No

Known Workarounds

We haven't had reports of the performance here being a blocker, but that could be due to lack of use. The amount of work done on keypress will depend on whether or not the generator has work to do. If it has a lot of work to do, then it will be doing that work on every change.
 
Disable the logging generator from design-time builds (this will result in errors where the generator is used, which are design time only errors).
Workaround:

  <Target Name="_disableLoggingGeneratorInDesignTime" BeforeTargets="ResolveOffByDefaultAnalyzers">
    <ItemGroup Condition="'$(DesignTimeBuild)' == 'true' OR '$(BuildingProject)' != 'true'">
      <OffByDefaultAnalyzer Include="Microsoft.Extensions.Logging.Generators.dll"
                            IsEnabled="$(EnableLoggingGenerator)"/>
    </ItemGroup>
  </Target>

Configuration

No response

Other information

No response

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Issue Details

---

Description

See more detail in #92914.

Reproduction Steps

Create a project that uses Logging source generator. Observe it's execution pattern - either in the debugger or through ETW.

Expected behavior

Changes unrelated to the logging code and it's type closure should not trigger regeneration of the logging source.

Actual behavior

Every change causes the entire pipeline to rerun.

Regression?

No

Known Workarounds

We haven't had reports of the performance here being a blocker, but that could be due to lack of use. The amount of work done on keypress will depend on whether or not the generator has work to do. If it has a lot of work to do, then it will be doing that work on every change.
 
Disable the logging generator from design-time builds (this will result in errors where the generator is used, which are design time only errors).
Workaround:

  <Target Name="_disableLoggingGeneratorInDesignTime" BeforeTargets="ResolveOffByDefaultAnalyzers">
    <ItemGroup Condition="'$(DesignTimeBuild)' == 'true' OR '$(BuildingProject)' != 'true'">
      <OffByDefaultAnalyzer Include="Microsoft.Extensions.Logging.Generators.dll"
                            IsEnabled="$(EnableLoggingGenerator)"/>
    </ItemGroup>
  </Target>

Configuration

No response

Other information

No response

Author:	ericstj
Assignees:	-
Labels:	area-Extensions-Logging
Milestone:	-

[ericstj]

We discussed improving the incremental characteristics of the runtime source generators and scoped it out of 9.0

[Youssef1313]

@ericstj Note: Maybe for design-time builds, the generator could generate minimal code (partial method definitions without implementation), which could be fast and incremental, and fixes IntelliSense. And for actual builds the implementation is generated.

One potential consideration that I'm not sure about is, in what context does a build for EnC/HotReload happens? Is it a design-time build or non-design-time?