Iterate on config binding generator parsing pipeline to benefit from input caching provided by the incremental-generator feature

[layomia]

Address feedback from @eiriktsarpalis and @sharwell in #82179 (review) and related discussions.

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Issue Details

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Address feedback from @eiriktsarpalis in #82179 (review) and related discussions.

Author:	layomia
Assignees:	layomia
Labels:	area-Extensions-Configuration, source-generator
Milestone:	8.0.0

[layomia]

Address feedback from #86285 (comment).

[layomia]

Triage: moving this issue to 9.0, mitigating 8.0 parsing perf with #90619.

• We haven't had customer reports of the performance problems driving this issue. This effort is preemptive based on best practice / code-review.
• Generator is off-by default. If enabled and perf issues arise, a workaround would be as follows:
  • for projects with no binding, disable the generator
  • for project with binding, remove it from design time builds with an MSBuild target

[layomia]

From @jaredpar in https://github.com/dotnet/runtime/pull/90835/files#r1303627652. Address in #89587:

The equals implementation on BinderInvocation uses ref equality, not value equality. That means the CreateSyntaxProvider call above is never cached. This is an issue for IDE performance.