Targets file should be more incremental

[jonwis]

CsWinRT/nuget/Microsoft.Windows.CsWinRT.IIDOptimizer.targets

Lines 52 to 65 in 3d85a63

	<Target Name="CsWinRTInvokeGuidPatcher"
	Condition="'$(DesignTimeBuild)' == ''"
	AfterTargets="Compile"
	BeforeTargets="Link"
	DependsOnTargets="CsWinRTGenerateIIDOptimizerResponseFile">
	<Message Text="$(CsWinRTIIDOptimizerCommand)" Importance="$(CsWinRTMessageImportance)" />
	<Exec Command="$(CsWinRTIIDOptimizerCommand)" ConsoleToMsBuild="true" IgnoreExitCode="true">
	<Output TaskParameter="ConsoleOutput" PropertyName="CsWinRTGuidPatchOutput" />
	<Output TaskParameter="ExitCode" PropertyName="CsWinRTGuidPatchExitCode"/>
	</Exec>
	</Target>

Analyzing build time of a large project internally. Noticed that the CsWinRTInvokeGuidPatcher target is running repeatedly even when things haven't changed.

• Add Inputs/Outputs attributes to the targets
• Generate a "marker" file if necessary
• Remove unused output properties

[jonwis]

See also microsoft/WindowsAppSDK#5595

[Sergio0694]

Not sure this is worth fixing (assuming we can even improve it much). The IID optimizer tool is basically dead. It doesn't do anything in basically all cases now, and you might as well just disable (set CsWinRTIIDOptimizerOptOut=true). I'd check to see if you're seeing any IIDs actually being patched. If you don't have any, then you can just disable the tool and you'll be all set. The IID optimizer is also going away in CsWinRT 3.0 entirely, as all IIDs will just be either present in the projections, or generated in the interop .dll.

@manodasanW thoughts?

[manodasanW]

My plan was to address this by setting CsWinRTIIDOptimizerOptOut by default in staging/2.3.

[Sergio0694]

Oh, that also works ahah 😄

[jonwis]

If I disable it with CsWinRTIIDOptimizerOptOut, how will I know if I needed it? Will something break?

[manodasanW]

Assuming you are on CsWinRT 2.1 or later, you should be fine with it disabled. IIDOptimizer was just a tool that rewrote certain patterns for getting the PIID to improve performance. We don't use those patterns it looks for anymore so it would be optimizing nothing. There should be an output in your build saying IID calculations/fetches patched which would be 0 if nothing got patched.