MSBuild task to get update FileAssemblyVersion for only projects with changes.

Question

Is there any way, using msbuild or otherwise, to detect which projects have changes in the current build and update the FileAssemblyVersion attribute in AssemblyInfo.cs for those projects only?

Answer 1

Assuming you've set up incremental [get and] compiles, the next step would be to hook into the MSBuild sequence. Have a look in FrameworkDir\Microsoft.Common.Targets. The problem is that things just are not set up to work in this way - the fact that there are _TimestampBeforeCompile and _TimeStampAfterCompile steps which just show that you cant determine a priori if something is going to compile. While you could theoretically hook in before [the language specific] CoreCompile [e.g., in Microsoft.CSharp.targets], the problem would be that you need to have the same Inputs as it does in order to determine if its going to happen, which would mean lots of cut and pasting and keeping in sync with system files. The other thing to be wary of is noted in the comment at the top of the _ComputeNonExistentFileProperty target.

So, outside of doing some very deep modifications to the sequence (e.g., hooking in a 'post build' bit which forces a second compile if a custom _TimeStampAfterCompile of yours detects that a compilation took place, I'd say there's no easy, recommended or supported way.

Having said that, the AssemblyFileVersion (you refer to FileAssemblyVersion, which doesnt exist :P) is easy to modify after the compile as its just a resource - you'll find tools for that. But I assume you're really talking about doing both it and the AssemblyVersion, which cant be tweaked after the fact in the same way.