Override One Property in a .targets file

Question

Background: I have several solutions with roughly 300 C++ projects across them, most of them shared. We are using Visual Studio 2013 and have a build script that compiles all of the projects in the correct order, ensuring dependencies are resolved ahead of time. Our development/engineering team builds all of the code through the build script and then attempts to debug using Visual Studio 2013.

Issue: The "build then debug" process results in Visual Studio telling us that the Projects are out of date. This stems from the ProjectEvaluationFingerprint property (in Line 39 Microsoft.CppBuild.targets) including a $(SolutionDir) in the output file. The recommended fix from Microsoft suggests removing the $(SolutionDir) from the file. As our developers tends to transition back and forth between projects, I do not want to manually change this .targets file on every developer's machine (and remember to change it back when they leave the project). I would like to override the property in the .vcxproj by using a .targets file explicitly for this.

The property in Microsoft.CppBuild.targets looks like:

<!-- Global up-to-date check support -->
<PropertyGroup>
   <ProjectEvaluationFingerprint>$(Configuration)|$(Platform)|$(SolutionDir)|$(ProjectEvaluationFingerprint)</ProjectEvaluationFingerprint>
</PropertyGroup>

Generally, I have been following Microsoft's How to: Use the Same Target in Multiple Project Files. I have created a .targets file (test.targets) that contains the following code (note the TEST text was to test evaluation of the property in both the build script and building the project in Visual Studio):

<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
    <ProjectEvaluationFingerprint>$(Configuration)|$(Platform)|TEST|$(ProjectEvaluationFingerprint)</ProjectEvaluationFingerprint>
</PropertyGroup>

I then import it using the following line in the .vcxproj

<Import Project="..\..\Config\VSPropertySheets\test.targets" />

The project.lastbuildstate file now reads:

#TargetFrameworkVersion=v4.0:PlatformToolSet=v120_xp:EnableManagedIncrementalBuild=false:VCToolArchitecture=Native32Bit
Debug|Win32|D:\views\devbranch\Products\SLN\|Debug|Win32|TEST|

It is appending the new ProjectEvaluationFingerprint to the existing one, so it is not overriding (I can understand this to a degree, but I'm no MSBuild expert).

Question: How can I override this one property using a .targets file? Do I need to use a replaceregexp task or do I have an easier option?

Answer 1

You can override this property, but you have to be careful about two things:

• the new setting you want is this: <ProjectEvaluationFingerprint>$(Configuration)|$(Platform)|TEST/ProjectEvaluationFingerprint> Note the removal of $(ProjectEvaluationFingerprint), which would contain the previous value of this tag
• the location where you put the import is important: you will want to put it at the very end of your project (i.e. after the Microsoft.CppBuild.targets import).

Concretely:

use_custom_fingerprint.targets <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003"> <PropertyGroup> <ProjectEvaluationFingerprint>$(Configuration)|$(Platform)</ProjectEvaluationFingerprint> </PropertyGroup> </Project>

project.vcxproj <Project ...> ... <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" /> <ImportGroup Label="ExtensionTargets"> </ImportGroup> <Import Project="use_custom_fingerprint.targets" /> </Project>

Note that I also tried the extension .props and this worked just the same.

Note: The new import after importing Microsoft.CppBuild.targets.$(Platform).user.props is not sufficient, it must be after Microsoft.CppBuild.targets.

Disclaimer: tried in Visual Studio 2015

Answer 2

I have the same problem. I was able to progress a step further than you, but I still haven't a full solution.

The reason why you have now the old fingerprint appended to the new one without solution dir is your line

<ProjectEvaluationFingerprint>$(Configuration)|$(Platform)|TEST|$(ProjectEvaluationFingerprint)</ProjectEvaluationFingerprint>

The

$(ProjectEvaluationFingerprint)

Holds the old fingerprint, so just remove this part from the value for ProjectEvaluationFingerprint and your lastbuildstate will have the desired value.

Sadly now (at least for me) Visual Studio always thinks the fingerprint is wrong and will re-link the project with every compile, not only when switching sln file.

I removed the line from the props sheet and the up-to-date check works again as expected as long as solution directory doesn't change. I then modified the Microsoft.CppBuild.targets directly and this works: No more "not up-to-date" projects, even when switching solution directory.