MSBuild Managed vs Unmanaged property

Question

Is there a way in MSBuild logic to determine if I am running managed vs unmanaged code? Not C++ vs C#, but just managed vs unmanaged? I'd like to set some properties (usually just version information) differently depending on whether the code is managed or unmanaged.

Answer 1

There are normally two things that change in a vcxproj file for managed complation (afaik, at least that's how we have it in our master c++/cli property sheet used for all cli projects: the CLRSupport property is set to true and the ClCompile ItemGroup has the CompileAsManaged metadata set to true. You can check on any of these or both. Here's a target which prints the values:

<Target Name="CheckManaged">
  <ItemGroup>
    <ClCompile Include="dummy.cpp" />
  </ItemGroup>

  <PropertyGroup>
    <CompileAsManaged>@(ClCompile->AnyHaveMetadataValue('CompileAsManaged','true'))</CompileAsManaged>
  </PropertyGroup>

  <Message Text="CompileAsManaged is $(CompileAsManaged) and CLRSupport is $(CLRSupport)" />

  <ItemGroup>
    <ClCompile Remove="dummy.cpp" />
  </ItemGroup>
</Target>

As you can see getting the CompileAsManaged metadata value requires some treatment: I'm adding an item to the ClCompile group because if the group is empty you canot use CompileAsManaged; normally you can just omit this.

Answer 2

In C++, each item in ClCompile (list of source files) has a CompileAsManaged metadata value. Setting properties is difficult since it can vary for each source file, but is more straightforward if you only expect (and support) keying off the whole-project setting. Toggle that in the IDE and see what changes in the vcxproj file. It has a few different values to choose from.