Conditional per TargetFramework in MsBuild 15

With the new MsBuild version it's really easy to target multiple frameworks and framework versions in .csproj project:

<TargetFrameworks>net40;net45;net461;netcoreapp1.1</TargetFrameworks>

Now, how do I get a constant defined for each of them so that I can have certain code only be part of e.g. netcoreapp1.1 pass and not full framework compilation?

I'd like to be able to add a preprocessor directive like this one:

#if NET_CORE
    // some code
#endif

And the same for full .NET Framework and possibly .NET Standard.

The other questions I found don't take new <TargetFrameworks> way of defining the framework into accounts. Stuff like this doesn't work:

<DefineConstants Condition=" '$(TargetFramework)' == '.NETCoreApp' ">NET_CORE</DefineConstants>

There are already various preprocessor symbols defined that you can use. From the docs:

.NET Framework

.NET Standard

.NET Core

.NET 5+

Additional <framework>_OR_GREATER Symbols

From the release of .NET6, a suite of <framework>_OR_GREATER symbols were added:

For example:

#if NETSTANDARD1_6
    Console.WriteLine("This is .Net Standard 1.6");
#endif

#if NETCOREAPP2_0
    Console.WriteLine("This is .Net Core 2.0");
#endif