Is there any way for an MSBuild project to determine whether the 32-bit or 64-bit version of MSBuild is running?

Question

After having found the answer to my question about the 64-bit version of MSBuild attempting to load 32-bit extensions, it has now become necessary for me to determine whether the 64-bit or 32-bit version of MSBuild is running so I can load the correct version of the DLL.

I can check the $(MSBuildBinPath) variable against a list of known paths, but that will not work if MSBuild is running from some non-standard location. This is not an elegant solution.

Is there some way to reliably determine whether the currently running MSBuild (or other process hosting the MSBuild engine) is 32-bit or 64-bit?

Answer 1

There is a related question at http://stackoverflow.com/questions/3505285/find-out-the-bitness-of-the-current-os-in-msbuild. In that question there is an answer by Blindy stating:

---

On a 64-bit OS, the following variables are defined:

ProgramFiles=C:\Program Files
ProgramFiles(x86)=C:\Program Files (x86)

So just test for ProgramFiles(x86) and if it's empty, use ProgramFiles.

Answer 2

Have you considered writing a custom MSBuild task that returns bitness of the current process?

See http://stackoverflow.com/questions/336633/how-to-detect-windows-64-bit-platform-with-net for an example.