All-

Does XST provide any pre-defined macros or constants?  For example:

  __BUILD_NUMBER
  __XST_VER

that could be used in source code as contents of a logic revision
register, or could be used to know which version of XST is in use?

If this is not available, is there a way to kludge it that's
"relatively automatic"?

To Xilinx:  I know that "ISE ain't Visual Studio", but helpful code
maintenance items such as this could easily be implemented.

-Jeff