anchor.diff:  @set PATH=%gcc%\;%PATH%
   @cd "%mesa%dxtn"
   @echo.
  -@RD /S /Q %abi%
  -@echo.
  +@if EXIST %abi% RD /S /Q %abi%
   @MD %abi%
   @set dxtn=gcc -shared
   @if %abi%==x86 set dxtn=%dxtn% -m32
  
positive.code: 
  
  :build_with_vs
  @RD /S /Q build\windows-%longabi%
  @echo.
  @set PATH=%mesa%Python\%abi%\;%mesa%Python\%abi%\Scripts\;%mesa%flexbison\;%mesa%m4\%abi%\usr\bin\;%PATH%
  @pip install -U mako
  @pip freeze > requirements.txt
  
negative.code: @if /I NOT %buildllvm%==y GOTO build_dxtn
  @echo.
  @cd "%mesa%llvm"
  @if EXIST %abi% RD /S /Q %abi%
  @if EXIST cmake-%abi% RD /S /Q cmake-%abi%
  @md cmake-%abi%
  @cd cmake-%abi%
  @set toolchain=Visual Studio 14
  