Suppress the compiler warnings marking them as external

Author: antonwolfy

conda-recipe/bld.bat

@@ -1,20 +1,25 @@
-REM A workaround for activate-dpcpp.bat issue to be addressed in 2021.4
+:: A workaround for activate-dpcpp.bat issue to be addressed in 2021.4
 set "LIB=%BUILD_PREFIX%\Library\lib;%BUILD_PREFIX%\compiler\lib;%LIB%"
 set "INCLUDE=%BUILD_PREFIX%\include;%INCLUDE%"
 
+:: Treat warnings from the INCLUDE as external (a part of the above workaround)
+:: The warning from the DPC++ compiler will be suppressed then
+set "CFLAGS=%FLAG% /external:env:INCLUDE"
+set "CXXFLAGS=%CXXFLAGS% /external:env:INCLUDE"
+
 "%PYTHON%" setup.py clean --all
 
 set "MKLROOT=%PREFIX%/Library"
 set "TBB_ROOT_HINT=%PREFIX%/Library"
 set "DPL_ROOT_HINT=%PREFIX%/Library"
 
-REM Overriding IPO is useful for building in resources constrained VMs (public CI)
+:: Overriding IPO is useful for building in resources constrained VMs (public CI)
 if DEFINED OVERRIDE_INTEL_IPO (
   set "CMAKE_ARGS=%CMAKE_ARGS% -DCMAKE_INTERPROCEDURAL_OPTIMIZATION:BOOL=FALSE"
 )
 
 FOR %%V IN (17.0.0 17 18.0.0 18 19.0.0 19 20.0.0 20 21.0.0 21 22.0.0 22) DO @(
-  REM set DIR_HINT if directory exists
+  :: set DIR_HINT if directory exists
   IF EXIST "%BUILD_PREFIX%\Library\lib\clang\%%V\" (
     set "SYCL_INCLUDE_DIR_HINT=%BUILD_PREFIX%\Library\lib\clang\%%V"
   )
@@ -24,8 +29,8 @@ set "PATCHED_CMAKE_VERSION=3.26"
 set "PLATFORM_DIR=%PREFIX%\Library\share\cmake-%PATCHED_CMAKE_VERSION%\Modules\Platform"
 set "FN=Windows-IntelLLVM.cmake"
 
-rem Save the original file, and copy patched file to
-rem fix the issue with IntelLLVM integration with cmake on Windows
+:: Save the original file, and copy patched file to
+:: fix the issue with IntelLLVM integration with cmake on Windows
 if EXIST "%PLATFORM_DIR%" (
   dir "%PLATFORM_DIR%\%FN%"
   copy /Y "%PLATFORM_DIR%\%FN%" .