changes to compiler name usage from clang++ to dpcpp (#270)

* In build_backend.py changed compiler from clang++ to dpcpp.
* Removed CC and CXX vars in setup.py since we want to build the extensions using the system compiler and not DPC++
* Provided environment variable hint to find level zero library to build on systems where level zero is in non default path

Co-authored-by: Adarsh Yoga <adarsh.yoga@intel.com>

Author: adarshyoga

dpctl-capi/cmake/modules/FindLevelZero.cmake

@@ -25,8 +25,8 @@
 # LEVEL_ZERO_LIBRARY - the full path to the ze_loader library
 # TODO: Add a way to record the version of the level_zero library
 
-find_library(LEVEL_ZERO_LIBRARY ze_loader)
-find_path(LEVEL_ZERO_INCLUDE_DIR NAMES level_zero/zet_api.h)
+find_library(LEVEL_ZERO_LIBRARY ze_loader HINTS $ENV{L0_LIB_DIR})
+find_path(LEVEL_ZERO_INCLUDE_DIR NAMES level_zero/zet_api.h HINTS $ENV{L0_INCLUDE_DIR})
 
 find_package_handle_standard_args(LevelZero DEFAULT_MSG
     LEVEL_ZERO_INCLUDE_DIR

scripts/build_backend.py

@@ -62,7 +62,7 @@
         "-DCMAKE_PREFIX_PATH=" + INSTALL_PREFIX,
         "-DDPCPP_INSTALL_DIR=" + DPCPP_ROOT,
         "-DCMAKE_C_COMPILER:PATH=" + os.path.join(DPCPP_ROOT, "bin", "clang"),
-        "-DCMAKE_CXX_COMPILER:PATH=" + os.path.join(DPCPP_ROOT, "bin", "clang++"),
+        "-DCMAKE_CXX_COMPILER:PATH=" + os.path.join(DPCPP_ROOT, "bin", "dpcpp"),
         "-DDPCTL_ENABLE_LO_PROGRAM_CREATION=ON",
         backends,
     ]
@@ -83,6 +83,8 @@
         "-DCMAKE_INSTALL_PREFIX=" + INSTALL_PREFIX,
         "-DCMAKE_PREFIX_PATH=" + INSTALL_PREFIX,
         "-DDPCPP_INSTALL_DIR=" + DPCPP_ROOT,
+        "-DCMAKE_C_COMPILER:PATH=" + os.path.join(DPCPP_ROOT, "bin", "clang-cl.exe"),
+        "-DCMAKE_CXX_COMPILER:PATH=" + os.path.join(DPCPP_ROOT, "bin", "dpcpp.exe"),
         backends,
     ]
     subprocess.check_call(cmake_args, stderr=subprocess.STDOUT, shell=True)

setup.py

@@ -43,15 +43,11 @@
 
 if IS_LIN:
     DPCPP_ROOT = os.environ["ONEAPI_ROOT"] + "/compiler/latest/linux"
-    os.environ["CC"] = DPCPP_ROOT + "/bin/clang"
-    os.environ["CXX"] = DPCPP_ROOT + "/bin/clang++"
     os.environ["DPCTL_SYCL_INTERFACE_LIBDIR"] = "dpctl"
     os.environ["DPCTL_SYCL_INTERFACE_INCLDIR"] = "dpctl/include"
     os.environ["CFLAGS"] = "-fPIC"
 
 elif IS_WIN:
-    os.environ["CC"] = "clang-cl.exe"
-    os.environ["CXX"] = "dpcpp.exe"
     os.environ["DPCTL_SYCL_INTERFACE_LIBDIR"] = "dpctl"
     os.environ["DPCTL_SYCL_INTERFACE_INCLDIR"] = "dpctl\include"
 
@@ -86,7 +82,7 @@ def get_sdl_ldflags():
 
 def get_other_cxxflags():
     if IS_LIN:
-        return ["-O3", "-fsycl", "-std=c++17"]
+        return ["-O3", "-std=c++17"]
     elif IS_MAC:
         return []
     elif IS_WIN: