add MacOS file paths to the lit.cfg file for sycl/test

The hard-coded paths need some attention from someone who understands
the structure of Xcode paths.  Presumably, there is a way to capture
these in a way that survives filesystem reorganization across OSX
versions.

Slight modifications to the original implementation by @alexbatashev.

Signed-off-by: Hammond, Jeff R <[email protected]>
Signed-off-by: Alexander Batashev [email protected] (please re-affirm the sign-off that was in your original patch set)

Author: Hammond, Jeff R

sycl/test/lit.cfg.py

@@ -40,7 +40,8 @@
         config.environment['LD_LIBRARY_PATH'] = os.path.pathsep.join((config.environment['LD_LIBRARY_PATH'], config.llvm_build_libs_dir))
     else:
         config.environment['LD_LIBRARY_PATH'] = config.llvm_build_libs_dir
-else:
+
+elif platform.system() == "Windows":
     config.available_features.add('windows')
     if 'LIB' in os.environ:
         config.environment['LIB'] = os.path.pathsep.join((config.environment['LIB'], config.llvm_build_libs_dir))
@@ -52,6 +53,16 @@
     else:
         config.environment['PATH'] = config.llvm_build_bins_dir
 
+elif platform.system() == "Darwin":
+    # FIXME: surely there is a more elegant way to instantiate the Xcode directories.
+    if 'CPATH' in os.environ:
+        config.environment['CPATH'] = os.path.pathsep.join((os.environ['CPATH'], "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1"))
+        config.environment['CPATH'] = os.path.pathsep.join((config.environment['CPATH'], "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/"))
+    else:
+        config.environment['CPATH'] = "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1"
+        config.environment['CPATH'] = os.path.pathsep.join((config.environment['CPATH'], "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/"))
+    config.environment['DYLD_LIBRARY_PATH'] = config.llvm_build_libs_dir
+
 # propagate the environment variable OCL_ICD_FILANEMES to use proper runtime.
 if 'OCL_ICD_FILENAMES' in os.environ:
     config.environment['OCL_ICD_FILENAMES'] = os.environ['OCL_ICD_FILENAMES']