build: prioritize public headers to avoid clash

CMakeLists.txt

@@ -166,13 +166,13 @@ endif()
 
 enable_testing()
 
-include_directories_with_host_compiler(${PROJECT_SOURCE_DIR}/include)
+include_directories_with_host_compiler_before(${PROJECT_SOURCE_DIR}/include)
 
 configure_file(
     "${PROJECT_SOURCE_DIR}/include/oneapi/dnnl/dnnl_config.h.in"
     "${PROJECT_BINARY_DIR}/include/oneapi/dnnl/dnnl_config.h"
 )
-include_directories_with_host_compiler(${PROJECT_BINARY_DIR}/include)
+include_directories_with_host_compiler_before(${PROJECT_BINARY_DIR}/include)
 
 configure_file(
     "${PROJECT_SOURCE_DIR}/README.binary.in"

cmake/utils.cmake

@@ -96,9 +96,17 @@ endmacro()
 macro(append_host_compiler_options var opts)
     if(NOT DNNL_DPCPP_HOST_COMPILER STREQUAL "DEFAULT")
         if(${var} MATCHES "-fsycl-host-compiler-options")
-            string(REGEX REPLACE
-                "(.*)(-fsycl-host-compiler-options=)\"(.*)\"(.*)"
-                "\\1\\2\"\\3 ${opts}\"\\4" ${var} ${${var}})
+            if("${ARGV2}" STREQUAL "BEFORE") # prepend
+                string(REGEX REPLACE
+                    "(.*)(-fsycl-host-compiler-options=)\"(.*)\"(.*)"
+                    "\\1\\2\"${opts} \\3\"\\4" ${var} ${${var}})
+            elseif("${ARGV2}" STREQUAL "") # append
+                string(REGEX REPLACE
+                    "(.*)(-fsycl-host-compiler-options=)\"(.*)\"(.*)"
+                    "\\1\\2\"\\3 ${opts}\"\\4" ${var} ${${var}})
+            else()
+                message(FATAL_ERROR "Unknown argument: ${ARGV2}")
+            endif()
         else()
             append(${var} "-fsycl-host-compiler-options=\"${opts}\"")
         endif()
@@ -112,6 +120,13 @@ macro(include_directories_with_host_compiler)
     endforeach()
 endmacro()
 
+macro(include_directories_with_host_compiler_before)
+    foreach(inc_dir ${ARGV})
+        include_directories(BEFORE ${inc_dir})
+        append_host_compiler_options(CMAKE_CXX_FLAGS "-I${inc_dir}" BEFORE)
+    endforeach()
+endmacro()
+
 macro(add_definitions_with_host_compiler)
     foreach(def ${ARGV})
         add_definitions(${def})