Remove the workaround via CMAKE_BINARY_DIR from DpctlExtCAPI

Author: vlad-perevezentsev

CMakeLists.txt

@@ -347,17 +347,12 @@ endif()
 # DpctlExtCAPI: Interface library for dpctl_ext C-API
 # Provides access to:
 # 1. Public C-API headers from dpctl_ext/apis/include
-# 2. Generated Cython headers from a specific build subdirectory
-
-# Set the specific directory for generated Cython headers
-set(DPCTL_EXT_GENERATED_INCLUDE_DIR ${CMAKE_CURRENT_BINARY_DIR})
+# 2. Generated Cython headers via per-target header interface libraries
 
 add_library(DpctlExtCAPI INTERFACE)
 target_include_directories(
     DpctlExtCAPI
-    INTERFACE
-        ${CMAKE_CURRENT_SOURCE_DIR}/dpctl_ext/apis/include
-        ${DPCTL_EXT_GENERATED_INCLUDE_DIR}
+    INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/dpctl_ext/apis/include
 )
 
 add_subdirectory(dpctl_ext)

dpctl_ext/CMakeLists.txt

@@ -159,9 +159,11 @@ function(build_dpctl_ext _trgt _src _dest)
     # TODO: create separate folder inside build folder that contains only
     #   headers related to this target and appropriate folder structure to
     #   eliminate shadow dependencies
-    get_filename_component(_generated_src_dir_dir ${_generated_src_dir} DIRECTORY)
+    # Go up two levels to build root for "dpctl_ext/tensor/_usmarray.h" resolution
+    get_filename_component(_parent_dir ${_generated_src_dir} DIRECTORY)
+    get_filename_component(_build_root ${_parent_dir} DIRECTORY)
     # TODO: do not set directory if we did not generate header
-    target_include_directories(${_trgt} INTERFACE ${_generated_src_dir_dir})
+    target_include_directories(${_trgt} INTERFACE ${_build_root})
     set(_rpath_value "$ORIGIN")
     if(BUILD_DPCTL_EXT_RELATIVE_PATH)
         set(_rpath_value "${_rpath_value}/${BUILD_DPCTL_EXT_RELATIVE_PATH}")

dpctl_ext/apis/include/dpctl_ext_capi.h

@@ -66,8 +66,8 @@
 
 // Include the generated Cython C-API headers for usm_ndarray
 // These headers are generated during build and placed in the build directory
-#include <dpctl_ext/tensor/_usmarray.h>
-#include <dpctl_ext/tensor/_usmarray_api.h>
+#include "dpctl_ext/tensor/_usmarray.h"
+#include "dpctl_ext/tensor/_usmarray_api.h"
 
 /*
  * Function to import dpctl_ext C-API and make it available.