Include ORT C/C++ API headers in the ORT Mobile AAR package

cmake/onnxruntime.cmake

@@ -14,6 +14,25 @@ if (${CMAKE_SYSTEM_NAME} STREQUAL "iOS")
   set(OUTPUT_STYLE xcode)
 endif()
 
+# This macro is to get the path of header files for mobile packaging, for iOS and Android
+macro(get_mobile_api_headers _HEADERS)
+  # include both c and cxx api
+  set(${_HEADERS}
+    "${REPO_ROOT}/include/onnxruntime/core/session/onnxruntime_c_api.h"
+    "${REPO_ROOT}/include/onnxruntime/core/session/onnxruntime_cxx_api.h"
+    "${REPO_ROOT}/include/onnxruntime/core/session/onnxruntime_cxx_inline.h"
+  )
+
+  # need to add header files for enabled EPs
+  foreach(f ${ONNXRUNTIME_PROVIDER_NAMES})
+    file(GLOB _provider_headers CONFIGURE_DEPENDS
+      "${REPO_ROOT}/include/onnxruntime/core/providers/${f}/*.h"
+    )
+    list(APPEND ${_HEADERS} "${_provider_headers}")
+    unset(_provider_headers)
+  endforeach()
+endmacro()
+
 #If you want to verify if there is any extra line in symbols.txt, run
 # nm -C -g --defined libonnxruntime.so |grep -v '\sA\s' | cut -f 3 -d ' ' | sort
 # after build
@@ -39,21 +58,7 @@ if(WIN32)
     "${ONNXRUNTIME_ROOT}/core/dll/onnxruntime.rc"
   )
 elseif(onnxruntime_BUILD_APPLE_FRAMEWORK)
-  # include both c and cxx api
-  set(APPLE_FRAMEWORK_HEADERS
-    "${REPO_ROOT}/include/onnxruntime/core/session/onnxruntime_c_api.h"
-    "${REPO_ROOT}/include/onnxruntime/core/session/onnxruntime_cxx_api.h"
-    "${REPO_ROOT}/include/onnxruntime/core/session/onnxruntime_cxx_inline.h"
-  )
-
-  # need to add header files for enabled EPs
-  foreach(f ${ONNXRUNTIME_PROVIDER_NAMES})
-    file(GLOB _provider_headers CONFIGURE_DEPENDS
-      "${REPO_ROOT}/include/onnxruntime/core/providers/${f}/*.h"
-    )
-    list(APPEND APPLE_FRAMEWORK_HEADERS "${_provider_headers}")
-    unset(_provider_headers)
-  endforeach()
+  get_mobile_api_headers(APPLE_FRAMEWORK_HEADERS)
 
   # apple framework requires the header file be part of the library
   onnxruntime_add_shared_library(onnxruntime
@@ -132,6 +137,18 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Android" OR (onnxruntime_MINIMAL_BUILD AND UNIX))
   endif()
 endif()
 
+# we need to copy C/C++ API headers to be packed into Android AAR package
+if(CMAKE_SYSTEM_NAME STREQUAL "Android" AND onnxruntime_BUILD_JAVA)
+  get_mobile_api_headers(ANDROID_AAR_HEADERS)
+  set(ANDROID_HEADERS_DIR ${CMAKE_CURRENT_BINARY_DIR}/android/headers)
+  file(MAKE_DIRECTORY ${ANDROID_HEADERS_DIR})
+  # copy the header files one by one
+  foreach(h_ ${ANDROID_AAR_HEADERS})
+    get_filename_component(HEADER_NAME_ ${h_} NAME)
+    configure_file(${h_} ${ANDROID_HEADERS_DIR}/${HEADER_NAME_} COPYONLY)
+  endforeach()
+endif()
+
 target_link_libraries(onnxruntime PRIVATE
     onnxruntime_session
     ${onnxruntime_libs}

tools/ci_build/github/android/build_aar_package.py

@@ -72,6 +72,29 @@ def _parse_build_settings(args):
     return build_settings
 
 
+# Add ORT C and C++ API headers to the AAR package (in fact a zip file)
+# Such that developers using ORT native API can extract libraries and header from AAR package without building ORT
+# TODO, see if we can use Gradle to add headers to AAR package directly, which is necessary if we want to
+# publish the packagee directly using Gradle in the pipeline
+def _add_headers_to_aar(aar_file_path, header_files_path):
+    import shutil
+    import tempfile
+    with tempfile.TemporaryDirectory() as temp_dir:
+        aar_content = os.path.join(temp_dir, 'aar_content')
+        shutil.unpack_archive(aar_file_path, aar_content, 'zip')
+
+        # copy necessary header files
+        shutil.copytree(header_files_path, os.path.join(aar_content, 'headers'))
+
+        # create the zip archive
+        zip_base_filename = os.path.join(temp_dir, 'aar_with_headers')
+        zip_filename = zip_base_filename + '.zip'
+        shutil.make_archive(zip_base_filename, 'zip', root_dir=aar_content)
+
+        # overwrite the existing AAR package
+        shutil.move(zip_filename, aar_file_path)
+
+
 def _build_aar(args):
     build_settings = _parse_build_settings(args)
     build_dir = os.path.abspath(args.build_dir)
@@ -89,6 +112,7 @@ def _build_aar(args):
     _base_build_command = [
         sys.executable, BUILD_PY, '--config=' + _build_config
     ] + build_settings['build_params']
+    header_files_path = ''
 
     # Build binary for each ABI, one by one
     for abi in build_settings['build_abis']:
@@ -116,6 +140,10 @@ def _build_aar(args):
                 os.remove(_target_lib_name)
             os.symlink(os.path.join(_build_dir, _build_config, lib_name), _target_lib_name)
 
+        # we only need to define the header files path once
+        if not header_files_path:
+            header_files_path = os.path.join(_build_dir, _build_config, 'android', 'headers')
+
     # The directory to publish final AAR
     _aar_publish_dir = os.path.join(build_dir, 'aar_out', _build_config)
     os.makedirs(_aar_publish_dir, exist_ok=True)
@@ -139,6 +167,11 @@ def _build_aar(args):
     # clean, build, and publish to a local directory
     subprocess.run(_gradle_command + ['clean'], env=_env, shell=_shell, check=True, cwd=JAVA_ROOT)
     subprocess.run(_gradle_command + ['build'], env=_env, shell=_shell, check=True, cwd=JAVA_ROOT)
+
+    # add C and C++ API headers to the intermediate aar package
+    aar_file_path = os.path.join(_aar_dir, 'outputs', 'aar', 'onnxruntime-release.aar')
+    _add_headers_to_aar(aar_file_path, header_files_path)
+
     subprocess.run(_gradle_command + ['publish'], env=_env, shell=_shell, check=True, cwd=JAVA_ROOT)