Fix rpath

Author: larryliu0820

CMakeLists.txt

@@ -800,6 +800,9 @@ if(EXECUTORCH_BUILD_PYBIND)
       torch
   )
 
+  # RPATH for _portable_lib.so
+  set(_portable_lib_rpath "$ORIGIN/../../../torch/lib")
+
   if(EXECUTORCH_BUILD_EXTENSION_MODULE)
     # Always use static linking for pybindings to avoid runtime symbol
     # resolution issues
@@ -834,6 +837,7 @@ if(EXECUTORCH_BUILD_PYBIND)
 
   if(EXECUTORCH_BUILD_QNN)
     list(APPEND _dep_libs qnn_executorch_backend)
+    string(APPEND _portable_lib_rpath ":$ORIGIN/../../backends/qualcomm")
   endif()
 
   if(EXECUTORCH_BUILD_ENN)
@@ -885,19 +889,19 @@ if(EXECUTORCH_BUILD_PYBIND)
   target_compile_options(portable_lib PUBLIC ${_pybind_compile_options})
   target_link_libraries(portable_lib PRIVATE ${_dep_libs})
 
-  # Set RPATH to find PyTorch libraries relative to the installation location
-  # This goes from executorch/extension/pybindings up to site-packages, then to
-  # torch/lib. Don't do this to APPLE, as it will error out on the following
-  # error:
+  # Set RPATH to find PyTorch and backend libraries relative to the installation
+  # location. This goes from executorch/extension/pybindings up to site-packages,
+  # then to torch/lib. If QNN is enabled, also add backends/qualcomm/.
+  # Don't do this to APPLE, as it will error out on the following error:
   #
   if(APPLE)
     # Skip setting @loader_path for APPLE, since it causes error like ld:
     # duplicate LC_RPATH '@loader_path' in '<site-packages>/torch/lib/
     # libtorch_cpu.dylib'
   else()
     set_target_properties(
-      portable_lib PROPERTIES BUILD_RPATH "$ORIGIN/../../../torch/lib"
-                              INSTALL_RPATH "$ORIGIN/../../../torch/lib"
+      portable_lib PROPERTIES BUILD_RPATH "${_portable_lib_rpath}"
+                              INSTALL_RPATH "${_portable_lib_rpath}"
     )
   endif()
 

backends/qualcomm/CMakeLists.txt

@@ -35,42 +35,50 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_SYSTEM_PROCESSOR MATCHES
 endif()
 
 if(NOT DEFINED QNN_SDK_ROOT)
-  if(_qnn_host_is_linux_x86)
-    find_package(
-      Python3
-      COMPONENTS Interpreter
-      REQUIRED
-    )
-    message(STATUS "QNN_SDK_ROOT not provided, downloading Qualcomm SDK")
-    execute_process(
-      COMMAND
-        ${Python3_EXECUTABLE}
-        ${EXECUTORCH_SOURCE_DIR}/backends/qualcomm/scripts/download_qnn_sdk.py
-        --print-sdk-path
-      WORKING_DIRECTORY ${EXECUTORCH_SOURCE_DIR}
-      RESULT_VARIABLE _qnn_sdk_download_result
-      OUTPUT_VARIABLE _qnn_sdk_download_output
-      ERROR_VARIABLE _qnn_sdk_download_error
-      OUTPUT_STRIP_TRAILING_WHITESPACE
-    )
-    if(NOT _qnn_sdk_download_result EQUAL 0 OR _qnn_sdk_download_output
-                                               STREQUAL ""
-    )
+    if(_qnn_host_is_linux_x86)
+      set(_qnn_default_sdk_dir
+          "${CMAKE_CURRENT_LIST_DIR}/sdk/qnn"
+      )
+
+      if(EXISTS "${_qnn_default_sdk_dir}" AND EXISTS "${_qnn_default_sdk_dir}/lib")
+        message(STATUS "Found cached Qualcomm SDK at ${_qnn_default_sdk_dir}")
+        set(QNN_SDK_ROOT
+            ${_qnn_default_sdk_dir}
+            CACHE PATH "Qualcomm SDK root directory" FORCE
+        )
+      else()
+        message(STATUS "QNN_SDK_ROOT not provided, downloading Qualcomm SDK")
+        execute_process(
+          COMMAND
+            ${PYTHON_EXECUTABLE}
+            ${EXECUTORCH_SOURCE_DIR}/backends/qualcomm/scripts/download_qnn_sdk.py
+            --print-sdk-path
+          WORKING_DIRECTORY ${EXECUTORCH_SOURCE_DIR}
+          RESULT_VARIABLE _qnn_sdk_download_result
+          OUTPUT_VARIABLE _qnn_sdk_download_output
+          ERROR_VARIABLE _qnn_sdk_download_error
+          OUTPUT_STRIP_TRAILING_WHITESPACE
+        )
+        if(NOT _qnn_sdk_download_result EQUAL 0 OR _qnn_sdk_download_output
+                                                   STREQUAL ""
+        )
+          message(
+            FATAL_ERROR
+              "Failed to download Qualcomm SDK. stdout: ${_qnn_sdk_download_output}\n"
+              "stderr: ${_qnn_sdk_download_error}"
+          )
+        endif()
+        set(QNN_SDK_ROOT
+            ${_qnn_sdk_download_output}
+            CACHE PATH "Qualcomm SDK root directory" FORCE
+        )
+      endif()
+    else()
       message(
         FATAL_ERROR
-          "Failed to download Qualcomm SDK. stdout: ${_qnn_sdk_download_output}\n"
-          "stderr: ${_qnn_sdk_download_error}"
+          "Please define QNN_SDK_ROOT, e.g. cmake <..> -DQNN_SDK_ROOT=<...>"
       )
     endif()
-    set(QNN_SDK_ROOT
-        ${_qnn_sdk_download_output}
-        CACHE PATH "Qualcomm SDK root directory" FORCE
-    )
-  else()
-    message(
-      FATAL_ERROR
-        "Please define QNN_SDK_ROOT, e.g. cmake <..> -DQNN_SDK_ROOT=<...>"
-    )
   endif()
 endif()