IntelSYCLConfig.cmake fails on Windows

[cwasser]

Hello,

I installed the oneAPI Base Toolkit 2025.1, and I am using it with CMake on Windows 11.

In the CMake file, I use the IntelSYCLConfig.cmake via:

find_package(IntelSYCL CONFIG REQUIRED)

This currently fails like this:

-- The CXX compiler identification is IntelLLVM 2025.1.0 with MSVC-like command-line
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: C:/Program Files (x86)/Intel/oneAPI/compiler/latest/bin/icx.exe - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
Intel(R) oneAPI DPC++/C++ Compiler for applications running on Intel(R) 64, Version 2025.1.0 Build 20250317
Copyright (C) 1985-2025 Intel Corporation. All rights reserved.

-- SYCL Compiler version: 20250100
-- SYCL_INCLUDE_DIR: C:/Program Files (x86)/Intel/oneAPI/compiler/latest/include
-- SYCL_LIBRARY=SYCL_LIBRARY-NOTFOUND
CMake Error at C:/Program Files (x86)/Intel/oneAPI/compiler/latest/lib/cmake/IntelSYCL/IntelSYCLConfig.cmake:223 (separate_arguments):
  separate_arguments given unexpected argument(s)
Call Stack (most recent call first):
  C:/Program Files (x86)/Intel/oneAPI/compiler/latest/lib/cmake/IntelSYCL/IntelSYCLConfig.cmake:380 (SYCL_FEATURE_TEST_BUILD)
  CMakeLists.txt:5 (find_package)


CMake Error at C:/Program Files (x86)/Intel/oneAPI/compiler/latest/lib/cmake/IntelSYCL/IntelSYCLConfig.cmake:386 (SYCL_FEATURE_TEST_EXTRACT):
  SYCL_FEATURE_TEST_EXTRACT Function invoked with incorrect arguments for
  function named: SYCL_FEATURE_TEST_EXTRACT
Call Stack (most recent call first):
  CMakeLists.txt:5 (find_package)


CMake Error at C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:233 (message):
  Could NOT find IntelSYCL (missing: SYCL_LIBRARY)

      Reason given by package: SYCL: It appears that the C:/Program Files (x86)/Intel/oneAPI/compiler/latest/bin/icx.exe does not support SYCL

Call Stack (most recent call first):
  C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:603 (_FPHSA_FAILURE_MESSAGE)
  C:/Program Files (x86)/Intel/oneAPI/compiler/latest/lib/cmake/IntelSYCL/IntelSYCLConfig.cmake:422 (find_package_handle_standard_args)
  CMakeLists.txt:5 (find_package)


CMake Error at CMakeLists.txt:5 (find_package):
  Found package configuration file:

    C:/Program Files (x86)/Intel/oneAPI/compiler/latest/lib/cmake/IntelSYCL/IntelSYCLConfig.cmake

  but it set IntelSYCL_FOUND to FALSE so package "IntelSYCL" is considered to
  be NOT FOUND.  Reason given by package:

  SYCL: It appears that the C:/Program Files
  (x86)/Intel/oneAPI/compiler/latest/bin/icx.exe does not support SYCL



-- Configuring incomplete, errors occurred!
PS E:\cpp\sycl_test>

I debugged this to C:\Program Files (x86)\Intel\oneAPI\compiler\latest\lib\cmake\IntelSYCL\IntelSYCLConfig.cmake:332

Lines 330-333 look like this:

#TODO by default use sycl7 for windows
if(WIN32)
  set(sycl_lib_suffix "7")
else()

The problem is that it is looking for sycl7. However, for me, I can only find sycl.lib or sycl8.lib:

> ls 'C:/Program Files (x86)/Intel/oneAPI/compiler/latest/lib/sycl*'

    Directory: C:\Program Files (x86)\Intel\oneAPI\compiler\latest\lib

Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a---          17.03.2025    20:45        3352918 sycl-devicelib-host.lib
-a---          17.03.2025    20:45        3352942 sycl-devicelib-host.new.lib
-a---          17.03.2025    20:45        2032372 sycl-preview.lib
-a---          17.03.2025    20:45        2036640 sycl-previewd.lib
-a---          17.03.2025    20:45        2016022 sycl.lib
-a---          17.03.2025    20:45        2032372 sycl8-preview.lib
-a---          17.03.2025    20:45        2036640 sycl8-previewd.lib
-a---          17.03.2025    20:45        2016022 sycl8.lib
-a---          17.03.2025    20:45        2020306 sycl8d.lib
-a---          17.03.2025    20:45        2020306 sycld.lib

Either remove the default sycl_lib_suffix completely, or also look for version 8 and other future versions. So you don't need to constantly update IntelSYCLConfig.cmake.

Locally, I fixed this by doing the following before the find_package call:

set(SYCL_LIB_SUFFIX "8")

Another problem is that on line 362 you are appending another SYCL_FLAG to a list:

# TODO verify if this is needed
# Windows: Add Exception handling
if(WIN32)
  list(APPEND SYCL_FLAGS "/EHsc")
endif()

This later breaks the separate_arguments on line 223.

You need to convert the list to a command line before line 223. I fixed this locally by inserting the following before line 223:

string(REPLACE ";" " " SYCL_CXX_FLAGS_LIST "${SYCL_CXX_FLAGS_LIST}")

I have attached the partially fixed IntelSYCLConfig.cmake

But I don't know if that is the best way to do this

Best regards,

Clemens

[Sravani_K_Intel]

There is a known issue when compiling SYCL code on Windows using CMake with the latest 2025.1 version of the compiler which can cause errors like

CMake Error at C:/Program Files/CMake/share/cmake-3.31/Modules/FindPackageHandleStandardArgs.cmake:233 (message):

  Could NOT find IntelSYCL (missing: SYCL_LIBRARY)

      Reason given by package: SYCL: It appears that the C:/Program Files (x86)/Intel/oneAPI/compiler/latest/bin/icx.exe does not support SYCL

Workaround: C:\Program Files (x86)\Intel\oneAPI\compiler\latest\lib\cmake\IntelSYCL\IntelSYCLConfig.cmake file needs to be updated with the following two changes:

• Line 332: Update set(sycl_lib_suffix "7") with set(sycl_lib_suffix "8")
• Line 365: Replace set(SYCL_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SYCL_FLAGS}") with

list(JOIN SYCL_FLAGS " " SYCL_FLAGS_STRING)

message(DEBUG "SYCL_FLAGS_STRING: ${SYCL_FLAGS_STRING}")

set(SYCL_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${SYCL_FLAGS_STRING}")

A fix for this issue will be available in an upcoming compiler release.