From ae21d75119357db9c3b300b4bef7a4c8f919410f Mon Sep 17 00:00:00 2001
From: seimtpow <82023680+seimtpow@users.noreply.github.com>
Date: Fri, 12 Jul 2024 16:41:14 +0100
Subject: [PATCH] Update FindFFT.cmake to Fix alias to alias issue (#250)

Co-authored-by: Seimon <seimon.powell@ukaea.uk>
---
 CMakeLists.txt      |  2 +-
 cmake/FindFFT.cmake | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 064a69d9..0587f20b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -282,7 +282,7 @@ set(TARGETS_FILE NESOTargets)
 set(INSTALL_CONFIGDIR lib/cmake/${PROJECT_NAME})
 
 install(
-  TARGETS ${PROJECT_NAME} ${NESO_LIBRARY_NAME}
+  TARGETS ${PROJECT_NAME} ${NESO_LIBRARY_NAME} fft
   EXPORT ${TARGETS_FILE}
   ARCHIVE DESTINATION lib
   LIBRARY DESTINATION lib
diff --git a/cmake/FindFFT.cmake b/cmake/FindFFT.cmake
index 6cb5298c..b75c8b3c 100644
--- a/cmake/FindFFT.cmake
+++ b/cmake/FindFFT.cmake
@@ -43,16 +43,22 @@ if(CMAKE_CXX_COMPILER_ORIGINAL)
   set(CMAKE_CXX_COMPILER ${CMAKE_CXX_COMPILER_ORIGINAL})
 endif()
 
+add_library(fft INTERFACE)
+add_library(fft::fft ALIAS fft)
 if(MKL_FOUND)
   set(FFT_IMPLEMENTATION "Intel_MKL")
   set(FFT_FOUND TRUE)
-  add_library(fft::fft ALIAS MKL::MKL_DPCPP)
+  if (TARGET MKL::MKL_SYCL) 
+      target_link_libraries(fft INTERFACE MKL::MKL_SYCL)
+  else()
+      target_link_libraries(fft INTERFACE MKL::MKL_DPCPP)
+  endif()
 else()
   find_package(PkgConfig REQUIRED)
   pkg_search_module(FFTW QUIET fftw3 IMPORTED_TARGET)
   if(FFTW_FOUND)
     set(FFT_IMPLEMENTATION fftw)
     set(FFT_FOUND TRUE)
-    add_library(fft::fft ALIAS PkgConfig::FFTW)
+    target_link_libraries(fft INTERFACE PkgConfig::FFTW)
   endif()
 endif()