sundials +sycl: add cxxflags=-fsycl via flag_handler (#40845)

share/spack/gitlab/cloud_pipelines/stacks/e4s-oneapi/spack.yaml

@@ -200,11 +200,11 @@ spack:
   - kokkos +sycl +openmp cxxstd=17 +tests +examples
   - kokkos-kernels build_type=Release %oneapi ^kokkos +sycl +openmp cxxstd=17 +tests +examples
   - slate +sycl
+  - sundials +sycl cxxstd=17 +examples-install
   - tau +mpi +opencl +level_zero ~pdt +syscall   # tau: requires libdrm.so to be installed
   # --
   # - ginkgo +oneapi                    # InstallError: Ginkgo's oneAPI backend requires theDPC++ compiler as main CXX compiler.
   # - hpctoolkit +level_zero            # dyninst@12.3.0%gcc: /usr/bin/ld: libiberty/./d-demangle.c:142: undefined reference to `_intel_fast_memcpy'; can't mix intel-tbb@%oneapi with dyninst%gcc
-  # - sundials +sycl cxxstd=17          # sundials: include/sunmemory/sunmemory_sycl.h:20:10: fatal error: 'CL/sycl.hpp' file not found
 
   - py-scipy
 

var/spack/repos/builtin/packages/sundials/package.py

@@ -292,6 +292,12 @@ class Sundials(CMakePackage, CudaPackage, ROCmPackage):
     # fix issues with exported PETSc target(s) in SUNDIALSConfig.cmake
     patch("sundials-v5.8.0.patch", when="@5.8.0")
 
+    def flag_handler(self, name, flags):
+        if name == "cxxflags":
+            if self.spec.satisfies("+sycl"):
+                flags.append("-fsycl")
+        return (flags, None, None)
+
     # ==========================================================================
     # SUNDIALS Settings
     # ==========================================================================