kokkos: rename 'std' variant to 'cxxstd'. (#39319)

Co-authored-by: Cristian Di Pietrantonio <cdipietrantonio@pawsey.org.au>

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

@@ -225,10 +225,10 @@ spack:
   # GPU
   - aml +ze
   - amrex +sycl dimensions=3
-  - arborx +sycl ^kokkos +sycl +openmp std=17 +tests +examples
+  - arborx +sycl ^kokkos +sycl +openmp cxxstd=17 +tests +examples
-  - cabana +sycl ^kokkos +sycl +openmp std=17 +tests +examples
+  - cabana +sycl ^kokkos +sycl +openmp cxxstd=17 +tests +examples
-  - kokkos +sycl +openmp std=17 +tests +examples
+  - kokkos +sycl +openmp cxxstd=17 +tests +examples
-  - kokkos-kernels build_type=Release %oneapi ^kokkos +sycl +openmp std=17 +tests +examples
+  - kokkos-kernels build_type=Release %oneapi ^kokkos +sycl +openmp cxxstd=17 +tests +examples
   # --
   # - ginkgo +oneapi                    # InstallError: Ginkgo's oneAPI backend requires theDPC++ compiler as main CXX compiler.
   # - hpctoolkit +level_zero            # intel-tbb: icpx: error: unknown argument: '-flifetime-dse=1'

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

@@ -187,7 +187,7 @@ class Ascent(CMakePackage, CudaPackage):
     depends_on("vtk-m+fpic", when="@0.8.0: +vtkh")
     depends_on("vtk-m~shared+fpic", when="@0.8.0: +vtkh~shared")
     # Ascent defaults to C++11
-    depends_on("kokkos std=11", when="+vtkh ^vtk-m +kokkos")
+    depends_on("kokkos cxxstd=11", when="+vtkh ^vtk-m +kokkos")
 
     #######################
     # VTK-h

var/spack/repos/builtin/packages/hpx-kokkos/package.py

@@ -42,7 +42,7 @@ class HpxKokkos(CMakePackage, CudaPackage, ROCmPackage):
 
     for cxxstd in cxxstds:
         depends_on("hpx cxxstd={0}".format(cxxstd), when="cxxstd={0}".format(cxxstd))
-        depends_on("kokkos std={0}".format(cxxstd), when="cxxstd={0}".format(cxxstd))
+        depends_on("kokkos cxxstd={0}".format(cxxstd), when="cxxstd={0}".format(cxxstd))
 
     # HPXKokkos explicitly supports CUDA and ROCm. Other GPU backends can be
     # used but without support in HPXKokkos. Other CPU backends, except Serial,

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

@@ -200,29 +200,30 @@ class Kokkos(CMakePackage, CudaPackage, ROCmPackage):
     depends_on("kokkos-nvcc-wrapper@master", when="@master+wrapper")
     conflicts("+wrapper", when="~cuda")
 
-    stds = ["11", "14", "17", "20"]
+    cxxstds = ["11", "14", "17", "20"]
-    # TODO: This should be named cxxstd for consistency with other packages
+    variant("cxxstd", default="17", values=cxxstds, multi=False, description="C++ standard")
-    variant("std", default="17", values=stds, multi=False, description="C++ standard")
     variant("pic", default=False, description="Build position independent code")
 
-    conflicts("std=11", when="@3.7:")
+    conflicts("cxxstd=11", when="@3.7:")
-    conflicts("std=14", when="@4.0:")
+    conflicts("cxxstd=14", when="@4.0:")
 
-    conflicts("+cuda", when="std=17 ^cuda@:10")
+    conflicts("+cuda", when="cxxstd=17 ^cuda@:10")
-    conflicts("+cuda", when="std=20 ^cuda@:11")
+    conflicts("+cuda", when="cxxstd=20 ^cuda@:11")
 
     # SYCL and OpenMPTarget require C++17 or higher
-    for stdver in stds[: stds.index("17")]:
+    for cxxstdver in cxxstds[: cxxstds.index("17")]:
-        conflicts("+sycl", when="std={0}".format(stdver), msg="SYCL requires C++17 or higher")
+        conflicts(
+            "+sycl", when="cxxstd={0}".format(cxxstdver), msg="SYCL requires C++17 or higher"
+        )
         conflicts(
             "+openmptarget",
-            when="std={0}".format(stdver),
+            when="cxxstd={0}".format(cxxstdver),
             msg="OpenMPTarget requires C++17 or higher",
         )
 
     # HPX should use the same C++ standard
-    for std in stds:
+    for cxxstd in cxxstds:
-        depends_on("hpx cxxstd={0}".format(std), when="+hpx std={0}".format(std))
+        depends_on("hpx cxxstd={0}".format(cxxstd), when="+hpx cxxstd={0}".format(cxxstd))
 
     # HPX version constraints
     depends_on("hpx@:1.6", when="@:3.5 +hpx")
@@ -283,7 +284,7 @@ def cmake_args(self):
 
         options = [
             from_variant("CMAKE_POSITION_INDEPENDENT_CODE", "pic"),
-            from_variant("CMAKE_CXX_STANDARD", "std"),
+            from_variant("CMAKE_CXX_STANDARD", "cxxstd"),
             from_variant("BUILD_SHARED_LIBS", "shared"),
         ]