Program against explicitly versioned NVTX V1 API

The explicit V1 API is always available. See discussion here:
NVIDIA/NVTX#96

Fixes: #1750

cub/cub/detail/nvtx.cuh

@@ -37,19 +37,23 @@
 #  pragma system_header
 #endif // no system header
 
-// Enable the functionality of this header if
+// Enable the functionality of this header if:
 // * The NVTX3 C API is available in CTK
 // * NVTX is not explicitly disabled
 // * C++14 is availabl for cuda::std::optional
-#if __has_include(<nvtx3/nvToolsExt.h>) && !defined(NVTX_DISABLE) && _CCCL_STD_VER >= 2014
+#if __has_include(<nvtx3/nvToolsExt.h> ) && !defined(NVTX_DISABLE) && _CCCL_STD_VER >= 2014
 // Include our NVTX3 C++ wrapper if not available from the CTK
 #  if __has_include(<nvtx3/nvtx3.hpp>) // TODO(bgruber): replace by a check for the first CTK version shipping the header
 #    include <nvtx3/nvtx3.hpp>
 #  else // __has_include(<nvtx3/nvtx3.hpp>)
 #    include "nvtx3.hpp"
 #  endif // __has_include(<nvtx3/nvtx3.hpp>)
 
-#  include <cuda/std/optional>
+// We expect the NVTX3 V1 C++ API to be available when nvtx3.hpp is available. This should work, because newer versions
+// of NVTX3 will continue to declare previous API versions. See also:
+// https://github.com/NVIDIA/NVTX/blob/release-v3/c/include/nvtx3/nvtx3.hpp#L2835-L2841.
+#  ifdef NVTX3_CPP_DEFINITIONS_V1_0
+#    include <cuda/std/optional>
 
 CUB_NAMESPACE_BEGIN
 namespace detail
@@ -62,26 +66,37 @@ struct NVTXCCCLDomain
 CUB_NAMESPACE_END
 
 // Hook for the NestedNVTXRangeGuard from the unit tests
-#  ifndef CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE
-#    define CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE(name)
-#  endif // !CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE
+#    ifndef CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE
+#      define CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE(name)
+#    endif // !CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE
 
 // Conditionally inserts a NVTX range starting here until the end of the current function scope in host code. Does
 // nothing in device code.
 // The optional is needed to defer the construction of an NVTX range (host-only code) and message string registration
 // into a dispatch region running only on the host, while preserving the semantic scope where the range is declared.
-#  define CUB_DETAIL_NVTX_RANGE_SCOPE_IF(condition, name)                                                               \
-    CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE(name)                                                                            \
-    ::cuda::std::optional<::nvtx3::scoped_range_in<CUB_NS_QUALIFIER::detail::NVTXCCCLDomain>> __cub_nvtx3_range;        \
-    NV_IF_TARGET(                                                                                                       \
-      NV_IS_HOST,                                                                                                       \
-      static const ::nvtx3::registered_string_in<CUB_NS_QUALIFIER::detail::NVTXCCCLDomain> __cub_nvtx3_func_name{name}; \
-      static const ::nvtx3::event_attributes __cub_nvtx3_func_attr{__cub_nvtx3_func_name};                              \
-      if (condition) __cub_nvtx3_range.emplace(__cub_nvtx3_func_attr);                                                  \
-      (void) __cub_nvtx3_range;)
+#    define CUB_DETAIL_NVTX_RANGE_SCOPE_IF(condition, name)                                                             \
+      CUB_DETAIL_BEFORE_NVTX_RANGE_SCOPE(name)                                                                          \
+      ::cuda::std::optional<::nvtx3::v1::scoped_range_in<CUB_NS_QUALIFIER::detail::NVTXCCCLDomain>> __cub_nvtx3_range;  \
+      NV_IF_TARGET(                                                                                                     \
+        NV_IS_HOST,                                                                                                     \
+        static const ::nvtx3::v1::registered_string_in<CUB_NS_QUALIFIER::detail::NVTXCCCLDomain> __cub_nvtx3_func_name{ \
+          name};                                                                                                        \
+        static const ::nvtx3::v1::event_attributes __cub_nvtx3_func_attr{__cub_nvtx3_func_name};                        \
+        if (condition) __cub_nvtx3_range.emplace(__cub_nvtx3_func_attr);                                                \
+        (void) __cub_nvtx3_range;)
 
-#  define CUB_DETAIL_NVTX_RANGE_SCOPE(name) CUB_DETAIL_NVTX_RANGE_SCOPE_IF(true, name)
-#else // __has_include(<nvtx3/nvToolsExt.h>) && !defined(NVTX_DISABLE) && _CCCL_STD_VER > 2011
+#    define CUB_DETAIL_NVTX_RANGE_SCOPE(name) CUB_DETAIL_NVTX_RANGE_SCOPE_IF(true, name)
+#  else // NVTX3_CPP_DEFINITIONS_V1_0
+#    if defined(_CCCL_COMPILER_MSVC)
+#      pragma message( \
+        "warning: nvtx3.hpp is available but does not define the V1 API. This is odd. Please open a GitHub issue at: https://github.com/NVIDIA/cccl/issues.")
+#    else
+#      warning nvtx3.hpp is available but does not define the V1 API. This is odd. Please open a GitHub issue at: https://github.com/NVIDIA/cccl/issues.
+#    endif
+#    define CUB_DETAIL_NVTX_RANGE_SCOPE_IF(condition, name)
+#    define CUB_DETAIL_NVTX_RANGE_SCOPE(name)
+#  endif // NVTX3_CPP_DEFINITIONS_V1_0
+#else // __has_include(<nvtx3/nvToolsExt.h> ) && !defined(NVTX_DISABLE) && _CCCL_STD_VER >= 2014
 #  define CUB_DETAIL_NVTX_RANGE_SCOPE_IF(condition, name)
 #  define CUB_DETAIL_NVTX_RANGE_SCOPE(name)
-#endif // __has_include(<nvtx3/nvToolsExt.h>) && !defined(NVTX_DISABLE) && _CCCL_STD_VER > 2011
+#endif // __has_include(<nvtx3/nvToolsExt.h> ) && !defined(NVTX_DISABLE) && _CCCL_STD_VER >= 2014