FindCUDAToolkit: nvtx3 target

nvtx3 is a header-only replacement for the previous shared library
implementations.

I implemented it as a separate target since while the header names match and
ideally it should be API compatible, forcing its include directory into the old
target would lengthen the include search path and could cause confusion or
possible build differences for projects using multiple build systems. This
keeps it explicit as a developer opt-in.

Implements: #21377
Resolves: #23835

Help/release/dev/find-cuda-toolkit-nvtx3.rst

@@ -0,0 +1,8 @@
+find-cuda-toolkit-nvtx3
+-----------------------
+
+* The :module:`FindCUDAToolkit` module now provides a target for
+  :ref:`nvtx3 <cuda_toolkit_nvtx3>` for CUDA 10.0+, which supersedes
+  :ref:`nvToolsExt <cuda_toolkit_nvToolsExt>`. A deprecation warning is emitted
+  when using ``nvToolsExt`` if the project requires CMake 3.25 and CUDA 10.0+
+  is used.

Modules/FindCUDAToolkit.cmake

@@ -121,6 +121,7 @@ of the following libraries that are part of the CUDAToolkit:
 - :ref:`nvidia-ML<cuda_toolkit_nvML>`
 - :ref:`nvRTC<cuda_toolkit_nvRTC>`
 - :ref:`nvToolsExt<cuda_toolkit_nvToolsExt>`
+- :ref:`nvtx3<cuda_toolkit_nvtx3>`
 - :ref:`OpenCL<cuda_toolkit_opencl>`
 - :ref:`cuLIBOS<cuda_toolkit_cuLIBOS>`
 
@@ -362,6 +363,8 @@ Targets Created:
 nvToolsExt
 """"""""""
 
+.. deprecated:: 3.25 With CUDA 10.0+, use :ref:`nvtx3 <cuda_toolkit_nvtx3>`.
+
 The `NVIDIA Tools Extension <https://docs.nvidia.com/gameworks/content/gameworkslibrary/nvtx/nvidia_tools_extension_library_nvtx.htm>`_.
 This is a shared library only.
 
@@ -369,6 +372,20 @@ Targets Created:
 
 - ``CUDA::nvToolsExt``
 
+.. _`cuda_toolkit_nvtx3`:
+
+nvtx3
+"""""
+
+.. versionadded:: 3.25
+
+The header-only `NVIDIA Tools Extension Library <https://nvidia.github.io/NVTX/doxygen/index.html>`_.
+Introduced in CUDA 10.0.
+
+Targets created:
+
+- ``CUDA::nvtx3``
+
 .. _`cuda_toolkit_opencl`:
 
 OpenCL
@@ -1011,6 +1028,21 @@ if(CUDAToolkit_FOUND)
   endif()
   _CUDAToolkit_find_and_add_import_lib(nvToolsExt ALT nvToolsExt64)
 
+  if(CUDAToolkit_VERSION VERSION_GREATER_EQUAL 10.0)
+    # nvToolsExt is deprecated since nvtx3 introduction.
+    # Warn only if the project requires a sufficiently new CMake to make migration possible.
+    if(CMAKE_MINIMUM_REQUIRED_VERSION VERSION_GREATER_EQUAL 3.25)
+      set_property(TARGET CUDA::nvToolsExt PROPERTY DEPRECATION "nvToolsExt has been superseded by nvtx3 since CUDA 10.0 and CMake 3.25. Use CUDA::nvtx3 and include <nvtx3/nvToolsExt.h> instead.")
+    endif()
+
+    # Header-only variant. Uses dlopen().
+    if(NOT TARGET CUDA::nvtx3)
+      add_library(CUDA::nvtx3 INTERFACE IMPORTED)
+      target_include_directories(CUDA::nvtx3 SYSTEM INTERFACE "${CUDAToolkit_INCLUDE_DIRS}")
+      target_link_libraries(CUDA::nvtx3 INTERFACE ${CMAKE_DL_LIBS})
+    endif()
+  endif()
+
   _CUDAToolkit_find_and_add_import_lib(OpenCL)
 endif()