CUDA: Add support for disabling CUDA_ARCHITECTURES

The ability to disable adding architectures completely for packaging purposes
and cases requiring passing the architectures flags explicitly has been
requested.
Support a false value for CUDA_ARCHITECTURES and CMAKE_CUDA_ARCHITECTURES
for this purpose.

Implements #20821.

1 files changed, 25 insertions, 0 deletions

diff --git a/Help/policy/CMP0104.rst b/Help/policy/CMP0104.rst
index ca2c571..8516716 100644
--- a/Help/policy/CMP0104.rst
+++ b/Help/policy/CMP0104.rst
@@ -23,9 +23,34 @@ The ``NEW`` behavior of this policy is to initialize
 :variable:`CMAKE_CUDA_COMPILER_ID <CMAKE_<LANG>_COMPILER_ID>` is ``NVIDIA``
 and raise an error if :prop_tgt:`CUDA_ARCHITECTURES` is empty during generation.
 
+If :prop_tgt:`CUDA_ARCHITECTURES` is set to a false value no architectures
+flags are passed to the compiler. This is intended to support packagers and
+the rare cases where full control over the passed flags is required.
+
 This policy was introduced in CMake version 3.18.  CMake version
 |release| warns when the policy is not set and uses ``OLD`` behavior.
 Use the :command:`cmake_policy` command to set it to ``OLD`` or ``NEW``
 explicitly.
 
 .. include:: DEPRECATED.txt
+
+Examples
+^^^^^^^^
+
+.. code-block:: cmake
+
+  set_property(TARGET tgt PROPERTY CUDA_ARCHITECTURES 35 50 72)
+
+Generates code for real and virtual architectures ``30``, ``50`` and ``72``.
+
+.. code-block:: cmake
+
+  set_property(TARGET tgt PROPERTY CUDA_ARCHITECTURES 70-real 72-virtual)
+
+Generates code for real architecture ``70`` and virtual architecture ``72``.
+
+.. code-block:: cmake
+
+  set_property(TARGET tgt PROPERTY CUDA_ARCHITECTURES OFF)
+
+CMake will not pass any architecture flags to the compiler.