CUDA: Enable support on QNX

This fixes the following two issues with the CUDA support on QNX:

* cuda target name is not derived correctly (should be `aarch64-qnx`).
* linking `cudart` must not be linked against `rt`, `dl`, `pthread`.

This enables to use cmake's native cuda support on QNX.

Fixes: #21381

Modules/Compiler/NVIDIA-CUDA.cmake

@@ -64,7 +64,7 @@ set(CMAKE_CUDA_RUNTIME_LIBRARY_LINK_OPTIONS_STATIC  "cudadevrt;cudart_static")
 set(CMAKE_CUDA_RUNTIME_LIBRARY_LINK_OPTIONS_SHARED  "cudadevrt;cudart")
 set(CMAKE_CUDA_RUNTIME_LIBRARY_LINK_OPTIONS_NONE    "")
 
-if(UNIX)
+if(UNIX AND NOT (CMAKE_SYSTEM_NAME STREQUAL "QNX"))
   list(APPEND CMAKE_CUDA_RUNTIME_LIBRARY_LINK_OPTIONS_STATIC "rt" "pthread" "dl")
 endif()
 

Modules/FindCUDA.cmake

@@ -732,6 +732,8 @@ if(CMAKE_CROSSCOMPILING)
     # Support for aarch64 cross compilation
     if (ANDROID_ARCH_NAME STREQUAL "arm64")
       set(CUDA_TOOLKIT_TARGET_NAME "aarch64-linux-androideabi")
+    elseif (CMAKE_SYSTEM_NAME STREQUAL "QNX")
+      set(CUDA_TOOLKIT_TARGET_NAME "aarch64-qnx")
     else()
       set(CUDA_TOOLKIT_TARGET_NAME "aarch64-linux")
     endif (ANDROID_ARCH_NAME STREQUAL "arm64")
@@ -902,7 +904,7 @@ if(CUDA_USE_STATIC_CUDA_RUNTIME)
     find_package(Threads REQUIRED)
     set(CMAKE_C_FLAGS ${_cuda_cmake_c_flags})
 
-    if(NOT APPLE)
+    if(NOT APPLE AND NOT (CMAKE_SYSTEM_NAME STREQUAL "QNX"))
       #On Linux, you must link against librt when using the static cuda runtime.
       find_library(CUDA_rt_LIBRARY rt)
       if (NOT CUDA_rt_LIBRARY)

Modules/FindCUDAToolkit.cmake

@@ -678,6 +678,8 @@ if(CMAKE_CROSSCOMPILING)
   elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "aarch64")
     if(ANDROID_ARCH_NAME STREQUAL "arm64")
       set(CUDAToolkit_TARGET_NAME "aarch64-linux-androideabi")
+    elseif (CMAKE_SYSTEM_NAME STREQUAL "QNX")
+      set(CUDAToolkit_TARGET_NAME "aarch64-qnx")
     else()
       set(CUDAToolkit_TARGET_NAME "aarch64-linux")
     endif(ANDROID_ARCH_NAME STREQUAL "arm64")
@@ -860,7 +862,7 @@ if(CUDAToolkit_FOUND)
       target_link_libraries(CUDA::cudart_static_deps INTERFACE Threads::Threads ${CMAKE_DL_LIBS})
     endif()
 
-    if(UNIX AND NOT APPLE)
+    if(UNIX AND NOT APPLE AND NOT (CMAKE_SYSTEM_NAME STREQUAL "QNX"))
       # On Linux, you must link against librt when using the static cuda runtime.
       find_library(CUDAToolkit_rt_LIBRARY rt)
       mark_as_advanced(CUDAToolkit_rt_LIBRARY)