CUDA: get header deps from compiler invocation when possible

Before CUDA 10.2 `nvcc` didn't support providing header dependency
information while compiling.

Modules/CMakeCUDAInformation.cmake

@@ -148,11 +148,11 @@ if(NOT CMAKE_CUDA_COMPILE_WHOLE_COMPILATION)
     "<CMAKE_CUDA_COMPILER> ${_CMAKE_CUDA_EXTRA_FLAGS} <DEFINES> <INCLUDES> <FLAGS> -x cu -c <SOURCE> -o <OBJECT>")
 endif()
 
-if(CMAKE_GENERATOR STREQUAL "Ninja")
+if(CMAKE_GENERATOR STREQUAL "Ninja" AND NOT CMAKE_DEPFILE_FLAGS_CUDA )
   set(CMAKE_CUDA_COMPILE_DEPENDENCY_DETECTION
     "<CMAKE_CUDA_COMPILER> ${_CMAKE_CUDA_EXTRA_FLAGS} <DEFINES> <INCLUDES> <FLAGS> -x cu -M <SOURCE> -MT <OBJECT> -o $DEP_FILE")
   #The Ninja generator uses the make file dependency files to determine what
-  #files need to be recompiled. Unfortunately, nvcc doesn't support building
+  #files need to be recompiled. Unfortunately, nvcc < 10.2 doesn't support building
   #a source file and generating the dependencies of said file in a single
   #invocation. Instead we have to state that you need to chain two commands.
   #

Modules/Compiler/NVIDIA-CUDA.cmake

@@ -18,6 +18,13 @@ else()
   set(_CMAKE_CUDA_EXTRA_DEVICE_LINK_FLAGS "")
 endif()
 
+if (NOT CMAKE_CUDA_COMPILER_VERSION VERSION_LESS 10.2)
+  # The -MD flag was only added to nvcc in 10.2 so
+  # before that we had to invoke the compiler twice
+  # to get header dependency information
+  set(CMAKE_DEPFILE_FLAGS_CUDA "-MD -MT <OBJECT> -MF <DEPFILE>")
+endif()
+
 if(NOT "x${CMAKE_CUDA_SIMULATE_ID}" STREQUAL "xMSVC")
   set(CMAKE_CUDA_COMPILE_OPTIONS_PIE -Xcompiler=-fPIE)
   set(CMAKE_CUDA_COMPILE_OPTIONS_PIC -Xcompiler=-fPIC)