CUDA: Add compiler detection for CUDA < 7.5

If the CUDA version macros are not defined, run `nvcc --version` and
extract the version from its output.

Fixes: #17920

Modules/CMakeDetermineCompilerId.cmake

@@ -52,6 +52,22 @@ function(CMAKE_DETERMINE_COMPILER_ID lang flagvar src)
     endforeach()
   endif()
 
+  # CUDA < 7.5 is missing version macros
+  if(lang STREQUAL "CUDA"
+     AND CMAKE_${lang}_COMPILER_ID STREQUAL "NVIDIA"
+     AND NOT CMAKE_${lang}_COMPILER_VERSION)
+    execute_process(
+      COMMAND "${CMAKE_${lang}_COMPILER}"
+      --version
+      OUTPUT_VARIABLE output ERROR_VARIABLE output
+      RESULT_VARIABLE result
+      TIMEOUT 10
+    )
+    if(output MATCHES [=[ V([0-9]+)\.([0-9]+)\.([0-9]+)]=])
+      set(CMAKE_${lang}_COMPILER_VERSION "${CMAKE_MATCH_1}.${CMAKE_MATCH_2}.${CMAKE_MATCH_3}")
+    endif()
+  endif()
+
   if (COMPILER_QNXNTO AND CMAKE_${lang}_COMPILER_ID STREQUAL "GNU")
     execute_process(
       COMMAND "${CMAKE_${lang}_COMPILER}"

Modules/Compiler/NVIDIA-DetermineCompiler.cmake

@@ -2,9 +2,11 @@
 set(_compiler_id_pp_test "defined(__NVCC__)")
 
 set(_compiler_id_version_compute "
-# define @PREFIX@COMPILER_VERSION_MAJOR @MACRO_DEC@(__CUDACC_VER_MAJOR__)
-# define @PREFIX@COMPILER_VERSION_MINOR @MACRO_DEC@(__CUDACC_VER_MINOR__)
-# define @PREFIX@COMPILER_VERSION_PATCH @MACRO_DEC@(__CUDACC_VER_BUILD__)
+# if defined(__CUDACC_VER_MAJOR__)
+#  define @PREFIX@COMPILER_VERSION_MAJOR @MACRO_DEC@(__CUDACC_VER_MAJOR__)
+#  define @PREFIX@COMPILER_VERSION_MINOR @MACRO_DEC@(__CUDACC_VER_MINOR__)
+#  define @PREFIX@COMPILER_VERSION_PATCH @MACRO_DEC@(__CUDACC_VER_BUILD__)
+# endif
 # if defined(_MSC_VER)
    /* _MSC_VER = VVRR */
 #  define @PREFIX@SIMULATE_VERSION_MAJOR @MACRO_DEC@(_MSC_VER / 100)