Address feedback

Author: boomanaiden154

llvm/cmake/modules/TableGen.cmake

@@ -22,10 +22,12 @@ function(tablegen project ofn)
   endif()
 
   # Use depfile instead of globbing arbitrary *.td(s) for Ninja.
-  if(CMAKE_GENERATOR MATCHES "Ninja")
+  cmake_policy(GET CMP0116 CMP0116_STATE)
+  if(CMAKE_GENERATOR MATCHES "Ninja" AND CMP0116_STATE STREQUAL NEW)
     # CMake emits build targets as relative paths but Ninja doesn't identify
     # absolute path (in *.d) as relative path (in build.ninja). Post CMP0116,
-    # CMake handles this discrepancy for us.
+    # CMake handles this discrepancy for us, otherwise we use the fallback
+    # logic.
     set(additional_cmdline
       -o ${ofn}
       -d ${ofn}.d

mlir/cmake/modules/AddMLIR.cmake

@@ -43,12 +43,12 @@ function(_pdll_tablegen project ofn)
   endif()
 
   # Use depfile instead of globbing arbitrary *.td(s) for Ninja.
-  if(CMAKE_GENERATOR MATCHES "Ninja")
-    # Make output path relative to build.ninja, assuming located on
-    # ${CMAKE_BINARY_DIR}.
+  cmake_policy(GET CMP0116 CMP0116_STATE)
+  if(CMAKE_GENERATOR MATCHES "Ninja" AND CMP0116_STATE STREQUAL NEW)
     # CMake emits build targets as relative paths but Ninja doesn't identify
     # absolute path (in *.d) as relative path (in build.ninja). Post CMP0116,
-    # CMake handles this discrepancy for us.
+    # CMake handles this discrepancy for us. Otherwise, we use the fallback
+    # logic.
     set(additional_cmdline
       -o ${ofn}
       -d ${ofn}.d