Add validation layer support for nullptr events (#929)

This commit adds checks in the validation layer for the case where
the event wait list parameter in urEnqueue entrypoints contains a
nullptr event.

Author: fabiomestre

scripts/templates/helper.py

@@ -1328,3 +1328,14 @@ def get_create_retain_release_functions(specs, namespace, tags):
     )
 
     return {"create": create_funcs, "retain": retain_funcs, "release": release_funcs}
+
+
+def get_event_wait_list_functions(specs, namespace, tags):
+    funcs = []
+    for s in specs:
+        for obj in s['objects']:
+            if re.match(r"function", obj['type']):
+                if any(x['name'] == 'phEventWaitList' for x in obj['params']) and any(
+                        x['name'] == 'numEventsInWaitList' for x in obj['params']):
+                    funcs.append(make_func_name(namespace, tags, obj))
+    return funcs

scripts/templates/valddi.cpp.mako

@@ -60,6 +60,16 @@ namespace ur_validation_layer
 
             %endfor
             %endfor
+            %if func_name in th.get_event_wait_list_functions(specs, n, tags):
+            if (phEventWaitList != NULL && numEventsInWaitList > 0) {
+                for (uint32_t i = 0; i < numEventsInWaitList; ++i) {
+                    if (phEventWaitList[i] == NULL) {
+                        return UR_RESULT_ERROR_INVALID_EVENT_WAIT_LIST;
+                    }
+                }
+            }
+            %endif
+
         }
 
         ${x}_result_t result = ${th.make_pfn_name(n, tags, obj)}( ${", ".join(th.make_param_lines(n, tags, obj, format=["name"]))} );