Merge master

7 files changed, 106 insertions, 106 deletions

diff --git a/src/core/lib/transport/connectivity_state.cc b/src/core/lib/transport/connectivity_state.cc
index 0da9165b8d..51ee20d7b0 100644
--- a/src/core/lib/transport/connectivity_state.cc
+++ b/src/core/lib/transport/connectivity_state.cc
@@ -48,7 +48,7 @@ void grpc_connectivity_state_init(grpc_connectivity_state_tracker* tracker,
                                   const char* name) {
   gpr_atm_no_barrier_store(&tracker->current_state_atm, init_state);
   tracker->current_error = GRPC_ERROR_NONE;
-  tracker->watchers = NULL;
+  tracker->watchers = nullptr;
   tracker->name = gpr_strdup(name);
 }
 
@@ -93,7 +93,7 @@ grpc_connectivity_state grpc_connectivity_state_get(
     gpr_log(GPR_DEBUG, "CONWATCH: %p %s: get %s", tracker, tracker->name,
             grpc_connectivity_state_name(cur));
   }
-  if (error != NULL) {
+  if (error != nullptr) {
     *error = GRPC_ERROR_REF(tracker->current_error);
   }
   return cur;
@@ -101,7 +101,7 @@ grpc_connectivity_state grpc_connectivity_state_get(
 
 bool grpc_connectivity_state_has_watchers(
     grpc_connectivity_state_tracker* connectivity_state) {
-  return connectivity_state->watchers != NULL;
+  return connectivity_state->watchers != nullptr;
 }
 
 bool grpc_connectivity_state_notify_on_state_change(
@@ -111,7 +111,7 @@ bool grpc_connectivity_state_notify_on_state_change(
       (grpc_connectivity_state)gpr_atm_no_barrier_load(
           &tracker->current_state_atm);
   if (GRPC_TRACER_ON(grpc_connectivity_state_trace)) {
-    if (current == NULL) {
+    if (current == nullptr) {
       gpr_log(GPR_DEBUG, "CONWATCH: %p %s: unsubscribe notify=%p", tracker,
               tracker->name, notify);
     } else {
@@ -120,17 +120,17 @@ bool grpc_connectivity_state_notify_on_state_change(
               grpc_connectivity_state_name(cur), notify);
     }
   }
-  if (current == NULL) {
+  if (current == nullptr) {
     grpc_connectivity_state_watcher* w = tracker->watchers;
-    if (w != NULL && w->notify == notify) {
+    if (w != nullptr && w->notify == notify) {
       GRPC_CLOSURE_SCHED(notify, GRPC_ERROR_CANCELLED);
       tracker->watchers = w->next;
       gpr_free(w);
       return false;
     }
-    while (w != NULL) {
+    while (w != nullptr) {
       grpc_connectivity_state_watcher* rm_candidate = w->next;
-      if (rm_candidate != NULL && rm_candidate->notify == notify) {
+      if (rm_candidate != nullptr && rm_candidate->notify == notify) {
         GRPC_CLOSURE_SCHED(notify, GRPC_ERROR_CANCELLED);
         w->next = w->next->next;
         gpr_free(rm_candidate);
@@ -186,7 +186,7 @@ void grpc_connectivity_state_set(grpc_connectivity_state_tracker* tracker,
   }
   GPR_ASSERT(cur != GRPC_CHANNEL_SHUTDOWN);
   gpr_atm_no_barrier_store(&tracker->current_state_atm, state);
-  while ((w = tracker->watchers) != NULL) {
+  while ((w = tracker->watchers) != nullptr) {
     *w->current = state;
     tracker->watchers = w->next;
     if (GRPC_TRACER_ON(grpc_connectivity_state_trace)) {
diff --git a/src/core/lib/transport/error_utils.cc b/src/core/lib/transport/error_utils.cc
index eb7cf192d8..2db87b5d29 100644
--- a/src/core/lib/transport/error_utils.cc
+++ b/src/core/lib/transport/error_utils.cc
@@ -24,10 +24,10 @@
 static grpc_error* recursively_find_error_with_field(grpc_error* error,
                                                      grpc_error_ints which) {
   // If the error itself has a status code, return it.
-  if (grpc_error_get_int(error, which, NULL)) {
+  if (grpc_error_get_int(error, which, nullptr)) {
     return error;
   }
-  if (grpc_error_is_special(error)) return NULL;
+  if (grpc_error_is_special(error)) return nullptr;
   // Otherwise, search through its children.
   uint8_t slot = error->first_err;
   while (slot != UINT8_MAX) {
@@ -36,7 +36,7 @@ static grpc_error* recursively_find_error_with_field(grpc_error* error,
     if (result) return result;
     slot = lerr->next;
   }
-  return NULL;
+  return nullptr;
 }
 
 void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
@@ -46,7 +46,7 @@ void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
   // until we find the first one that has a status code.
   grpc_error* found_error =
       recursively_find_error_with_field(error, GRPC_ERROR_INT_GRPC_STATUS);
-  if (found_error == NULL) {
+  if (found_error == nullptr) {
     /// If no grpc-status exists, retry through the tree to find a http2 error
     /// code
     found_error =
@@ -55,7 +55,7 @@ void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
 
   // If we found an error with a status code above, use that; otherwise,
   // fall back to using the parent error.
-  if (found_error == NULL) found_error = error;
+  if (found_error == nullptr) found_error = error;
 
   grpc_status_code status = GRPC_STATUS_UNKNOWN;
   intptr_t integer;
@@ -66,9 +66,9 @@ void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
     status = grpc_http2_error_to_grpc_status((grpc_http2_error_code)integer,
                                              deadline);
   }
-  if (code != NULL) *code = status;
+  if (code != nullptr) *code = status;
 
-  if (http_error != NULL) {
+  if (http_error != nullptr) {
     if (grpc_error_get_int(found_error, GRPC_ERROR_INT_HTTP2_ERROR, &integer)) {
       *http_error = (grpc_http2_error_code)integer;
     } else if (grpc_error_get_int(found_error, GRPC_ERROR_INT_GRPC_STATUS,
@@ -82,19 +82,17 @@ void grpc_error_get_status(grpc_error* error, grpc_millis deadline,
 
   // If the error has a status message, use it.  Otherwise, fall back to
   // the error description.
-  if (slice != NULL) {
+  if (slice != nullptr) {
     if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_GRPC_MESSAGE, slice)) {
       if (!grpc_error_get_str(found_error, GRPC_ERROR_STR_DESCRIPTION, slice)) {
         *slice = grpc_slice_from_static_string("unknown error");
       }
     }
   }
-
-  if (found_error == NULL) found_error = error;
 }
 
 bool grpc_error_has_clear_grpc_status(grpc_error* error) {
-  if (grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, NULL)) {
+  if (grpc_error_get_int(error, GRPC_ERROR_INT_GRPC_STATUS, nullptr)) {
     return true;
   }
   uint8_t slot = error->first_err;
diff --git a/src/core/lib/transport/metadata.cc b/src/core/lib/transport/metadata.cc
index 1522e789fc..7596afa59b 100644
--- a/src/core/lib/transport/metadata.cc
+++ b/src/core/lib/transport/metadata.cc
@@ -241,7 +241,7 @@ grpc_mdelem grpc_mdelem_create(
     grpc_slice key, grpc_slice value,
     grpc_mdelem_data* compatible_external_backing_store) {
   if (!grpc_slice_is_interned(key) || !grpc_slice_is_interned(value)) {
-    if (compatible_external_backing_store != NULL) {
+    if (compatible_external_backing_store != nullptr) {
       return GRPC_MAKE_MDELEM(compatible_external_backing_store,
                               GRPC_MDELEM_STORAGE_EXTERNAL);
     }
@@ -329,7 +329,7 @@ grpc_mdelem grpc_mdelem_create(
 }
 
 grpc_mdelem grpc_mdelem_from_slices(grpc_slice key, grpc_slice value) {
-  grpc_mdelem out = grpc_mdelem_create(key, value, NULL);
+  grpc_mdelem out = grpc_mdelem_create(key, value, nullptr);
   grpc_slice_unref_internal(key);
   grpc_slice_unref_internal(value);
   return out;
@@ -342,7 +342,7 @@ grpc_mdelem grpc_mdelem_from_grpc_metadata(grpc_metadata* metadata) {
   grpc_slice value_slice =
       grpc_slice_maybe_static_intern(metadata->value, &changed);
   return grpc_mdelem_create(key_slice, value_slice,
-                            changed ? NULL : (grpc_mdelem_data*)metadata);
+                            changed ? nullptr : (grpc_mdelem_data*)metadata);
 }
 
 static size_t get_base64_encoded_size(size_t raw_length) {
@@ -476,7 +476,7 @@ void* grpc_mdelem_get_user_data(grpc_mdelem md, void (*destroy_func)(void*)) {
   switch (GRPC_MDELEM_STORAGE(md)) {
     case GRPC_MDELEM_STORAGE_EXTERNAL:
     case GRPC_MDELEM_STORAGE_ALLOCATED:
-      return NULL;
+      return nullptr;
     case GRPC_MDELEM_STORAGE_STATIC:
       return (void*)grpc_static_mdelem_user_data[GRPC_MDELEM_DATA(md) -
                                                  grpc_static_mdelem_table];
@@ -486,12 +486,12 @@ void* grpc_mdelem_get_user_data(grpc_mdelem md, void (*destroy_func)(void*)) {
       if (gpr_atm_acq_load(&im->destroy_user_data) == (gpr_atm)destroy_func) {
         return (void*)gpr_atm_no_barrier_load(&im->user_data);
       } else {
-        return NULL;
+        return nullptr;
       }
       return result;
     }
   }
-  GPR_UNREACHABLE_CODE(return NULL);
+  GPR_UNREACHABLE_CODE(return nullptr);
 }
 
 void* grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void*),
@@ -500,7 +500,7 @@ void* grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void*),
     case GRPC_MDELEM_STORAGE_EXTERNAL:
     case GRPC_MDELEM_STORAGE_ALLOCATED:
       destroy_func(user_data);
-      return NULL;
+      return nullptr;
     case GRPC_MDELEM_STORAGE_STATIC:
       destroy_func(user_data);
       return (void*)grpc_static_mdelem_user_data[GRPC_MDELEM_DATA(md) -
@@ -508,12 +508,12 @@ void* grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void*),
     case GRPC_MDELEM_STORAGE_INTERNED: {
       interned_metadata* im = (interned_metadata*)GRPC_MDELEM_DATA(md);
       GPR_ASSERT(!is_mdelem_static(md));
-      GPR_ASSERT((user_data == NULL) == (destroy_func == NULL));
+      GPR_ASSERT((user_data == nullptr) == (destroy_func == nullptr));
       gpr_mu_lock(&im->mu_user_data);
       if (gpr_atm_no_barrier_load(&im->destroy_user_data)) {
         /* user data can only be set once */
         gpr_mu_unlock(&im->mu_user_data);
-        if (destroy_func != NULL) {
+        if (destroy_func != nullptr) {
           destroy_func(user_data);
         }
         return (void*)gpr_atm_no_barrier_load(&im->user_data);
@@ -524,7 +524,7 @@ void* grpc_mdelem_set_user_data(grpc_mdelem md, void (*destroy_func)(void*),
       return user_data;
     }
   }
-  GPR_UNREACHABLE_CODE(return NULL);
+  GPR_UNREACHABLE_CODE(return nullptr);
 }
 
 bool grpc_mdelem_eq(grpc_mdelem a, grpc_mdelem b) {
diff --git a/src/core/lib/transport/metadata_batch.cc b/src/core/lib/transport/metadata_batch.cc
index 85f1409a1e..9c95339ba0 100644
--- a/src/core/lib/transport/metadata_batch.cc
+++ b/src/core/lib/transport/metadata_batch.cc
@@ -32,17 +32,17 @@ static void assert_valid_list(grpc_mdelem_list* list) {
 #ifndef NDEBUG
   grpc_linked_mdelem* l;
 
-  GPR_ASSERT((list->head == NULL) == (list->tail == NULL));
+  GPR_ASSERT((list->head == nullptr) == (list->tail == nullptr));
   if (!list->head) return;
-  GPR_ASSERT(list->head->prev == NULL);
-  GPR_ASSERT(list->tail->next == NULL);
-  GPR_ASSERT((list->head == list->tail) == (list->head->next == NULL));
+  GPR_ASSERT(list->head->prev == nullptr);
+  GPR_ASSERT(list->tail->next == nullptr);
+  GPR_ASSERT((list->head == list->tail) == (list->head->next == nullptr));
 
   size_t verified_count = 0;
   for (l = list->head; l; l = l->next) {
     GPR_ASSERT(!GRPC_MDISNULL(l->md));
-    GPR_ASSERT((l->prev == NULL) == (l == list->head));
-    GPR_ASSERT((l->next == NULL) == (l == list->tail));
+    GPR_ASSERT((l->prev == nullptr) == (l == list->head));
+    GPR_ASSERT((l->next == nullptr) == (l == list->tail));
     if (l->next) GPR_ASSERT(l->next->prev == l);
     if (l->prev) GPR_ASSERT(l->prev->next == l);
     verified_count++;
@@ -53,7 +53,7 @@ static void assert_valid_list(grpc_mdelem_list* list) {
 
 static void assert_valid_callouts(grpc_metadata_batch* batch) {
 #ifndef NDEBUG
-  for (grpc_linked_mdelem* l = batch->list.head; l != NULL; l = l->next) {
+  for (grpc_linked_mdelem* l = batch->list.head; l != nullptr; l = l->next) {
     grpc_slice key_interned = grpc_slice_intern(GRPC_MDKEY(l->md));
     grpc_metadata_batch_callouts_index callout_idx =
         GRPC_BATCH_INDEX_OF(key_interned);
@@ -102,7 +102,7 @@ static grpc_error* maybe_link_callout(grpc_metadata_batch* batch,
   if (idx == GRPC_BATCH_CALLOUTS_COUNT) {
     return GRPC_ERROR_NONE;
   }
-  if (batch->idx.array[idx] == NULL) {
+  if (batch->idx.array[idx] == nullptr) {
     if (grpc_static_callout_is_default[idx]) ++batch->list.default_count;
     batch->idx.array[idx] = storage;
     return GRPC_ERROR_NONE;
@@ -120,8 +120,8 @@ static void maybe_unlink_callout(grpc_metadata_batch* batch,
     return;
   }
   if (grpc_static_callout_is_default[idx]) --batch->list.default_count;
-  GPR_ASSERT(batch->idx.array[idx] != NULL);
-  batch->idx.array[idx] = NULL;
+  GPR_ASSERT(batch->idx.array[idx] != nullptr);
+  batch->idx.array[idx] = nullptr;
 }
 
 grpc_error* grpc_metadata_batch_add_head(grpc_metadata_batch* batch,
@@ -135,9 +135,9 @@ grpc_error* grpc_metadata_batch_add_head(grpc_metadata_batch* batch,
 static void link_head(grpc_mdelem_list* list, grpc_linked_mdelem* storage) {
   assert_valid_list(list);
   GPR_ASSERT(!GRPC_MDISNULL(storage->md));
-  storage->prev = NULL;
+  storage->prev = nullptr;
   storage->next = list->head;
-  if (list->head != NULL) {
+  if (list->head != nullptr) {
     list->head->prev = storage;
   } else {
     list->tail = storage;
@@ -172,9 +172,9 @@ static void link_tail(grpc_mdelem_list* list, grpc_linked_mdelem* storage) {
   assert_valid_list(list);
   GPR_ASSERT(!GRPC_MDISNULL(storage->md));
   storage->prev = list->tail;
-  storage->next = NULL;
-  storage->reserved = NULL;
-  if (list->tail != NULL) {
+  storage->next = nullptr;
+  storage->reserved = nullptr;
+  if (list->tail != nullptr) {
     list->tail->next = storage;
   } else {
     list->head = storage;
@@ -200,12 +200,12 @@ grpc_error* grpc_metadata_batch_link_tail(grpc_metadata_batch* batch,
 static void unlink_storage(grpc_mdelem_list* list,
                            grpc_linked_mdelem* storage) {
   assert_valid_list(list);
-  if (storage->prev != NULL) {
+  if (storage->prev != nullptr) {
     storage->prev->next = storage->next;
   } else {
     list->head = storage->next;
   }
-  if (storage->next != NULL) {
+  if (storage->next != nullptr) {
     storage->next->prev = storage->prev;
   } else {
     list->tail = storage->prev;
@@ -260,12 +260,13 @@ void grpc_metadata_batch_clear(grpc_metadata_batch* batch) {
 }
 
 bool grpc_metadata_batch_is_empty(grpc_metadata_batch* batch) {
-  return batch->list.head == NULL && batch->deadline == GRPC_MILLIS_INF_FUTURE;
+  return batch->list.head == nullptr &&
+         batch->deadline == GRPC_MILLIS_INF_FUTURE;
 }
 
 size_t grpc_metadata_batch_size(grpc_metadata_batch* batch) {
   size_t size = 0;
-  for (grpc_linked_mdelem* elem = batch->list.head; elem != NULL;
+  for (grpc_linked_mdelem* elem = batch->list.head; elem != nullptr;
        elem = elem->next) {
     size += GRPC_MDELEM_LENGTH(elem->md);
   }
diff --git a/src/core/lib/transport/service_config.cc b/src/core/lib/transport/service_config.cc
index 60b70a5f91..cbafc33840 100644
--- a/src/core/lib/transport/service_config.cc
+++ b/src/core/lib/transport/service_config.cc
@@ -64,11 +64,11 @@ grpc_service_config* grpc_service_config_create(const char* json_string) {
   service_config->json_string = gpr_strdup(json_string);
   service_config->json_tree =
       grpc_json_parse_string(service_config->json_string);
-  if (service_config->json_tree == NULL) {
+  if (service_config->json_tree == nullptr) {
     gpr_log(GPR_INFO, "failed to parse JSON for service config");
     gpr_free(service_config->json_string);
     gpr_free(service_config);
-    return NULL;
+    return nullptr;
   }
   return service_config;
 }
@@ -83,9 +83,9 @@ void grpc_service_config_parse_global_params(
     const grpc_service_config* service_config,
     void (*process_json)(const grpc_json* json, void* arg), void* arg) {
   const grpc_json* json = service_config->json_tree;
-  if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return;
-  for (grpc_json* field = json->child; field != NULL; field = field->next) {
-    if (field->key == NULL) return;
+  if (json->type != GRPC_JSON_OBJECT || json->key != nullptr) return;
+  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
+    if (field->key == nullptr) return;
     if (strcmp(field->key, "methodConfig") == 0) continue;
     process_json(field, arg);
   }
@@ -94,13 +94,13 @@ void grpc_service_config_parse_global_params(
 const char* grpc_service_config_get_lb_policy_name(
     const grpc_service_config* service_config) {
   const grpc_json* json = service_config->json_tree;
-  if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return NULL;
-  const char* lb_policy_name = NULL;
-  for (grpc_json* field = json->child; field != NULL; field = field->next) {
-    if (field->key == NULL) return NULL;
+  if (json->type != GRPC_JSON_OBJECT || json->key != nullptr) return nullptr;
+  const char* lb_policy_name = nullptr;
+  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
+    if (field->key == nullptr) return nullptr;
     if (strcmp(field->key, "loadBalancingPolicy") == 0) {
-      if (lb_policy_name != NULL) return NULL;  // Duplicate.
-      if (field->type != GRPC_JSON_STRING) return NULL;
+      if (lb_policy_name != nullptr) return nullptr;  // Duplicate.
+      if (field->type != GRPC_JSON_STRING) return nullptr;
       lb_policy_name = field->value;
     }
   }
@@ -110,10 +110,10 @@ const char* grpc_service_config_get_lb_policy_name(
 // Returns the number of names specified in the method config \a json.
 static size_t count_names_in_method_config_json(grpc_json* json) {
   size_t num_names = 0;
-  for (grpc_json* field = json->child; field != NULL; field = field->next) {
-    if (field->key != NULL && strcmp(field->key, "name") == 0) {
+  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
+    if (field->key != nullptr && strcmp(field->key, "name") == 0) {
       if (field->type != GRPC_JSON_ARRAY) return -1;
-      for (grpc_json* name = field->child; name != NULL; name = name->next) {
+      for (grpc_json* name = field->child; name != nullptr; name = name->next) {
         if (name->type != GRPC_JSON_OBJECT) return -1;
         ++num_names;
       }
@@ -125,26 +125,26 @@ static size_t count_names_in_method_config_json(grpc_json* json) {
 // Returns a path string for the JSON name object specified by \a json.
 // Returns NULL on error.  Caller takes ownership of result.
 static char* parse_json_method_name(grpc_json* json) {
-  if (json->type != GRPC_JSON_OBJECT) return NULL;
-  const char* service_name = NULL;
-  const char* method_name = NULL;
-  for (grpc_json* child = json->child; child != NULL; child = child->next) {
-    if (child->key == NULL) return NULL;
-    if (child->type != GRPC_JSON_STRING) return NULL;
+  if (json->type != GRPC_JSON_OBJECT) return nullptr;
+  const char* service_name = nullptr;
+  const char* method_name = nullptr;
+  for (grpc_json* child = json->child; child != nullptr; child = child->next) {
+    if (child->key == nullptr) return nullptr;
+    if (child->type != GRPC_JSON_STRING) return nullptr;
     if (strcmp(child->key, "service") == 0) {
-      if (service_name != NULL) return NULL;  // Duplicate.
-      if (child->value == NULL) return NULL;
+      if (service_name != nullptr) return nullptr;  // Duplicate.
+      if (child->value == nullptr) return nullptr;
       service_name = child->value;
     } else if (strcmp(child->key, "method") == 0) {
-      if (method_name != NULL) return NULL;  // Duplicate.
-      if (child->value == NULL) return NULL;
+      if (method_name != nullptr) return nullptr;  // Duplicate.
+      if (child->value == nullptr) return nullptr;
       method_name = child->value;
     }
   }
-  if (service_name == NULL) return NULL;  // Required field.
+  if (service_name == nullptr) return nullptr;  // Required field.
   char* path;
   gpr_asprintf(&path, "/%s/%s", service_name,
-               method_name == NULL ? "*" : method_name);
+               method_name == nullptr ? "*" : method_name);
   return path;
 }
 
@@ -157,18 +157,18 @@ static bool parse_json_method_config(
     grpc_slice_hash_table_entry* entries, size_t* idx) {
   // Construct value.
   void* method_config = create_value(json);
-  if (method_config == NULL) return false;
+  if (method_config == nullptr) return false;
   // Construct list of paths.
   bool success = false;
   gpr_strvec paths;
   gpr_strvec_init(&paths);
-  for (grpc_json* child = json->child; child != NULL; child = child->next) {
-    if (child->key == NULL) continue;
+  for (grpc_json* child = json->child; child != nullptr; child = child->next) {
+    if (child->key == nullptr) continue;
     if (strcmp(child->key, "name") == 0) {
       if (child->type != GRPC_JSON_ARRAY) goto done;
-      for (grpc_json* name = child->child; name != NULL; name = name->next) {
+      for (grpc_json* name = child->child; name != nullptr; name = name->next) {
         char* path = parse_json_method_name(name);
-        if (path == NULL) goto done;
+        if (path == nullptr) goto done;
         gpr_strvec_add(&paths, path);
       }
     }
@@ -193,26 +193,26 @@ grpc_slice_hash_table* grpc_service_config_create_method_config_table(
     void* (*ref_value)(void* value), void (*unref_value)(void* value)) {
   const grpc_json* json = service_config->json_tree;
   // Traverse parsed JSON tree.
-  if (json->type != GRPC_JSON_OBJECT || json->key != NULL) return NULL;
+  if (json->type != GRPC_JSON_OBJECT || json->key != nullptr) return nullptr;
   size_t num_entries = 0;
-  grpc_slice_hash_table_entry* entries = NULL;
-  for (grpc_json* field = json->child; field != NULL; field = field->next) {
-    if (field->key == NULL) return NULL;
+  grpc_slice_hash_table_entry* entries = nullptr;
+  for (grpc_json* field = json->child; field != nullptr; field = field->next) {
+    if (field->key == nullptr) return nullptr;
     if (strcmp(field->key, "methodConfig") == 0) {
-      if (entries != NULL) return NULL;  // Duplicate.
-      if (field->type != GRPC_JSON_ARRAY) return NULL;
+      if (entries != nullptr) return nullptr;  // Duplicate.
+      if (field->type != GRPC_JSON_ARRAY) return nullptr;
       // Find number of entries.
-      for (grpc_json* method = field->child; method != NULL;
+      for (grpc_json* method = field->child; method != nullptr;
            method = method->next) {
         size_t count = count_names_in_method_config_json(method);
-        if (count <= 0) return NULL;
+        if (count <= 0) return nullptr;
         num_entries += count;
       }
       // Populate method config table entries.
       entries = (grpc_slice_hash_table_entry*)gpr_malloc(
           num_entries * sizeof(grpc_slice_hash_table_entry));
       size_t idx = 0;
-      for (grpc_json* method = field->child; method != NULL;
+      for (grpc_json* method = field->child; method != nullptr;
            method = method->next) {
         if (!parse_json_method_config(method, create_value, ref_value,
                                       unref_value, entries, &idx)) {
@@ -221,17 +221,17 @@ grpc_slice_hash_table* grpc_service_config_create_method_config_table(
             unref_value(entries[i].value);
           }
           gpr_free(entries);
-          return NULL;
+          return nullptr;
         }
       }
       GPR_ASSERT(idx == num_entries);
     }
   }
   // Instantiate method config table.
-  grpc_slice_hash_table* method_config_table = NULL;
-  if (entries != NULL) {
-    method_config_table =
-        grpc_slice_hash_table_create(num_entries, entries, unref_value, NULL);
+  grpc_slice_hash_table* method_config_table = nullptr;
+  if (entries != nullptr) {
+    method_config_table = grpc_slice_hash_table_create(num_entries, entries,
+                                                       unref_value, nullptr);
     gpr_free(entries);
   }
   return method_config_table;
@@ -242,7 +242,7 @@ void* grpc_method_config_table_get(const grpc_slice_hash_table* table,
   void* value = grpc_slice_hash_table_get(table, path);
   // If we didn't find a match for the path, try looking for a wildcard
   // entry (i.e., change "/service/method" to "/service/*").
-  if (value == NULL) {
+  if (value == nullptr) {
     char* path_str = grpc_slice_to_c_string(path);
     const char* sep = strrchr(path_str, '/') + 1;
     const size_t len = (size_t)(sep - path_str);
diff --git a/src/core/lib/transport/transport.cc b/src/core/lib/transport/transport.cc
index ed2f02de55..d867123d6f 100644
--- a/src/core/lib/transport/transport.cc
+++ b/src/core/lib/transport/transport.cc
@@ -178,9 +178,10 @@ void grpc_transport_set_pops(grpc_transport* transport, grpc_stream* stream,
                              grpc_polling_entity* pollent) {
   grpc_pollset* pollset;
   grpc_pollset_set* pollset_set;
-  if ((pollset = grpc_polling_entity_pollset(pollent)) != NULL) {
+  if ((pollset = grpc_polling_entity_pollset(pollent)) != nullptr) {
     transport->vtable->set_pollset(transport, stream, pollset);
-  } else if ((pollset_set = grpc_polling_entity_pollset_set(pollent)) != NULL) {
+  } else if ((pollset_set = grpc_polling_entity_pollset_set(pollent)) !=
+             nullptr) {
     transport->vtable->set_pollset_set(transport, stream, pollset_set);
   } else {
     abort();
diff --git a/src/core/lib/transport/transport_op_string.cc b/src/core/lib/transport/transport_op_string.cc
index 24e74c10c5..e69ab02570 100644
--- a/src/core/lib/transport/transport_op_string.cc
+++ b/src/core/lib/transport/transport_op_string.cc
@@ -47,7 +47,7 @@ static void put_metadata(gpr_strvec* b, grpc_mdelem md) {
 
 static void put_metadata_list(gpr_strvec* b, grpc_metadata_batch md) {
   grpc_linked_mdelem* m;
-  for (m = md.list.head; m != NULL; m = m->next) {
+  for (m = md.list.head; m != nullptr; m = m->next) {
     if (m != md.list.head) gpr_strvec_add(b, gpr_strdup(", "));
     put_metadata(b, m->md);
   }
@@ -121,7 +121,7 @@ char* grpc_transport_stream_op_batch_string(
     gpr_strvec_add(&b, tmp);
   }
 
-  out = gpr_strvec_flatten(&b, NULL);
+  out = gpr_strvec_flatten(&b, nullptr);
   gpr_strvec_destroy(&b);
 
   return out;
@@ -135,10 +135,10 @@ char* grpc_transport_op_string(grpc_transport_op* op) {
   gpr_strvec b;
   gpr_strvec_init(&b);
 
-  if (op->on_connectivity_state_change != NULL) {
+  if (op->on_connectivity_state_change != nullptr) {
     if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
     first = false;
-    if (op->connectivity_state != NULL) {
+    if (op->connectivity_state != nullptr) {
       gpr_asprintf(&tmp, "ON_CONNECTIVITY_STATE_CHANGE:p=%p:from=%s",
                    op->on_connectivity_state_change,
                    grpc_connectivity_state_name(*op->connectivity_state));
@@ -175,25 +175,25 @@ char* grpc_transport_op_string(grpc_transport_op* op) {
     gpr_strvec_add(&b, tmp);
   }
 
-  if (op->bind_pollset != NULL) {
+  if (op->bind_pollset != nullptr) {
     if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
     first = false;
     gpr_strvec_add(&b, gpr_strdup("BIND_POLLSET"));
   }
 
-  if (op->bind_pollset_set != NULL) {
+  if (op->bind_pollset_set != nullptr) {
     if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
     first = false;
     gpr_strvec_add(&b, gpr_strdup("BIND_POLLSET_SET"));
   }
 
-  if (op->send_ping != NULL) {
+  if (op->send_ping != nullptr) {
     if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
-    first = false;
+    // first = false;
     gpr_strvec_add(&b, gpr_strdup("SEND_PING"));
   }
 
-  out = gpr_strvec_flatten(&b, NULL);
+  out = gpr_strvec_flatten(&b, nullptr);
   gpr_strvec_destroy(&b);
 
   return out;