text: // util header file
  //
  // Copyright 2017 Google Inc.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #include <stdlib.h>  // for size_t
  
  // Declare it - we'll either use ours or whatever autoconf found.
  // Including <bsd/string.h> would maybe be nicer, but it doesn't seem to
  // actually define this symbol unless we set _GNU_SOURCE.
  void explicit_bzero(void *s, size_t len);
  