zircon/third_party/lib/jitterentropy/BUILD.gn

# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

library("jitterentropy") {
  kernel = true
  sources = [
    "jitterentropy-base.c",
  ]
  include_dirs = [ "arch/$zircon_cpu" ]

  # According to its documentation, jitterentropy must be compiled at
  # optimization level -O0.
  #
  # TODO(SEC-14): Test the code generated at various optimization
  # levels. If there is a significant difference in entropy quality,
  # replace the relevant C code by assembly code to protect against future
  # compiler changes.
  configs -= [ "$zx/public/gn/config:opt_level" ]
  configs += [ ":config" ]
}

config("config") {
  visibility = [ ":*" ]
  cflags = [
    "-O0",

    # The original Makefile also specifies -fwrapv.
    "-fwrapv",
  ]
}