# Copyright 2015 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build/config/chrome_build.gni")

declare_args() {
  # Compile for Address Sanitizer to find memory bugs.
  is_asan = false

  # Compile for Leak Sanitizer to find leaks.
  is_lsan = false

  # Compile for Memory Sanitizer to find uninitialized reads.
  is_msan = false

  # Compile for Thread Sanitizer to find threading bugs.
  is_tsan = false

  # Compile for Undefined Behaviour Sanitizer to find various types of
  # undefined behaviour (excludes vptr checks).
  is_ubsan = false

  # Compile for Undefined Behaviour Sanitizer's vptr checks.
  is_ubsan_vptr = false

  # Track where uninitialized memory originates from. From fastest to slowest:
  # 0 - no tracking, 1 - track only the initial allocation site, 2 - track the
  # chain of stores leading from allocation site to use site.
  msan_track_origins = 2

  # Use dynamic libraries instrumented by one of the sanitizers instead of the
  # standard system libraries. Set this flag to download prebuilt binaries from
  # GCS.
  use_prebuilt_instrumented_libraries = false

  # Enable building with SyzyAsan which can find certain types of memory
  # errors. Only works on Windows. See
  # https://code.google.com/p/sawbuck/wiki/SyzyASanHowTo
  is_syzyasan = false

  # By default, Control Flow Integrity will crash the program if it detects a
  # violation. Set this to true to print detailed diagnostics instead.
  use_cfi_diag = false

  # Compile for fuzzing with LLVM LibFuzzer.
  # See http://www.chromium.org/developers/testing/libfuzzer
  use_libfuzzer = false
}

# Args that are in turn dependent on other args must be in a separate
# declare_args block. User overrides are only applied at the end of a
# declare_args block.
declare_args() {
  # Compile with Control Flow Integrity to protect virtual calls and casts.
  # See http://clang.llvm.org/docs/ControlFlowIntegrity.html
  is_cfi = is_linux && !is_chromeos && target_cpu == "x64" &&
           is_chrome_branded && is_official_build

  # Use libc++ (buildtools/third_party/libc++ and
  # buildtools/third_party/libc++abi) instead of stdlibc++ as standard library.
  # This is intended to be used for instrumented builds.
  use_custom_libcxx =
      (is_asan && is_linux) || is_tsan || is_msan || is_ubsan || use_libfuzzer

  use_sanitizer_coverage = use_libfuzzer
}

using_sanitizer =
    is_asan || is_lsan || is_tsan || is_msan || is_ubsan || is_ubsan_vptr

assert(!using_sanitizer || is_clang,
       "Sanitizers (is_*san) require setting is_clang = true in 'gn args'")

# MSan only links Chrome properly in release builds (brettw -- 9/1/2015). The
# same is possibly true for the other non-ASan sanitizers. But regardless of
# whether it links, one would normally never run a sanitizer in debug mode.
# Running in debug mode probably indicates you forgot to set the "is_debug =
# false" flag in the build args. ASan seems to run fine in debug mode.
#
# If you find a use-case where you want to compile a sanitizer in debug mode
# and have verified it works, ask brettw and we can consider removing it from
# this condition. We may also be able to find another way to enable your case
# without having people accidentally get broken builds by compiling an
# unsupported or unadvisable configurations.
#
# For one-off testing, just comment this assertion out.
assert(
    !is_debug || !(is_msan || is_lsan || is_tsan || is_ubsan || is_ubsan_vptr),
    "Sanitizers should generally be used in release (set is_debug=false).")

assert(!(is_android && is_asan && !is_component_build),
       "is_asan on Android requires is_component_build to be set")