c++.gni - mozsearch

# Copyright 2017 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("//chromium/build/config/chromeos/ui_mode.gni")

import("//chromium/build/config/sanitizers/sanitizers.gni")

declare_args() {

  # Use in-tree libc++ (buildtools/third_party/libc++ and

  # buildtools/third_party/libc++abi) instead of the system C++ library for C++

  # standard library support.

  # Don't check in changes that set this to false for more platforms; doing so

  # is not supported.

  use_custom_libcxx =

      is_fuchsia || is_android || is_mac || is_linux || is_chromeos_lacros ||

      (is_ios && !use_xcode_clang) || (is_win && is_clang) ||

      (is_chromeos && default_toolchain != "//chromium/build/toolchain/cros:target")

  # Use libc++ instead of stdlibc++ when using the host_cpu toolchain, even if

  # use_custom_libcxx is false. This is useful for cross-compiles where a custom

  # toolchain for the target_cpu has been set as the default toolchain, but

  # use_custom_libcxx should still be true when building for the host.  The

  # expected usage is to set use_custom_libcxx=false and

  # use_custom_libcxx_for_host=true in the passed in buildargs.

  use_custom_libcxx_for_host = false

  # Builds libcxx Natvis into the symbols for type visualization.

  # Set to false to workaround http://crbug.com/966676 and

  # http://crbug.com/966687.

  libcxx_natvis_include = true

  # When set, enables libc++ debug mode with iterator debugging.

  # Iterator debugging is generally useful for catching bugs. But it can

  # introduce extra locking to check the state of an iterator against the state

  # of the current object. For iterator- and thread-heavy code, this can

  # significantly slow execution - two orders of magnitude slowdown has been

  # seen (crbug.com/903553) and iterator debugging also slows builds by making

  # generation of snapshot_blob.bin take ~40-60 s longer. Therefore this

  # defaults to off.

  enable_iterator_debugging = false

use_custom_libcxx =

    use_custom_libcxx || (use_custom_libcxx_for_host && !is_a_target_toolchain)

use_custom_libcxx = use_custom_libcxx && !is_nacl

declare_args() {

  # WARNING: Setting this to a non-default value is highly discouraged.

  # If true, libc++ will be built as a shared library; otherwise libc++ will be

  # linked statically. Setting this to something other than the default is

  # unsupported and can be broken by libc++ rolls. Note that if this is set to

  # true, you must also set libcxx_abi_unstable=false, which is bad for

  # performance and memory use.

  libcxx_is_shared = use_custom_libcxx && is_component_build

# libc++abi needs to be exported from executables to be picked up by shared

# libraries on certain instrumented builds.

export_libcxxabi_from_executables =

    use_custom_libcxx && !is_apple && !is_win && !is_component_build &&

    (is_asan || is_ubsan_vptr)

# On Android, many shared libraries get loaded from the context of a JRE.  In

# this case, there's no "main executable" to export libc++abi from.  We could

# export libc++abi from each "toplevel" shared library instead, but that would

# require adding an explicit dependency for each one, and might introduce

# subtle, hard-to-fix problems down the line if the dependency is missing.

# export_libcxxabi_from_executables was added to avoid having an RPATH set in

# static sanitizer builds just for executables to find libc++.  But on Android,

# the Bionic dynamic loader doesn't even look at RPATH; instead, LD_LIBRARY_PATH

# is set for tests. Because of this, we make libc++ a shared library on android

# since it should get loaded properly.

if (is_android && export_libcxxabi_from_executables) {

  export_libcxxabi_from_executables = false

  libcxx_is_shared = true

libcxx_prefix = "//buildtools/third_party/libc++/trunk"

libcxxabi_prefix = "//buildtools/third_party/libc++abi/trunk"