| # 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("//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_ios || |
| (is_linux && |
| (!is_chromeos || default_toolchain != "//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 |
| } |
| |
| use_custom_libcxx = |
| use_custom_libcxx || (use_custom_libcxx_for_host && current_cpu == host_cpu) |
| 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_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" |