blob: a363ab7ce7673c5a7d721664b75e952346a1f792 [file] [log] [blame]
# 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/c++/c++.gni")
import("//build/config/chrome_build.gni")
import("//build/config/clang/clang.gni")
import("//build/config/compiler/compiler.gni")
import("//build/config/sanitizers/sanitizers.gni")
import("//build/config/sysroot.gni")
import("//build/toolchain/toolchain.gni")
import("//buildtools/deps_revisions.gni")
# This build configuration is used by both Fuchsia and POSIX systems.
assert(is_posix || is_fuchsia)
group("posix") {
visibility = [ "//:optimize_gn_gen" ]
}
# This is included by reference in the //build/config/compiler:runtime_library
# config that is applied to all targets. It is here to separate out the logic
# that is Posix-only. Please see that target for advice on what should go in
# :runtime_library vs. :compiler.
config("runtime_library") {
asmflags = []
cflags = []
cflags_c = []
cflags_cc = []
cflags_objc = []
cflags_objcc = []
defines = []
ldflags = []
lib_dirs = []
libs = []
if (use_custom_libcxx) {
if (is_component_build) {
# In component builds, symbols from libc++.so are exported for all DSOs to
# use. If the system libc++ gets loaded (indirectly through a system
# library), then it will conflict with our libc++.so. Add a custom ABI
# version to avoid conflicts.
defines += [ "_LIBCPP_ABI_VERSION=Cr" ]
} else {
# Don't leak any symbols on a static build.
defines += [ "_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS" ]
if (!export_libcxxabi_from_executables) {
defines += [ "_LIBCXXABI_DISABLE_VISIBILITY_ANNOTATIONS" ]
}
}
cflags_cc += [
"-nostdinc++",
"-isystem" + rebase_path("$libcxx_prefix/include", root_build_dir),
"-isystem" + rebase_path("$libcxxabi_prefix/include", root_build_dir),
]
defines += [
"CR_LIBCXX_REVISION=$libcxx_svn_revision",
"CR_LIBCXXABI_REVISION=$libcxxabi_svn_revision",
"_LIBCPP_ENABLE_NODISCARD",
]
# TODO(xiaohuic): https://crbug/917533 Crashes on internal ChromeOS build.
# Do unconditionally once the underlying problem is fixed.
if (!(is_chromeos && is_chrome_branded)) {
defines += [ "_LIBCPP_ABI_UNSTABLE" ]
}
# Make sure we don't link against libc++ or libstdc++.
if (is_clang) {
# //build/config/android:runtime_library adds -nostdlib, which suppresses
# linking against all system libraries. -nostdlib++ would be redundant,
# and would generate an unused warning in this case.
if (!is_android) {
ldflags += [ "-nostdlib++" ]
}
} else {
# Gcc has a built-in abs() definition with default visibility.
# If it was not disabled, it would conflict with libc++'s abs()
# with hidden visibility.
cflags += [ "-fno-builtin-abs" ]
ldflags += [ "-nodefaultlibs" ]
# Unfortunately, there's no way to disable linking against just libc++
# (gcc doesn't have -notstdlib++:
# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83931); -nodefaultlibs
# removes all of the default libraries, so add back the ones that we need.
libs += [
"c",
"gcc_s",
"m",
"rt",
]
}
}
if (!is_mac && !is_ios && sysroot != "") {
# Pass the sysroot to all C compiler variants, the assembler, and linker.
sysroot_flags = [ "--sysroot=" + rebase_path(sysroot, root_build_dir) ]
if (is_linux) {
# This is here so that all files get recompiled after a sysroot roll and
# when turning the sysroot on or off. (defines are passed via the command
# line, and build system rebuilds things when their commandline
# changes). Nothing should ever read this define.
sysroot_hash =
exec_script("//build/linux/sysroot_scripts/install-sysroot.py",
[ "--print-hash=$current_cpu" ],
"trim string",
[ "//build/linux/sysroot_scripts/sysroots.json" ])
defines += [ "CR_SYSROOT_HASH=$sysroot_hash" ]
}
asmflags += sysroot_flags
link_sysroot_flags =
[ "--sysroot=" + rebase_path(link_sysroot, root_build_dir) ]
ldflags += link_sysroot_flags
# When use_custom_libcxx=true, some -isystem flags get passed to
# cflags_cc to set up libc++ include paths. We want to make sure
# the sysroot includes take lower precendence than the libc++
# ones, so they must appear later in the command line. However,
# the gn reference states "These variant-specific versions of
# cflags* will be appended on the compiler command line after
# 'cflags'." Because of this, we must set the sysroot flags for
# all cflags variants instead of using 'cflags' directly.
cflags_c += sysroot_flags
cflags_cc += sysroot_flags
cflags_objc += sysroot_flags
cflags_objcc += sysroot_flags
# Need to get some linker flags out of the sysroot.
ld_paths = exec_script("sysroot_ld_path.py",
[
rebase_path("//build/linux/sysroot_ld_path.sh",
root_build_dir),
rebase_path(link_sysroot),
],
"list lines")
foreach(ld_path, ld_paths) {
ld_path = rebase_path(ld_path, root_build_dir)
ldflags += [
"-L" + ld_path,
"-Wl,-rpath-link=" + ld_path,
]
}
}
}