blob: 572d7a8a45dc6d2a1eeead295523210ea0d966c2 [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/chrome_build.gni")
import("//build/config/chromecast_build.gni")
import("//build/config/chromeos/args.gni")
import("//build/config/chromeos/ui_mode.gni")
import("//build/config/compiler/pgo/pgo.gni")
import("//build/config/sanitizers/sanitizers.gni")
import("//build/toolchain/cc_wrapper.gni")
import("//build/toolchain/goma.gni")
import("//build/toolchain/toolchain.gni")
import("//build_overrides/build.gni")
if (is_android) {
import("//build/config/android/abi.gni")
}
if (current_cpu == "arm" || current_cpu == "arm64") {
import("//build/config/arm.gni")
}
if (is_apple) {
import("//build/config/apple/symbols.gni")
}
declare_args() {
# Default to warnings as errors for default workflow, where we catch
# warnings with known toolchains. Allow overriding this e.g. for Chromium
# builds on Linux that could use a different version of the compiler.
# With GCC, warnings in no-Chromium code are always not treated as errors.
treat_warnings_as_errors = true
# How many symbols to include in the build. This affects the performance of
# the build since the symbols are large and dealing with them is slow.
# 2 means regular build with symbols.
# 1 means minimal symbols, usually enough for backtraces only. Symbols with
# internal linkage (static functions or those in anonymous namespaces) may not
# appear when using this level.
# 0 means no symbols.
# -1 means auto-set according to debug/release and platform.
symbol_level = -1
# Android-only: Strip the debug info of libraries within lib.unstripped to
# reduce size. As long as symbol_level > 0, this will still allow stacks to be
# symbolized.
strip_debug_info = false
# Compile in such a way as to enable profiling of the generated code. For
# example, don't omit the frame pointer and leave in symbols.
enable_profiling = false
# use_debug_fission: whether to use split DWARF debug info
# files. This can reduce link time significantly, but is incompatible
# with some utilities such as icecc and ccache. Requires gold and
# gcc >= 4.8 or clang.
# http://gcc.gnu.org/wiki/DebugFission
#
# This is a placeholder value indicating that the code below should set
# the default. This is necessary to delay the evaluation of the default
# value expression until after its input values such as use_gold have
# been set, e.g. by a toolchain_args() block.
use_debug_fission = "default"
# Enables support for ThinLTO, which links 3x-10x faster than full LTO. See
# also http://blog.llvm.org/2016/06/thinlto-scalable-and-incremental-lto.html
# Use it by default on official-optimized android and Chrome OS builds, but
# not ARC or linux-chromeos since it's been seen to not play nicely with
# Chrome's clang. crbug.com/1033839
use_thin_lto =
is_cfi ||
(is_official_build && chrome_pgo_phase != 1 &&
(is_linux || is_win || (is_android && target_os != "chromeos") ||
((is_chromeos_ash || is_chromeos_lacros) && is_chromeos_device)))
# If true, use Goma for ThinLTO code generation where applicable.
use_goma_thin_lto = false
# Whether we're using a sample profile collected on an architecture different
# than the one we're compiling for.
#
# It's currently not possible to collect AFDO profiles on anything but
# x86{,_64}.
using_mismatched_sample_profile = current_cpu != "x64" && current_cpu != "x86"
# Whether an error should be raised on attempts to make debug builds with
# is_component_build=false. Very large debug symbols can have unwanted side
# effects so this is enforced by default for chromium.
forbid_non_component_debug_builds = build_with_chromium
# Exclude unwind tables by default for official builds as unwinding can be
# done from stack dumps produced by Crashpad at a later time "offline" in the
# crash server. Since this increases binary size, we don't recommend including
# them in shipping builds.
# For unofficial (e.g. development) builds and non-Chrome branded (e.g. Cronet
# which doesn't use Crashpad, crbug.com/479283) builds it's useful to be able
# to unwind at runtime.
exclude_unwind_tables = is_official_build
# Where to redirect clang crash diagnoses
clang_diagnostic_dir =
rebase_path("//tools/clang/crashreports", root_build_dir)
# Mark binaries as compatible with Shadow Stack of Control-flow Enforcement
# Technology (CET). If Windows version and hardware supports the feature and
# it's enabled by OS then additional validation of return address will be
# performed as mitigation against Return-oriented programming (ROP).
# https://chromium.googlesource.com/chromium/src/+/main/docs/design/sandbox.md#cet-shadow-stack
enable_cet_shadow_stack = target_cpu == "x64"
}
assert(!is_cfi || use_thin_lto, "CFI requires ThinLTO")
# If true, optimize for size. Does not affect windows builds.
# Linux & Mac favor speed over size.
# TODO(brettw) it's weird that Mac and desktop Linux are different. We should
# explore favoring size over speed in this case as well.
optimize_for_size = is_android || is_chromecast || is_fuchsia || is_ios
declare_args() {
# Whether we should consider the profile we're using to be accurate. Accurate
# profiles have the benefit of (potentially substantial) binary size
# reductions, by instructing the compiler to optimize cold and uncovered
# functions heavily for size. This often comes at the cost of performance.
sample_profile_is_accurate = optimize_for_size
}
# Determine whether to enable or disable frame pointers, based on the platform
# and build arguments.
# TODO(crbug.com/1052397): Consider changing is_chromeos_ash to is_chromeos after
# lacros-chrome switches to target_os="chromeos".
if (is_chromeos_ash || is_chromeos_lacros) {
# ChromeOS generally prefers frame pointers, to support CWP.
# However, Clang does not currently generate usable frame pointers in ARM
# 32-bit builds (https://bugs.llvm.org/show_bug.cgi?id=18505) so disable them
# there to avoid the unnecessary overhead.
enable_frame_pointers = current_cpu != "arm"
} else if (is_apple || is_linux || is_chromeos) {
enable_frame_pointers = true
} else if (is_win) {
# 64-bit Windows ABI doesn't support frame pointers.
if (current_cpu == "x64") {
enable_frame_pointers = false
} else {
enable_frame_pointers = true
}
} else if (is_android) {
enable_frame_pointers =
enable_profiling ||
# Ensure that stacks from arm64 crash dumps are usable (crbug.com/391706).
current_cpu == "arm64" ||
# For x86 Android, unwind tables are huge without frame pointers
# (crbug.com/762629). Enabling frame pointers grows the code size slightly
# but overall shrinks binaries considerably by avoiding huge unwind
# tables.
(current_cpu == "x86" && !exclude_unwind_tables && optimize_for_size) ||
using_sanitizer ||
# For caller-callee instrumentation version which needs frame pointers to
# get the caller address.
use_call_graph
} else {
# Explicitly ask for frame pointers, otherwise:
# * Stacks may be missing for sanitizer and profiling builds.
# * Debug tcmalloc can crash (crbug.com/636489).
enable_frame_pointers = using_sanitizer || enable_profiling || is_debug
}
# In general assume that if we have frame pointers then we can use them to
# unwind the stack. However, this requires that they are enabled by default for
# most translation units, that they are emitted correctly, and that the
# compiler or platform provides a way to access them.
can_unwind_with_frame_pointers = enable_frame_pointers
if (current_cpu == "arm" && arm_use_thumb) {
# We cannot currently unwind ARM Thumb frame pointers correctly.
# See https://bugs.llvm.org/show_bug.cgi?id=18505
can_unwind_with_frame_pointers = false
} else if (is_win) {
# Windows 32-bit does provide frame pointers, but the compiler does not
# provide intrinsics to access them, so we don't use them.
can_unwind_with_frame_pointers = false
}
assert(!can_unwind_with_frame_pointers || enable_frame_pointers)
# Unwinding with CFI table is only possible on static library builds and
# requried only when frame pointers are not enabled.
can_unwind_with_cfi_table = is_android && !is_component_build &&
!enable_frame_pointers && current_cpu == "arm"
# Whether or not cfi table should be enabled on arm.
# TODO(crbug.com/1090409): Replace can_unwind_with_cfi_table with this once
# sampling profiler is enabled on android.
enable_arm_cfi_table = is_android && !is_component_build && current_cpu == "arm"
declare_args() {
# Set to true to use lld, the LLVM linker.
# Not supported for macOS (see docs/mac_lld.md), and not functional at all for
# iOS. But used for mac cross-compile on linux (may not work properly).
# The default linker everywhere else.
use_lld = is_clang && (!is_apple || host_os == "linux")
}
declare_args() {
# Whether to use the gold linker from binutils instead of lld or bfd.
use_gold = !use_lld && !(is_chromecast && is_linux &&
(current_cpu == "arm" || current_cpu == "mipsel")) &&
(((is_linux || is_chromeos_lacros) &&
(current_cpu == "x64" || current_cpu == "x86" ||
current_cpu == "arm" || current_cpu == "arm64" ||
current_cpu == "mipsel" || current_cpu == "mips64el")) ||
(is_android && (current_cpu == "x86" || current_cpu == "x64" ||
current_cpu == "arm" || current_cpu == "arm64")))
}
# Use relative paths for debug info. This is important to make the build
# results independent of the checkout and build directory names, which
# in turn is important for goma compile hit rate.
# Setting this to true may make it harder to debug binaries on Linux, see
# https://chromium.googlesource.com/chromium/src/+/main/docs/linux/debugging.md#Source-level-debug-with-fdebug_compilation_dir
# It's not clear if the crash server will correctly handle dSYMs with relative
# paths, so we disable this feature for official benefit. The main benefit is
# deterministic builds to reduce compile times, so this is less relevant for
# official builders.
strip_absolute_paths_from_debug_symbols_default =
# TODO(crbug.com/1010267): remove '!use_clang_coverage', coverage build has
# dependency to absolute path of source files.
!use_clang_coverage &&
(is_android || is_fuchsia || is_nacl || (is_win && use_lld) || is_linux ||
is_chromeos || (is_apple && !enable_dsyms))
# If the platform uses stripped absolute paths by default, then we don't expose
# it as a configuration option. If this is causing problems, please file a bug.
if (strip_absolute_paths_from_debug_symbols_default) {
strip_absolute_paths_from_debug_symbols = true
} else {
declare_args() {
strip_absolute_paths_from_debug_symbols = false
}
}
# If it wasn't manually set, then default use_debug_fission to false.
assert(
use_debug_fission == "default" || use_debug_fission || !use_debug_fission,
"Invalid use_debug_fission.")
if (use_debug_fission == "default") {
use_debug_fission = is_debug && !is_android && !is_fuchsia && !is_apple &&
!is_win && (use_gold || use_lld) && cc_wrapper == ""
}
# If it wasn't manually set, set to an appropriate default.
assert(symbol_level >= -1 && symbol_level <= 2, "Invalid symbol_level")
if (symbol_level == -1) {
if (is_android && !is_component_build && !use_debug_fission) {
# Reduce symbol level when it will cause invalid elf files to be created
# (due to file size). https://crbug.com/648948.
symbol_level = 1
} else if (is_chromeos_device) {
# Use lower symbol level in Simple Chrome build for faster link time.
# For Simple Chrome, this should take precedence over is_official_build,
# turned on by --internal.
if ((target_cpu == "x64" || target_cpu == "x86") && !is_debug) {
# For release x86/x64 build, specify symbol_level=0 for faster link time.
# x86/x64 shows backtraces with symbol_level=0 (arm requires
# symbol_level=1).
symbol_level = 0
} else {
symbol_level = 1
}
} else if (using_sanitizer) {
# Sanitizers need line table info for stack traces. They don't need type
# info or variable info, so we can leave that out to speed up the build.
# Sanitizers also require symbols for filename suppressions to work.
symbol_level = 1
} else if ((!is_nacl && !is_linux && !is_chromeos && !is_fuchsia &&
current_os != "aix") || is_debug || is_official_build ||
is_chromecast) {
# Linux builds slower by having symbols as part of the target binary,
# whereas Mac and Windows have them separate, so in Release Linux, default
# them off, but keep them on for Official builds and Chromecast builds.
symbol_level = 2
} else {
symbol_level = 0
}
}
# Split dwarf works only for symbol_level == 2.
use_debug_fission = use_debug_fission && symbol_level == 2
# Non-component debug builds with symbol_level = 2 are an undesirable (very slow
# build times) and unsupported (some test binaries will fail with > 4 GB PDBs)
# combination. This is only checked when current_toolchain == default_toolchain
# because the is_component_build flag is set to false in various components of
# the build (like nacl) and we don't want to assert on those.
# iOS does not support component builds so add an exception for this platform.
if (forbid_non_component_debug_builds) {
assert(symbol_level != 2 || current_toolchain != default_toolchain ||
is_component_build || !is_debug || is_ios,
"Can't do non-component debug builds at symbol_level=2")
}
# Assert that the configuration isn't going to hit https://crbug.com/648948.
# An exception is made when target_os == "chromeos" as we only use the Android
# toolchain there to build relatively small binaries.
assert(
ignore_elf32_limitations || !is_android || target_os == "chromeos" ||
is_component_build || symbol_level < 2 || use_debug_fission,
"Android 32-bit non-component builds without DWARF Fission cannot " +
"have symbol_level=2 due to 4GiB file size limit, see " +
"https://crbug.com/648948. " + "If you really want to try this out, " +
"set ignore_elf32_limitations=true.")