blob: 267c920f3e95647db5cfcacc71204cc0ab82eda8 [file] [log] [blame]
# Copyright (c) 2013 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/android/config.gni")
import("//build/config/chrome_build.gni")
import("//build/config/compiler/compiler.gni")
import("//build/config/nacl/config.gni")
import("//build/toolchain/cc_wrapper.gni")
import("//build/toolchain/toolchain.gni")
if (current_cpu == "arm" || current_cpu == "arm64") {
import("//build/config/arm.gni")
}
if (current_cpu == "mipsel" || current_cpu == "mips64el") {
import("//build/config/mips.gni")
}
if (is_win) {
import("//build/config/win/visual_studio_version.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
# Normally, Android builds are lightly optimized, even for debug builds, to
# keep binary size down. Setting this flag to true disables such optimization
android_full_debug = false
# Whether to use the binary binutils checked into third_party/binutils.
# These are not multi-arch so cannot be used except on x86 and x86-64 (the
# only two architectures that are currently checked in). Turn this off when
# you are using a custom toolchain and need to control -B in cflags.
linux_use_bundled_binutils =
is_linux && (current_cpu == "x64" || current_cpu == "x86")
binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
root_build_dir)
# Compile in such a way as to make it possible for the profiler to unwind full
# stack frames. Setting this flag has a large effect on the performance of the
# generated code than just setting profiling, but gives the profiler more
# information to analyze.
# Requires profiling to be set to true.
enable_full_stack_frames_for_profiling = false
# Whether to use the gold linker from binutils instead of lld or bfd.
use_gold =
!use_lld && is_linux &&
(current_cpu == "x64" || current_cpu == "x86" || current_cpu == "arm")
# When we are going to use gold we need to find it.
# This is initialized below, after use_gold might have been overridden.
gold_path = 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"
if (is_win) {
# Whether the VS xtree header has been patched to disable warning 4702. If
# it has, then we don't need to disable 4702 (unreachable code warning).
# The patch is preapplied to the internal toolchain and hence all bots.
msvs_xtree_patched = false
}
# Omit unwind support in official builds to save space.
# We can use breakpad for these builds.
exclude_unwind_tables = is_chrome_branded && is_official_build
# If true, gold linker will save symbol table inside object files.
# This speeds up gdb startup by 60%
gdb_index = false
# 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_ios
# If this is set to true, or if LLVM_FORCE_HEAD_REVISION is set to 1
# in the environment, we use the revision in the llvm repo to determine
# the CLANG_REVISION to use, instead of the version hard-coded into
# //tools/clang/scripts/update.py. This should only be used in
# conjunction with setting LLVM_FORCE_HEAD_REVISION in the
# environment when `gclient runhooks` is run as well.
llvm_force_head_revision = false
}
if (is_clang && !is_nacl) {
update_args = [ "--print-revision" ]
if (llvm_force_head_revision) {
update_args += [ "--llvm-force-head-revision" ]
}
clang_revision =
exec_script("//tools/clang/scripts/update.py", update_args, "trim string")
}
# Apply the default logic for these values if they were not set explicitly.
if (gold_path == false) {
if (use_gold) {
gold_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
root_build_dir)
} else {
gold_path = ""
}
}
if (use_debug_fission == "default") {
use_debug_fission = is_debug && !is_win && use_gold &&
linux_use_bundled_binutils && cc_wrapper == ""
}
# default_include_dirs ---------------------------------------------------------
#
# This is a separate config so that third_party code (which would not use the
# source root and might have conflicting versions of some headers) can remove
# this and specify their own include paths.
config("default_include_dirs") {
include_dirs = [
"//",
root_gen_dir,
]
}
# compiler ---------------------------------------------------------------------
#
# Base compiler configuration.
#
# See also "runtime_library" below for related stuff and a discussion about
# where stuff should go. Put warning related stuff in the "warnings" config.
config("compiler") {
asmflags = []
cflags = []
cflags_c = []
cflags_cc = []
cflags_objc = []
cflags_objcc = []
ldflags = []
defines = []
configs = []
# System-specific flags. If your compiler flags apply to one of the
# categories here, add it to the associated file to keep this shared config
# smaller.
if (is_win) {
configs += [ "//build/config/win:compiler" ]
} else if (is_android) {
configs += [ "//build/config/android:compiler" ]
} else if (is_linux) {
configs += [ "//build/config/linux:compiler" ]
} else if (is_nacl) {
configs += [ "//build/config/nacl:compiler" ]
} else if (is_ios || is_mac) {
configs += [ "//build/config/mac:compiler" ]
}
# Applies to all Posix systems.
if (is_posix) {
configs += [ "//build/config/posix:compiler" ]
}
# See the definitions below.
configs += [
":compiler_cpu_abi",
":compiler_codegen",
]
# In general, Windows is totally different, but all the other builds share
# some common GCC configuration.
if (!is_win) {
# Common GCC compiler flags setup.
# --------------------------------
cflags += [ "-fno-strict-aliasing" ] # See http://crbug.com/32204
cflags_cc += [
# If this is removed then remove the corresponding /Zc:threadSafeInit- for
# Windows.
"-fno-threadsafe-statics",
# Not exporting C++ inline functions can generally be applied anywhere
# so we do so here. Normal function visibility is controlled by
# //build/config/gcc:symbol_visibility_hidden.
"-fvisibility-inlines-hidden",
]
# Stack protection.
if (is_mac) {
cflags += [ "-fstack-protector-all" ]
} else if (is_posix && !is_chromeos && !is_nacl) {
# TODO(phajdan.jr): Use -fstack-protector-strong when our gcc supports it.
cflags += [ "--param=ssp-buffer-size=4" ]
# The x86 toolchain currently has problems with stack-protector.
if (is_android && current_cpu == "x86") {
cflags += [ "-fno-stack-protector" ]
} else {
cflags += [ "-fstack-protector" ]
}
}
# Linker warnings.
if (!(is_chromeos && current_cpu == "arm") &&
!(is_android && use_order_profiling) && !is_mac && !is_ios) {
# TODO(jochen): Enable this on chromeos on arm. http://crbug.com/356580
# TODO(lizeb,pasko): Fix link errors when linking with order_profiling=1
# crbug.com/485542
ldflags += [ "-Wl,--fatal-warnings" ]
}
}
if (is_clang && is_debug) {
# Allow comparing the address of references and 'this' against 0
# in debug builds. Technically, these can never be null in
# well-defined C/C++ and Clang can optimize such checks away in
# release builds, but they may be used in asserts in debug builds.
cflags_cc += [
"-Wno-undefined-bool-conversion",
"-Wno-tautological-undefined-compare",
]
}
if (is_clang && !is_nacl) {
# This is here so that all files get recompiled after a clang roll and
# when turning clang on or off. (defines are passed via the command line,
# and build system rebuild things when their commandline changes). Nothing
# should ever read this define.
defines += [ "CR_CLANG_REVISION=$clang_revision" ]
}
# Non-Mac Posix compiler flags setup.
# -----------------------------------
if (is_posix && !(is_mac || is_ios)) {
if (enable_profiling) {
# Explicitly ask for frame pointers. Otherwise they are omitted when
# any optimization level is used (and Android debug builds use -Os).
cflags += [ "-fno-omit-frame-pointer" ]
if (!is_debug) {
cflags += [ "-g" ]
if (enable_full_stack_frames_for_profiling) {
cflags += [
"-fno-inline",
"-fno-optimize-sibling-calls",
]
}
}
}
defines += [ "_FILE_OFFSET_BITS=64" ]
if (!is_android) {
defines += [
"_LARGEFILE_SOURCE",
"_LARGEFILE64_SOURCE",
]
}
if (!is_nacl) {
if (exclude_unwind_tables) {
cflags += [
"-fno-unwind-tables",
"-fno-asynchronous-unwind-tables",
]
defines += [ "NO_UNWIND_TABLES" ]
} else {
cflags += [ "-funwind-tables" ]
}
}
}
# Linux/Android common flags setup.
# ---------------------------------
if (is_linux || is_android) {
cflags += [
"-fPIC",
"-pipe", # Use pipes for communicating between sub-processes. Faster.
]
ldflags += [
"-fPIC",
"-Wl,-z,noexecstack",
"-Wl,-z,now",
"-Wl,-z,relro",
]
if (!using_sanitizer && !use_cfi_diag) {
ldflags += [ "-Wl,-z,defs" ]
}
}
# Linux-specific compiler flags setup.
# ------------------------------------
if (is_posix && use_lld && !is_nacl) {
ldflags += [ "-fuse-ld=lld" ]
} else if (use_gold) {
ldflags += [
"-B$gold_path",
# Newer gccs and clangs support -fuse-ld, use the flag to force gold
# selection.
# gcc -- http://gcc.gnu.org/onlinedocs/gcc-4.8.0/gcc/Optimize-Options.html
"-fuse-ld=gold",
# Experimentation found that using four linking threads
# saved ~20% of link time.
# https://groups.google.com/a/chromium.org/group/chromium-dev/browse_thread/thread/281527606915bb36
# Only apply this to the target linker, since the host
# linker might not be gold, but isn't used much anyway.
# TODO(raymes): Disable threading because gold is frequently
# crashing on the bots: crbug.com/161942.
#"-Wl,--threads",
#"-Wl,--thread-count=4",
]
if (gdb_index) {
ldflags += [ "-Wl,--gdb-index" ]
}
# TODO(thestig): Make this flag work with GN.
#if (!is_official_build && !is_chromeos && !(is_asan || is_lsan || is_tsan || is_msan)) {
# ldflags += [
# "-Wl,--detect-odr-violations",
# ]
#}
} else if (linux_use_bundled_binutils) {
# Gold is the default linker for the bundled binutils so we explicitly
# enable the bfd linker when use_gold is not set.
ldflags += [ "-fuse-ld=bfd" ]
}
if (is_posix && (use_gold || (use_lld && !is_nacl)) && !using_sanitizer &&
!(is_android && use_order_profiling)) {
# TODO(crbug.com/576197) - gcc on x86 platforms + gold + icf=all
# doesn't currently work. Once it does, use icf=all everywhere.
if (is_clang || (target_cpu != "x86" && target_cpu != "x64")) {
ldflags += [ "-Wl,--icf=all" ]
} else {
ldflags += [ "-Wl,--icf=safe" ]
}
}
if (linux_use_bundled_binutils) {
cflags += [ "-B$binutils_path" ]
}
# Clang-specific compiler flags setup.
# ------------------------------------
if (is_clang) {
cflags += [ "-fcolor-diagnostics" ]
}
# Makes builds independent of absolute file path.
# clang-cl (used if is_win) doesn't expose this flag.
# Currently disabled for nacl since its toolchain lacks this flag (too old).
# TODO(zforman): Once nacl's toolchain is updated, remove check.
if (is_clang && is_linux) {
absolute_path = rebase_path("//.")
cflags += [ "-fdebug-prefix-map=$absolute_path=." ]
}
# C++11 compiler flags setup.
# ---------------------------
if (is_linux || is_android || (is_nacl && is_clang)) {
# gnu++11 instead of c++11 is needed because some code uses typeof() (a
# GNU extension).
# TODO(thakis): Eventually switch this to c++11 instead,
# http://crbug.com/427584
cflags_cc += [ "-std=gnu++11" ]
} else if (!is_win && !is_nacl) {
# TODO(mcgrathr) - the NaCl GCC toolchain doesn't support either gnu++11
# or c++11; we technically don't need this toolchain any more, but there
# are still a few buildbots using it, so until those are turned off
# we need the !is_nacl clause and the (is_nacl && is_clang) clause, above.
cflags_cc += [ "-std=c++11" ]
}
if (is_mac) {
# Tell the compiler to use libc++'s headers and the linker to link
# against libc++. The latter part normally requires OS X 10.7,
# but we still support running on 10.6. How does this work? Two
# parts:
# 1. Chromium's clang doesn't error on -mmacosx-version-min=10.6
# combined with -stdlib=libc++ (it normally silently produced a
# binary that doesn't run on 10.6)
# 2. Further down, library_dirs is set to
# third_party/libc++-static, which contains a static
# libc++.a library. The linker then links against that instead
# of against /usr/lib/libc++.dylib when it sees the -lc++ flag
# added by the driver.
#
# In component builds, just link to the system libc++. This has
# the effect of making everything depend on libc++, which means
# component-build binaries won't run on 10.6 (no libc++ there),
# but for a developer-only configuration that's ok. (We don't
# want to raise the deployment target yet so that official and
# dev builds have the same deployment target. This affects
# things like which functions are considered deprecated.)
cflags_cc += [ "-stdlib=libc++" ]
ldflags += [ "-stdlib=libc++" ]
if (!is_component_build && !is_asan) {
ldflags += [
"-L",
rebase_path("//third_party/libc++-static", root_build_dir),
]
}
}
# Add flags for link-time optimization. These flags enable
# optimizations/transformations that require whole-program visibility at link
# time, so they need to be applied to all translation units, and we may end up
# with miscompiles if only part of the program is compiled with LTO flags. For
# that reason, we cannot allow targets to enable or disable these flags, for
# example by disabling the optimize configuration.
# TODO(pcc): Make this conditional on is_official_build rather than on gn
# flags for specific features.
if (!is_debug && (allow_posix_link_time_opt || is_cfi) && !is_nacl) {
cflags += [ "-flto" ]
ldflags += [ "-flto" ]
# Apply a lower LTO optimization level as the default is too slow.
if (is_linux) {
if (use_lld) {
ldflags += [ "-Wl,--lto-O1" ]
} else {
ldflags += [ "-Wl,-plugin-opt,O1" ]
}
} else if (is_mac) {
ldflags += [ "-Wl,-mllvm,-O1" ]
}
# Work-around for http://openradar.appspot.com/20356002
if (is_mac) {
ldflags += [ "-Wl,-all_load" ]
}
# Allows the linker to apply ICF to the LTO object file. Also, when
# targeting ARM, without this flag, LTO produces a .text section that is
# larger than the maximum call displacement, preventing the linker from
# relocating calls (http://llvm.org/PR22999).
if (is_linux) {
ldflags += [ "-Wl,-plugin-opt,-function-sections" ]
}
# TODO(pcc): Make these flags work correctly with CFI.
if (!is_cfi) {
cflags += [ "-fwhole-program-vtables" ]
ldflags += [ "-fwhole-program-vtables" ]
}
}
# Pass the same C/C++ flags to the objective C/C++ compiler.
cflags_objc += cflags_c
cflags_objcc += cflags_cc
# Assign any flags set for the C compiler to asmflags so that they are sent
# to the assembler. The Windows assembler takes different types of flags
# so only do so for posix platforms.
if (is_posix) {
asmflags += cflags
asmflags += cflags_c
}
}
# This provides the basic options to select the target CPU and ABI.
# It is factored out of "compiler" so that special cases can use this
# without using everything that "compiler" brings in. Options that
# tweak code generation for a particular CPU do not belong here!
# See "compiler_codegen", below.
config("compiler_cpu_abi") {
cflags = []
ldflags = []
if (is_posix && !(is_mac || is_ios)) {
# CPU architecture. We may or may not be doing a cross compile now, so for
# simplicity we always explicitly set the architecture.
if (current_cpu == "x64") {
cflags += [
"-m64",
"-march=x86-64",
]
ldflags += [ "-m64" ]
} else if (current_cpu == "x86") {
cflags += [ "-m32" ]
ldflags += [ "-m32" ]
if (!is_nacl) {
cflags += [
"-msse2",
"-mfpmath=sse",
"-mmmx",
]
}
} else if (current_cpu == "arm") {
if (is_clang && !is_android && !is_nacl) {
cflags += [ "--target=arm-linux-gnueabihf" ]
ldflags += [ "--target=arm-linux-gnueabihf" ]
}
if (!is_nacl) {
cflags += [
"-march=$arm_arch",
"-mfloat-abi=$arm_float_abi",
]
if (arm_use_thumb) {
cflags += [ "-mthumb" ]
if (is_android && !is_clang) {
# Clang doesn't support this option.
cflags += [ "-mthumb-interwork" ]
}
}
}
if (arm_tune != "") {
cflags += [ "-mtune=$arm_tune" ]
}
} else if (current_cpu == "mipsel") {
if (mips_arch_variant == "r6") {
if (is_clang) {
cflags += [
"--target=mipsel-linux-gnu",
"-march=mips32r6",
]
ldflags += [ "--target=mipsel-linux-gnu" ]
} else {
cflags += [
"-mips32r6",
"-Wa,-mips32r6",
]
if (is_android) {
ldflags += [
"-mips32r6",
"-Wl,-melf32ltsmip",
]
}
}
} else if (mips_arch_variant == "r2") {
if (is_clang) {
if (is_android) {
cflags += [
"--target=mipsel-linux-android",
"-march=mipsel",
"-mcpu=mips32r2",
]
ldflags += [ "--target=mipsel-linux-android" ]
} else {
cflags += [
"--target=mipsel-linux-gnu",
"-march=mipsel",
"-mcpu=mips32r2",
]
ldflags += [ "--target=mipsel-linux-gnu" ]
}
} else {
cflags += [
"-mips32r2",
"-Wa,-mips32r2",
]
if (mips_float_abi == "hard" && mips_fpu_mode != "") {
cflags += [ "-m$mips_fpu_mode" ]
}
}
} else if (mips_arch_variant == "r1") {
if (is_clang) {
if (is_android) {
cflags += [
"--target=mipsel-linux-android",
"-march=mipsel",
"-mcpu=mips32",
]
ldflags += [ "--target=mipsel-linux-android" ]
} else {
cflags += [
"--target=mipsel-linux-gnu",
"-march=mipsel",
"-mcpu=mips32",
]
ldflags += [ "--target=mipsel-linux-gnu" ]
}
} else {
cflags += [
"-mips32",
"-Wa,-mips32",
]
}
}
if (mips_dsp_rev == 1) {
cflags += [ "-mdsp" ]
} else if (mips_dsp_rev == 2) {
cflags += [ "-mdspr2" ]
}
cflags += [ "-m${mips_float_abi}-float" ]
} else if (current_cpu == "mips64el") {
if (mips_arch_variant == "r6") {
cflags += [
"-mips64r6",
"-Wa,-mips64r6",
]
ldflags += [ "-mips64r6" ]
} else if (mips_arch_variant == "r2") {
cflags += [
"-mips64r2",
"-Wa,-mips64r2",
]
ldflags += [ "-mips64r2" ]
}
} else if (current_cpu == "pnacl" && is_nacl_nonsfi) {
if (target_cpu == "x86" || target_cpu == "x64") {
cflags += [
"-arch",
"x86-32-nonsfi",
"--pnacl-bias=x86-32-nonsfi",
"--target=i686-unknown-nacl",
]
ldflags += [
"-arch",
"x86-32-nonsfi",
"--target=i686-unknown-nacl",
]
} else if (target_cpu == "arm") {
cflags += [
"-arch",
"arm-nonsfi",
"--pnacl-bias=arm-nonsfi",
"--target=armv7-unknown-nacl-gnueabihf",
]
ldflags += [
"-arch",
"arm-nonsfi",
"--target=armv7-unknown-nacl-gnueabihf",
]
}
}
}
asmflags = cflags
}
# This provides options to tweak code generation that are necessary
# for particular Chromium code or for working around particular
# compiler bugs (or the combination of the two).
config("compiler_codegen") {
configs = []
cflags = []
if (is_nacl) {
configs += [ "//build/config/nacl:compiler_codegen" ]
} else if (is_posix && !is_mac && !is_ios) {
if (current_cpu == "x86") {
if (is_clang) {
cflags += [
# Else building libyuv gives clang's register allocator issues,
# see llvm.org/PR15798 / crbug.com/233709
"-momit-leaf-frame-pointer",
]
}
} else if (current_cpu == "arm") {
if (is_android && !is_clang) {
# Clang doesn't support these flags.
cflags += [
# The tree-sra optimization (scalar replacement for
# aggregates enabling subsequent optimizations) leads to
# invalid code generation when using the Android NDK's
# compiler (r5-r7). This can be verified using
# webkit_unit_tests' WTF.Checked_int8_t test.
"-fno-tree-sra",
# The following option is disabled to improve binary
# size and performance in gcc 4.9.
"-fno-caller-saves",
]
}
}
}
asmflags = cflags
}
# This is separate from :compiler_codegen (and not even a sub-config there)
# so that some targets can remove it from the list with:
# configs -= [ "//build/config/compiler:clang_stackrealign" ]
# See https://crbug.com/556393 for details of where it must be avoided.
config("clang_stackrealign") {
if (is_clang && current_cpu == "x86" && is_linux) {
cflags = [
# Align the stack on 16-byte boundaries, http://crbug.com/418554.
"-mstack-alignment=16",
"-mstackrealign",
]
}
}
config("compiler_arm_fpu") {
if (current_cpu == "arm" && !is_ios && !is_nacl) {
cflags = [ "-mfpu=$arm_fpu" ]
asmflags = cflags
} else if (current_cpu == "arm64" && !is_ios && !is_nacl) {
cflags = [ "-mcpu=$arm_fpu" ]
asmflags = cflags
}
}
# runtime_library -------------------------------------------------------------
#
# Sets the runtime library and associated options.
#
# How do you determine what should go in here vs. "compiler" above? Consider if
# a target might choose to use a different runtime library (ignore for a moment
# if this is possible or reasonable on your system). If such a target would want
# to change or remove your option, put it in the runtime_library config. If a
# target wants the option regardless, put it in the compiler config.
config("runtime_library") {
defines = []
configs = []
# System-specific flags. If your compiler flags apply to one of the
# categories here, add it to the associated file to keep this shared config
# smaller.
if (is_win) {
configs += [ "//build/config/win:runtime_library" ]
} else if (is_linux) {
configs += [ "//build/config/linux:runtime_library" ]
} else if (is_ios) {
configs += [ "//build/config/ios:runtime_library" ]
} else if (is_mac) {
configs += [ "//build/config/mac:runtime_library" ]
} else if (is_android) {
configs += [ "//build/config/android:runtime_library" ]
}
if (is_posix) {
configs += [ "//build/config/posix:runtime_library" ]
}
if (is_component_build) {
defines += [ "COMPONENT_BUILD" ]
}
}
# default_warnings ------------------------------------------------------------
#
# Collects all warning flags that are used by default. This is used as a
# subconfig of both chromium_code and no_chromium_code. This way these
# flags are guaranteed to appear on the compile command line after -Wall.
config("default_warnings") {
cflags = []
cflags_cc = []
if (is_win) {
if (treat_warnings_as_errors) {
cflags += [ "/WX" ]
}
cflags += [
# Warnings permanently disabled:
# C4091: 'typedef ': ignored on left of 'X' when no variable is
# declared.
# This happens in a number of Windows headers. Dumb.
"/wd4091",
# C4127: conditional expression is constant
# This warning can in theory catch dead code and other problems, but
# triggers in far too many desirable cases where the conditional
# expression is either set by macros or corresponds some legitimate
# compile-time constant expression (due to constant template args,
# conditionals comparing the sizes of different types, etc.). Some of
# these can be worked around, but it's not worth it.
"/wd4127",
# C4251: 'identifier' : class 'type' needs to have dll-interface to be
# used by clients of class 'type2'
# This is necessary for the shared library build.
"/wd4251",
# C4351: new behavior: elements of array 'array' will be default
# initialized
# This is a silly "warning" that basically just alerts you that the
# compiler is going to actually follow the language spec like it's
# supposed to, instead of not following it like old buggy versions did.
# There's absolutely no reason to turn this on.
"/wd4351",
# C4355: 'this': used in base member initializer list
# It's commonly useful to pass |this| to objects in a class' initializer
# list. While this warning can catch real bugs, most of the time the
# constructors in question don't attempt to call methods on the passed-in
# pointer (until later), and annotating every legit usage of this is
# simply more hassle than the warning is worth.
"/wd4355",
# C4503: 'identifier': decorated name length exceeded, name was
# truncated
# This only means that some long error messages might have truncated
# identifiers in the presence of lots of templates. It has no effect on
# program correctness and there's no real reason to waste time trying to
# prevent it.
"/wd4503",
# Warning C4589 says: "Constructor of abstract class ignores
# initializer for virtual base class." Disable this warning because it
# is flaky in VS 2015 RTM. It triggers on compiler generated
# copy-constructors in some cases.
"/wd4589",
# C4611: interaction between 'function' and C++ object destruction is
# non-portable
# This warning is unavoidable when using e.g. setjmp/longjmp. MSDN
# suggests using exceptions instead of setjmp/longjmp for C++, but
# Chromium code compiles without exception support. We therefore have to
# use setjmp/longjmp for e.g. JPEG decode error handling, which means we
# have to turn off this warning (and be careful about how object
# destruction happens in such cases).
"/wd4611",
# Warnings to evaluate and possibly fix/reenable later:
"/wd4100", # Unreferenced formal function parameter.
"/wd4121", # Alignment of a member was sensitive to packing.
"/wd4244", # Conversion: possible loss of data.
"/wd4505", # Unreferenced local function has been removed.
"/wd4510", # Default constructor could not be generated.
"/wd4512", # Assignment operator could not be generated.
"/wd4610", # Class can never be instantiated, constructor required.
"/wd4838", # Narrowing conversion. Doesn't seem to be very useful.
"/wd4995", # 'X': name was marked as #pragma deprecated
"/wd4996", # Deprecated function warning.
# These are variable shadowing warnings that are new in VS2015. We
# should work through these at some point -- they may be removed from
# the RTM release in the /W4 set.
"/wd4456",
"/wd4457",
"/wd4458",
"/wd4459",
]
if (visual_studio_version == "2015") {
cflags += [
# C4312 is a VS 2015 64-bit warning for integer to larger pointer.
# TODO(brucedawson): fix warnings, crbug.com/554200
"/wd4312",
# TODO(brucedawson): http://crbug.com/593448 - C4595 is an 'illegal
# inline operator new' warning that is new in VS 2015 Update 2.
# This is equivalent to clang's no-inline-new-delete warning.
# See http://bugs.icu-project.org/trac/ticket/11122
"/wd4595",
]
if (current_cpu == "x86") {
cflags += [
# VC++ 2015 changes 32-bit size_t truncation warnings from 4244 to
# 4267. Example: short TruncTest(size_t x) { return x; }
# Since we disable 4244 we need to disable 4267 during migration.
# TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
"/wd4267",
]
}
}
# VS xtree header file needs to be patched or 4702 (unreachable code
# warning) is reported if _HAS_EXCEPTIONS=0. Disable the warning if xtree is
# not patched.
if (!msvs_xtree_patched &&
exec_script("../../win_is_xtree_patched.py", [], "value") == 0) {
cflags += [ "/wd4702" ] # Unreachable code.
}
# Building with Clang on Windows is a work in progress and very
# experimental. See crbug.com/82385.
# Keep this in sync with the similar block in build/common.gypi
if (is_clang) {
cflags += [
# TODO(hans): Make this list shorter eventually, http://crbug.com/504657
"-Wno-microsoft-enum-value", # http://crbug.com/505296
"-Wno-unknown-pragmas", # http://crbug.com/505314
"-Wno-microsoft-cast", # http://crbug.com/550065
]
}
} else {
if (is_mac && !is_nacl) {
# When compiling Objective-C, warns if a method is used whose
# availability is newer than the deployment target. This is not
# required when compiling Chrome for iOS.
cflags += [ "-Wpartial-availability" ]
}
# Suppress warnings about ABI changes on ARM (Clang doesn't give this
# warning).
if (current_cpu == "arm" && !is_clang) {
cflags += [ "-Wno-psabi" ]
}
if (!is_clang) {
cflags_cc += [
# See comment for -Wno-c++11-narrowing.
"-Wno-narrowing",
]
# Don't warn about the "typedef 'foo' locally defined but not used"
# for gcc 4.8.
# TODO: remove this flag once all builds work. See crbug.com/227506
cflags += [ "-Wno-unused-local-typedefs" ]
# Don't warn about "maybe" uninitialized. Clang doesn't include this
# in -Wall but gcc does, and it gives false positives.
cflags += [ "-Wno-maybe-uninitialized" ]
}
}
# Common Clang and GCC warning setup.
if (!is_win || is_clang) {
cflags += [
# Disables.
"-Wno-missing-field-initializers", # "struct foo f = {0};"
"-Wno-unused-parameter", # Unused function parameters.
]
}
if (is_chromeos) {
# TODO(thakis): Remove, http://crbug.com/263960
if (is_clang) {
cflags_cc += [ "-Wno-reserved-user-defined-literal" ]
} else {
cflags_cc += [ "-Wno-literal-suffix" ]
}
}
if (is_clang) {
cflags += [
# TODO(thakis): Consider -Wloop-analysis (turns on
# -Wrange-loop-analysis too).
# This warns on using ints as initializers for floats in
# initializer lists (e.g. |int a = f(); CGSize s = { a, a };|),
# which happens in several places in chrome code. Not sure if
# this is worth fixing.
"-Wno-c++11-narrowing",
# Warns on switches on enums that cover all enum values but
# also contain a default: branch. Chrome is full of that.
"-Wno-covered-switch-default",
# Clang considers the `register` keyword as deprecated, but e.g.
# code generated by flex (used in angle) contains that keyword.
# http://crbug.com/255186
"-Wno-deprecated-register",
# TODO(thakis): This used to be implied by -Wno-unused-function,
# which we no longer use. Check if it makes sense to remove
# this as well. http://crbug.com/316352
"-Wno-unneeded-internal-declaration",
# TODO(hans): Get this cleaned up, http://crbug.com/428099
"-Wno-inconsistent-missing-override",
]
# NaCl's Clang compiler and Chrome's hermetic Clang compiler will almost
# always have different versions. Certain flags may not be recognized by
# one version or the other.
if (!is_nacl) {
# Flags NaCl (Clang 3.7) does not recognize.
cflags += [
# TODO(thakis): Enable this, crbug.com/507717
"-Wno-shift-negative-value",
# TODO(thakis): https://crbug.com/604888
"-Wno-undefined-var-template",
]
}
}
}
# chromium_code ---------------------------------------------------------------
#
# Toggles between higher and lower warnings for code that is (or isn't)
# part of Chromium.
config("chromium_code") {
if (is_win) {
cflags = [ "/W4" ] # Warning level 4.
} else {
cflags = [ "-Wall" ]
if (treat_warnings_as_errors) {
cflags += [ "-Werror" ]
}
if (is_clang) {
# Enable -Wextra for chromium_code when we control the compiler.
cflags += [ "-Wextra" ]
}
# In Chromium code, we define __STDC_foo_MACROS in order to get the
# C99 macros on Mac and Linux.
defines = [
"__STDC_CONSTANT_MACROS",
"__STDC_FORMAT_MACROS",
]
if (!is_debug && !using_sanitizer &&
(!is_linux || !is_clang || is_official_build)) {
# _FORTIFY_SOURCE isn't really supported by Clang now, see
# http://llvm.org/bugs/show_bug.cgi?id=16821.
# It seems to work fine with Ubuntu 12 headers though, so use it in
# official builds.
#
# Non-chromium code is not guaranteed to compile cleanly with
# _FORTIFY_SOURCE. Also, fortified build may fail when optimizations are
# disabled, so only do that for Release build.
defines += [ "_FORTIFY_SOURCE=2" ]
}
}
configs = [ ":default_warnings" ]
}
config("no_chromium_code") {
cflags = []
cflags_cc = []
defines = []
if (is_win) {
cflags += [
"/W3", # Warning level 3.
"/wd4800", # Disable warning when forcing value to bool.
"/wd4267", # TODO(jschuh): size_t to int.
"/wd4996", # Deprecated function warning.
]
defines += [
"_CRT_NONSTDC_NO_WARNINGS",
"_CRT_NONSTDC_NO_DEPRECATE",
]
} else {
# GCC may emit unsuppressible warnings so don't add -Werror for no chromium
# code. crbug.com/589724
if (treat_warnings_as_errors && is_clang) {
cflags += [ "-Werror" ]
}
if (is_clang && !is_nacl) {
# TODO(thakis): Remove !is_nacl once
# https://codereview.webrtc.org/1552863002/ made its way into chromium.
cflags += [ "-Wall" ]
}
}
if (is_clang) {
cflags += [
# Lots of third-party libraries have unused variables. Instead of
# suppressing them individually, we just blanket suppress them here.
"-Wno-unused-variable",
]
}
if (is_linux || is_android) {
cflags_cc += [
# Don't warn about hash_map in third-party code.
"-Wno-deprecated",
]
}
configs = [ ":default_warnings" ]
}
# rtti ------------------------------------------------------------------------
#
# Allows turning Run-Time Type Identification on or off.
config("rtti") {
if (is_win) {
cflags_cc = [ "/GR" ]
}
}
config("no_rtti") {
# CFI diagnostics and UBsan vptr require RTTI.
if (!use_cfi_diag && !is_ubsan_vptr) {
if (is_win) {
cflags_cc = [ "/GR-" ]
} else {
cflags_cc = [ "-fno-rtti" ]
cflags_objcc = cflags_cc
}
}
}
# Warnings ---------------------------------------------------------------------
# This will generate warnings when using Clang if code generates exit-time
# destructors, which will slow down closing the program.
# TODO(thakis): Make this a blacklist instead, http://crbug.com/101600
config("wexit_time_destructors") {
# TODO: Enable on Windows too, http://crbug.com/404525
if (is_clang && !is_win) {
cflags = [ "-Wexit-time-destructors" ]
}
}
# On Windows compiling on x64, VC will issue a warning when converting
# size_t to int because it will truncate the value. Our code should not have
# these warnings and one should use a static_cast or a checked_cast for the
# conversion depending on the case. However, a lot of code still needs to be
# fixed. Apply this config to such targets to disable the warning.
#
# Note that this can be applied regardless of platform and architecture to
# clean up the call sites. This will only apply the flag when necessary.
#
# TODO(jschuh): crbug.com/167187 fix this and delete this config.
config("no_size_t_to_int_warning") {
if (is_win && current_cpu == "x64") {
cflags = [ "/wd4267" ]
}
}
# Some code presumes that pointers to structures/objects are compatible
# regardless of whether what they point to is already known to be valid.
# gcc 4.9 and earlier had no way of suppressing this warning without
# supressing the rest of them. Here we centralize the identification of
# the gcc 4.9 toolchains.
config("no_incompatible_pointer_warnings") {
cflags = []
if (is_clang) {
cflags += [ "-Wno-incompatible-pointer-types" ]
} else if (current_cpu == "mipsel") {
cflags += [ "-w" ]
} else if (is_chromeos && current_cpu == "arm") {
cflags += [ "-w" ]
}
}
# Optimization -----------------------------------------------------------------
#
# The BUILDCONFIG file sets the "default_optimization" config on targets by
# default. It will be equivalent to either "optimize" (release) or
# "no_optimize" (debug) optimization configs.
#
# You can override the optimization level on a per-target basis by removing the
# default config and then adding the named one you want:
#
# configs -= [ "//build/config/compiler:default_optimization" ]
# configs += [ "//build/config/compiler:optimize_max" ]
# Shared settings for both "optimize" and "optimize_max" configs.
# IMPORTANT: On Windows "/O1" and "/O2" must go before the common flags.
if (is_win) {
common_optimize_on_cflags = [
"/Ob2", # Both explicit and auto inlining.
"/Oy-", # Disable omitting frame pointers, must be after /O2.
"/d2Zi+", # Improve debugging of optimized code.
"/Zc:inline", # Remove unreferenced COMDAT (faster links).
]
if (!is_asan) {
common_optimize_on_cflags += [
# Put data in separate COMDATs. This allows the linker
# to put bit-identical constants at the same address even if
# they're unrelated constants, which saves binary size.
# This optimization can't be used when ASan is enabled because
# it is not compatible with the ASan ODR checker.
"/Gw",
]
}
common_optimize_on_ldflags = [ "/OPT:ICF" ] # Redundant COMDAT folding.
if (is_official_build) {
common_optimize_on_ldflags += [
"/OPT:REF", # Remove unreferenced data.
"/LTCG", # Link-time code generation.
# Set the number of LTCG code-gen threads to eight. The default is four.
# This gives a 5-10% link speedup.
"/cgthreads:8",
]
}
} else {
common_optimize_on_cflags = [
# Don't emit the GCC version ident directives, they just end up in the
# .comment section taking up binary size.
"-fno-ident",
# Put data and code in their own sections, so that unused symbols
# can be removed at link time with --gc-sections.
"-fdata-sections",
"-ffunction-sections",
]
common_optimize_on_ldflags = []
if (is_android) {
# We don't omit frame pointers on arm64 since they are required
# to correctly unwind stackframes which contain system library
# function frames (crbug.com/391706).
if (!using_sanitizer && !enable_profiling && target_cpu != "arm64") {
common_optimize_on_cflags += [ "-fomit-frame-pointer" ]
}
# TODO(jdduke) Re-enable on mips after resolving linking
# issues with libc++ (crbug.com/456380).
if (current_cpu != "mipsel" && current_cpu != "mips64el") {
common_optimize_on_ldflags += [
# Warn in case of text relocations.
"-Wl,--warn-shared-textrel",
]
}
}
if (is_mac || is_ios) {
if (symbol_level == 2) {
# Mac dead code stripping requires symbols.
common_optimize_on_ldflags += [ "-Wl,-dead_strip" ]
}
} else {
# Non-Mac Posix linker flags.
common_optimize_on_ldflags += [
# Specifically tell the linker to perform optimizations.
# See http://lwn.net/Articles/192624/ .
"-Wl,-O1",
"-Wl,--gc-sections",
]
if (!using_sanitizer) {
# Functions interposed by the sanitizers can make ld think
# that some libraries aren't needed when they actually are,
# http://crbug.com/234010. As workaround, disable --as-needed.
common_optimize_on_ldflags += [ "-Wl,--as-needed" ]
}
}
}
# Default "optimization on" config.
config("optimize") {
if (is_win) {
if (is_official_build && full_wpo_on_official) {
common_optimize_on_cflags += [ "/GL" ]
}
# Favor size over speed, /O1 must be before the common flags. The GYP
# build also specifies /Os and /GF but these are implied by /O1.
cflags = [ "/O1" ] + common_optimize_on_cflags + [ "/Oi" ]
} else if (optimize_for_size) {
# Favor size over speed.
cflags = [ "-Os" ] + common_optimize_on_cflags
} else {
cflags = [ "-O2" ] + common_optimize_on_cflags
}
ldflags = common_optimize_on_ldflags
}
# Same config as 'optimize' but without the WPO flag.
config("optimize_no_wpo") {
if (is_win) {
# Favor size over speed, /O1 must be before the common flags. The GYP
# build also specifies /Os and /GF but these are implied by /O1.
cflags = [ "/O1" ] + common_optimize_on_cflags + [ "/Oi" ]
} else if (optimize_for_size) {
# Favor size over speed.
cflags = [ "-Os" ] + common_optimize_on_cflags
} else {
cflags = [ "-O2" ] + common_optimize_on_cflags
}
ldflags = common_optimize_on_ldflags
}
# Turn off optimizations.
config("no_optimize") {
if (is_win) {
cflags = [
"/Od", # Disable optimization.
"/Ob0", # Disable all inlining (on by default).
]
} else if (is_android && !android_full_debug) {
# On Android we kind of optimize some things that don't affect debugging
# much even when optimization is disabled to get the binary size down.
cflags = [
"-Os",
"-fdata-sections",
"-ffunction-sections",
]
# We don't omit frame pointers on arm64 since they are required
# to correctly unwind stackframes which contain system library
# function frames (crbug.com/391706).
if (!using_sanitizer && !enable_profiling && target_cpu != "arm64") {
cflags += [ "-fomit-frame-pointer" ]
}
# Don't use gc-sections since it can cause links to succeed when they
# actually shouldn't. http://crbug.com/159847
ldflags = common_optimize_on_ldflags - [ "-Wl,--gc-sections" ]
} else {
cflags = [ "-O0" ]
ldflags = []
}
}
# Turns up the optimization level. On Windows, this implies whole program
# optimization and link-time code generation which is very expensive and should
# be used sparingly.
config("optimize_max") {
if (is_nacl_irt) {
# The NaCl IRT is a special case and always wants its own config.
# Various components do:
# if (!is_debug) {
# configs -= [ "//build/config/compiler:default_optimization" ]
# configs += [ "//build/config/compiler:optimize_max" ]
# }
# So this config has to have the selection logic just like
# "default_optimization", below.
configs = [ "//build/config/nacl:irt_optimize" ]
} else {
ldflags = common_optimize_on_ldflags
if (is_win) {
# Favor speed over size, /O2 must be before the common flags. The GYP
# build also specifies /Ot, /Oi, and /GF, but these are implied by /O2.
cflags = [ "/O2" ] + common_optimize_on_cflags
# TODO(thakis): Remove is_clang here, https://crbug.com/598772
if (is_official_build && !is_clang) {
cflags += [
"/GL", # Whole program optimization.
# Disable Warning 4702 ("Unreachable code") for the WPO/PGO builds.
# Probably anything that this would catch that wouldn't be caught in a
# normal build isn't going to actually be a bug, so the incremental
# value of C4702 for PGO builds is likely very small.
"/wd4702",
]
}
} else {
cflags = [ "-O2" ] + common_optimize_on_cflags
}
}
}
# The default optimization applied to all targets. This will be equivalent to
# either "optimize" or "no_optimize", depending on the build flags.
config("default_optimization") {
if (is_nacl_irt) {
# The NaCl IRT is a special case and always wants its own config.
# It gets optimized the same way regardless of the type of build.
configs = [ "//build/config/nacl:irt_optimize" ]
} else if (is_debug) {
configs = [ ":no_optimize" ]
} else {
configs = [ ":optimize" ]
}
}
# Symbols ----------------------------------------------------------------------
# The BUILDCONFIG file sets the "default_symbols" config on targets by
# default. It will be equivalent to one the three specific symbol levels.
#
# You can override the symbol level on a per-target basis by removing the
# default config and then adding the named one you want:
#
# configs -= [ "//build/config/compiler:default_symbols" ]
# configs += [ "//build/config/compiler:symbols" ]
# Full symbols.
config("symbols") {
if (is_win) {
import("//build/toolchain/goma.gni")
if (use_goma) {
cflags = [ "/Z7" ] # No PDB file
} else {
cflags = [ "/Zi" ] # Produce PDB file, no edit and continue.
}
if (is_win_fastlink && visual_studio_version != "2013") {
# Tell VS 2015+ to create a PDB that references debug
# information in .obj and .lib files instead of copying
# it all. This flag is incompatible with /PROFILE
ldflags = [ "/DEBUG:FASTLINK" ]
} else {
ldflags = [ "/DEBUG" ]
}
} else {
if (is_ios) {
cflags = [ "-gdwarf-2" ]
} else {
cflags = [ "-g2" ]
}
if (use_debug_fission) {
cflags += [ "-gsplit-dwarf" ]
}
asmflags = cflags
ldflags = []
}
}
# Minimal symbols.
config("minimal_symbols") {
if (is_win) {
# Linker symbols for backtraces only.
cflags = []
if (is_win_fastlink && visual_studio_version != "2013") {
# Tell VS 2015+ to create a PDB that references debug
# information in .obj and .lib files instead of copying
# it all. This flag is incompatible with /PROFILE
ldflags = [ "/DEBUG:FASTLINK" ]
} else {
ldflags = [ "/DEBUG" ]
}
} else {
cflags = [ "-g1" ]
if (use_debug_fission) {
cflags += [ "-gsplit-dwarf" ]
}
asmflags = cflags
ldflags = []
}
}
# No symbols.
config("no_symbols") {
if (!is_win) {
cflags = [ "-g0" ]
asmflags = cflags
}
}
# Default symbols.
config("default_symbols") {
if (symbol_level == 0) {
configs = [ ":no_symbols" ]
} else if (symbol_level == 1) {
configs = [ ":minimal_symbols" ]
} else if (symbol_level == 2) {
configs = [ ":symbols" ]
} else {
assert(false)
}
}
if (is_ios || is_mac) {
# On Mac and iOS, this enables support for ARC (automatic ref-counting).
# See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
config("enable_arc") {
common_flags = [ "-fobjc-arc" ]
cflags_objc = common_flags
cflags_objcc = common_flags
}
}