blob: ece1c6292909134a07aad45956c87abb8efab5b3 [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")
if (current_cpu == "arm") {
import("//build/config/arm.gni")
}
if (current_cpu == "mipsel" || current_cpu == "mips64el") {
import("//build/config/mips.gni")
}
if (is_posix) {
import("//build/config/gcc/gcc_version.gni")
}
if (is_win) {
import("//build/config/win/visual_studio_version.gni")
}
import("//build/toolchain/ccache.gni")
import("//build/config/sanitizers/sanitizers.gni")
declare_args() {
# 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"
# 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
# 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
# Use gold for linking on 64-bit Linux only (on 32-bit it runs out of
# address space, and it doesn't support cross-compiling).
use_gold = is_linux && current_cpu == "x64"
# 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
use_debug_fission = is_debug && !is_win && use_gold &&
linux_use_bundled_binutils && !use_ccache
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
}
}
# 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,
]
}
# TODO(GYP): is_ubsan, is_ubsan_vptr
if (!is_win) {
using_sanitizer = is_asan || is_lsan || is_tsan || is_msan
}
# 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") {
cflags = []
cflags_c = []
cflags_cc = []
ldflags = []
defines = []
# In general, Windows is totally different, but all the other builds share
# some common GCC configuration. This section sets up Windows and the common
# GCC flags, and then we handle the other non-Windows platforms specifically
# below.
if (is_win) {
# Windows compiler flags setup.
# -----------------------------
cflags += [
"/Gy", # Enable function-level linking.
"/GS", # Enable buffer security checking.
"/FS", # Preserve previous PDB behavior.
]
# 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 += [
# Many files use intrinsics without including this header.
# TODO(hans): Fix those files, or move this to sub-GYPs.
"/FIIntrin.h",
]
if (visual_studio_version == "2013") {
cflags += [ "-fmsc-version=1800" ]
} else if (visual_studio_version == "2015") {
cflags += [ "-fmsc-version=1900" ]
}
if (current_cpu == "x86") {
cflags += [ "-m32" ]
} else {
cflags += [ "-m64" ]
}
if (exec_script("//build/win/use_ansi_codes.py", [], "trim string") ==
"True") {
cflags += [
# cmd.exe doesn't understand ANSI escape codes by default,
# so only enable them if something emulating them is around.
"-fansi-escape-codes",
]
}
}
} else {
# Common GCC compiler flags setup.
# --------------------------------
cflags += [ "-fno-strict-aliasing" ] # See http://crbug.com/32204
cflags_cc += [
"-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_linux) {
cflags += [
"-fstack-protector",
"--param=ssp-buffer-size=4",
]
}
# Linker warnings.
if (!(is_chromeos && current_cpu == "arm") && !is_mac && !is_ios) {
# TODO(jochen): Enable this on chromeos on arm. http://crbug.com/356580
ldflags += [ "-Wl,--fatal-warnings" ]
}
# Common options for AddressSanitizer, LeakSanitizer, ThreadSanitizer and
# MemorySanitizer
if (using_sanitizer) {
cflags += [
"-fno-omit-frame-pointer",
"-gline-tables-only",
]
}
if (is_asan) {
asan_blacklist_path =
rebase_path("//tools/memory/asan/blacklist.txt", root_build_dir)
cflags += [
"-fsanitize=address",
"-fsanitize-blacklist=$asan_blacklist_path",
]
if (is_mac) {
cflags += [ "-mllvm -asan-globals=0" ] # http://crbug.com/352073
# TODO(GYP): deal with mac_bundles.
}
}
if (is_lsan) {
cflags += [ "-fsanitize=leak" ]
}
if (is_tsan) {
tsan_blacklist_path =
rebase_path("//tools/memory/tsan_v2/ignores.txt", root_build_dir)
cflags += [
"-fsanitize=thread",
"-fsanitize-blacklist=$tsan_blacklist_path",
]
}
if (is_msan) {
msan_blacklist_path =
rebase_path("//tools/msan/blacklist.txt", root_build_dir)
cflags += [
"-fsanitize=memory",
"-fsanitize-memory-track-origins=$msan_track_origins",
"-fsanitize-blacklist=$msan_blacklist_path",
]
}
if (use_custom_libcxx) {
cflags_cc += [ "-nostdinc++" ]
include_dirs = [
"//buildtools/third_party/libc++/trunk/include",
"//buildtools/third_party/libc++abi/trunk/include",
]
}
}
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=" + exec_script("//tools/clang/scripts/update.py",
[ "--print-revision" ],
"trim string") ]
}
# Mac-specific compiler flags setup.
# ----------------------------------
if (is_mac || is_ios) {
# These flags are shared between the C compiler and linker.
common_mac_flags = []
# CPU architecture.
if (current_cpu == "x64") {
common_mac_flags += [
"-arch",
"x86_64",
]
} else if (current_cpu == "x86") {
common_mac_flags += [
"-arch",
"i386",
]
} else if (current_cpu == "arm") {
common_mac_flags += [
"-arch",
"armv7",
]
}
cflags += common_mac_flags
# Without this, the constructors and destructors of a C++ object inside
# an Objective C struct won't be called, which is very bad.
cflags_objcc = [ "-fobjc-call-cxx-cdtors" ]
cflags_c += [ "-std=c99" ]
ldflags += common_mac_flags
} else if (is_posix) {
# Non-Mac Posix compiler flags setup.
# -----------------------------------
if (enable_profiling && !is_debug) {
# The GYP build spams this define into every compilation unit, as we do
# here, but it only appears to be used in base and a couple other places.
# TODO(abarth): Should we move this define closer to where it's used?
defines += [ "ENABLE_PROFILING" ]
cflags += [
"-fno-omit-frame-pointer",
"-g",
]
if (enable_full_stack_frames_for_profiling) {
cflags += [
"-fno-inline",
"-fno-optimize-sibling-calls",
]
}
}
# 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_clang) {
cflags += [
# Else building libyuv gives clang's register allocator issues,
# see llvm.org/PR15798 / crbug.com/233709
"-momit-leaf-frame-pointer",
# Align the stack on 16-byte boundaries, http://crbug.com/418554.
"-mstack-alignment=16",
"-mstackrealign",
]
}
} else if (current_cpu == "arm") {
cflags += [
"-march=$arm_arch",
"-mfloat-abi=$arm_float_abi",
]
if (arm_tune != "") {
cflags += [ "-mtune=$arm_tune" ]
}
if (arm_use_thumb) {
cflags += [ "-mthumb" ]
if (is_android && !is_clang) { # Clang doesn't support this option.
cflags += [ "-mthumb-interwork" ]
}
}
if (!is_clang) {
# Clang doesn't support these flags.
cflags += [
# The tree-sra optimization (scalar replacement for
# aggregates enabling subsequent optimizations) leads to
# invalid code generation when using the Android NDK's
# compiler (r5-r7). This can be verified using
# webkit_unit_tests' WTF.Checked_int8_t test.
"-fno-tree-sra",
# The following option is disabled to improve binary
# size and performance in gcc 4.9.
"-fno-caller-saves",
]
}
} else if (current_cpu == "mipsel") {
if (mips_arch_variant == "r6") {
cflags += [
"-mips32r6",
"-Wa,-mips32r6",
]
if (is_android) {
ldflags += [
"-mips32r6",
"-Wl,-melf32ltsmip",
]
}
} else if (mips_arch_variant == "r2") {
cflags += [
"-mips32r2",
"-Wa,-mips32r2",
]
if (mips_float_abi == "hard" && mips_fpu_mode != "") {
cflags += [ "-m$mips_fpu_mode" ]
}
} else if (mips_arch_variant == "r1") {
cflags += [
"-mips32",
"-Wa,-mips32",
]
}
if (mips_dsp_rev == 1) {
cflags += [ "-mdsp" ]
} else if (mips_dsp_rev == 2) {
cflags += [ "-mdspr2" ]
}
cflags += [ "-m${mips_float_abi}-float" ]
} else if (current_cpu == "mips64el") {
if (mips_arch_variant == "r6") {
cflags += [
"-mips64r6",
"-Wa,-mips64r6",
]
ldflags += [ "-mips64r6" ]
} else if (mips_arch_variant == "r2") {
cflags += [
"-mips64r2",
"-Wa,-mips64r2",
]
ldflags += [ "-mips64r2" ]
}
}
defines += [ "_FILE_OFFSET_BITS=64" ]
if (!is_android) {
defines += [
"_LARGEFILE_SOURCE",
"_LARGEFILE64_SOURCE",
]
}
# Omit unwind support in official builds to save space. We can use breakpad
# for these builds.
if (is_chrome_branded && is_official_build) {
cflags += [
"-fno-unwind-tables",
"-fno-asynchronous-unwind-tables",
]
defines += [ "NO_UNWIND_TABLES" ]
} else {
cflags += [ "-funwind-tables" ]
}
}
# Linux/Android common flags setup.
# ---------------------------------
if (is_linux || is_android) {
cflags += [
"-fPIC",
"-pipe", # Use pipes for communicating between sub-processes. Faster.
]
ldflags += [
"-fPIC",
"-Wl,-z,noexecstack",
"-Wl,-z,now",
"-Wl,-z,relro",
]
if (!using_sanitizer) {
ldflags += [ "-Wl,-z,defs" ]
}
}
# Linux-specific compiler flags setup.
# ------------------------------------
if (is_linux) {
cflags += [ "-pthread" ]
ldflags += [ "-pthread" ]
}
if (use_gold) {
gold_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
root_build_dir)
ldflags += [
"-B$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 (!is_asan && !is_msan && !is_lsan && !is_tsan) {
# TODO(brettw) common.gypi has this only for target toolset.
ldflags += [ "-Wl,--icf=all" ]
}
# 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",
# ]
#}
}
if (linux_use_bundled_binutils) {
binutils_path = rebase_path("//third_party/binutils/Linux_x64/Release/bin",
root_build_dir)
cflags += [ "-B$binutils_path" ]
}
# Clang-specific compiler flags setup.
# ------------------------------------
if (is_clang) {
cflags += [ "-fcolor-diagnostics" ]
}
# C++11 compiler flags setup.
# ---------------------------
if (is_linux || is_android || is_nacl) {
# 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) {
cflags_cc += [ "-std=c++11" ]
}
# Android-specific flags setup.
# -----------------------------
if (is_android) {
cflags += [
"-ffunction-sections",
"-funwind-tables",
"-fno-short-enums",
]
if (!is_clang) {
# Clang doesn't support these flags.
cflags += [ "-finline-limit=64" ]
}
if (is_asan) {
# Android build relies on -Wl,--gc-sections removing unreachable code.
# ASan instrumentation for globals inhibits this and results in a library
# with unresolvable relocations.
# TODO(eugenis): find a way to reenable this.
cflags += [ "-mllvm -asan-globals=0" ]
}
defines += [ "ANDROID" ]
# The NDK has these things, but doesn't define the constants
# to say that it does. Define them here instead.
defines += [ "HAVE_SYS_UIO_H" ]
# Use gold for Android for most CPU architectures.
if (current_cpu == "x86" || current_cpu == "x64" || current_cpu == "arm") {
ldflags += [ "-fuse-ld=gold" ]
if (is_clang) {
# Let clang find the ld.gold in the NDK.
ldflags += [ "--gcc-toolchain=" +
rebase_path(android_toolchain_root, root_build_dir) ]
}
}
ldflags += [
"-Wl,--no-undefined",
# Don't allow visible symbols from libgcc or libc++ to be
# re-exported.
"-Wl,--exclude-libs=libgcc.a",
"-Wl,--exclude-libs=libc++_static.a",
# Don't allow visible symbols from libraries that contain
# assembly code with symbols that aren't hidden properly.
# http://crbug.com/448386
"-Wl,--exclude-libs=libvpx_assembly_arm.a",
]
if (current_cpu == "arm") {
ldflags += [
# Enable identical code folding to reduce size.
"-Wl,--icf=safe",
]
}
if (is_clang) {
if (current_cpu == "arm") {
cflags += [ "-target arm-linux-androideabi" ]
ldflags += [ "-target arm-linux-androideabi" ]
} else if (current_cpu == "x86") {
cflags += [ "-target x86-linux-androideabi" ]
ldflags += [ "-target x86-linux-androideabi" ]
}
}
}
}
config("compiler_arm_fpu") {
if (current_cpu == "arm" && !is_ios) {
cflags = [ "-mfpu=$arm_fpu" ]
}
}
# 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") {
cflags = []
defines = []
ldflags = []
lib_dirs = []
libs = []
if (is_component_build) {
# Component mode: dynamic CRT.
defines += [ "COMPONENT_BUILD" ]
if (is_win) {
# Since the library is shared, it requires exceptions or will give errors
# about things not matching, so keep exceptions on.
if (is_debug) {
cflags += [ "/MDd" ]
} else {
cflags += [ "/MD" ]
}
}
} else {
# Static CRT.
if (is_win) {
if (is_debug) {
cflags += [ "/MTd" ]
} else {
cflags += [ "/MT" ]
}
}
}
if (is_win) {
defines += [
"__STD_C",
"_CRT_RAND_S",
"_CRT_SECURE_NO_DEPRECATE",
"_HAS_EXCEPTIONS=0",
"_SCL_SECURE_NO_DEPRECATE",
]
}
# Android standard library setup.
if (is_android) {
if (is_clang) {
# Work around incompatibilities between bionic and clang headers.
defines += [
"__compiler_offsetof=__builtin_offsetof",
"nan=__builtin_nan",
]
}
defines += [ "__GNU_SOURCE=1" ] # Necessary for clone().
# TODO(jdduke) Re-enable on mips after resolving linking
# issues with libc++ (crbug.com/456380).
if (current_cpu != "mipsel" && current_cpu != "mips64el") {
ldflags += [ "-Wl,--warn-shared-textrel" ]
}
ldflags += [ "-nostdlib" ]
# NOTE: The libc++ header include paths below are specified in cflags
# rather than include_dirs because they need to come after include_dirs.
# Think of them like system headers, but don't use '-isystem' because the
# arm-linux-androideabi-4.4.3 toolchain (circa Gingerbread) will exhibit
# strange errors. The include ordering here is important; change with
# caution.
cflags += [
"-isystem" +
rebase_path("$android_libcpp_root/libcxx/include", root_build_dir),
"-isystem" + rebase_path(
"$android_ndk_root/sources/cxx-stl/llvm-libc++abi/libcxxabi/include",
root_build_dir),
"-isystem" +
rebase_path("$android_ndk_root/sources/android/support/include",
root_build_dir),
]
lib_dirs += [ "$android_libcpp_root/libs/$android_app_abi" ]
libs += [ "$android_libcpp_library" ]
if (current_cpu == "mipsel") {
libs += [
# ld linker is used for mips Android, and ld does not accept library
# absolute path prefixed by "-l"; Since libgcc does not exist in mips
# sysroot the proper library will be linked.
# TODO(gordanac): Remove once gold linker is used for mips Android.
"gcc",
]
} else {
libs += [
# Manually link the libgcc.a that the cross compiler uses. This is
# absolute because the linker will look inside the sysroot if it's not.
rebase_path(android_libgcc_file),
]
}
libs += [
"c",
"dl",
"m",
]
# Clang with libc++ does not require an explicit atomic library reference.
if (!is_clang) {
libs += [ "atomic" ]
}
}
}
# default_warning_flags collects all warning flags that are used by default.
# This is in a variable instead of a config so that it can be used in
# both chromium_code and no_chromium_code. This way these flags are guaranteed
# to appear on the compile command line after -Wall.
default_warning_flags = []
default_warning_flags_cc = []
if (is_win) {
if (!is_clang || current_cpu != "x86") {
default_warning_flags += [ "/WX" ] # Treat warnings as errors.
}
default_warning_flags += [
# Warnings permanently disabled:
# TODO(GYP) The GYP build doesn't have this globally enabled but disabled
# for a bunch of individual targets. Re-enable this globally when those
# targets are fixed.
"/wd4018", # Comparing signed and unsigned values.
# 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.
"/wd4481", # Nonstandard extension: override specifier.
"/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.
"/wd4996", # Deprecated function warning.
]
# 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) {
default_warning_flags += [ "/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) {
default_warning_flags += [
# TODO(hans): Make this list shorter eventually, http://crbug.com/504657
"-Qunused-arguments", # http://crbug.com/504658
"-Wno-microsoft", # http://crbug.com/505296
"-Wno-switch", # http://crbug.com/505308
"-Wno-unknown-pragmas", # http://crbug.com/505314
"-Wno-unused-function", # http://crbug.com/505316
"-Wno-unused-value", # http://crbug.com/505318
"-Wno-unused-local-typedef", # http://crbug.com/411648
]
}
} else {
# Common GCC warning setup.
default_warning_flags += [
# Enables.
"-Wendif-labels", # Weird old-style text after an #endif.
"-Werror", # Warnings as errors.
# Disables.
"-Wno-missing-field-initializers", # "struct foo f = {0};"
"-Wno-unused-parameter", # Unused function parameters.
]
if (is_mac) {
default_warning_flags += [ "-Wnewline-eof" ]
if (!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.
default_warning_flags += [ "-Wpartial-availability" ]
}
}
if (gcc_version >= 48) {
default_warning_flags_cc += [
# See comment for -Wno-c++11-narrowing.
"-Wno-narrowing",
# TODO(thakis): Remove, http://crbug.com/263960
"-Wno-literal-suffix",
]
}
# Suppress warnings about ABI changes on ARM (Clang doesn't give this
# warning).
if (current_cpu == "arm" && !is_clang) {
default_warning_flags += [ "-Wno-psabi" ]
}
if (is_android) {
# Disable any additional warnings enabled by the Android build system but
# which chromium does not build cleanly with (when treating warning as
# errors).
default_warning_flags += [
"-Wno-extra",
"-Wno-ignored-qualifiers",
"-Wno-type-limits",
]
default_warning_flags_cc += [
# Disabling c++0x-compat should be handled in WebKit, but
# this currently doesn't work because gcc_version is not set
# correctly when building with the Android build system.
# TODO(torne): Fix this in WebKit.
"-Wno-error=c++0x-compat",
# Other things unrelated to -Wextra:
"-Wno-non-virtual-dtor",
"-Wno-sign-promo",
]
}
if (gcc_version >= 48) {
# 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
default_warning_flags += [ "-Wno-unused-local-typedefs" ]
}
}
if (is_clang) {
default_warning_flags += [
# 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",
# Don't die on dtoa code that uses a char as an array index.
# This is required solely for base/third_party/dmg_fp/dtoa.cc.
# TODO(brettw) move this to that project then!
"-Wno-char-subscripts",
# 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(thakis): Remove, http://crbug.com/263960
"-Wno-reserved-user-defined-literal",
]
# 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 does not recognize.
default_warning_flags += [
# TODO(hans): Get this cleaned up, http://crbug.com/428099
"-Wno-inconsistent-missing-override",
# TODO(thakis): Enable this, crbug.com/507717
"-Wno-shift-negative-value",
]
}
}
# 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",
# GCC turns on -Wsign-compare for C++ under -Wall, but clang doesn't,
# so we specify it explicitly.
# TODO(fischman): remove this if http://llvm.org/PR10448 obsoletes it.
# http://code.google.com/p/chromium/issues/detail?id=90453
"-Wsign-compare",
]
# 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 (!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" ]
}
}
cflags += default_warning_flags
cflags_cc = default_warning_flags_cc
}
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",
]
}
if (is_linux) {
# Don't warn about ignoring the return value from e.g. close(). This is
# off by default in some gccs but on by default in others. BSD systems do
# not support this option, since they are usually using gcc 4.2.1, which
# does not have this flag yet.
cflags += [ "-Wno-unused-result" ]
}
if (is_clang) {
cflags += [
# TODO(mgiuca): Move this suppression into individual third-party
# libraries as required. http://crbug.com/505301.
"-Wno-overloaded-virtual",
# 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 += [
# Don't warn about printf format problems. This is off by default in gcc
# but on in Ubuntu's gcc(!).
"-Wno-format",
]
cflags_cc += [
# Don't warn about hash_map in third-party code.
"-Wno-deprecated",
]
}
cflags += default_warning_flags
cflags_cc += default_warning_flags_cc
}
# rtti ------------------------------------------------------------------------
#
# Allows turning Run-Time Type Identification on or off.
config("rtti") {
if (is_win) {
cflags_cc = [ "/GR" ]
}
}
config("no_rtti") {
if (is_win) {
cflags_cc = [ "/GR-" ]
} else {
cflags_cc = [ "-fno-rtti" ]
}
}
# 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" ]
}
}
# Optimization -----------------------------------------------------------------
#
# Note that BUILDCONFIG.gn sets up a variable "default_optimization_config"
# which it will assign to the config it implicitly applies to every target. If
# you want to override the optimization level for your target, remove this
# config (which will expand differently for debug or release builds), and then
# add back the one you want to override it with:
#
# configs -= default_optimization_config
# 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.
]
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:REF" ]
} 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) {
if (!using_sanitizer) {
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) {
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. On Windows, this favors size over speed.
config("optimize") {
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 (is_android || is_ios) {
cflags = [ "-Os" ] + common_optimize_on_cflags # Favor size over speed.
} 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).
"/RTC1", # Runtime checks for stack frame and uninitialized variables.
]
} 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",
]
if (!using_sanitizer) {
cflags += [ "-fomit-frame-pointer" ]
}
ldflags = common_optimize_on_ldflags
} else {
cflags = [ "-O0" ]
}
}
# 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") {
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
if (is_official_build) {
# TODO(GYP): TODO(dpranke): Should these only be on in an official
# build, or on all the time? For now we'll require official build so
# that the compile is clean.
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",
]
ldflags += [ "/LTCG" ]
}
} else {
cflags = [ "-O2" ] + common_optimize_on_cflags
}
}
# 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.
}
ldflags = [ "/DEBUG" ]
} else {
cflags = [ "-g2" ]
if (use_debug_fission) {
cflags += [ "-gsplit-dwarf" ]
}
}
}
config("minimal_symbols") {
if (is_win) {
# Linker symbols for backtraces only.
ldflags = [ "/DEBUG" ]
} else {
cflags = [ "-g1" ]
if (use_debug_fission) {
cflags += [ "-gsplit-dwarf" ]
}
}
}
config("no_symbols") {
if (!is_win) {
cflags = [ "-g0" ]
}
}