|  | # 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") | 
|  | } | 
|  |  | 
|  | 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_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 += [ | 
|  | "/fallback", | 
|  | "-m32", | 
|  | ] | 
|  | } else { | 
|  | cflags += [ "-m64" ] | 
|  | } | 
|  | } | 
|  | } 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" ] | 
|  | } | 
|  |  | 
|  | if (is_clang && !is_nacl && !is_debug) { | 
|  | # Non-unique section names appears to make linker dead stripping | 
|  | # less effective. See http://crbug.com/483026#c20 | 
|  | # TODO(hans): Remove this if resolved upstream. | 
|  | cflags += [ "-funique-section-names" ] | 
|  | } | 
|  | } | 
|  |  | 
|  | # 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. | 
|  | if (current_cpu == "x64") { | 
|  | # --icf=safe disables much more folding on x86_64 than elsewhere, see | 
|  | # http://crbug.com/492177.  Turning it on saves over 12 MB of binary | 
|  | # size, but it seems to regress cold startup time by over a second | 
|  | # (see http://crbug.com/492809). | 
|  | # TODO(thakis): Check if disabling ICF would inmprove android cold start | 
|  | # times by several seconds too. | 
|  | ldflags += [ "-Wl,--icf=safe" ] | 
|  | } else { | 
|  | 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. | 
|  | android_libcpp_root = "$android_ndk_root/sources/cxx-stl/llvm-libc++" | 
|  |  | 
|  | cflags += [ | 
|  | "-isystem" + | 
|  | rebase_path("$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" ] | 
|  |  | 
|  | if (component_mode == "shared_library") { | 
|  | android_libcpp_library = "c++_shared" | 
|  | } else { | 
|  | android_libcpp_library = "c++_static" | 
|  | } | 
|  |  | 
|  | 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", | 
|  |  | 
|  | # 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. | 
|  | "-Qunused-arguments", | 
|  | "-Wno-c++11-compat-deprecated-writable-strings", | 
|  | "-Wno-deprecated-declarations", | 
|  | "-Wno-empty-body", | 
|  | "-Wno-enum-conversion", | 
|  | "-Wno-extra-tokens", | 
|  | "-Wno-ignored-attributes", | 
|  | "-Wno-incompatible-pointer-types", | 
|  | "-Wno-int-to-void-pointer-cast", | 
|  | "-Wno-invalid-noreturn", | 
|  | "-Wno-logical-op-parentheses", | 
|  | "-Wno-microsoft", | 
|  | "-Wno-missing-braces", | 
|  | "-Wno-missing-declarations", | 
|  | "-Wno-msvc-include", | 
|  | "-Wno-null-dereference", | 
|  | "-Wno-overloaded-virtual", | 
|  | "-Wno-parentheses", | 
|  | "-Wno-pointer-sign", | 
|  | "-Wno-reorder", | 
|  | "-Wno-return-type-c-linkage", | 
|  | "-Wno-self-assign", | 
|  | "-Wno-sometimes-uninitialized", | 
|  | "-Wno-switch", | 
|  | "-Wno-tautological-compare", | 
|  | "-Wno-unknown-pragmas", | 
|  | "-Wno-unsequenced", | 
|  | "-Wno-unused-function", | 
|  | "-Wno-unused-private-field", | 
|  | "-Wno-unused-value", | 
|  | "-Wno-unused-variable", | 
|  | "-Wno-unused-local-typedef",  # http://crbug.com/411648 | 
|  | "-Wno-inconsistent-missing-override",  #http://crbug.com/428099 | 
|  | ] | 
|  | } | 
|  | } 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. | 
|  | "-Wno-inconsistent-missing-override", | 
|  | ] | 
|  | } | 
|  | } | 
|  |  | 
|  | # 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_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. | 
|  | if (is_win) { | 
|  | common_optimize_on_cflags = [ | 
|  | "/O2", | 
|  | "/Ob2",  # both explicit and auto inlining. | 
|  | "/Oy-",  # disable omitting frame pointers, must be after /o2. | 
|  | "/Os",  # favor size over speed. | 
|  | ] | 
|  | 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") { | 
|  | cflags = common_optimize_on_cflags | 
|  | ldflags = common_optimize_on_ldflags | 
|  | if (is_win) { | 
|  | cflags += [ "/Os" ]  # favor size over speed. | 
|  | } else if (is_android || is_ios) { | 
|  | cflags += [ "-Os" ]  # Favor size over speed. | 
|  | } else { | 
|  | cflags += [ "-O2" ] | 
|  | } | 
|  | } | 
|  |  | 
|  | # 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") { | 
|  | cflags = common_optimize_on_cflags | 
|  | ldflags = common_optimize_on_ldflags | 
|  | if (is_win) { | 
|  | cflags -= [ "/Os" ] | 
|  | cflags += [ "/Ot" ]  # Favor speed over size. | 
|  | 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" ] | 
|  | } | 
|  | } | 
|  |  | 
|  | # 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" ] | 
|  | } | 
|  | } |