build/config/BUILD.gn

# 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/allocator.gni")
import("//build/config/chrome_build.gni")
import("//build/config/chromecast_build.gni")
import("//build/config/crypto.gni")
import("//build/config/features.gni")
import("//build/config/sanitizers/sanitizers.gni")
import("//build/config/ui.gni")
import("//build/toolchain/goma.gni")

# One common error that happens is that GYP-generated headers within gen/ get
# included rather than the GN-generated ones within gen/ subdirectories.
# TODO(GYP_GONE): Remove once GYP is gone (as well as exec_script exception).
assert(
    exec_script("//build/dir_exists.py", [ "obj.host" ], "string") == "False",
    "GYP artifacts detected in $root_build_dir.$0x0A" +
        "You must wipe this directory before building with GN.")

declare_args() {
  # When set (the default) enables C++ iterator debugging in debug builds.
  # Iterator debugging is always off in release builds (technically, this flag
  # affects the "debug" config, which is always available but applied by
  # default only in debug builds).
  #
  # Iterator debugging is generally useful for catching bugs. But it can
  # introduce extra locking to check the state of an iterator against the state
  # of the current object. For iterator- and thread-heavy code, this can
  # significantly slow execution.
  enable_iterator_debugging = true

  # Set to true to enable dcheck in Release builds.
  dcheck_always_on = false

  # Normally we try to decide whether to use precompiled headers or
  # not based on the other build arguments, but in some cases it is
  # easiest to force them off explicitly.
  disable_precompiled_headers = false
}

# TODO(brettw) Most of these should be removed. Instead of global feature
# flags, we should have more modular flags that apply only to a target and its
# dependents. For example, depending on the "x11" meta-target should define
# USE_X11 for all dependents so that everything that could use X11 gets the
# define, but anything that doesn't depend on X11 doesn't see it.
#
# For now we define these globally to match the current GYP build.
config("feature_flags") {
  # Don't use deprecated V8 APIs anywhere.
  defines = [ "V8_DEPRECATION_WARNINGS" ]
  if (enable_mdns) {
    defines += [ "ENABLE_MDNS=1" ]
  }
  if (enable_notifications) {
    defines += [ "ENABLE_NOTIFICATIONS" ]
  }
  if (enable_pepper_cdms) {
    # TODO(brettw) should probably be "=1"
    defines += [ "ENABLE_PEPPER_CDMS" ]
  }
  if (enable_browser_cdms) {
    # TODO(brettw) should probably be "=1"
    defines += [ "ENABLE_BROWSER_CDMS" ]
  }
  if (enable_plugins) {
    defines += [ "ENABLE_PLUGINS=1" ]
  }
  if (enable_pdf) {
    defines += [ "ENABLE_PDF=1" ]
  }
  if (enable_basic_printing || enable_print_preview) {
    # Convenience define for ENABLE_BASIC_PRINTING || ENABLE_PRINT_PREVIEW.
    defines += [ "ENABLE_PRINTING=1" ]
    if (enable_basic_printing) {
      # Enable basic printing support and UI.
      defines += [ "ENABLE_BASIC_PRINTING=1" ]
    }
    if (enable_print_preview) {
      # Enable printing with print preview.
      # Can be defined without ENABLE_BASIC_PRINTING.
      defines += [ "ENABLE_PRINT_PREVIEW=1" ]
    }
  }
  if (enable_spellcheck) {
    defines += [ "ENABLE_SPELLCHECK=1" ]
  }
  if (use_browser_spellchecker) {
    defines += [ "USE_BROWSER_SPELLCHECKER=1" ]
  }
  if (dcheck_always_on) {
    defines += [ "DCHECK_ALWAYS_ON=1" ]
  }
  if (use_udev) {
    # TODO(brettw) should probably be "=1".
    defines += [ "USE_UDEV" ]
  }
  if (ui_compositor_image_transport) {
    # TODO(brettw) should probably be "=1".
    defines += [ "UI_COMPOSITOR_IMAGE_TRANSPORT" ]
  }
  if (use_ash) {
    defines += [ "USE_ASH=1" ]
  }
  if (use_aura) {
    defines += [ "USE_AURA=1" ]
  }
  if (use_pango) {
    defines += [ "USE_PANGO=1" ]
  }
  if (use_cairo) {
    defines += [ "USE_CAIRO=1" ]
  }
  if (use_clipboard_aurax11) {
    defines += [ "USE_CLIPBOARD_AURAX11=1" ]
  }
  if (use_default_render_theme) {
    defines += [ "USE_DEFAULT_RENDER_THEME=1" ]
  }
  if (use_glib) {
    defines += [ "USE_GLIB=1" ]
  }
  if (use_openssl_certs) {
    defines += [ "USE_OPENSSL_CERTS=1" ]
  }
  if (use_nss_certs) {
    defines += [ "USE_NSS_CERTS=1" ]
  }
  if (use_ozone) {
    defines += [ "USE_OZONE=1" ]
  }
  if (use_x11) {
    defines += [ "USE_X11=1" ]
  }
  if (use_allocator != "tcmalloc") {
    defines += [ "NO_TCMALLOC" ]
  }
  if (is_asan || is_lsan || is_tsan || is_msan) {
    defines += [
      "MEMORY_TOOL_REPLACES_ALLOCATOR",
      "MEMORY_SANITIZER_INITIAL_SIZE",
    ]
  }
  if (is_asan) {
    defines += [ "ADDRESS_SANITIZER" ]
  }
  if (is_lsan) {
    defines += [
      "LEAK_SANITIZER",
      "WTF_USE_LEAK_SANITIZER=1",
    ]
  }
  if (is_tsan) {
    defines += [
      "THREAD_SANITIZER",
      "DYNAMIC_ANNOTATIONS_EXTERNAL_IMPL=1",
      "WTF_USE_DYNAMIC_ANNOTATIONS_NOIMPL=1",
    ]
  }
  if (is_msan) {
    defines += [ "MEMORY_SANITIZER" ]
  }
  if (is_ubsan || is_ubsan_vptr || is_ubsan_security) {
    defines += [ "UNDEFINED_SANITIZER" ]
  }
  if (enable_webrtc) {
    defines += [ "ENABLE_WEBRTC=1" ]
  }
  if (!enable_nacl) {
    defines += [ "DISABLE_NACL" ]
  }
  if (enable_extensions) {
    defines += [ "ENABLE_EXTENSIONS=1" ]
  }
  if (enable_task_manager) {
    defines += [ "ENABLE_TASK_MANAGER=1" ]
  }
  if (enable_themes) {
    defines += [ "ENABLE_THEMES=1" ]
  }
  if (enable_captive_portal_detection) {
    defines += [ "ENABLE_CAPTIVE_PORTAL_DETECTION=1" ]
  }
  if (enable_session_service) {
    defines += [ "ENABLE_SESSION_SERVICE=1" ]
  }
  if (enable_rlz) {
    defines += [ "ENABLE_RLZ" ]
  }
  if (enable_plugin_installation) {
    defines += [ "ENABLE_PLUGIN_INSTALLATION=1" ]
  }
  if (enable_app_list) {
    defines += [ "ENABLE_APP_LIST=1" ]
  }
  if (enable_settings_app) {
    defines += [ "ENABLE_SETTINGS_APP=1" ]
  }
  if (enable_supervised_users) {
    defines += [ "ENABLE_SUPERVISED_USERS=1" ]
  }
  if (enable_service_discovery) {
    defines += [ "ENABLE_SERVICE_DISCOVERY=1" ]
  }
  if (enable_image_loader_extension) {
    defines += [ "IMAGE_LOADER_EXTENSION=1" ]
  }
  if (enable_topchrome_md) {
    defines += [ "ENABLE_TOPCHROME_MD=1" ]
  }
  if (enable_wayland_server) {
    defines += [ "ENABLE_WAYLAND_SERVER=1" ]
  }
  if (enable_wifi_display) {
    defines += [ "ENABLE_WIFI_DISPLAY=1" ]
  }
  if (proprietary_codecs) {
    defines += [ "USE_PROPRIETARY_CODECS" ]
  }
  if (enable_hangout_services_extension) {
    defines += [ "ENABLE_HANGOUT_SERVICES_EXTENSION=1" ]
  }
  if (enable_video_hole) {
    defines += [ "VIDEO_HOLE=1" ]
  }
  if (safe_browsing_mode == 1) {
    defines += [ "FULL_SAFE_BROWSING" ]
    defines += [ "SAFE_BROWSING_CSD" ]
    defines += [ "SAFE_BROWSING_DB_LOCAL" ]
  } else if (safe_browsing_mode == 2) {
    defines += [ "SAFE_BROWSING_DB_REMOTE" ]
  }
  if (is_official_build) {
    defines += [ "OFFICIAL_BUILD" ]
  }
  if (is_chrome_branded) {
    defines += [ "GOOGLE_CHROME_BUILD" ]
  } else {
    defines += [ "CHROMIUM_BUILD" ]
  }
  if (enable_media_router) {
    defines += [ "ENABLE_MEDIA_ROUTER=1" ]
  }
  if (enable_webvr) {
    defines += [ "ENABLE_WEBVR" ]
  }
  if (is_syzyasan) {
    defines += [
      "SYZYASAN",
      "MEMORY_TOOL_REPLACES_ALLOCATOR",
      "MEMORY_SANITIZER_INITIAL_SIZE",
    ]
  }
  if (!fieldtrial_testing_like_official_build && !is_chrome_branded) {
    defines += [ "FIELDTRIAL_TESTING_ENABLED" ]
  }
}

# Debug/release ----------------------------------------------------------------

config("debug") {
  defines = [
    "_DEBUG",
    "DYNAMIC_ANNOTATIONS_ENABLED=1",
    "WTF_USE_DYNAMIC_ANNOTATIONS=1",
  ]

  if (is_nacl) {
    defines += [ "DYNAMIC_ANNOTATIONS_PREFIX=NACL_" ]
  }

  if (is_win) {
    if (!enable_iterator_debugging) {
      # Iterator debugging is enabled by default by the compiler on debug
      # builds, and we have to tell it to turn it off.
      defines += [ "_HAS_ITERATOR_DEBUGGING=0" ]
    }
  } else if (is_linux && current_cpu == "x64" && enable_iterator_debugging) {
    # Enable libstdc++ debugging facilities to help catch problems early, see
    # http://crbug.com/65151 .
    # TODO(phajdan.jr): Should we enable this for all of POSIX?
    defines += [ "_GLIBCXX_DEBUG=1" ]
  }
}

config("release") {
  defines = [ "NDEBUG" ]

  # Sanitizers.
  if (is_tsan) {
    defines += [
      "DYNAMIC_ANNOTATIONS_ENABLED=1",
      "WTF_USE_DYNAMIC_ANNOTATIONS=1",
    ]
  } else {
    defines += [ "NVALGRIND" ]
    if (!is_nacl) {
      # NaCl always enables dynamic annotations. Currently this value is set to
      # 1 for all .nexes.
      defines += [ "DYNAMIC_ANNOTATIONS_ENABLED=0" ]
    }
  }
}

# Default libraries ------------------------------------------------------------

# This config defines the default libraries applied to all targets.
config("default_libs") {
  if (is_win) {
    # TODO(brettw) this list of defaults should probably be smaller, and
    # instead the targets that use the less common ones (e.g. wininet or
    # winspool) should include those explicitly.
    libs = [
      "advapi32.lib",
      "comdlg32.lib",
      "dbghelp.lib",
      "delayimp.lib",
      "dnsapi.lib",
      "gdi32.lib",
      "kernel32.lib",
      "msimg32.lib",
      "odbc32.lib",
      "odbccp32.lib",
      "ole32.lib",
      "oleaut32.lib",
      "psapi.lib",
      "shell32.lib",
      "shlwapi.lib",
      "user32.lib",
      "usp10.lib",
      "uuid.lib",
      "version.lib",
      "wininet.lib",
      "winmm.lib",
      "winspool.lib",
      "ws2_32.lib",

      # Please don't add more stuff here. We should actually be making this
      # list smaller, since all common things should be covered. If you need
      # some extra libraries, please just add a libs = [ "foo.lib" ] to your
      # target that needs it.
    ]
  } else if (is_android) {
    libs = [
      "dl",
      "m",
    ]
  } else if (is_mac) {
    # Targets should choose to explicitly link frameworks they require. Since
    # linking can have run-time side effects, nothing should be listed here.
    libs = []
  } else if (is_ios) {
    # The libraries listed here will be specified for both the target and the
    # host. Only the common ones should be listed here.
    libs = [
      "CoreFoundation.framework",
      "CoreGraphics.framework",
      "CoreText.framework",
      "Foundation.framework",
    ]
  } else if (is_linux) {
    libs = [
      "dl",
      "rt",
    ]
  }
}

# Executable configs -----------------------------------------------------------

# Windows linker setup for EXEs and DLLs.
if (is_win) {
  _windows_linker_configs = [
    "//build/config/win:sdk_link",
    "//build/config/win:common_linker_setup",
  ]
}

# This config defines the configs applied to all executables.
config("executable_config") {
  configs = []

  if (is_win) {
    configs += _windows_linker_configs
  } else if (is_mac) {
    configs += [
      "//build/config/mac:mac_dynamic_flags",
      "//build/config/mac:mac_executable_flags",
    ]
  } else if (is_linux || is_android) {
    configs += [ "//build/config/gcc:executable_ldconfig" ]
    if (is_android) {
      configs += [ "//build/config/android:executable_config" ]
    } else if (is_chromecast) {
      configs += [ "//build/config/chromecast:executable_config" ]
    }
  }
}

# Shared library configs -------------------------------------------------------

# This config defines the configs applied to all shared libraries.
config("shared_library_config") {
  configs = []

  if (is_win) {
    configs += _windows_linker_configs
  } else if (is_mac) {
    configs += [ "//build/config/mac:mac_dynamic_flags" ]
  } else if (is_chromecast) {
    configs += [ "//build/config/chromecast:shared_library_config" ]
  }
}

# Add this config to your target to enable precompiled headers.
#
# Precompiled headers are done on a per-target basis. If you have just a couple
# of files, the time it takes to precompile (~2 seconds) can actually be longer
# than the time saved. On a Z620, a 100 file target compiles about 2 seconds
# faster with precompiled headers, with greater savings for larger targets.
#
# Recommend precompiled headers for targets with more than 50 .cc files.
config("precompiled_headers") {
  if (!is_official_build && !use_goma && !disable_precompiled_headers) {
    if (is_win) {
      # This is a string rather than a file GN knows about. It has to match
      # exactly what's in the /FI flag below, and what might appear in the
      # source code in quotes for an #include directive.
      precompiled_header = "build/precompile.h"

      # This is a file that GN will compile with the above header. It will be
      # implicitly added to the sources (potentially multiple times, with one
      # variant for each language used in the target).
      precompiled_source = "//build/precompile.cc"

      # Force include the header.
      cflags = [ "/FI$precompiled_header" ]

      # Disable warning for "this file was empty after preprocessing". This
      # error is generated only in C mode for ANSI compatibility. It conflicts
      # with precompiled headers since the source file that's "compiled" for
      # making the precompiled header is empty.
      #
      # This error doesn't happen every time. In VS2013, it seems if the .pch
      # file doesn't exist, no error will be generated (probably MS tested this
      # case but forgot the other one?). To reproduce this error, do a build,
      # then delete the precompile.c.obj file, then build again.
      cflags_c = [ "/wd4206" ]
    } else if (is_mac) {
      precompiled_header = "build/precompile.h"
      precompiled_source = "//build/precompile.h"
    }
  }
}