LaCrOS: Prepare //build for target_os switch of lacros-chrome.

The patch is made in preparation to switching lacros build from
target_os=linux to target_os=chromeos. This will prevent lacros from
changing behaviour after the switch.

Unlike other patches with similar changes, //build changes are done
manually following similar rules outlined in http://go/lacros-macros.

Bug: 1052397
Cq-Depend: chromium:2581632
Change-Id: Ieda2c12eafa2e3f1a75ca024ecda60362fb2515e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2581183Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Yuta Hijikata <ythjkt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837967}

build/config/android/abi.gni

@@ -12,8 +12,8 @@ import("//build/config/chromeos/ui_mode.gni")
 # NOTE: Because Chrome OS builds may depend on targets built with the Android
 # toolchain, this GNI file may be read and processed from within Chrome OS
 # toolchains. Checking |is_android| here would therefore be too restrictive.
-assert(is_android || is_chromeos ||
-       (is_linux && chromeos_is_browser_only && also_build_ash_chrome))
+assert(is_android || is_chromeos_ash ||
+       (is_chromeos_lacros && also_build_ash_chrome))
 
 declare_args() {
   # Adds intrumentation to each function. Writes a file with the order that

build/config/android/config.gni

@@ -11,8 +11,8 @@ import("//build/config/chromeos/ui_mode.gni")
 # NOTE: Because Chrome OS builds may depend on targets built with the Android
 # toolchain, this GNI file may be read and processed from within Chrome OS
 # toolchains. Checking |is_android| here would therefore be too restrictive.
-if (is_android || is_chromeos ||
-    (is_linux && chromeos_is_browser_only && also_build_ash_chrome)) {
+if (is_android || is_chromeos_ash ||
+    (is_chromeos_lacros && also_build_ash_chrome)) {
   import("//build/config/chromecast_build.gni")
   import("//build_overrides/build.gni")
   import("abi.gni")

build/config/c++/BUILD.gn

 import("//build/config/c++/c++.gni")
 import("//build/config/chrome_build.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/dcheck_always_on.gni")
 import("//buildtools/deps_revisions.gni")
 
@@ -20,7 +21,7 @@ declare_args() {
 
 # TODO(xiaohuic): https://crbug/917533 Crashes on internal ChromeOS build.
 # Do unconditionally once the underlying problem is fixed.
-if (is_chromeos && is_chrome_branded) {
+if (is_chromeos_ash && is_chrome_branded) {
   libcxx_abi_unstable = false
 }
 

build/config/c++/c++.gni

@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 
 declare_args() {
@@ -10,11 +11,11 @@ declare_args() {
   # standard library support.
   # Don't check in changes that set this to false for more platforms; doing so
   # is not supported.
-  use_custom_libcxx =
-      is_fuchsia || is_android || is_mac || (is_ios && !use_xcode_clang) ||
-      (is_win && is_clang) ||
-      ((is_linux || is_chromeos) &&
-       (!is_chromeos || default_toolchain != "//build/toolchain/cros:target"))
+  use_custom_libcxx = is_fuchsia || is_android || is_mac ||
+                      (is_ios && !use_xcode_clang) || (is_win && is_clang) ||
+                      ((is_linux || is_chromeos) &&
+                       (!is_chromeos_ash ||
+                        default_toolchain != "//build/toolchain/cros:target"))
 
   # Use libc++ instead of stdlibc++ when using the host_cpu toolchain, even if
   # use_custom_libcxx is false. This is useful for cross-compiles where a custom

build/config/chromeos/BUILD.gn

@@ -3,8 +3,9 @@
 # found in the LICENSE file.
 
 import("//build/config/chromeos/rules.gni")
+import("//build/config/chromeos/ui_mode.gni")
 
-assert(is_chromeos)
+assert(is_chromeos_ash)
 
 declare_args() {
   # The location to a file used to dump symbols ordered by Call-Chain Clustering (C3)

build/config/chromeos/rules.gni

@@ -4,10 +4,11 @@
 
 import("//build/config/chrome_build.gni")
 import("//build/config/chromeos/args.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/gclient_args.gni")
 import("//build/config/python.gni")
 
-assert(is_chromeos)
+assert(is_chromeos_ash)
 
 # Determine the real paths for various items in the SDK, which may be used
 # in the 'generate_runner_script' template below. We do so outside the template

build/config/compiler/BUILD.gn

@@ -8,6 +8,7 @@ import("//build/config/c++/c++.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/chromeos/args.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/clang/clang.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/coverage/coverage.gni")
@@ -118,7 +119,7 @@ declare_args() {
   # the space overhead is too great. We should use some mixture of profiles and
   # optimization settings to better tune the size increase.
   thin_lto_enable_optimizations =
-      (is_chromeos || is_android || is_win) && is_official_build
+      (is_chromeos_ash || is_android || is_win) && is_official_build
 
   # Initialize all local variables with a pattern. This flag will fill
   # uninitialized floating-point types (and 32-bit pointers) with 0xFF and the
@@ -147,7 +148,7 @@ declare_args() {
   enable_wmax_tokens =
       !is_official_build &&
       ((is_mac && target_cpu == "x64" && !use_system_xcode) ||
-       (is_linux && !is_chromeos && target_cpu == "x64") ||
+       ((is_linux || is_chromeos_lacros) && target_cpu == "x64") ||
        (is_win && target_cpu == "x86") || (is_win && target_cpu == "x64") ||
        (is_android && target_cpu == "arm") ||
        (is_android && target_cpu == "arm64"))
@@ -175,13 +176,14 @@ declare_args() {
   # other architectures.
   #
   # lld doesn't have the bug.
-  use_icf = (is_posix || is_fuchsia) && !is_debug && !using_sanitizer &&
-            !use_clang_coverage && !(is_android && use_order_profiling) &&
-            (use_lld || (use_gold && (is_chromeos || !(current_cpu == "x86" ||
-                                                       current_cpu == "x64"))))
+  use_icf =
+      (is_posix || is_fuchsia) && !is_debug && !using_sanitizer &&
+      !use_clang_coverage && !(is_android && use_order_profiling) &&
+      (use_lld || (use_gold && (is_chromeos_ash || !(current_cpu == "x86" ||
+                                                     current_cpu == "x64"))))
 }
 
-if (is_android || (is_chromeos && is_chromeos_device)) {
+if (is_android || (is_chromeos_ash && is_chromeos_device)) {
   # Set the path to use orderfile for linking Chrome
   # Note that this is for using only one orderfile for linking
   # the Chrome binary/library.
@@ -192,7 +194,7 @@ if (is_android || (is_chromeos && is_chromeos_device)) {
       # Allow downstream tools to set orderfile path with
       # another variable.
       chrome_orderfile_path = default_chrome_orderfile
-    } else if (is_chromeos && is_chromeos_device) {
+    } else if (is_chromeos_ash && is_chromeos_device) {
       chrome_orderfile_path = "//chromeos/profiles/chromeos.orderfile.txt"
     }
   }
@@ -240,7 +242,7 @@ config("compiler") {
     configs += [ "//build/config/android:compiler" ]
   } else if (is_linux || is_chromeos) {
     configs += [ "//build/config/linux:compiler" ]
-    if (is_chromeos) {
+    if (is_chromeos_ash) {
       configs += [ "//build/config/chromeos:compiler" ]
     }
   } else if (is_nacl) {
@@ -291,7 +293,7 @@ config("compiler") {
       } else {
         cflags += [ "-fstack-protector" ]
       }
-    } else if ((is_posix && !is_chromeos && !is_nacl) || is_fuchsia) {
+    } else if ((is_posix && !is_chromeos_ash && !is_nacl) || is_fuchsia) {
       # TODO(phajdan.jr): Use -fstack-protector-strong when our gcc supports it.
       # See also https://crbug.com/533294
       cflags += [ "--param=ssp-buffer-size=4" ]
@@ -662,7 +664,7 @@ config("compiler") {
         import_instr_limit = -1
         if (is_android) {
           import_instr_limit = 5
-        } else if (is_chromeos) {
+        } else if (is_chromeos_ash) {
           # Not much performance difference was noted between the default (100)
           # and these. ARM was originally set lower than x86 to keep the size
           # bloat of ThinLTO to <10%, but that's potentially no longer true.
@@ -1213,7 +1215,7 @@ config("compiler_arm_thumb") {
 }
 
 config("compiler_arm") {
-  if (current_cpu == "arm" && is_chromeos) {
+  if (current_cpu == "arm" && is_chromeos_ash) {
     # arm is normally the default mode for clang, but on chromeos a wrapper
     # is used to pass -mthumb, and therefor change the default.
     cflags = [ "-marm" ]
@@ -1652,7 +1654,7 @@ config("chromium_code") {
     # ChromeOS: http://crbug.com/940863
     # Chromecast: http://crbug.com/942554
     has_dchecks = is_debug || dcheck_always_on
-    if (!has_dchecks && is_chromeos && is_chrome_branded) {
+    if (!has_dchecks && is_chromeos_ash && is_chrome_branded) {
       # Temporarily disable -Wextra-semi for Chrome on Chrome OS.
     } else if (is_chromecast && chromecast_branding != "public") {
       # Temporarily disable -Wextra-semi for Chromecast.
@@ -1755,7 +1757,8 @@ config("no_rtti") {
 # (de)allocate memory on a different heap, which would spell trouble if pointers
 # to heap-allocated memory are passed over shared library boundaries.
 config("export_dynamic") {
-  if (is_linux || export_libcxxabi_from_executables) {
+  # TODO(crbug.com/1052397): Revisit after target_os flip is completed.
+  if (is_linux || is_chromeos_lacros || export_libcxxabi_from_executables) {
     ldflags = [ "-rdynamic" ]
   }
 }
@@ -1894,7 +1897,7 @@ config("no_incompatible_pointer_warnings") {
     cflags += [ "-Wno-incompatible-pointer-types" ]
   } else if (current_cpu == "mipsel" || current_cpu == "mips64el") {
     cflags += [ "-w" ]
-  } else if (is_chromeos && current_cpu == "arm") {
+  } else if (is_chromeos_ash && current_cpu == "arm") {
     cflags += [ "-w" ]
   }
 }
@@ -2037,7 +2040,7 @@ config("optimize") {
     } else {
       cflags = [ "-Os" ] + common_optimize_on_cflags
     }
-  } else if (is_chromeos) {
+  } else if (is_chromeos_ash) {
     # TODO(gbiv): This is partially favoring size over speed. CrOS exclusively
     # uses clang, and -Os in clang is more of a size-conscious -O2 than "size at
     # any cost" (AKA -Oz). It'd be nice to:
@@ -2185,9 +2188,8 @@ if (is_clang && is_a_target_toolchain) {
   } else if (clang_use_default_sample_profile) {
     assert(build_with_chromium,
            "Our default profiles currently only apply to Chromium")
-    assert(
-        is_android || chromeos_is_browser_only || is_chromeos || is_chromecast,
-        "The current platform has no default profile")
+    assert(is_android || is_chromeos_lacros || is_chromeos_ash || is_chromecast,
+           "The current platform has no default profile")
     if (is_android || is_chromecast) {
       _clang_sample_profile = "//chrome/android/profiles/afdo.prof"
     } else {
@@ -2471,7 +2473,7 @@ if (is_apple) {
   }
 }
 
-if (is_chromeos && is_chromeos_device) {
+if (is_chromeos_ash && is_chromeos_device) {
   # This config is intended to be a temporary to facilitate
   # the transition to use orderfile in Chrome OS. Once orderfile
   # use becomes a default in Chrome OS, this config should not
@@ -2483,7 +2485,7 @@ if (is_chromeos && is_chromeos_device) {
   }
 }
 
-if (is_android || (is_chromeos && is_chromeos_device)) {
+if (is_android || (is_chromeos_ash && is_chromeos_device)) {
   # Use orderfile for linking Chrome on Android and Chrome OS.
   # This config enables using an orderfile for linking in LLD.
   # TODO: Consider using call graph sort instead, at least on Android.

build/config/compiler/compiler.gni

@@ -5,6 +5,7 @@
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/chromeos/args.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/compiler/pgo/pgo.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/toolchain/cc_wrapper.gni")
@@ -125,7 +126,9 @@ declare_args() {
 
 # Determine whether to enable or disable frame pointers, based on the platform
 # and build arguments.
-if (is_chromeos) {
+# TODO(crbug.com/1052397): Consider changing is_chromeos_ash to is_chromeos after
+# lacros-chrome switches to target_os="chromeos".
+if (is_chromeos_ash) {
   # ChromeOS generally prefers frame pointers, to support CWP.
   # However, Clang does not currently generate usable frame pointers in ARM
   # 32-bit builds (https://bugs.llvm.org/show_bug.cgi?id=18505) so disable them
@@ -197,14 +200,14 @@ declare_args() {
 
 declare_args() {
   # Whether to use the gold linker from binutils instead of lld or bfd.
-  use_gold =
-      !use_lld && !(is_chromecast && is_linux &&
-                    (current_cpu == "arm" || current_cpu == "mipsel")) &&
-      ((is_linux && (current_cpu == "x64" || current_cpu == "x86" ||
-                     current_cpu == "arm" || current_cpu == "arm64" ||
-                     current_cpu == "mipsel" || current_cpu == "mips64el")) ||
-       (is_android && (current_cpu == "x86" || current_cpu == "x64" ||
-                       current_cpu == "arm" || current_cpu == "arm64")))
+  use_gold = !use_lld && !(is_chromecast && is_linux &&
+                           (current_cpu == "arm" || current_cpu == "mipsel")) &&
+             (((is_linux || is_chromeos_lacros) &&
+               (current_cpu == "x64" || current_cpu == "x86" ||
+                current_cpu == "arm" || current_cpu == "arm64" ||
+                current_cpu == "mipsel" || current_cpu == "mips64el")) ||
+              (is_android && (current_cpu == "x86" || current_cpu == "x64" ||
+                              current_cpu == "arm" || current_cpu == "arm64")))
 }
 
 # Use relative paths for debug info. This is important to make the build

build/config/compiler/pgo/BUILD.gn

@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/clang/clang.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/compiler/pgo/pgo.gni")
@@ -49,7 +50,7 @@ config("pgo_optimization_flags") {
     } else if (is_mac) {
       _pgo_target = "mac"
       inputs = [ "//chrome/build/mac.pgo.txt" ]
-    } else if (is_linux) {
+    } else if (is_linux || is_chromeos_lacros) {
       _pgo_target = "linux"
       inputs = [ "//chrome/build/linux.pgo.txt" ]
     }

build/config/compiler/pgo/pgo.gni

@@ -13,7 +13,10 @@ declare_args() {
   #     2 : Used during the PGO (optimization) phase.
   chrome_pgo_phase = 0
   if (is_official_build &&
-      (is_win || is_mac || (is_linux && !chromeos_is_browser_only && !is_chromecast))) {
+      # TODO(crbug.com/1052397): Remove chromeos_is_browser_only once
+      # target_os switch for lacros-chrome is completed.
+      (is_win || is_mac ||
+       (is_linux && !chromeos_is_browser_only && !is_chromecast))) {
     chrome_pgo_phase = 2
   }
 

build/config/features.gni

@@ -30,7 +30,7 @@ declare_args() {
 
   use_dbus = (is_linux || is_chromeos) && !is_chromecast
 
-  use_gio = is_linux && !is_chromeos && !is_chromecast
+  use_gio = is_linux && !is_chromecast
 }
 #
 # =============================================

build/config/linux/BUILD.gn

@@ -24,11 +24,13 @@ config("compiler") {
 config("runtime_library") {
   # Set here because OS_CHROMEOS cannot be autodetected in build_config.h like
   # OS_LINUX and the like.
-  if (is_chromeos) {
+  # TODO(crbug.com/1052397): Consider changing is_chromeos_ash to is_chromeos after
+  # lacros-chrome switches to target_os="chromeos".
+  if (is_chromeos_ash) {
     defines = [ "OS_CHROMEOS" ]
   }
 
-  if ((!(is_chromeos || chromeos_is_browser_only) ||
+  if ((!(is_chromeos_ash || is_chromeos_lacros) ||
        default_toolchain != "//build/toolchain/cros:target") &&
       (!use_custom_libcxx || current_cpu == "mipsel")) {
     libs = [ "atomic" ]

build/config/linux/gtk/BUILD.gn

@@ -5,7 +5,7 @@
 import("//build/config/linux/gtk/gtk.gni")
 import("//build/config/linux/pkg_config.gni")
 
-assert(is_linux && !is_chromeos, "This file should only be referenced on Linux")
+assert(is_linux, "This file should only be referenced on Linux")
 
 # GN doesn't check visibility for configs so we give this an obviously internal
 # name to discourage random targets from accidentally depending on this and
@@ -31,12 +31,12 @@ group("gtk") {
 
     # These are all for WebRTC.
     "//examples:peerconnection_client",
-    "//remoting/host/linux",
-    "//remoting/host/it2me:common",
-    "//remoting/host/it2me:remote_assistance_host",
     "//remoting/host:common",
-    "//remoting/host/file_transfer",
     "//remoting/host:remoting_me2me_host_static",
+    "//remoting/host/file_transfer",
+    "//remoting/host/it2me:common",
+    "//remoting/host/it2me:remote_assistance_host",
+    "//remoting/host/linux",
     "//remoting/test:it2me_standalone_host_main",
     "//webrtc/examples:peerconnection_client",
   ]

build/config/linux/pangocairo/pangocairo.gni

@@ -7,5 +7,7 @@ import("//build/config/ui.gni")
 
 declare_args() {
   use_pangocairo =
-      is_linux && !is_chromeos && !is_chromecast && !chromeos_is_browser_only
+      # TODO(crbug.com/1052397): Remove !chromeos_is_browser_only once
+      # lacros-chrome switches to target_os="chromeos"
+      is_linux && !is_chromecast && !chromeos_is_browser_only
 }

build/config/logging.gni

@@ -2,9 +2,11 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/dcheck_always_on.gni")
 
 declare_args() {
   # Use LogErrorNotReached() for NOTREACHED().
-  enable_log_error_not_reached = is_chromeos && !(is_debug || dcheck_always_on)
+  enable_log_error_not_reached =
+      is_chromeos_ash && !(is_debug || dcheck_always_on)
 }

build/config/ozone.gni

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import("//build/config/chromecast_build.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/ui.gni")
 import("//build/toolchain/toolchain.gni")
 
@@ -65,11 +66,11 @@ declare_args() {
       } else {
         ozone_platform = "cast"
       }
-    } else if (is_chromeos) {
+    } else if (is_chromeos_ash) {
       ozone_platform = "x11"
       ozone_platform_drm = true
       ozone_platform_x11 = true
-    } else if (is_linux) {
+    } else if (is_linux || is_chromeos_lacros) {
       ozone_platform = "x11"
       ozone_platform_wayland = true
       ozone_platform_x11 = true

build/config/sanitizers/sanitizers.gni

@@ -5,6 +5,7 @@
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/chromeos/args.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/profiling/profiling.gni")
 import("//build/toolchain/toolchain.gni")
 
@@ -55,15 +56,20 @@ declare_args() {
   #
   # Disable this on linux-chromeos to avoid using ThinLTO there;
   # crbug.com/1033839. Similarly, don't use this on ARC builds.
-  is_cfi = is_official_build &&
-           ((target_os == "linux" && !is_chromeos && target_cpu == "x64") ||
-            (target_os == "chromeos" && is_chromeos_device))
+  #
+  # TODO(crbug.com/1159424): Reassess the validity of the next expression.
+  is_cfi =
+      is_official_build &&
+      (((target_os == "linux" || is_chromeos_lacros) && target_cpu == "x64") ||
+       (target_os == "chromeos" && is_chromeos_device && !is_chromeos_lacros))
 
   # Enable checks for indirect function calls via a function pointer.
   # TODO(pcc): remove this when we're ready to add these checks by default.
   # https://crbug.com/701919
-  use_cfi_icall = target_os == "linux" && !is_chromeos && target_cpu == "x64" &&
-                  is_official_build
+  #
+  # TODO(crbug.com/1159424): Reassess the validity of the next expression.
+  use_cfi_icall = (target_os == "linux" || is_chromeos_lacros) &&
+                  target_cpu == "x64" && is_official_build
 
   # Print detailed diagnostics when Control Flow Integrity detects a violation.
   use_cfi_diag = false

build/config/ui.gni

@@ -29,8 +29,7 @@ declare_args() {
   # Indicates if the UI toolkit depends on X11.
   # Enabled by default. Can be disabled if Ozone only build is required and
   # vice-versa.
-  use_x11 =
-      is_linux && !is_chromecast && !is_chromeos && !chromeos_is_browser_only
+  use_x11 = is_linux && !is_chromecast && !is_chromeos_lacros
 
   # Indicates if Aura is enabled. Aura is a low-level windowing library, sort
   # of a replacement for GDI or GTK.
@@ -46,14 +45,14 @@ declare_args() {
 }
 
 # Make sure glib is not used if building for ChromeOS/Chromecast
-assert(!use_glib || (is_linux && !is_chromeos && !is_chromecast))
+assert(!use_glib || (is_linux && !is_chromecast))
 
 # Whether to use atk, the Accessibility ToolKit library
 use_atk = is_linux && !is_chromecast && use_glib
 
 # Whether using Xvfb to provide a display server for a test might be
 # necessary.
-use_xvfb_in_this_config = (is_linux && !is_chromeos) || chromeos_is_browser_only
+use_xvfb_in_this_config = is_linux || is_chromeos_lacros
 #
 # =============================================
 #   PLEASE DO NOT ADD MORE FLAGS TO THIS FILE

build/toolchain/concurrent_links.gni

@@ -8,6 +8,7 @@
 assert(current_toolchain == default_toolchain)
 
 import("//build/config/android/config.gni")
+import("//build/config/chromeos/ui_mode.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/mac/symbols.gni")
 import("//build/config/sanitizers/sanitizers.gni")
@@ -36,7 +37,8 @@ if (concurrent_links == -1) {
     } else {
       _args += [ "--mem_per_link_gb=10" ]
     }
-  } else if (use_clang_coverage || use_sanitizer_coverage || use_fuzzing_engine) {
+  } else if (use_clang_coverage || use_sanitizer_coverage ||
+             use_fuzzing_engine) {
     # Sanitizer coverage instrumentation increases linker memory consumption
     # significantly.
     _args = [ "--mem_per_link_gb=16" ]
@@ -60,7 +62,7 @@ if (concurrent_links == -1) {
     } else {
       _args = [ "--mem_per_link_gb=4" ]
     }
-  } else if (is_linux && !is_chromeos && symbol_level == 0) {
+  } else if ((is_linux || is_chromeos_lacros) && symbol_level == 0) {
     # Memory consumption on link without debug symbols is low on linux.
     _args = [ "--mem_per_link_gb=3" ]
   } else {