Make is_starboard a global variable

base/BUILD.gn

@@ -1792,7 +1792,7 @@ component("base") {
       "process/process_metrics_posix.cc",
       "sync_socket_posix.cc",
 
-      # base/posix/unix_domain_socket.cc:91:22: error: implicit conversion loses integer precision: 
+      # base/posix/unix_domain_socket.cc:91:22: error: implicit conversion loses integer precision:
       "posix/unix_domain_socket.cc",
       "posix/unix_domain_socket.h",
 
@@ -2742,7 +2742,7 @@ if (use_custom_libcxx && enable_safe_libcxx && !is_debug) {
     sources = [ "nodebug_assertion.cc" ]
     deps = [ ":base_static" ]
     if (is_starboard) {
-      deps += ["//starboard:starboard_group"]
+      deps += [ "//starboard:starboard_group" ]
     }
   }
 }

build/config/BUILDCONFIG.gn

@@ -301,6 +301,8 @@ if (is_cobalt) {
   }
 }
 
+import("//cobalt/build/configs/starboard.gni")
+
 # =============================================================================
 # OS DEFINITIONS
 # =============================================================================

build/config/c++/BUILD.gn

@@ -72,7 +72,7 @@ config("runtime_library") {
       "-isystem" + rebase_path("$libcxx_prefix/include", root_build_dir),
       "-isystem" + rebase_path("$libcxxabi_prefix/include", root_build_dir),
     ]
-    if (is_cobalt && is_cobalt_hermetic_build) {
+    if (is_cobalt && is_cobalt_hermetic_build && current_toolchain == cobalt_toolchain) {
       cflags_cc += [
         "-isystem" + rebase_path("//third_party/musl/include", root_build_dir),
         "-isystem" +

build/toolchain/linux/BUILD.gn

@@ -111,7 +111,6 @@ clang_toolchain("clang_x64") {
   toolchain_args = {
     current_cpu = "x64"
     current_os = "linux"
-    is_starboard = false
   }
 }
 

buildtools/third_party/libc++/BUILD.gn

@@ -216,7 +216,7 @@ target(_libcxx_target_type, "libc++") {
     }
   }
 
-  if (is_cobalt && is_cobalt_hermetic_build) {
+  if (is_cobalt && is_cobalt_hermetic_build && current_toolchain == cobalt_toolchain) {
     # TODO: b/384652502 - Cobalt: Fix compiler errors building hermetically.
     sources -= [ "trunk/src/atomic.cpp" ]
     deps += [

cobalt/build/configs/BUILD.gn

@@ -23,7 +23,8 @@ config("cobalt_config") {
   ]
   if (current_toolchain == starboard_toolchain) {
     configs += [ "//${starboard_path}/platform_configuration" ]
-  } else if (is_cobalt_hermetic_build) {
+  } else if (is_cobalt_hermetic_build &&
+             current_toolchain == cobalt_toolchain) {
     configs += [
       # TODO: b/390500840 - Remove hardcoded x64 config, switch config based on platform.
       "//starboard/build/config/modular/x64",

cobalt/build/configs/cobalt.gni

@@ -17,7 +17,3 @@ declare_args() {
   is_cobalt = false
   cobalt_is_release_build = false
 }
-
-declare_args() {
-  is_starboard = is_cobalt && target_os != "android"
-}

cobalt/build/configs/modular_variables.gni

@@ -17,5 +17,4 @@ declare_args() {
   use_custom_libc = false
 }
 
-is_cobalt_hermetic_build =
-    is_starboard && use_custom_libc && current_toolchain == cobalt_toolchain
+is_cobalt_hermetic_build = is_starboard && use_custom_libc

cobalt/build/configs/starboard.gni

@@ -0,0 +1,18 @@
+# Copyright 2024 The Cobalt Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+declare_args() {
+  is_starboard = is_cobalt && target_os != "android" &&
+                 current_toolchain == default_toolchain
+}

starboard/BUILD.gn

@@ -114,7 +114,7 @@ if (is_cobalt_hermetic_build) {
       "//starboard/client_porting/eztime",
     ]
 
-    if (!sb_is_evergreen) {
+    if (!sb_is_evergreen && current_toolchain == cobalt_toolchain) {
       # For modular builds, we need to wrap any POSIX APIs that may not be ABI
       # equivalent across the Cobalt toolchain and the platform toolchain. For
       # non-Evergreen builds, this is done via the below wrapper implementations

starboard/linux/x64x11/toolchain/BUILD.gn

@@ -21,26 +21,11 @@ overridable_clang_toolchain("starboard") {
   toolchain_args = {
     current_os = "linux"
     current_cpu = "x64"
+    is_starboard = true
   }
   propagates_configs = true
 }
 
-overridable_clang_toolchain("cobalt") {
-  clang_base_path = clang_base_path
-  toolchain_args = {
-    current_os = "linux"
-    current_cpu = "x64"
-  }
-}
-
-overridable_clang_toolchain("target") {
-  clang_base_path = clang_base_path
-  toolchain_args = {
-    current_os = "linux"
-    current_cpu = "x64"
-  }
-}
-
 clang_toolchain("native_target") {
   toolchain_args = {
     is_starboard = false

starboard/shared/modular/BUILD.gn

@@ -46,7 +46,8 @@ if ((sb_is_modular || sb_is_evergreen_compatible) &&
   }
 }
 
-if (is_cobalt_hermetic_build && !sb_is_evergreen) {
+if (is_cobalt_hermetic_build && !sb_is_evergreen &&
+    current_toolchain == cobalt_toolchain) {
   source_set("cobalt_layer_posix_abi_wrappers") {
     sources = [
       "cobalt_layer_posix_directory_abi_wrappers.cc",