Set sb_is_modular appropriately, build linux using sb_is_modular (#1206)

b/294267479
b/294230277

Set sb_is_modular = sb_is_evergreen ||
build_with_separate-cobalt_toolchain
Set sb_is_evergreen = !build_with_separate-cobalt_toolchain

This PR forces linux-modular builds to be built with sb_is_modular =
true and sb_is_evergreen = false

Change-Id: Ie9464ce4350023063f2ca0dfbecb2e917cd4ba3b

starboard/BUILD.gn

@@ -89,7 +89,7 @@ group("starboard") {
     "//starboard/client_porting/eztime",
   ]
 
-  if (sb_is_modular) {
+  if (sb_is_modular && current_toolchain == cobalt_toolchain) {
     public_deps += [
       "//third_party/llvm-project/compiler-rt:compiler_rt",
       "//third_party/llvm-project/libcxx:cxx",
@@ -192,7 +192,7 @@ if (current_toolchain == starboard_toolchain) {
     } else {
       public_deps += [ "//third_party/crashpad/wrapper:wrapper_stub" ]
     }
-    if (!sb_is_modular) {
+    if (!sb_is_evergreen) {
       public_deps += [ "//$starboard_path:starboard_platform" ]
     }
   }

starboard/build/config/BUILD.gn

@@ -229,7 +229,8 @@ config("warnings_as_errors") {
 # override flags specified in a platform's "platform_configuration" config,
 # which is where these particular flags would otherwise naturally fit.
 config("default_compiler_flags") {
-  if (is_starboardized_toolchain && sb_is_modular && target_cpu == "arm") {
+  if (is_starboardized_toolchain && sb_is_modular &&
+      current_toolchain == cobalt_toolchain && target_cpu == "arm") {
     cflags = [ "-mfpu=vfpv3" ]
     asmflags = cflags
   }

starboard/build/config/BUILDCONFIG.gn

@@ -117,6 +117,9 @@ import("//starboard/build/config/toolchain_variables.gni")
 import("//$starboard_path/platform_configuration/configuration.gni")
 import("//starboard/build/config/build_assertions.gni")
 
+# TODO(b/295399926) Clean up flag by moving to modular/helper_var.gni
+sb_is_modular = sb_is_evergreen || build_with_separate_cobalt_toolchain
+
 declare_args() {
   use_tsan = getenv("USE_TSAN") == 1
 }

starboard/evergreen/shared/platform_configuration/configuration.gni

@@ -14,9 +14,7 @@
 
 import("//starboard/build/config/base_configuration.gni")
 
-sb_is_modular = true
-
-sb_is_evergreen = true
+sb_is_evergreen = !build_with_separate_cobalt_toolchain
 
 cobalt_font_package = "empty"
 

starboard/extension/BUILD.gn

@@ -26,7 +26,7 @@ target(gtest_target_type, "extension_test") {
     "//testing/gmock",
     "//testing/gtest",
   ]
-  if (sb_is_modular) {
+  if (sb_is_modular && current_toolchain == cobalt_toolchain) {
     deps += cobalt_platform_dependencies
   }
 }

starboard/linux/shared/platform_configuration/BUILD.gn

@@ -143,7 +143,7 @@ config("platform_configuration") {
     "rt",
   ]
 
-  if (!sb_is_modular) {
+  if (!sb_is_modular || current_toolchain != cobalt_toolchain) {
     ldflags += [ "-static-libstdc++" ]
   }