--- chromium-88.0.4324.41/build/config/compiler/BUILD.gn.build-gentoo	2020-12-10 13:02:40.000000000 +0100
+++ chromium-88.0.4324.41/build/config/compiler/BUILD.gn	2020-12-11 00:22:54.836399245 +0100
@@ -259,8 +259,6 @@ config("compiler") {
 
   configs += [
     # See the definitions below.
-    ":clang_revision",
-    ":compiler_cpu_abi",
     ":compiler_codegen",
     ":compiler_deterministic",
   ]
@@ -1472,9 +1470,6 @@ config("default_warnings") {
       # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63872
       cflags += [ "-Wno-unused-local-typedefs" ]
 
-      # Don't warn about "maybe" uninitialized. Clang doesn't include this
-      # in -Wall but gcc does, and it gives false positives.
-      cflags += [ "-Wno-maybe-uninitialized" ]
       cflags += [ "-Wno-deprecated-declarations" ]
 
       # -Wcomment gives too many false positives in the case a
@@ -1528,48 +1523,6 @@ config("default_warnings") {
         # Currently goma can not handle case sensitiveness for windows well.
         cflags += [ "-Wno-nonportable-include-path" ]
       }
-
-      if (current_toolchain == host_toolchain || !use_xcode_clang) {
-        # Flags NaCl (Clang 3.7) and Xcode 9.2 (Clang clang-900.0.39.2) do not
-        # recognize.
-        cflags += [
-          # An ABI compat warning we don't care about, https://crbug.com/1102157
-          # TODO(thakis): Push this to the (few) targets that need it,
-          # instead of having a global flag.
-          "-Wno-psabi",
-
-          # Ignore warnings about MSVC optimization pragmas.
-          # TODO(thakis): Only for no_chromium_code? http://crbug.com/912662
-          "-Wno-ignored-pragma-optimize",
-
-          # TODO(https://crbug.com/989932): Evaluate and possibly enable.
-          "-Wno-implicit-int-float-conversion",
-
-          # TODO(https://crbug.com/999886): Clean up, enable.
-          "-Wno-final-dtor-non-final-class",
-
-          # TODO(https://crbug.com/1016945) Clean up, enable.
-          "-Wno-builtin-assume-aligned-alignment",
-
-          # TODO(https://crbug.com/1028110): Evaluate and possible enable.
-          "-Wno-deprecated-copy",
-
-          # TODO(https://crbug.com/1050281): Clean up, enable.
-          "-Wno-non-c-typedef-for-linkage",
-        ]
-
-        cflags_c += [
-          # TODO(https://crbug.com/995993): Clean up and enable.
-          "-Wno-implicit-fallthrough",
-        ]
-
-        if (enable_wmax_tokens) {
-          cflags += [ "-Wmax-tokens" ]
-        } else {
-          # TODO(https://crbug.com/1049569): Remove after Clang 87b235db.
-          cflags += [ "-Wno-max-tokens" ]
-        }
-      }
     }
   }
 }
@@ -1609,15 +1562,6 @@ config("chromium_code") {
       "__STDC_FORMAT_MACROS",
     ]
 
-    if (!is_debug && !using_sanitizer && current_cpu != "s390x" &&
-        current_cpu != "s390" && current_cpu != "ppc64" &&
-        current_cpu != "mips" && current_cpu != "mips64") {
-      # 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" ]
-    }
-
     if (is_mac) {
       cflags_objc = [ "-Wobjc-missing-property-synthesis" ]
       cflags_objcc = [ "-Wobjc-missing-property-synthesis" ]
@@ -2017,7 +1961,8 @@ config("default_stack_frames") {
 }
 
 # Default "optimization on" config.
-config("optimize") {
+config("optimize") { }
+config("xoptimize") {
   if (is_win) {
     if (chrome_pgo_phase != 2) {
       # Favor size over speed, /O1 must be before the common flags.
@@ -2052,7 +1997,8 @@ config("optimize") {
 }
 
 # Turn off optimizations.
-config("no_optimize") {
+config("no_optimize") { }
+config("xno_optimize") {
   if (is_win) {
     cflags = [
       "/Od",  # Disable optimization.
@@ -2092,7 +2038,8 @@ config("no_optimize") {
 # 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") {
+config("optimize_max") { }
+config("xoptimize_max") {
   if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # Various components do:
@@ -2124,7 +2071,8 @@ config("optimize_max") {
 #
 # TODO(crbug.com/621335) - rework how all of these configs are related
 # so that we don't need this disclaimer.
-config("optimize_speed") {
+config("optimize_speed") { }
+config("xoptimize_speed") {
   if (is_nacl && is_nacl_irt) {
     # The NaCl IRT is a special case and always wants its own config.
     # Various components do:
@@ -2149,7 +2097,8 @@ config("optimize_speed") {
   }
 }
 
-config("optimize_fuzzing") {
+config("optimize_fuzzing") { }
+config("xoptimize_fuzzing") {
   cflags = [ "-O1" ] + common_optimize_on_cflags
   ldflags = common_optimize_on_ldflags
   visibility = [ ":default_optimization" ]
@@ -2264,7 +2213,8 @@ config("win_pdbaltpath") {
 }
 
 # Full symbols.
-config("symbols") {
+config("symbols") { }
+config("xsymbols") {
   if (is_win) {
     if (is_clang) {
       cflags = [ "/Z7" ]  # Debug information in the .obj files.
@@ -2366,7 +2316,8 @@ config("symbols") {
 # Minimal symbols.
 # This config guarantees to hold symbol for stack trace which are shown to user
 # when crash happens in unittests running on buildbot.
-config("minimal_symbols") {
+config("minimal_symbols") { }
+config("xminimal_symbols") {
   if (is_win) {
     # Functions, files, and line tables only.
     cflags = []
@@ -2423,7 +2374,8 @@ config("minimal_symbols") {
 # This configuration contains function names only. That is, the compiler is
 # told to not generate debug information and the linker then just puts function
 # names in the final debug information.
-config("no_symbols") {
+config("no_symbols") { }
+config("xno_symbols") {
   if (is_win) {
     ldflags = [ "/DEBUG" ]