Revert of [GN]: BUILD file housecleaning

tools/gn/ninja_binary_target_writer.cc

 // 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.
 
 #include "tools/gn/ninja_binary_target_writer.h"
 
 #include <cstring>
 #include <set>
 #include <sstream>
 
@@ skipping 402 matching lines @@
   }
 
   bool has_precompiled_headers =
       target_->config_values().has_precompiled_headers();
 
   EscapeOptions opts = GetFlagOptions();
   if (used_types.Get(SOURCE_S) || used_types.Get(SOURCE_ASM)) {
     WriteOneFlag(SUBSTITUTION_ASMFLAGS, false, Toolchain::TYPE_NONE,
                  &ConfigValues::asmflags, opts);
   }
+  // TODO(andybons): Remove SOURCE_S and SOURCE_ASM checks once asmflags is
+  // used.
   if (used_types.Get(SOURCE_C) || used_types.Get(SOURCE_CPP) ||
-      used_types.Get(SOURCE_M) || used_types.Get(SOURCE_MM)) {
+      used_types.Get(SOURCE_M) || used_types.Get(SOURCE_MM) ||
+      used_types.Get(SOURCE_S) || used_types.Get(SOURCE_ASM)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS, false, Toolchain::TYPE_NONE,
                  &ConfigValues::cflags, opts);
   }
-  if (used_types.Get(SOURCE_C)) {
+  if (used_types.Get(SOURCE_C) || used_types.Get(SOURCE_S) ||
+      used_types.Get(SOURCE_ASM)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS_C, has_precompiled_headers,
                  Toolchain::TYPE_CC, &ConfigValues::cflags_c, opts);
   }
   if (used_types.Get(SOURCE_CPP)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS_CC, has_precompiled_headers,
                  Toolchain::TYPE_CXX, &ConfigValues::cflags_cc, opts);
   }
   if (used_types.Get(SOURCE_M)) {
     WriteOneFlag(SUBSTITUTION_CFLAGS_OBJC, has_precompiled_headers,
                  Toolchain::TYPE_OBJC, &ConfigValues::cflags_objc, opts);
@@ skipping 589 matching lines @@
           "\n"
           "In the latter case, either rename one of the files or move one of\n"
           "the sources to a separate source_set to avoid them both being in\n"
           "the same target.");
       g_scheduler->FailWithError(err);
       return false;
     }
   }
   return true;
 }