Add GN variables for controlling header checking.

tools/gn/command_check.cc

 // Copyright 2014 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/commands.h"
 #include "tools/gn/header_checker.h"
 #include "tools/gn/setup.h"
 #include "tools/gn/standard_out.h"
 #include "tools/gn/trace.h"
 
 namespace commands {
 
 const char kCheck[] = "check";
 const char kCheck_HelpShort[] =
     "check: Check header dependencies.";
 const char kCheck_Help[] =
-    "gn check <out_dir> [<target label>]\n"
+    "gn check <out_dir> [<target label>] [--force]\n"
     "\n"
     "  \"gn check\" is the same thing as \"gn gen\" with the \"--check\" flag\n"
     "  except that this command does not write out any build files. It's\n"
     "  intended to be an easy way to manually trigger include file checking.\n"
     "\n"
     "  The <label_pattern> can take exact labels or patterns that match more\n"
     "  than one (although not general regular expressions). If specified,\n"
     "  only those matching targets will be checked.\n"
     "  See \"gn help label_pattern\" for details.\n"
     "\n"
+    "  --force\n"
+    "      Ignores specifications of \"check_includes = false\" and checks\n"
+    "      all target's files that match the target label.\n"
+    "\n"
     "  See \"gn help\" for the common command-line switches.\n"
     "\n"
     "Examples\n"
     "\n"
     "  gn check out/Debug\n"
     "      Check everything.\n"
     "\n"
     "  gn check out/Default //foo:bar\n"
     "      Check only the files in the //foo:bar target.\n"
     "\n"
@@ skipping 19 matching lines @@
     // Compute the target to check (empty means everything).
     if (!ResolveTargetsFromCommandLinePattern(setup, args[1], false,
                                               &targets_to_check))
       return 1;
     if (targets_to_check.size() == 0) {
       OutputString("No matching targets.\n");
       return 1;
     }
   }
 
+  const CommandLine* cmdline = CommandLine::ForCurrentProcess();
+  bool force = cmdline->HasSwitch("force");
+
   if (!CheckPublicHeaders(&setup->build_settings(),
                           setup->builder()->GetAllResolvedTargets(),
-                          targets_to_check))
+                          targets_to_check,
+                          force))
     return 1;
 
   OutputString("Header dependency check OK\n", DECORATION_GREEN);
   return 0;
 }
 
 bool CheckPublicHeaders(const BuildSettings* build_settings,
                         const std::vector<const Target*>& all_targets,
-                        const std::vector<const Target*>& to_check) {
+                        const std::vector<const Target*>& to_check,
+                        bool force_check) {
   ScopedTrace trace(TraceItem::TRACE_CHECK_HEADERS, "Check headers");
 
   scoped_refptr<HeaderChecker> header_checker(
       new HeaderChecker(build_settings, all_targets));
 
   std::vector<Err> header_errors;
-  header_checker->Run(to_check, &header_errors);
+  header_checker->Run(to_check, force_check, &header_errors);
   for (size_t i = 0; i < header_errors.size(); i++) {
     if (i > 0)
       OutputString("___________________\n", DECORATION_YELLOW);
     header_errors[i].PrintToStdout();
   }
   return header_errors.empty();
 }
 
 }  // namespace commands