Add a --force command line option to the alternate_version_generator to allow...

chrome/installer/test/alternate_version_generator_main.cc

 // Copyright (c) 2011 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.
 
 // This file provides a command-line interface to
 // upgrade_test::GenerateAlternateVersion().
 
 #include <cstdio>
 #include <cstdlib>
 
 #include "base/at_exit.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "chrome/installer/test/alternate_version_generator.h"
 
 namespace {
 
 const wchar_t kDefaultMiniInstallerFile[] = L"mini_installer.exe";
 const wchar_t kDefaultOutPath[] = L"mini_installer_new.exe";
 
 namespace switches {
 
+const char kForce[] = "force";
 const char kHelp[] = "help";
 const char kMiniInstaller[] = "mini_installer";
 const char kOut[] = "out";
 const char kPrevious[] = "previous";
 
 }  // namespace switches
 
 namespace errors {
 
 enum ErrorCode {
@@ skipping 30 matching lines @@
     if (!detail.empty())
       fwprintf(stderr, L" (%s)\n", detail.c_str());
     else
       fwprintf(stderr, L"\n");
   }
 
   fwprintf(stderr,
 L"Usage: %s [ OPTIONS ]\n"
 L" Where OPTIONS is one or more of:\n"
 L" --help                     Display this help message.\n"
+L" --force                    Overwrite any existing output files.\n"
 L" --mini_installer=SRC_PATH  Path to mini_installer.exe.  Default value is\n"
 L"                            \"mini_installer.exe\" in the same directory as\n"
 L"                            this program.\n"
 L" --out=OUT_PATH             Path to output file. Default value is\n"
 L"                            \"mini_installer_new.exe\" in the current\n"
 L"                            directory.\n"
 L" --previous                 OUT_PATH will have a lower version than\n"
 L"                            SRC_PATH.  By default, OUT_PATH will have a\n"
 L"                            higher version.\n"
 L" --7za_path=7ZA_PATH        Path to the directory holding 7za.exe. Defaults\n"
@@ skipping 52 matching lines @@
   }
 
   if (!file_util::PathExists(mini_installer)) {
     DumpUsage(*cmd_line, errors::MINI_INSTALLER_NOT_FOUND,
               mini_installer.value());
     return EXIT_FAILURE;
   }
 
   FilePath out;
   GetOutPath(*cmd_line, &out);
-  if (file_util::PathExists(out)) {
+  if (!cmd_line->HasSwitch(switches::kForce) && file_util::PathExists(out)) {
     DumpUsage(*cmd_line, errors::OUT_FILE_EXISTS, out.value());
     return EXIT_FAILURE;
   }
 
   upgrade_test::Direction direction = GetDirection(*cmd_line);
 
   std::wstring original_version;
   std::wstring new_version;
 
   if (upgrade_test::GenerateAlternateVersion(mini_installer, out, direction,
                                              &original_version, &new_version)) {
     fwprintf(stdout, L"Generated version %s from version %s\n",
              new_version.c_str(), original_version.c_str());
     return EXIT_SUCCESS;
   }
 
   DumpUsage(*cmd_line, errors::GENERATION_FAILED, mini_installer.value());
   return EXIT_FAILURE;
 }