Command-line tool to generate a newly versioned mini_installer.exe

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 kMiniInstallerExe[] = L"mini_installer.exe";

[robertshield, 2011/01/28 18:36:22]

Have the word "default" in the names of these two constants to imply that they
are used in the absence of any overriding input?

[grt (UTC plus 2), 2011/01/28 19:13:33]

Done.

+const wchar_t kMiniInstallerNewExe[] = L"mini_installer_new.exe";
+
+namespace switches {
+
+const char kHelp[] = "help";
+const char kMiniInstaller[] = "mini_installer";
+const char kOut[] = "out";
+const char kPrevious[] = "previous";
+
+}  // namespace switches
+
+namespace errors {
+
+enum ErrorCode {
+  SHOW_HELP,
+  MINI_INSTALLER_NOT_FOUND,
+  OUT_FILE_EXISTS,
+  GENERATION_FAILED
+};
+
+const wchar_t* const Messages[] = {
+  NULL,
+  L"original mini_installer.exe not found",
+  L"output file already exists",
+  L"failed to generate a newly versioned mini_installer.exe"
+};
+
+const wchar_t* GetErrorMessage(ErrorCode error_code) {
+  DCHECK_LE(0, error_code);
+  DCHECK_GT(arraysize(Messages), static_cast<size_t>(error_code));
+  return Messages[error_code];
+}
+
+}  // namespace errors
+
+// Display usage information to stderr along with an optional error message with
+// details.
+void DumpUsage(const CommandLine& cmd_line,
+               errors::ErrorCode error_code,
+               const std::wstring& detail) {
+  const wchar_t* error_message = errors::GetErrorMessage(error_code);
+  if (error_message != NULL) {
+    fwprintf(stderr, L"%s: %s", cmd_line.GetProgram().value().c_str(),
+             errors::GetErrorMessage(error_code));
+    if (!detail.empty())
+      fwprintf(stderr, L" (%s)\n", detail.c_str());
+    else
+      fwprintf(stderr, L"\n");
+  }
+
+  fwprintf(stderr,
+L"Usage: %s [ --mini_installer=SRC_PATH ] [--out=OUT_PATH ] [ --previous ]\n"

[robertshield, 2011/01/28 18:36:22]

Does this line wrap properly on the command line? I figured the program name
would be longer than 8 characters.

[grt (UTC plus 2), 2011/01/28 19:13:33]

Done.

+L"          [ --7za_path=7ZA_PATH ]\n"
+L" --help                     Display this help message.\n"
+L" --mini_installer=SRC_PATH  Relative or absolute path to mini_installer.exe.\n"  // NOLINT

[grt (UTC plus 2), 2011/01/28 16:49:53]

some of these are longer than 80 cols since the text is formatted to wrap at 80
when displayed.  should i 1) leave them as-is, 2) reformat the text to wrap
sooner so that the strings fit in 80 cols, or 3) wrap the strings as-is so that
the strings in the source code don't wrap at the same points as the program
output?

[robertshield, 2011/01/28 18:36:22]

Prefer 2) as the option that provides the most readability both on the command
line and in the source code.

[grt (UTC plus 2), 2011/01/28 19:13:33]

Done.

+L"                            Default value is \"mini_installer.exe\" in the same\n"  // NOLINT
+L"                            directory as this program.\n"
+L" --out=OUT_PATH             Relative or absolute path to output file. Default\n"  // NOLINT
+L"                            value is \"mini_installer_new.exe\" in the current\n"  // NOLINT
+L"                            directory.\n"
+L" --previous                 OUT_PATH will have a lower version than SRC_PATH.\n"  // NOLINT
+L"                            By default, OUT_PATH will have a higher version.\n"  // NOLINT
+L" --7za_path=7ZA_PATH        Relative or absolute path to the directory holding\n"  // NOLINT
+L"                            7za.exe. Default value is\n"
+L"                            ..\\..\\third_party\\lzma_sdk\\Executable relative to\n"  // NOLINT
+L"                            the directory holding this program.",
+           cmd_line.GetProgram().value().c_str());
+}
+
+// Gets the path to the source mini_installer.exe on which to operate, putting
+// the result in |mini_installer|.  Returns true on success.
+bool GetMiniInstallerPath(const CommandLine& cmd_line,
+                          FilePath* mini_installer) {

[robertshield, 2011/01/28 18:36:22]

DCHECK(mini_installer)

[grt (UTC plus 2), 2011/01/28 19:13:33]

Done.

+  FilePath result = cmd_line.GetSwitchValuePath(switches::kMiniInstaller);
+  if (result.empty() && PathService::Get(base::DIR_EXE, &result))
+    result = result.Append(kMiniInstallerExe);
+  if (result.empty())
+    return false;
+  *mini_installer = result;
+  return true;
+}
+
+// Gets the path to the output file, putting the result in |out|.
+void GetOutPath(const CommandLine& cmd_line, FilePath* out) {

[robertshield, 2011/01/28 18:36:22]

DCHECK(out)

[grt (UTC plus 2), 2011/01/28 19:13:33]

Done.

+  FilePath result = cmd_line.GetSwitchValuePath(switches::kOut);
+  if (result.empty())
+    *out = FilePath(kMiniInstallerNewExe);
+  else
+    *out = result;
+}
+
+// Returns the direction in which the version should be adjusted.
+upgrade_test::Direction GetDirection(const CommandLine& cmd_line) {
+  return cmd_line.HasSwitch(switches::kPrevious) ?
+      upgrade_test::PREVIOUS_VERSION : upgrade_test::NEXT_VERSION;
+}
+
+}  // namespace
+
+// The main program.
+int wmain(int argc, wchar_t *argv[]) {
+  base::AtExitManager exit_manager;
+  CommandLine::Init(0, NULL);
+  CommandLine* cmd_line = CommandLine::ForCurrentProcess();
+
+  if (cmd_line->HasSwitch(switches::kHelp)) {
+    DumpUsage(*cmd_line, errors::SHOW_HELP, std::wstring());
+    return EXIT_SUCCESS;
+  }
+
+  FilePath mini_installer;
+  if (!GetMiniInstallerPath(*cmd_line, &mini_installer)) {
+    DumpUsage(*cmd_line, errors::MINI_INSTALLER_NOT_FOUND, std::wstring());
+    return EXIT_FAILURE;
+  }
+
+  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)) {
+    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;
+}