Make Crashpad use the user data dir, rather than always default location

chrome/install_static/user_data_dir.cc

+// Copyright 2016 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 "chrome/install_static/user_data_dir.h"
+
+#include <windows.h>
+#include <assert.h>
+
+#include "chrome/install_static/install_details.h"
+#include "chrome/install_static/install_util.h"
+#include "chrome/install_static/policy_path_parser.h"
+#include "chrome_elf/nt_registry/nt_registry.h"
+
+namespace install_static {
+
+namespace {
+
+std::wstring g_user_data_dir;

[grt (UTC plus 2), 2016/11/22 21:06:58]

this will introduce a global dtor, which is banned. maybe make it a ptr that's
nullptr during static initialization and leaked after it's set?

[scottmg, 2016/11/22 21:59:57]

Done.

[That rule is pretty lax on Windows tbh, they're everywhere. :(]

+std::wstring g_invalid_user_data_dir;
+
+// Retrieves a registry policy for the user data directory from the registry, if
+// one is set. If there's none set in either HKLM or HKCU, |user_data_dir| will
+// be unmodified.
+void GetUserDataDirFromRegistryPolicyIfSet(const InstallConstants& mode,
+                                           std::wstring* user_data_dir) {
+  assert(user_data_dir);
+  std::wstring policies_path = L"SOFTWARE\\Policies\\";
+  AppendChromeInstallSubDirectory(mode, false /* !include_suffix */,
+                                  &policies_path);
+
+  std::wstring value;
+
+  constexpr wchar_t kUserDataDirRegistryKeyName[] = L"UserDataDir";
+
+  // First, try HKLM.
+  if (nt::QueryRegValueSZ(nt::HKLM, nt::NONE, policies_path.c_str(),
+                          kUserDataDirRegistryKeyName, &value)) {
+    *user_data_dir = ExpandPathVariables(value);
+    return;
+  }
+
+  // Second, try HKCU.
+  if (nt::QueryRegValueSZ(nt::HKCU, nt::NONE, policies_path.c_str(),
+                             kUserDataDirRegistryKeyName, &value)) {
+    *user_data_dir = ExpandPathVariables(value);
+    return;
+  }
+}
+
+std::wstring MakeAbsoluteFilePath(const std::wstring& input) {
+  wchar_t file_path[MAX_PATH];
+  if (!_wfullpath(file_path, input.c_str(), _countof(file_path)))
+    return std::wstring();
+  return file_path;
+}
+
+// The same as GetUserDataDirectory(), but directly queries the global command
+// line object for the --user-data-dir flag. This is the more commonly used
+// function, where GetUserDataDirectory() is used primiarily for testing.
+bool GetUserDataDirectoryUsingProcessCommandLine(
+    const InstallConstants& mode,
+    std::wstring* result,
+    std::wstring* invalid_supplied_directory) {
+  return GetUserDataDirectoryImpl(
+      GetSwitchValueFromCommandLine(::GetCommandLine(), kUserDataDirSwitch),
+      mode, result, invalid_supplied_directory);
+}
+
+// Populates |result| with the default User Data directory for the current
+// user. Returns false if all attempts at locating a User Data directory fail.
+// TODO(ananta)
+// http://crbug.com/604923
+// Unify this with the Browser Distribution code.
+bool GetDefaultUserDataDirectory(const InstallConstants& mode,
+                                 std::wstring* result) {
+  // This environment variable should be set on Windows Vista and later
+  // (https://msdn.microsoft.com/library/windows/desktop/dd378457.aspx).
+  std::wstring user_data_dir = GetEnvironmentString16(L"LOCALAPPDATA");
+
+  if (user_data_dir.empty()) {
+    // LOCALAPPDATA was not set; fallback to the temporary files path.
+    DWORD size = ::GetTempPath(0, nullptr);
+    if (!size)
+      return false;
+    user_data_dir.resize(size + 1);
+    size = ::GetTempPath(size + 1, &user_data_dir[0]);
+    if (!size || size >= user_data_dir.size())
+      return false;
+    user_data_dir.resize(size);
+  }
+
+  result->swap(user_data_dir);
+  if ((*result)[result->length() - 1] != L'\\')
+    result->push_back(L'\\');
+  AppendChromeInstallSubDirectory(mode, true /* include_suffix */, result);
+  result->push_back(L'\\');
+  result->append(L"User Data");
+  return true;
+}
+
+}  // namespace
+
+bool GetUserDataDirectoryImpl(
+    const std::wstring& user_data_dir_from_command_line,
+    const InstallConstants& mode,
+    std::wstring* result,
+    std::wstring* invalid_supplied_directory) {
+  std::wstring user_data_dir = user_data_dir_from_command_line;
+
+  GetUserDataDirFromRegistryPolicyIfSet(mode, &user_data_dir);
+
+  // On Windows, trailing separators leave Chrome in a bad state. See
+  // crbug.com/464616.
+  while (!user_data_dir.empty() &&
+         (user_data_dir.back() == '\\' || user_data_dir.back() == '/')) {
+    user_data_dir.pop_back();
+  }
+
+  bool got_valid_directory =
+      !user_data_dir.empty() && RecursiveDirectoryCreate(user_data_dir);
+  if (!got_valid_directory) {
+    *invalid_supplied_directory = user_data_dir;
+    got_valid_directory = GetDefaultUserDataDirectory(mode, &user_data_dir);
+  }
+
+  // The Chrome implementation CHECKs() here in the browser process. We
+  // don't as this function is used to initialize crash reporting, so
+  // we would get no report of this failure.
+  assert(got_valid_directory);
+  if (!got_valid_directory)
+    return false;
+
+  *result = MakeAbsoluteFilePath(user_data_dir);
+  return true;
+}
+
+bool GetUserDataDirectory(std::wstring* user_data_dir,
+                          std::wstring* invalid_user_data_dir) {
+  if (g_user_data_dir.empty()) {
+    if (!GetUserDataDirectoryUsingProcessCommandLine(
+            *InstallDetails::Get().mode(), &g_user_data_dir,
+            &g_invalid_user_data_dir)) {
+      return false;
+    }
+    assert(!g_user_data_dir.empty());
+  }
+  *user_data_dir = g_user_data_dir;
+  if (invalid_user_data_dir)
+    *invalid_user_data_dir = g_invalid_user_data_dir;
+  return true;
+}
+
+}  // namespace install_static