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// Copyright (c) 2012 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.
// mini_installer.exe is the first exe that is run when chrome is being
// installed or upgraded. It is designed to be extremely small (~5KB with no
// extra resources linked) and it has two main jobs:
// 1) unpack the resources (possibly decompressing some)
// 2) run the real installer (setup.exe) with appropriate flags.
// In order to be really small the app doesn't link against the CRT and
// defines the following compiler/linker flags:
// EnableIntrinsicFunctions="true" compiler: /Oi
// BasicRuntimeChecks="0"
// BufferSecurityCheck="false" compiler: /GS-
// EntryPointSymbol="MainEntryPoint" linker: /ENTRY
// IgnoreAllDefaultLibraries="true" linker: /NODEFAULTLIB
// OptimizeForWindows98="1" liker: /OPT:NOWIN98
// linker: /SAFESEH:NO
// have the linker merge the sections, saving us ~500 bytes.
#pragma comment(linker, "/MERGE:.rdata=.text")
#include <windows.h>
#include <shellapi.h>
#include "chrome/installer/mini_installer/appid.h"
#include "chrome/installer/mini_installer/configuration.h"
#include "chrome/installer/mini_installer/decompress.h"
#include "chrome/installer/mini_installer/exit_code.h"
#include "chrome/installer/mini_installer/mini_installer_constants.h"
#include "chrome/installer/mini_installer/mini_string.h"
#include "chrome/installer/mini_installer/pe_resource.h"
namespace mini_installer {
typedef DWORD ProcessExitCode;
typedef StackString<MAX_PATH> PathString;
typedef StackString<MAX_PATH * 4> CommandString;
// This structure passes data back and forth for the processing
// of resource callbacks.
struct Context {
// Input to the call back method. Specifies the dir to save resources.
const wchar_t* base_path;
// First output from call back method. Full path of Chrome archive.
PathString* chrome_resource_path;
// Second output from call back method. Full path of Setup archive/exe.
PathString* setup_resource_path;
// A helper class used to manipulate the Windows registry. Typically, members
// return Windows last-error codes a la the Win32 registry API.
class RegKey {
RegKey() : key_(NULL) { }
~RegKey() { Close(); }
// Opens the key named |sub_key| with given |access| rights. Returns
// ERROR_SUCCESS or some other error.
LONG Open(HKEY key, const wchar_t* sub_key, REGSAM access);
// Returns true if a key is open.
bool is_valid() const { return key_ != NULL; }
// Read a REG_SZ value from the registry into the memory indicated by |value|
// (of |value_size| wchar_t units). Returns ERROR_SUCCESS,
// ERROR_FILE_NOT_FOUND, ERROR_MORE_DATA, or some other error. |value| is
// guaranteed to be null-terminated on success.
LONG ReadValue(const wchar_t* value_name,
wchar_t* value,
size_t value_size) const;
// Write a REG_SZ value to the registry. |value| must be null-terminated.
// Returns ERROR_SUCCESS or an error code.
LONG WriteValue(const wchar_t* value_name, const wchar_t* value);
// Closes the key if it was open.
void Close();
RegKey(const RegKey&);
RegKey& operator=(const RegKey&);
HKEY key_;
}; // class RegKey
LONG RegKey::Open(HKEY key, const wchar_t* sub_key, REGSAM access) {
return ::RegOpenKeyEx(key, sub_key, NULL, access, &key_);
LONG RegKey::ReadValue(const wchar_t* value_name,
wchar_t* value,
size_t value_size) const {
DWORD type;
DWORD byte_length = static_cast<DWORD>(value_size * sizeof(wchar_t));
LONG result = ::RegQueryValueEx(key_, value_name, NULL, &type,
if (result == ERROR_SUCCESS) {
if (type != REG_SZ) {
} else if (byte_length == 0) {
*value = L'\0';
} else if (value[byte_length/sizeof(wchar_t) - 1] != L'\0') {
if ((byte_length / sizeof(wchar_t)) < value_size)
value[byte_length / sizeof(wchar_t)] = L'\0';
return result;
LONG RegKey::WriteValue(const wchar_t* value_name, const wchar_t* value) {
return ::RegSetValueEx(key_, value_name, 0, REG_SZ,
reinterpret_cast<const BYTE*>(value),
(lstrlen(value) + 1) * sizeof(wchar_t));
void RegKey::Close() {
if (key_ != NULL) {
key_ = NULL;
// Helper function to read a value from registry. Returns true if value
// is read successfully and stored in parameter value. Returns false otherwise.
// |size| is measured in wchar_t units.
bool ReadValueFromRegistry(HKEY root_key, const wchar_t *sub_key,
const wchar_t *value_name, wchar_t *value,
size_t size) {
RegKey key;
if (key.Open(root_key, sub_key, KEY_QUERY_VALUE) == ERROR_SUCCESS &&
key.ReadValue(value_name, value, size) == ERROR_SUCCESS) {
return true;
return false;
// Opens the Google Update ClientState key for a product.
bool OpenClientStateKey(HKEY root_key, const wchar_t* app_guid, REGSAM access,
RegKey* key) {
PathString client_state_key;
return client_state_key.assign(kClientStateKeyBase) &&
client_state_key.append(app_guid) &&
access | KEY_WOW64_32KEY) == ERROR_SUCCESS);
// This function sets the flag in registry to indicate that Google Update
// should try full installer next time. If the current installer works, this
// flag is cleared by setup.exe at the end of install. The flag will by default
// be written to HKCU, but if --system-level is included in the command line,
// it will be written to HKLM instead.
// TODO(grt): Write a unit test for this that uses registry virtualization.
void SetInstallerFlags(const Configuration& configuration) {
RegKey key;
const HKEY root_key =
configuration.is_system_level() ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
// This is ignored if multi-install is true.
const wchar_t* app_guid =
configuration.has_chrome_frame() ?
google_update::kChromeFrameAppGuid :
StackString<128> value;
// When multi_install is true, we are potentially:
// 1. Performing a multi-install of some product(s) on a clean machine.
// Neither the product(s) nor the multi-installer will have a ClientState
// key in the registry, so there is nothing to be done.
// 2. Upgrading an existing multi-install. The multi-installer will have a
// ClientState key in the registry. Only it need be modified.
// 3. Migrating a single-install into a multi-install. The product will have
// a ClientState key in the registry. Only it need be modified.
// To handle all cases, we inspect the product's ClientState to see if it
// exists and its "ap" value does not contain "-multi". This is case 3, so we
// modify the product's ClientState. Otherwise, we check the
// multi-installer's ClientState and modify it if it exists.
if (configuration.is_multi_install()) {
if (OpenClientStateKey(root_key, app_guid, key_access, &key)) {
// The product has a client state key. See if it's a single-install.
ret = key.ReadValue(kApRegistryValue, value.get(), value.capacity());
if (ret != ERROR_FILE_NOT_FOUND &&
(ret != ERROR_SUCCESS ||
FindTagInStr(value.get(), kMultiInstallTag, NULL))) {
// Error or case 2: modify the multi-installer's value.
app_guid = google_update::kMultiInstallAppGuid;
} // else case 3: modify this value.
} else {
// case 1 or 2: modify the multi-installer's value.
app_guid = google_update::kMultiInstallAppGuid;
if (!key.is_valid()) {
if (!OpenClientStateKey(root_key, app_guid, key_access, &key))
ret = key.ReadValue(kApRegistryValue, value.get(), value.capacity());
// The conditions below are handling two cases:
// 1. When ap value is present, we want to add the required tag only if it is
// not present.
// 2. When ap value is missing, we are going to create it with the required
// tag.
if ((ret == ERROR_SUCCESS) || (ret == ERROR_FILE_NOT_FOUND)) {
if (!StrEndsWith(value.get(), kFullInstallerSuffix) &&
value.append(kFullInstallerSuffix)) {
key.WriteValue(kApRegistryValue, value.get());
// Gets the setup.exe path from Registry by looking the value of Uninstall
// string. |size| is measured in wchar_t units.
bool GetSetupExePathForGuidFromRegistry(bool system_level,
const wchar_t* app_guid,
wchar_t* path,
size_t size) {
const HKEY root_key = system_level ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
RegKey key;
return OpenClientStateKey(root_key, app_guid, KEY_QUERY_VALUE, &key) &&
(key.ReadValue(kUninstallRegistryValue, path, size) == ERROR_SUCCESS);
// Gets the setup.exe path from Registry by looking the value of Uninstall
// string. |size| is measured in wchar_t units.
bool GetSetupExePathFromRegistry(const Configuration& configuration,
wchar_t* path,
size_t size) {
bool system_level = configuration.is_system_level();
// If this is a multi install, first try looking in the binaries for the path.
if (configuration.is_multi_install() && GetSetupExePathForGuidFromRegistry(
system_level, google_update::kMultiInstallAppGuid, path, size)) {
return true;
// Failing that, look in Chrome Frame's client state key if --chrome-frame was
// specified.
if (configuration.has_chrome_frame() && GetSetupExePathForGuidFromRegistry(
system_level, google_update::kChromeFrameAppGuid, path, size)) {
return true;
// Make a last-ditch effort to look in the Chrome client state key.
if (GetSetupExePathForGuidFromRegistry(
system_level, configuration.chrome_app_guid(), path, size)) {
return true;
return false;
// Calls CreateProcess with good default parameters and waits for the process to
// terminate returning the process exit code. |exit_code|, if non-NULL, is
// populated with the process exit code.
bool RunProcessAndWait(const wchar_t* exe_path, wchar_t* cmdline,
ProcessExitCode* exit_code) {
STARTUPINFOW si = {sizeof(si)};
if (!::CreateProcess(exe_path, cmdline, NULL, NULL, FALSE, CREATE_NO_WINDOW,
NULL, NULL, &si, &pi)) {
return false;
bool ret = true;
DWORD wr = ::WaitForSingleObject(pi.hProcess, INFINITE);
if (WAIT_OBJECT_0 != wr) {
ret = false;
} else if (exit_code) {
if (!::GetExitCodeProcess(pi.hProcess, exit_code))
ret = false;
return ret;
// Append any command line params passed to mini_installer to the given buffer
// so that they can be passed on to setup.exe. We do not return any error from
// this method and simply skip making any changes in case of error.
void AppendCommandLineFlags(const Configuration& configuration,
CommandString* buffer) {
PathString full_exe_path;
size_t len = ::GetModuleFileName(NULL, full_exe_path.get(),
if (!len || len >= full_exe_path.capacity())
const wchar_t* exe_name = GetNameFromPathExt(full_exe_path.get(), len);
if (exe_name == NULL)
const wchar_t* cmd_to_append = L"";
if (!StrEndsWith(configuration.program(), exe_name)) {
// Current executable name not in the command line so just append
// the whole command line.
cmd_to_append = configuration.command_line();
} else if (configuration.argument_count() > 1) {
const wchar_t* tmp = SearchStringI(configuration.command_line(), exe_name);
tmp = SearchStringI(tmp, L" ");
cmd_to_append = tmp;
// Windows defined callback used in the EnumResourceNames call. For each
// matching resource found, the callback is invoked and at this point we write
// it to disk. We expect resource names to start with 'chrome' or 'setup'. Any
// other name is treated as an error.
BOOL CALLBACK OnResourceFound(HMODULE module, const wchar_t* type,
wchar_t* name, LONG_PTR context) {
if (NULL == context)
return FALSE;
Context* ctx = reinterpret_cast<Context*>(context);
PEResource resource(name, type, module);
if ((!resource.IsValid()) ||
(resource.Size() < 1) ||
(resource.Size() > kMaxResourceSize)) {
return FALSE;
PathString full_path;
if (!full_path.assign(ctx->base_path) ||
!full_path.append(name) ||
return FALSE;
if (StrStartsWith(name, kChromeArchivePrefix)) {
if (!ctx->chrome_resource_path->assign(full_path.get()))
return FALSE;
} else if (StrStartsWith(name, kSetupPrefix)) {
if (!ctx->setup_resource_path->assign(full_path.get()))
return FALSE;
} else {
// Resources should either start with 'chrome' or 'setup'. We don't handle
// anything else.
return FALSE;
return TRUE;
#if defined(COMPONENT_BUILD)
// An EnumResNameProc callback that writes the resource |name| to disk in the
// directory |base_path_ptr| (which must end with a path separator).
BOOL CALLBACK WriteResourceToDirectory(HMODULE module,
const wchar_t* type,
wchar_t* name,
LONG_PTR base_path_ptr) {
const wchar_t* base_path = reinterpret_cast<const wchar_t*>(base_path_ptr);
PathString full_path;
PEResource resource(name, type, module);
return (resource.IsValid() &&
full_path.assign(base_path) &&
full_path.append(name) &&
// Finds and writes to disk resources of various types. Returns false
// if there is a problem in writing any resource to disk. setup.exe resource
// can come in one of three possible forms:
// - Resource type 'B7', compressed using LZMA (*.7z)
// - Resource type 'BL', compressed using LZ (*.ex_)
// - Resource type 'BN', uncompressed (*.exe)
// If setup.exe is present in more than one form, the precedence order is
// BN < BL < B7
// For more details see chrome/tools/build/win/
// For component builds (where setup.ex_ is always used), all files stored as
// uncompressed 'BN' resources are also extracted. This is generally the set of
// DLLs/resources needed by setup.exe to run.
bool UnpackBinaryResources(const Configuration& configuration, HMODULE module,
const wchar_t* base_path, PathString* archive_path,
PathString* setup_path) {
// Generate the setup.exe path where we patch/uncompress setup resource.
PathString setup_dest_path;
if (!setup_dest_path.assign(base_path) ||
return false;
// Prepare the input to OnResourceFound method that needs a location where
// it will write all the resources.
Context context = {
// Get the resources of type 'B7' (7zip archive).
// We need a chrome archive to do the installation. So if there
// is a problem in fetching B7 resource, just return an error.
if (!::EnumResourceNames(module, kLZMAResourceType, OnResourceFound,
reinterpret_cast<LONG_PTR>(&context)) ||
archive_path->length() == 0)
return false;
// If we found setup 'B7' resource, handle it.
if (setup_path->length() > 0) {
CommandString cmd_line;
PathString exe_path;
// Get the path to setup.exe first.
bool success = true;
if (!GetSetupExePathFromRegistry(configuration, exe_path.get(),
exe_path.capacity()) ||
!cmd_line.append(exe_path.get()) ||
!cmd_line.append(L" --") ||
!cmd_line.append(kCmdUpdateSetupExe) ||
!cmd_line.append(L"=\"") ||
!cmd_line.append(setup_path->get()) ||
!cmd_line.append(L"\" --") ||
!cmd_line.append(kCmdNewSetupExe) ||
!cmd_line.append(L"=\"") ||
!cmd_line.append(setup_dest_path.get()) ||
!cmd_line.append(L"\"")) {
success = false;
// Get any command line option specified for mini_installer and pass them
// on to setup.exe. This is important since switches such as
// --multi-install and --chrome-frame affect where setup.exe will write
// installer results for consumption by Google Update.
AppendCommandLineFlags(configuration, &cmd_line);
ProcessExitCode exit_code = SUCCESS_EXIT_CODE;
if (success &&
(!RunProcessAndWait(exe_path.get(), cmd_line.get(), &exit_code) ||
exit_code != SUCCESS_EXIT_CODE)) {
success = false;
if (!success)
return success && setup_path->assign(setup_dest_path.get());
// setup.exe wasn't sent as 'B7', lets see if it was sent as 'BL'
// (compressed setup).
if (!::EnumResourceNames(module, kLZCResourceType, OnResourceFound,
reinterpret_cast<LONG_PTR>(&context)) &&
return false;
if (setup_path->length() > 0) {
// Uncompress LZ compressed resource. Setup is packed with 'MSCF'
// as opposed to old DOS way of 'SZDD'. Hence we don't use LZCopy.
bool success = mini_installer::Expand(setup_path->get(),
if (success) {
if (!setup_path->assign(setup_dest_path.get())) {
success = false;
#if defined(COMPONENT_BUILD)
// Extract the (uncompressed) modules required by setup.exe.
if (!::EnumResourceNames(module, kBinResourceType, WriteResourceToDirectory,
return false;
return success;
// setup.exe still not found. So finally check if it was sent as 'BN'
// (uncompressed setup).
// TODO(tommi): We don't need BN anymore so let's remove it (and remove
// it from
if (!::EnumResourceNames(module, kBinResourceType, OnResourceFound,
reinterpret_cast<LONG_PTR>(&context)) &&
return false;
if (setup_path->length() > 0) {
if (setup_path->comparei(setup_dest_path.get()) != 0) {
if (!::MoveFileEx(setup_path->get(), setup_dest_path.get(),
} else if (!setup_path->assign(setup_dest_path.get())) {
return setup_path->length() > 0;
// Executes setup.exe, waits for it to finish and returns the exit code.
bool RunSetup(const Configuration& configuration, const wchar_t* archive_path,
const wchar_t* setup_path, ProcessExitCode* exit_code) {
// There could be three full paths in the command line for setup.exe (path
// to exe itself, path to archive and path to log file), so we declare
// total size as three + one additional to hold command line options.
CommandString cmd_line;
// Get the path to setup.exe first.
if (::lstrlen(setup_path) > 0) {
if (!cmd_line.assign(L"\"") ||
!cmd_line.append(setup_path) ||
return false;
} else if (!GetSetupExePathFromRegistry(configuration, cmd_line.get(),
cmd_line.capacity())) {
return false;
// Append the command line param for chrome archive file
if (!cmd_line.append(L" --") ||
#if defined(COMPONENT_BUILD)
// For faster developer turnaround, the component build generates
// uncompressed archives.
!cmd_line.append(kCmdUncompressedArchive) ||
!cmd_line.append(kCmdInstallArchive) ||
!cmd_line.append(L"=\"") ||
!cmd_line.append(archive_path) ||
return false;
// Get any command line option specified for mini_installer and pass them
// on to setup.exe
AppendCommandLineFlags(configuration, &cmd_line);
return RunProcessAndWait(NULL, cmd_line.get(), exit_code);
// Deletes given files and working dir.
void DeleteExtractedFiles(const wchar_t* base_path,
const wchar_t* archive_path,
const wchar_t* setup_path) {
// Delete the temp dir (if it is empty, otherwise fail).
// Creates a temporary directory under |base_path| and returns the full path
// of created directory in |work_dir|. If successful return true, otherwise
// false. When successful, the returned |work_dir| will always have a trailing
// backslash and this function requires that |base_path| always includes a
// trailing backslash as well.
// We do not use GetTempFileName here to avoid running into AV software that
// might hold on to the temp file as soon as we create it and then we can't
// delete it and create a directory in its place. So, we use our own mechanism
// for creating a directory with a hopefully-unique name. In the case of a
// collision, we retry a few times with a new name before failing.
bool CreateWorkDir(const wchar_t* base_path, PathString* work_dir) {
if (!work_dir->assign(base_path) || !work_dir->append(kTempPrefix))
return false;
// Store the location where we'll append the id.
size_t end = work_dir->length();
// Check if we'll have enough buffer space to continue.
// The name of the directory will use up 11 chars and then we need to append
// the trailing backslash and a terminator. We've already added the prefix
// to the buffer, so let's just make sure we've got enough space for the rest.
if ((work_dir->capacity() - end) < (arraysize("fffff.tmp") + 1))
return false;
// Generate a unique id. We only use the lowest 20 bits, so take the top
// 12 bits and xor them with the lower bits.
DWORD id = ::GetTickCount();
id ^= (id >> 12);
int max_attempts = 10;
while (max_attempts--) {
// This converts 'id' to a string in the format "78563412" on windows
// because of little endianness, but we don't care since it's just
// a name.
if (!HexEncode(&id, sizeof(id), work_dir->get() + end,
work_dir->capacity() - end)) {
return false;
// We only want the first 5 digits to remain within the 8.3 file name
// format (compliant with previous implementation).
work_dir->truncate_at(end + 5);
// for consistency with the previous implementation which relied on
// GetTempFileName, we append the .tmp extension.
if (::CreateDirectory(work_dir->get(), NULL)) {
// Yay! Now let's just append the backslash and we're done.
return work_dir->append(L"\\");
++id; // Try a different name.
return false;
// Creates and returns a temporary directory in |work_dir| that can be used to
// extract mini_installer payload. |work_dir| ends with a path separator.
bool GetWorkDir(HMODULE module, PathString* work_dir) {
PathString base_path;
DWORD len = ::GetTempPath(base_path.capacity(), base_path.get());
if (!len || len >= base_path.capacity() ||
!CreateWorkDir(base_path.get(), work_dir)) {
// Problem creating the work dir under TEMP path, so try using the
// current directory as the base path.
len = ::GetModuleFileName(module, base_path.get(), base_path.capacity());
if (len >= base_path.capacity() || !len)
return false; // Can't even get current directory? Return an error.
wchar_t* name = GetNameFromPathExt(base_path.get(), len);
if (!name)
return false;
*name = L'\0';
return CreateWorkDir(base_path.get(), work_dir);
return true;
// Returns true for ".." and "." directories.
bool IsCurrentOrParentDirectory(const wchar_t* dir) {
return dir &&
dir[0] == L'.' &&
(dir[1] == L'\0' || (dir[1] == L'.' && dir[2] == L'\0'));
// Best effort directory tree deletion including the directory specified
// by |path|, which must not end in a separator.
// The |path| argument is writable so that each recursion can use the same
// buffer as was originally allocated for the path. The path will be unchanged
// upon return.
void RecursivelyDeleteDirectory(PathString* path) {
// |path| will never have a trailing backslash.
size_t end = path->length();
if (!path->append(L"\\*.*"))
WIN32_FIND_DATA find_data = {0};
HANDLE find = ::FindFirstFile(path->get(), &find_data);
do {
// Use the short name if available to make the most of our buffer.
const wchar_t* name = find_data.cAlternateFileName[0] ?
find_data.cAlternateFileName : find_data.cFileName;
if (IsCurrentOrParentDirectory(name))
path->truncate_at(end + 1); // Keep the trailing backslash.
if (!path->append(name))
continue; // Continue in spite of too long names.
if (find_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
} else {
} while (::FindNextFile(find, &find_data));
// Restore the path and delete the directory before we return.
// Enumerates subdirectories of |parent_dir| and deletes all subdirectories
// that match with a given |prefix|. |parent_dir| must have a trailing
// backslash.
// The process is done on a best effort basis, so conceivably there might
// still be matches left when the function returns.
void DeleteDirectoriesWithPrefix(const wchar_t* parent_dir,
const wchar_t* prefix) {
// |parent_dir| is guaranteed to always have a trailing backslash.
PathString spec;
if (!spec.assign(parent_dir) || !spec.append(prefix) || !spec.append(L"*.*"))
WIN32_FIND_DATA find_data = {0};
HANDLE find = ::FindFirstFileEx(spec.get(), FindExInfoStandard, &find_data,
FindExSearchLimitToDirectories, NULL, 0);
PathString path;
do {
if (find_data.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
// Use the short name if available to make the most of our buffer.
const wchar_t* name = find_data.cAlternateFileName[0] ?
find_data.cAlternateFileName : find_data.cFileName;
if (IsCurrentOrParentDirectory(name))
if (path.assign(parent_dir) && path.append(name))
} while (::FindNextFile(find, &find_data));
// Attempts to free up space by deleting temp directories that previous
// installer runs have failed to clean up.
void DeleteOldChromeTempDirectories() {
static const wchar_t* const kDirectoryPrefixes[] = {
L"chrome_" // Previous installers created directories with this prefix
// and there are still some lying around.
PathString temp;
// GetTempPath always returns a path with a trailing backslash.
DWORD len = ::GetTempPath(temp.capacity(), temp.get());
// GetTempPath returns 0 or number of chars copied, not including the
// terminating '\0'.
if (!len || len >= temp.capacity())
for (int i = 0; i < arraysize(kDirectoryPrefixes); ++i) {
DeleteDirectoriesWithPrefix(temp.get(), kDirectoryPrefixes[i]);
// Checks the command line for specific mini installer flags.
// If the function returns true, the command line has been processed and all
// required actions taken. The installer must exit and return the returned
// |exit_code|.
bool ProcessNonInstallOperations(const Configuration& configuration,
ProcessExitCode* exit_code) {
bool ret = false;
switch (configuration.operation()) {
case Configuration::CLEANUP:
// Cleanup has already taken place in DeleteOldChromeTempDirectories at
// this point, so just tell our caller to exit early.
*exit_code = SUCCESS_EXIT_CODE;
ret = true;
default: break;
return ret;
// Returns true if we should delete the temp files we create (default).
// Returns false iff the user has manually created a ChromeInstallerCleanup
// string value in the registry under HKCU\\Software\\[Google|Chromium]
// and set its value to "0". That explicitly forbids the mini installer from
// deleting these files.
// Support for this has been publicly mentioned in troubleshooting tips so
// we continue to support it.
bool ShouldDeleteExtractedFiles() {
wchar_t value[2] = {0};
if (ReadValueFromRegistry(HKEY_CURRENT_USER, kCleanupRegistryKey,
kCleanupRegistryValue, value, arraysize(value)) &&
value[0] == L'0') {
return false;
return true;
// Main function. First gets a working dir, unpacks the resources and finally
// executes setup.exe to do the install/upgrade.
ProcessExitCode WMain(HMODULE module) {
// Always start with deleting potential leftovers from previous installations.
// This can make the difference between success and failure. We've seen
// many installations out in the field fail due to out of disk space problems
// so this could buy us some space.
// TODO(grt): Make the exit codes more granular so we know where the popular
// errors truly are.
// Parse the command line.
Configuration configuration;
if (!configuration.Initialize())
return exit_code;
// If the --cleanup switch was specified on the command line, then that means
// we should only do the cleanup and then exit.
if (ProcessNonInstallOperations(configuration, &exit_code))
return exit_code;
// First get a path where we can extract payload
PathString base_path;
if (!GetWorkDir(module, &base_path))
// Set the magic suffix in registry to try full installer next time. We ignore
// any errors here and we try to set the suffix for user level unless
// --system-level is on the command line in which case we set it for system
// level instead. This only applies to the Google Chrome distribution.
PathString archive_path;
PathString setup_path;
if (!UnpackBinaryResources(configuration, module, base_path.get(),
&archive_path, &setup_path)) {
} else {
// While unpacking the binaries, we paged in a whole bunch of memory that
// we don't need anymore. Let's give it back to the pool before running
// setup.
::SetProcessWorkingSetSize(::GetCurrentProcess(), -1, -1);
if (!RunSetup(configuration, archive_path.get(), setup_path.get(),
&exit_code)) {
if (ShouldDeleteExtractedFiles())
DeleteExtractedFiles(base_path.get(), archive_path.get(), setup_path.get());
return exit_code;
} // namespace mini_installer
int MainEntryPoint() {
mini_installer::ProcessExitCode result =
// VC Express editions don't come with the memset CRT obj file and linking to
// the obj files between versions becomes a bit problematic. Therefore,
// simply implement memset.
// This also avoids having to explicitly set the __sse2_available hack when
// linking with both the x64 and x86 obj files which is required when not
// linking with the std C lib in certain instances (including Chromium) with
// MSVC. __sse2_available determines whether to use SSE2 intructions with
// std C lib routines, and is set by MSVC's std C lib implementation normally.
extern "C" {
#pragma function(memset)
void* memset(void* dest, int c, size_t count) {
void* start = dest;
while (count--) {
*reinterpret_cast<char*>(dest) = static_cast<char>(c);
dest = reinterpret_cast<char*>(dest) + 1;
return start;
} // extern "C"