Make Chrome Frame registration and unregistration more robust.

chrome/installer/util/self_reg_work_item.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.
 
 #include "chrome/installer/util/self_reg_work_item.h"
 
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "chrome/installer/util/logging_installer.h"
 
 // Default registration export names.
 const char kDefaultRegistrationEntryPoint[] = "DllRegisterServer";
 const char kDefaultUnregistrationEntryPoint[] = "DllUnregisterServer";
 
 // User-level registration export names.
 const char kUserRegistrationEntryPoint[] = "DllRegisterUserServer";
 const char kUserUnregistrationEntryPoint[] = "DllUnregisterUserServer";
 
 SelfRegWorkItem::SelfRegWorkItem(const std::wstring& dll_path,
                                  bool do_register,
                                  bool user_level_registration)
     : do_register_(do_register), dll_path_(dll_path),
       user_level_registration_(user_level_registration) {
 }
 
 SelfRegWorkItem::~SelfRegWorkItem() {
 }
 
+// This is designed to unmux error codes that may be shoe-horned in to HRESULT
+// return codes by ORing a number into the top four bits of the facility code.
+// Any number thus found will be returned in |error_code|. The "cleaned"
+// HRESULT is then returned. Note that this will do the wrong thing for
+// high-valued facility codes.
+HRESULT UnMuxHRESULTErrorCode(HRESULT hr, int* error_code) {
+  DCHECK(error_code);
+  *error_code = (hr & 0x07800000) >> 23;

[grt (UTC plus 2), 2011/09/06 14:56:55]

why not do this only if the customer bit is set?  conceivably, this work item
could be used to register a component that doesn't do the muxing magic.

[robertshield, 2011/09/06 20:23:42]

Good idea, done.

+  return hr & 0xF87FFFFF;
+}
+
 bool SelfRegWorkItem::RegisterDll(bool do_register) {
   VLOG(1) << "COM " << (do_register ? "registration of " : "unregistration of ")
           << dll_path_;
 
   HMODULE dll_module = ::LoadLibraryEx(dll_path_.c_str(), NULL,
                                        LOAD_WITH_ALTERED_SEARCH_PATH);
   bool success = false;
   if (NULL != dll_module) {
     typedef HRESULT (WINAPI* RegisterFunc)();
     RegisterFunc register_server_func = NULL;
     if (do_register) {
       register_server_func = reinterpret_cast<RegisterFunc>(
           ::GetProcAddress(dll_module, user_level_registration_ ?
               kUserRegistrationEntryPoint : kDefaultRegistrationEntryPoint));
     } else {
       register_server_func = reinterpret_cast<RegisterFunc>(
           ::GetProcAddress(dll_module, user_level_registration_ ?
               kUserUnregistrationEntryPoint :
               kDefaultUnregistrationEntryPoint));
     }
 
     if (NULL != register_server_func) {
       HRESULT hr = register_server_func();
       success = SUCCEEDED(hr);
       if (!success) {
-        PLOG(ERROR) << "Failed to " << (do_register ? "register" : "unregister")
-                    << " DLL at " << dll_path_.c_str() <<
-                    base::StringPrintf(" 0x%08X", hr);
+        int error_code = 0;
+        HRESULT unmuxed_hr = UnMuxHRESULTErrorCode(hr, &error_code);
+        LOG(ERROR) << "Failed to " << (do_register ? "register" : "unregister")
+                   << " DLL at " << dll_path_.c_str() << ", hr="
+                   << base::StringPrintf(" 0x%08X", unmuxed_hr) << ", code="
+                   << error_code;
       }
     } else {
       LOG(ERROR) << "COM registration export function not found";
     }
     ::FreeLibrary(dll_module);
   } else {
     PLOG(WARNING) << "Failed to load: " << dll_path_;
   }
   return success;
 }
 
 bool SelfRegWorkItem::Do() {
   bool success = RegisterDll(do_register_);
   if (ignore_failure_)
     success = true;
   return success;
 }
 
 void SelfRegWorkItem::Rollback() {
   if (!ignore_failure_) {
     RegisterDll(!do_register_);
   }
 }