Bug 1334665: Eliminate runtime dynamic linking for pre-win7 functions in ipc/mscom; r=jimm

MozReview-Commit-ID: 7ySl728hdka

--HG--
extra : rebase_source : fd5914c70fb89176a71ffbc636c0f39662cf9d38

ipc/mscom/ProxyStream.cpp

@@ -4,7 +4,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "DynamicallyLinkedFunctionPtr.h"
 #include "mozilla/mscom/EnsureMTA.h"
 #include "mozilla/mscom/ProxyStream.h"
 #include "mozilla/mscom/Utils.h"
@@ -74,13 +73,7 @@ ProxyStream::ProxyStream(const BYTE* aInitBuf, const int aInitBufSize)
 already_AddRefed<IStream>
 ProxyStream::InitStream(const BYTE* aInitBuf, const UINT aInitBufSize)
 {
-  // Need to link to this as ordinal 12 for Windows XP
-  static DynamicallyLinkedFunctionPtr<decltype(&::SHCreateMemStream)>
-    pSHCreateMemStream(L"shlwapi.dll", reinterpret_cast<const char*>(12));
-  if (!pSHCreateMemStream) {
-    return nullptr;
-  }
-  return already_AddRefed<IStream>(pSHCreateMemStream(aInitBuf, aInitBufSize));
+  return already_AddRefed<IStream>(::SHCreateMemStream(aInitBuf, aInitBufSize));
 }
 
 ProxyStream::ProxyStream(ProxyStream&& aOther)

ipc/mscom/Utils.cpp

@@ -4,67 +4,21 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// We need Windows 7 headers
-#ifdef NTDDI_VERSION
-#undef NTDDI_VERSION
-#endif
-#define NTDDI_VERSION 0x06010000
-#ifdef _WIN32_WINNT
-#undef _WIN32_WINNT
-#endif
-#define _WIN32_WINNT 0x0601
-
-#include "DynamicallyLinkedFunctionPtr.h"
 #include "mozilla/mscom/Utils.h"
 #include "mozilla/RefPtr.h"
 
+#include <objbase.h>
 #include <objidl.h>
 
-static bool
-IsCurrentThreadMTALegacy()
-{
-  // We don't use RefPtr for token because CoGetContextToken does *not*
-  // increment its refcount!
-  IUnknown* token = nullptr;
-  HRESULT hr =
-    CoGetContextToken(reinterpret_cast<ULONG_PTR*>(&token));
-  if (FAILED(hr)) {
-    return false;
-  }
-
-  RefPtr<IComThreadingInfo> threadingInfo;
-  hr = token->QueryInterface(IID_IComThreadingInfo,
-                             getter_AddRefs(threadingInfo));
-  if (FAILED(hr)) {
-    return false;
-  }
-
-  APTTYPE aptType;
-  hr = threadingInfo->GetCurrentApartmentType(&aptType);
-  if (FAILED(hr)) {
-    return false;
-  }
-
-  return aptType == APTTYPE_MTA;
-}
-
 namespace mozilla {
 namespace mscom {
 
 bool
 IsCurrentThreadMTA()
 {
-  static DynamicallyLinkedFunctionPtr<decltype(&::CoGetApartmentType)>
-    pCoGetApartmentType(L"ole32.dll", "CoGetApartmentType");
-
-  if (!pCoGetApartmentType) {
-    // XP and Vista do not expose the newer API.
-    return IsCurrentThreadMTALegacy();
-  }
-
   APTTYPE aptType;
   APTTYPEQUALIFIER aptTypeQualifier;
-  HRESULT hr = pCoGetApartmentType(&aptType, &aptTypeQualifier);
+  HRESULT hr = CoGetApartmentType(&aptType, &aptTypeQualifier);
   if (FAILED(hr)) {
     return false;
   }

ipc/mscom/moz.build

@@ -14,14 +14,11 @@ EXPORTS.mozilla.mscom += [
     'Utils.h',
 ]
 
-SOURCES += [
-    'Utils.cpp',
-]
-
 UNIFIED_SOURCES += [
     'EnsureMTA.cpp',
     'MainThreadRuntime.cpp',
     'ProxyStream.cpp',
+    'Utils.cpp',
 ]
 
 if CONFIG['ACCESSIBILITY']: