DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (d38398e5144e)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * 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/. */

#ifdef ACCESSIBILITY
#include "mozilla/mscom/Registration.h"
#include "nsTArray.h"
#endif

#include "mozilla/mscom/Utils.h"
#include "mozilla/RefPtr.h"

#include <objbase.h>
#include <objidl.h>

namespace mozilla {
namespace mscom {

bool
IsCurrentThreadMTA()
{
  APTTYPE aptType;
  APTTYPEQUALIFIER aptTypeQualifier;
  HRESULT hr = CoGetApartmentType(&aptType, &aptTypeQualifier);
  if (FAILED(hr)) {
    return false;
  }

  return aptType == APTTYPE_MTA;
}

bool
IsProxy(IUnknown* aUnknown)
{
  if (!aUnknown) {
    return false;
  }

  // Only proxies implement this interface, so if it is present then we must
  // be dealing with a proxied object.
  RefPtr<IClientSecurity> clientSecurity;
  HRESULT hr = aUnknown->QueryInterface(IID_IClientSecurity,
                                        (void**)getter_AddRefs(clientSecurity));
  if (SUCCEEDED(hr) || hr == RPC_E_WRONG_THREAD) {
    return true;
  }
  return false;
}

#ifdef ACCESSIBILITY
static bool
IsVtableIndexFromParentInterface(TYPEATTR* aTypeAttr,
                                 unsigned long aVtableIndex)
{
  MOZ_ASSERT(aTypeAttr);

  // This is the number of functions declared in this interface (excluding
  // parent interfaces).
  unsigned int numExclusiveFuncs = aTypeAttr->cFuncs;

  // This is the number of vtable entries (which includes parent interfaces).
  // TYPEATTR::cbSizeVft is the entire vtable size in bytes, so we need to
  // divide in order to compute the number of entries.
  unsigned int numVtblEntries = aTypeAttr->cbSizeVft / sizeof(void*);

  // This is the index of the first entry in the vtable that belongs to this
  // interface and not a parent.
  unsigned int firstVtblIndex = numVtblEntries - numExclusiveFuncs;

  // If aVtableIndex is less than firstVtblIndex, then we're asking for an
  // index that may belong to a parent interface.
  return aVtableIndex < firstVtblIndex;
}

bool
IsVtableIndexFromParentInterface(REFIID aInterface, unsigned long aVtableIndex)
{
  RefPtr<ITypeInfo> typeInfo;
  if (!RegisteredProxy::Find(aInterface, getter_AddRefs(typeInfo))) {
    return false;
  }

  TYPEATTR* typeAttr = nullptr;
  HRESULT hr = typeInfo->GetTypeAttr(&typeAttr);
  if (FAILED(hr)) {
    return false;
  }

  bool result = IsVtableIndexFromParentInterface(typeAttr, aVtableIndex);

  typeInfo->ReleaseTypeAttr(typeAttr);
  return result;
}

bool
IsInterfaceEqualToOrInheritedFrom(REFIID aInterface, REFIID aFrom,
                                  unsigned long aVtableIndexHint)
{
  if (aInterface == aFrom) {
    return true;
  }

  // We expect this array to be length 1 but that is not guaranteed by the API.
  AutoTArray<RefPtr<ITypeInfo>, 1> typeInfos;

  // Grab aInterface's ITypeInfo so that we may obtain information about its
  // inheritance hierarchy.
  RefPtr<ITypeInfo> typeInfo;
  if (RegisteredProxy::Find(aInterface, getter_AddRefs(typeInfo))) {
    typeInfos.AppendElement(Move(typeInfo));
  }

  /**
   * The main loop of this function searches the hierarchy of aInterface's
   * parent interfaces, searching for aFrom.
   */
  while (!typeInfos.IsEmpty()) {
    RefPtr<ITypeInfo> curTypeInfo(Move(typeInfos.LastElement()));
    typeInfos.RemoveElementAt(typeInfos.Length() - 1);

    TYPEATTR* typeAttr = nullptr;
    HRESULT hr = curTypeInfo->GetTypeAttr(&typeAttr);
    if (FAILED(hr)) {
      break;
    }

    bool isFromParentVtable = IsVtableIndexFromParentInterface(typeAttr,
                                                               aVtableIndexHint);
    WORD numParentInterfaces = typeAttr->cImplTypes;

    curTypeInfo->ReleaseTypeAttr(typeAttr);
    typeAttr = nullptr;

    if (!isFromParentVtable) {
      // The vtable index cannot belong to this interface (otherwise the IIDs
      // would already have matched and we would have returned true). Since we
      // now also know that the vtable index cannot possibly be contained inside
      // curTypeInfo's parent interface, there is no point searching any further
      // up the hierarchy from here. OTOH we still should check any remaining
      // entries that are still in the typeInfos array, so we continue.
      continue;
    }

    for (WORD i = 0; i < numParentInterfaces; ++i) {
      HREFTYPE refCookie;
      hr = curTypeInfo->GetRefTypeOfImplType(i, &refCookie);
      if (FAILED(hr)) {
        continue;
      }

      RefPtr<ITypeInfo> nextTypeInfo;
      hr = curTypeInfo->GetRefTypeInfo(refCookie,
                                       getter_AddRefs(nextTypeInfo));
      if (FAILED(hr)) {
        continue;
      }

      hr = nextTypeInfo->GetTypeAttr(&typeAttr);
      if (FAILED(hr)) {
        continue;
      }

      IID nextIid = typeAttr->guid;

      nextTypeInfo->ReleaseTypeAttr(typeAttr);
      typeAttr = nullptr;

      if (nextIid == aFrom) {
        return true;
      }

      typeInfos.AppendElement(Move(nextTypeInfo));
    }
  }

  return false;
}
#endif // ifdef ACCESSIBILITY

} // namespace mscom
} // namespace mozilla