root/base/win/scoped_variant.cc

DEFINITIONS

1. Reset
2. Release
3. Swap
4. Receive
5. Copy
6. Compare
7. Set
8. Set
9. Set
10. Set
11. Set
12. Set
13. Set
14. Set
15. Set
16. Set
17. Set
18. SetDate
19. Set
20. Set
21. Set
22. Set
23. Set
24. IsLeakableVarType

// Copyright (c) 2010 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 "base/win/scoped_variant.h"
#include "base/logging.h"

namespace base {
namespace win {

// Global, const instance of an empty variant.
const VARIANT ScopedVariant::kEmptyVariant = { VT_EMPTY };

ScopedVariant::~ScopedVariant() {
  COMPILE_ASSERT(sizeof(ScopedVariant) == sizeof(VARIANT), ScopedVariantSize);
  ::VariantClear(&var_);
}

ScopedVariant::ScopedVariant(const wchar_t* str) {
  var_.vt = VT_EMPTY;
  Set(str);
}

ScopedVariant::ScopedVariant(const wchar_t* str, UINT length) {
  var_.vt = VT_BSTR;
  var_.bstrVal = ::SysAllocStringLen(str, length);
}

ScopedVariant::ScopedVariant(int value, VARTYPE vt) {
  var_.vt = vt;
  var_.lVal = value;
}

ScopedVariant::ScopedVariant(double value, VARTYPE vt) {
  DCHECK(vt == VT_R8 || vt == VT_DATE);
  var_.vt = vt;
  var_.dblVal = value;
}

ScopedVariant::ScopedVariant(IDispatch* dispatch) {
  var_.vt = VT_EMPTY;
  Set(dispatch);
}

ScopedVariant::ScopedVariant(IUnknown* unknown) {
  var_.vt = VT_EMPTY;
  Set(unknown);
}

ScopedVariant::ScopedVariant(SAFEARRAY* safearray) {
  var_.vt = VT_EMPTY;
  Set(safearray);
}

ScopedVariant::ScopedVariant(const VARIANT& var) {
  var_.vt = VT_EMPTY;
  Set(var);
}

void ScopedVariant::Reset(const VARIANT& var) {
  if (&var != &var_) {
    ::VariantClear(&var_);
    var_ = var;
  }
}

VARIANT ScopedVariant::Release() {
  VARIANT var = var_;
  var_.vt = VT_EMPTY;
  return var;
}

void ScopedVariant::Swap(ScopedVariant& var) {
  VARIANT tmp = var_;
  var_ = var.var_;
  var.var_ = tmp;
}

VARIANT* ScopedVariant::Receive() {
  DCHECK(!IsLeakableVarType(var_.vt)) << "variant leak. type: " << var_.vt;
  return &var_;
}

VARIANT ScopedVariant::Copy() const {
  VARIANT ret = { VT_EMPTY };
  ::VariantCopy(&ret, &var_);
  return ret;
}

int ScopedVariant::Compare(const VARIANT& var, bool ignore_case) const {
  ULONG flags = ignore_case ? NORM_IGNORECASE : 0;
  HRESULT hr = ::VarCmp(const_cast<VARIANT*>(&var_), const_cast<VARIANT*>(&var),
                        LOCALE_USER_DEFAULT, flags);
  int ret = 0;

  switch (hr) {
    case VARCMP_LT:
      ret = -1;
      break;

    case VARCMP_GT:
    case VARCMP_NULL:
      ret = 1;
      break;

    default:
      // Equal.
      break;
  }

  return ret;
}

void ScopedVariant::Set(const wchar_t* str) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_BSTR;
  var_.bstrVal = ::SysAllocString(str);
}

void ScopedVariant::Set(int8 i8) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_I1;
  var_.cVal = i8;
}

void ScopedVariant::Set(uint8 ui8) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_UI1;
  var_.bVal = ui8;
}

void ScopedVariant::Set(int16 i16) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_I2;
  var_.iVal = i16;
}

void ScopedVariant::Set(uint16 ui16) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_UI2;
  var_.uiVal = ui16;
}

void ScopedVariant::Set(int32 i32) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_I4;
  var_.lVal = i32;
}

void ScopedVariant::Set(uint32 ui32) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_UI4;
  var_.ulVal = ui32;
}

void ScopedVariant::Set(int64 i64) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_I8;
  var_.llVal = i64;
}

void ScopedVariant::Set(uint64 ui64) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_UI8;
  var_.ullVal = ui64;
}

void ScopedVariant::Set(float r32) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_R4;
  var_.fltVal = r32;
}

void ScopedVariant::Set(double r64) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_R8;
  var_.dblVal = r64;
}

void ScopedVariant::SetDate(DATE date) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_DATE;
  var_.date = date;
}

void ScopedVariant::Set(IDispatch* disp) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_DISPATCH;
  var_.pdispVal = disp;
  if (disp)
    disp->AddRef();
}

void ScopedVariant::Set(bool b) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_BOOL;
  var_.boolVal = b ? VARIANT_TRUE : VARIANT_FALSE;
}

void ScopedVariant::Set(IUnknown* unk) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  var_.vt = VT_UNKNOWN;
  var_.punkVal = unk;
  if (unk)
    unk->AddRef();
}

void ScopedVariant::Set(SAFEARRAY* array) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  if (SUCCEEDED(::SafeArrayGetVartype(array, &var_.vt))) {
    var_.vt |= VT_ARRAY;
    var_.parray = array;
  } else {
    DCHECK(!array) << "Unable to determine safearray vartype";
    var_.vt = VT_EMPTY;
  }
}

void ScopedVariant::Set(const VARIANT& var) {
  DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
  if (FAILED(::VariantCopy(&var_, &var))) {
    DLOG(ERROR) << "VariantCopy failed";
    var_.vt = VT_EMPTY;
  }
}

ScopedVariant& ScopedVariant::operator=(const VARIANT& var) {
  if (&var != &var_) {
    VariantClear(&var_);
    Set(var);
  }
  return *this;
}

bool ScopedVariant::IsLeakableVarType(VARTYPE vt) {
  bool leakable = false;
  switch (vt & VT_TYPEMASK) {
    case VT_BSTR:
    case VT_DISPATCH:
    // we treat VT_VARIANT as leakable to err on the safe side.
    case VT_VARIANT:
    case VT_UNKNOWN:
    case VT_SAFEARRAY:

    // very rarely used stuff (if ever):
    case VT_VOID:
    case VT_PTR:
    case VT_CARRAY:
    case VT_USERDEFINED:
    case VT_LPSTR:
    case VT_LPWSTR:
    case VT_RECORD:
    case VT_INT_PTR:
    case VT_UINT_PTR:
    case VT_FILETIME:
    case VT_BLOB:
    case VT_STREAM:
    case VT_STORAGE:
    case VT_STREAMED_OBJECT:
    case VT_STORED_OBJECT:
    case VT_BLOB_OBJECT:
    case VT_VERSIONED_STREAM:
    case VT_BSTR_BLOB:
      leakable = true;
      break;
  }

  if (!leakable && (vt & VT_ARRAY) != 0) {
    leakable = true;
  }

  return leakable;
}

}  // namespace win
}  // namespace base