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// Copyright 2010 The Chromium Authors
// 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 <wrl/client.h>
#include <algorithm>
#include <functional>
#include "base/check.h"
#include "base/logging.h"
#include "base/win/propvarutil.h"
#include "base/win/variant_conversions.h"
namespace base {
namespace win {
// Global, const instance of an empty variant.
const VARIANT ScopedVariant::kEmptyVariant = {{{VT_EMPTY}}};
ScopedVariant::ScopedVariant(ScopedVariant&& var) {
var_.vt = VT_EMPTY;
Reset(var.Release());
}
ScopedVariant::~ScopedVariant() {
static_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(long value, VARTYPE vt) { // NOLINT(runtime/int)
var_.vt = vt;
var_.lVal = value;
}
ScopedVariant::ScopedVariant(int value) {
var_.vt = VT_I4;
var_.lVal = value;
}
ScopedVariant::ScopedVariant(bool value) {
var_.vt = VT_BOOL;
var_.boolVal = value ? VARIANT_TRUE : VARIANT_FALSE;
}
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& other, bool ignore_case) const {
DCHECK(!V_ISARRAY(&var_))
<< "Comparison is not supported when |this| owns a SAFEARRAY";
DCHECK(!V_ISARRAY(&other))
<< "Comparison is not supported when |other| owns a SAFEARRAY";
const bool this_is_empty = var_.vt == VT_EMPTY || var_.vt == VT_NULL;
const bool other_is_empty = other.vt == VT_EMPTY || other.vt == VT_NULL;
// 1. VT_NULL and VT_EMPTY is always considered less-than any other VARTYPE.
if (this_is_empty)
return other_is_empty ? 0 : -1;
if (other_is_empty)
return 1;
// 2. If both VARIANTS have either VT_UNKNOWN or VT_DISPATCH even if the
// VARTYPEs do not match, the address of its IID_IUnknown is compared to
// guarantee a logical ordering even though it is not a meaningful order.
// e.g. (a.Compare(b) != b.Compare(a)) unless (a == b).
const bool this_is_unknown = var_.vt == VT_UNKNOWN || var_.vt == VT_DISPATCH;
const bool other_is_unknown =
other.vt == VT_UNKNOWN || other.vt == VT_DISPATCH;
if (this_is_unknown && other_is_unknown) {
// https://docs.microsoft.com/en-us/windows/win32/com/rules-for-implementing-queryinterface
// Query IID_IUnknown to determine whether the two variants point
// to the same instance of an object
Microsoft::WRL::ComPtr<IUnknown> this_unknown;
Microsoft::WRL::ComPtr<IUnknown> other_unknown;
V_UNKNOWN(&var_)->QueryInterface(IID_PPV_ARGS(&this_unknown));
V_UNKNOWN(&other)->QueryInterface(IID_PPV_ARGS(&other_unknown));
if (this_unknown.Get() == other_unknown.Get())
return 0;
// std::less for any pointer type yields a strict total order even if the
// built-in operator< does not.
return std::less<>{}(this_unknown.Get(), other_unknown.Get()) ? -1 : 1;
}
// 3. If the VARTYPEs do not match, then the value of the VARTYPE is compared.
if (V_VT(&var_) != V_VT(&other))
return (V_VT(&var_) < V_VT(&other)) ? -1 : 1;
const VARTYPE shared_vartype = V_VT(&var_);
// 4. Comparing VT_BSTR values is a lexicographical comparison of the contents
// of the BSTR, taking into account |ignore_case|.
if (shared_vartype == VT_BSTR) {
ULONG flags = ignore_case ? NORM_IGNORECASE : 0;
HRESULT hr =
::VarBstrCmp(V_BSTR(&var_), V_BSTR(&other), LOCALE_USER_DEFAULT, flags);
DCHECK(SUCCEEDED(hr) && hr != VARCMP_NULL)
<< "unsupported variant comparison: " << var_.vt << " and " << other.vt;
switch (hr) {
case VARCMP_LT:
return -1;
case VARCMP_GT:
case VARCMP_NULL:
return 1;
default:
return 0;
}
}
// 5. Otherwise returns the lexicographical comparison of the values held by
// the two VARIANTS that share the same VARTYPE.
return ::VariantCompare(var_, other);
}
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_t i8) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_I1;
var_.cVal = i8;
}
void ScopedVariant::Set(uint8_t ui8) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_UI1;
var_.bVal = ui8;
}
void ScopedVariant::Set(int16_t i16) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_I2;
var_.iVal = i16;
}
void ScopedVariant::Set(uint16_t ui16) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_UI2;
var_.uiVal = ui16;
}
void ScopedVariant::Set(int32_t i32) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_I4;
var_.lVal = i32;
}
void ScopedVariant::Set(uint32_t ui32) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_UI4;
var_.ulVal = ui32;
}
void ScopedVariant::Set(int64_t i64) {
DCHECK(!IsLeakableVarType(var_.vt)) << "leaking variant: " << var_.vt;
var_.vt = VT_I8;
var_.llVal = i64;
}
void ScopedVariant::Set(uint64_t 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=(ScopedVariant&& var) {
if (var.ptr() != &var_)
Reset(var.Release());
return *this;
}
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