gecko-dev/layout/style/nsRuleData.cpp

56 lines
1.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
#include "nsRuleData.h"
#include "mozilla/Poison.h"
#include <stdint.h>
inline size_t
nsRuleData::GetPoisonOffset()
{
// Fill in mValueOffsets such that mValueStorage + mValueOffsets[i]
// will yield the frame poison value for all uninitialized value
// offsets.
static_assert(sizeof(uintptr_t) == sizeof(size_t),
"expect uintptr_t and size_t to be the same size");
static_assert(uintptr_t(-1) > uintptr_t(0),
"expect uintptr_t to be unsigned");
static_assert(size_t(-1) > size_t(0),
"expect size_t to be unsigned");
uintptr_t framePoisonValue = mozPoisonValue();
return size_t(framePoisonValue - uintptr_t(mValueStorage)) /
sizeof(nsCSSValue);
}
nsRuleData::nsRuleData(uint32_t aSIDs, nsCSSValue* aValueStorage,
nsPresContext* aContext, nsStyleContext* aStyleContext)
: mSIDs(aSIDs),
mPresContext(aContext),
mStyleContext(aStyleContext),
mValueStorage(aValueStorage)
{
#ifndef MOZ_VALGRIND
size_t framePoisonOffset = GetPoisonOffset();
for (size_t i = 0; i < nsStyleStructID_Length; ++i) {
mValueOffsets[i] = framePoisonOffset;
}
#endif
}
#ifdef DEBUG
nsRuleData::~nsRuleData()
{
#ifndef MOZ_VALGRIND
// assert nothing in mSIDs has poison value
size_t framePoisonOffset = GetPoisonOffset();
for (size_t i = 0; i < nsStyleStructID_Length; ++i) {
MOZ_ASSERT(!(mSIDs & (1 << i)) || mValueOffsets[i] != framePoisonOffset,
"value in SIDs was left with poison offset");
}
#endif
}
#endif