dawn-cmake/src/dawn_native/EnumMaskIterator.h
Corentin Wallez 738aa17493 EnumMaskIterator: ASSERT when the mask is too big.
This will catch errors when someone updates an enum used with
EnumMaskIterator without updating EnumBitmaskSize. Previously it would
just ignore the extra bits, which produced super confusing bugs.

Bug: dawn:635
Change-Id: Ib0bf3f252db317a1bfdeb687b2426801a79b524d
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/38260
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Stephen White <senorblanco@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
2021-01-21 10:11:54 +00:00

83 lines
2.4 KiB
C++

// Copyright 2020 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef DAWNNATIVE_ENUMMASKITERATOR_H_
#define DAWNNATIVE_ENUMMASKITERATOR_H_
#include "common/BitSetIterator.h"
#include "dawn_native/EnumClassBitmasks.h"
namespace dawn_native {
template <typename T>
class EnumMaskIterator final {
static constexpr size_t N = EnumBitmaskSize<T>::value;
static_assert(N > 0, "");
using U = std::underlying_type_t<T>;
public:
EnumMaskIterator(const T& mask) : mBitSetIterator(std::bitset<N>(static_cast<U>(mask))) {
// If you hit this ASSERT it means that you forgot to update EnumBitmaskSize<T>::value;
ASSERT(U(mask) == 0 || Log2(uint64_t(U(mask))) < N);
}
class Iterator final {
public:
Iterator(const typename BitSetIterator<N, U>::Iterator& iter) : mIter(iter) {
}
Iterator& operator++() {
++mIter;
return *this;
}
bool operator==(const Iterator& other) const {
return mIter == other.mIter;
}
bool operator!=(const Iterator& other) const {
return mIter != other.mIter;
}
T operator*() const {
U value = *mIter;
return static_cast<T>(U(1) << value);
}
private:
typename BitSetIterator<N, U>::Iterator mIter;
};
Iterator begin() const {
return Iterator(mBitSetIterator.begin());
}
Iterator end() const {
return Iterator(mBitSetIterator.end());
}
private:
BitSetIterator<N, U> mBitSetIterator;
};
template <typename T>
EnumMaskIterator<T> IterateEnumMask(const T& mask) {
return EnumMaskIterator<T>(mask);
}
} // namespace dawn_native
#endif // DAWNNATIVE_ENUMMASKITERATOR_H_