Method computeOffsets

libsolidity/ast/Types.cpp:142–175

}

void StorageOffsets::computeOffsets(TypePointers const& _types, u256 _baseSlot)
{
	bigint slotOffset = bigint(_baseSlot);
	unsigned byteOffset = 0;
	std::map<size_t, std::pair<u256, unsigned>> offsets;
	for (size_t i = 0; i < _types.size(); ++i)
	{
		Type const* type = _types[i];
		solAssert(type->canBeStored());
		solAssert(type->storageBytes() <= 32);
		if (byteOffset + type->storageBytes() > 32)
		{
			// would overflow, go to next slot
			++slotOffset;
			byteOffset = 0;
		}
		solAssert(slotOffset < bigint(1) << 256, "Object extends past the end of storage.");
		offsets[i] = std::make_pair(u256(slotOffset), byteOffset);
		solAssert(type->storageSize() >= 1, "Invalid storage size.");
		if (type->storageSize() == 1 && byteOffset + type->storageBytes() <= 32)
			byteOffset += type->storageBytes();
		else
		{
			slotOffset += type->storageSize();
			byteOffset = 0;
		}
	}
	if (byteOffset > 0)
		++slotOffset;

	solAssert(slotOffset < bigint(1) << 256, "Object extends past the end of storage.");
	m_storageSize = u256(slotOffset - _baseSlot);
	swap(m_offsets, offsets);
}

std::pair<u256, unsigned> const* StorageOffsets::offset(size_t _index) const
{