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/*
This file is part of cpp-ethereum.
cpp-ethereum is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
cpp-ethereum is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @author Christian <c@ethdev.com>
* @date 2015
* Code generation utils that handle arrays.
*/
#pragma once
namespace dev
{
namespace solidity
{
class CompilerContext;
class Type;
class ArrayType;
/**
* Class that provides code generation for handling arrays.
*/
class ArrayUtils
{
public:
ArrayUtils(CompilerContext& _context): m_context(_context) {}
/// Copies an array to an array in storage. The arrays can be of different types only if
/// their storage representation is the same.
/// Stack pre: source_reference [source_byte_offset/source_length] target_reference target_byte_offset
/// Stack post: target_reference target_byte_offset
void copyArrayToStorage(ArrayType const& _targetType, ArrayType const& _sourceType) const;
/// Clears the given dynamic or static array.
/// Stack pre: storage_ref storage_byte_offset
/// Stack post:
void clearArray(ArrayType const& _type) const;
/// Clears the length and data elements of the array referenced on the stack.
/// Stack pre: reference (excludes byte offset)
/// Stack post:
void clearDynamicArray(ArrayType const& _type) const;
/// Changes the size of a dynamic array and clears the tail if it is shortened.
/// Stack pre: reference (excludes byte offset) new_length
/// Stack post:
void resizeDynamicArray(ArrayType const& _type) const;
/// Appends a loop that clears a sequence of storage slots of the given type (excluding end).
/// Stack pre: end_ref start_ref
/// Stack post: end_ref
void clearStorageLoop(Type const& _type) const;
/// Converts length to size (number of storage slots or calldata/memory bytes).
/// if @a _pad then add padding to multiples of 32 bytes for calldata/memory.
/// Stack pre: length
/// Stack post: size
void convertLengthToSize(ArrayType const& _arrayType, bool _pad = false) const;
/// Retrieves the length (number of elements) of the array ref on the stack. This also
/// works for statically-sized arrays.
/// Stack pre: reference (excludes byte offset for dynamic storage arrays)
/// Stack post: reference length
void retrieveLength(ArrayType const& _arrayType) const;
/// Retrieves the value at a specific index. If the location is storage, only retrieves the
/// position.
/// Stack pre: reference [length] index
/// Stack post for storage: slot byte_offset
/// Stack post for calldata: value
void accessIndex(ArrayType const& _arrayType) const;
private:
/// Adds the given number of bytes to a storage byte offset counter and also increments
/// the storage offset if adding this number again would increase the counter over 32.
/// @param byteOffsetPosition the stack offset of the storage byte offset
/// @param storageOffsetPosition the stack offset of the storage slot offset
void incrementByteOffset(unsigned _byteSize, unsigned _byteOffsetPosition, unsigned _storageOffsetPosition) const;
CompilerContext& m_context;
};
}
}