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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 2014
* Routines used by both the compiler and the expression compiler.
*/
#pragma once
#include <libsolidity/CompilerContext.h>
#include <libsolidity/ASTForward.h>
namespace dev {
namespace solidity {
class Type; // forward
class CompilerUtils
{
public:
CompilerUtils(CompilerContext& _context): m_context(_context) {}
/// Loads data from memory to the stack.
/// @param _offset offset in memory (or calldata)
/// @param _bytes number of bytes to load
/// @param _leftAligned if true, store left aligned on stack (otherwise right aligned)
/// @param _fromCalldata if true, load from calldata, not from memory
/// @param _padToWordBoundaries if true, assume the data is padded to word (32 byte) boundaries
/// @returns the number of bytes consumed in memory (can be different from _bytes if
/// _padToWordBoundaries is true)
unsigned loadFromMemory(unsigned _offset, unsigned _bytes = 32, bool _leftAligned = false,
bool _fromCalldata = false, bool _padToWordBoundaries = false);
/// Stores data from stack in memory.
/// @param _offset offset in memory
/// @param _type type of the data on the stack
/// @param _padToWordBoundaries if true, pad the data to word (32 byte) boundaries
/// @returns the number of bytes written to memory (can be different from _bytes if
/// _padToWordBoundaries is true)
unsigned storeInMemory(unsigned _offset, Type const& _type = IntegerType(256), bool _padToWordBoundaries = false);
/// Dynamic version of @see storeInMemory, expects the memory offset below the value on the stack
/// and also updates that.
/// Stack pre: memory_offset value...
/// Stack post: (memory_offset+length)
void storeInMemoryDynamic(Type const& _type, bool _padToWordBoundaries = true);
/// @returns _size rounded up to the next multiple of 32 (the number of bytes occupied in the
/// padded calldata)
static unsigned getPaddedSize(unsigned _size) { return ((_size + 31) / 32) * 32; }
/// Moves the value that is at the top of the stack to a stack variable.
void moveToStackVariable(VariableDeclaration const& _variable);
/// Copies a variable of type @a _type from a stack depth of @a _stackDepth to the top of the stack.
void copyToStackTop(unsigned _stackDepth, Type const& _type);
/// Removes the current value from the top of the stack.
void popStackElement(Type const& _type);
template <class T>
static unsigned getSizeOnStack(std::vector<T> const& _variables);
static unsigned getSizeOnStack(std::vector<std::shared_ptr<Type const>> const& _variableTypes);
/// Appends code that computes tha SHA3 hash of the topmost stack element of type @a _type.
/// If @a _pad is set, padds the type to muliples of 32 bytes.
/// @note Only works for types of fixed size.
void computeHashStatic(Type const& _type = IntegerType(256), bool _padToWordBoundaries = false);
/// Copies a byte array to a byte array in storage.
/// Stack pre: [source_reference] target_reference
/// Stack post: target_reference
void copyByteArrayToStorage(ByteArrayType const& _targetType, ByteArrayType const& _sourceType) const;
/// Clears the length and data elements of the byte array referenced on the stack.
/// Stack pre: reference
/// Stack post:
void clearByteArray(ByteArrayType const& _type) const;
/// Bytes we need to the start of call data.
/// - The size in bytes of the function (hash) identifier.
static const unsigned int dataStartOffset;
private:
/// Prepares the given type for storing in memory by shifting it if necessary.
unsigned prepareMemoryStore(Type const& _type, bool _padToWordBoundaries) const;
/// Appends a loop that clears a sequence of storage slots (excluding end).
/// Stack pre: end_ref start_ref
/// Stack post: end_ref
void clearStorageLoop() const;
CompilerContext& m_context;
};
template <class T>
unsigned CompilerUtils::getSizeOnStack(std::vector<T> const& _variables)
{
unsigned size = 0;
for (T const& variable: _variables)
size += variable->getType()->getSizeOnStack();
return size;
}
}
}
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