solidity/libsolidity/codegen/YulUtilFunctions.h

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/*
This file is part of solidity.
solidity 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.
solidity 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 solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Component that can generate various useful Yul functions.
*/
#pragma once
#include <liblangutil/EVMVersion.h>
#include <libsolidity/codegen/MultiUseYulFunctionCollector.h>
#include <memory>
#include <string>
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#include <vector>
namespace dev
{
namespace solidity
{
class Type;
class ArrayType;
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class MappingType;
/**
* Component that can generate various useful Yul functions.
*/
class YulUtilFunctions
{
public:
explicit YulUtilFunctions(
langutil::EVMVersion _evmVersion,
std::shared_ptr<MultiUseYulFunctionCollector> _functionCollector
):
m_evmVersion(_evmVersion),
m_functionCollector(std::move(_functionCollector))
{}
/// @returns a function that combines the address and selector to a single value
/// for use in the ABI.
std::string combineExternalFunctionIdFunction();
/// @returns a function that splits the address and selector from a single value
/// for use in the ABI.
std::string splitExternalFunctionIdFunction();
/// @returns a function that copies raw bytes of dynamic length from calldata
/// or memory to memory.
/// Pads with zeros and might write more than exactly length.
std::string copyToMemoryFunction(bool _fromCalldata);
// @returns the name of a function that has the equivalent logic of an
// `assert` or `require` call.
std::string requireOrAssertFunction(bool _assert, Type const* _messageType = nullptr);
/// @returns the name of a function that takes a (cleaned) value of the given value type and
/// left-aligns it, usually for use in non-padded encoding.
std::string leftAlignFunction(Type const& _type);
std::string shiftLeftFunction(size_t _numBits);
std::string shiftRightFunction(size_t _numBits);
/// @returns the name of a function f(value, toInsert) -> newValue which replaces the
/// _numBytes bytes starting at byte position _shiftBytes (counted from the least significant
/// byte) by the _numBytes least significant bytes of `toInsert`.
std::string updateByteSliceFunction(size_t _numBytes, size_t _shiftBytes);
/// @returns the name of a function that rounds its input to the next multiple
/// of 32 or the input if it is a multiple of 32.
std::string roundUpFunction();
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std::string overflowCheckedUIntAddFunction(size_t _bits);
std::string overflowCheckedUIntMulFunction(size_t _bits);
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/// @returns computes the difference between two values.
/// Assumes the input to be in range for the type.
std::string overflowCheckedUIntSubFunction();
std::string arrayLengthFunction(ArrayType const& _type);
/// @returns the name of a function that computes the number of bytes required
/// to store an array in memory given its length (internally encoded, not ABI encoded).
/// The function reverts for too large lengths.
std::string arrayAllocationSizeFunction(ArrayType const& _type);
/// @returns the name of a function that converts a storage slot number
/// a memory pointer or a calldata pointer to the slot number / memory pointer / calldata pointer
/// for the data position of an array which is stored in that slot / memory area / calldata area.
std::string arrayDataAreaFunction(ArrayType const& _type);
/// @returns the name of a function that advances an array data pointer to the next element.
/// Only works for memory arrays, calldata arrays and storage arrays that store one item per slot.
std::string nextArrayElementFunction(ArrayType const& _type);
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/// @returns the name of a function that performs index access for mappings.
/// @param _mappingType the type of the mapping
/// @param _keyType the type of the value provided
std::string mappingIndexAccessFunction(MappingType const& _mappingType, Type const& _keyType);
/// @returns a function that reads a value type from storage.
/// Performs bit mask/sign extend cleanup and appropriate left / right shift, but not validation.
/// @param _splitFunctionTypes if false, returns the address and function signature in a
/// single variable.
std::string readFromStorage(Type const& _type, size_t _offset, bool _splitFunctionTypes);
/// @returns a function that extracts a value type from storage slot that has been
/// retrieved already.
/// Performs bit mask/sign extend cleanup and appropriate left / right shift, but not validation.
/// @param _splitFunctionTypes if false, returns the address and function signature in a
/// single variable.
std::string extractFromStorageValue(Type const& _type, size_t _offset, bool _splitFunctionTypes);
/// Performs cleanup after reading from a potentially compressed storage slot.
/// The function does not perform any validation, it just masks or sign-extends
/// higher order bytes or left-aligns (in case of bytesNN).
/// The storage cleanup expects the value to be right-aligned with potentially
/// dirty higher order bytes.
/// @param _splitFunctionTypes if false, returns the address and function signature in a
/// single variable.
std::string cleanupFromStorageFunction(Type const& _type, bool _splitFunctionTypes);
/// @returns the name of a function that prepares a value of the given type
/// for being stored in storage. This usually includes cleanup and right-alignment
/// to fit the number of bytes in storage.
/// The resulting value might still have dirty higher order bits.
std::string prepareStoreFunction(Type const& _type);
/// @returns the name of a function that allocates memory.
/// Modifies the "free memory pointer"
/// Arguments: size
/// Return value: pointer
std::string allocationFunction();
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/// @returns the name of the function that converts a value of type @a _from
/// to a value of type @a _to. The resulting vale is guaranteed to be in range
/// (i.e. "clean"). Asserts on failure.
///
/// This is used for data being encoded or general type conversions in the code.
std::string conversionFunction(Type const& _from, Type const& _to);
/// @returns the name of the cleanup function for the given type and
/// adds its implementation to the requested functions.
/// The cleanup function defers to the validator function with "assert"
/// if there is no reasonable way to clean a value.
std::string cleanupFunction(Type const& _type);
/// @returns the name of the validator function for the given type and
/// adds its implementation to the requested functions.
/// @param _revertOnFailure if true, causes revert on invalid data,
/// otherwise an assertion failure.
///
/// This is used for data decoded from external sources.
std::string validatorFunction(Type const& _type, bool _revertOnFailure = false);
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std::string packedHashFunction(std::vector<Type const*> const& _givenTypes, std::vector<Type const*> const& _targetTypes);
/// @returns the name of a function that reverts and uses returndata (if available)
/// as reason string.
std::string forwardingRevertFunction();
/// @returns a string containing a comma-separated list of variable names consisting of @a _baseName suffixed
/// with increasing integers in the range [@a _startSuffix, @a _endSuffix), if @a _startSuffix < @a _endSuffix,
/// and with decreasing integers in the range [@a _endSuffix, @a _startSuffix), if @a _endSuffix < @a _startSuffix.
/// If @a _startSuffix == @a _endSuffix, the empty string is returned.
static std::string suffixedVariableNameList(std::string const& _baseName, size_t _startSuffix, size_t _endSuffix);
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std::string incrementCheckedFunction(Type const& _type);
std::string decrementCheckedFunction(Type const& _type);
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std::string negateNumberCheckedFunction(Type const& _type);
/// @returns the name of a function that returns the zero value for the
/// provided type
std::string zeroValueFunction(Type const& _type);
private:
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/// Special case of conversionFunction - handles everything that does not
/// use exactly one variable to hold the value.
std::string conversionFunctionSpecial(Type const& _from, Type const& _to);
langutil::EVMVersion m_evmVersion;
std::shared_ptr<MultiUseYulFunctionCollector> m_functionCollector;
};
}
}