mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
ef6ff2f055
Deprecates `block.difficulty` and disallow `difficulty()` in inline assembly for EVM versions >= paris. The change is due to the renaming introduced by EIP-4399 (see: https://eips.ethereum.org/EIPS/eip-4399). Introduces `block.prevrandao` in Solidity and `prevrandao()` in inline assembly for EVM versions >= paris. Co-authored-by: Alex Beregszaszi <alex@rtfs.hu> Co-authored-by: Daniel <daniel@ekpyron.org> Co-authored-by: matheusaaguiar <95899911+matheusaaguiar@users.noreply.github.com> Co-authored-by: Nikola Matić <nikola.matic@ethereum.org>
77 lines
2.6 KiB
C++
77 lines
2.6 KiB
C++
/*
|
|
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/>.
|
|
*/
|
|
// SPDX-License-Identifier: GPL-3.0
|
|
/**
|
|
* Optimiser component that uses the simplification rules to simplify expressions.
|
|
*/
|
|
|
|
#include <libyul/optimiser/ExpressionSimplifier.h>
|
|
|
|
#include <libyul/optimiser/SimplificationRules.h>
|
|
#include <libyul/optimiser/OptimiserStep.h>
|
|
#include <libyul/optimiser/OptimizerUtilities.h>
|
|
#include <libyul/AST.h>
|
|
#include <libyul/Utilities.h>
|
|
|
|
#include <libevmasm/SemanticInformation.h>
|
|
|
|
using namespace std;
|
|
using namespace solidity;
|
|
using namespace solidity::yul;
|
|
|
|
void ExpressionSimplifier::run(OptimiserStepContext& _context, Block& _ast)
|
|
{
|
|
ExpressionSimplifier{_context.dialect}(_ast);
|
|
}
|
|
|
|
void ExpressionSimplifier::visit(Expression& _expression)
|
|
{
|
|
ASTModifier::visit(_expression);
|
|
|
|
while (auto const* match = SimplificationRules::findFirstMatch(
|
|
_expression,
|
|
m_dialect,
|
|
[this](YulString _var) { return variableValue(_var); }
|
|
))
|
|
_expression = match->action().toExpression(debugDataOf(_expression), evmVersionFromDialect(m_dialect));
|
|
|
|
if (auto* functionCall = get_if<FunctionCall>(&_expression))
|
|
if (optional<evmasm::Instruction> instruction = toEVMInstruction(m_dialect, functionCall->functionName.name))
|
|
for (auto op: evmasm::SemanticInformation::readWriteOperations(*instruction))
|
|
if (op.startParameter && op.lengthParameter)
|
|
{
|
|
Expression& startArgument = functionCall->arguments.at(*op.startParameter);
|
|
Expression const& lengthArgument = functionCall->arguments.at(*op.lengthParameter);
|
|
if (
|
|
knownToBeZero(lengthArgument) &&
|
|
!knownToBeZero(startArgument) &&
|
|
!holds_alternative<FunctionCall>(startArgument)
|
|
)
|
|
startArgument = Literal{debugDataOf(startArgument), LiteralKind::Number, "0"_yulstring, {}};
|
|
}
|
|
}
|
|
|
|
bool ExpressionSimplifier::knownToBeZero(Expression const& _expression) const
|
|
{
|
|
if (auto const* literal = get_if<Literal>(&_expression))
|
|
return valueOfLiteral(*literal) == 0;
|
|
else if (auto const* identifier = get_if<Identifier>(&_expression))
|
|
return valueOfIdentifier(identifier->name) == 0;
|
|
else
|
|
return false;
|
|
}
|