mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
400 lines
13 KiB
C++
400 lines
13 KiB
C++
/*
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This file is part of solidity.
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solidity is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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solidity is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with solidity. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <libsolidity/analysis/ViewPureChecker.h>
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#include <libevmasm/SemanticInformation.h>
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#include <libsolidity/inlineasm/AsmData.h>
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#include <libsolidity/ast/ExperimentalFeatures.h>
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#include <functional>
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using namespace std;
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using namespace dev;
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using namespace dev::solidity;
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namespace
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{
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class AssemblyViewPureChecker: public boost::static_visitor<void>
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{
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public:
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explicit AssemblyViewPureChecker(std::function<void(StateMutability, SourceLocation const&)> _reportMutability):
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m_reportMutability(_reportMutability) {}
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void operator()(assembly::Label const&) { }
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void operator()(assembly::Instruction const& _instruction)
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{
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checkInstruction(_instruction.location, _instruction.instruction);
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}
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void operator()(assembly::Literal const&) {}
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void operator()(assembly::Identifier const&) {}
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void operator()(assembly::FunctionalInstruction const& _instr)
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{
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checkInstruction(_instr.location, _instr.instruction);
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for (auto const& arg: _instr.arguments)
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boost::apply_visitor(*this, arg);
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}
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void operator()(assembly::ExpressionStatement const& _expr)
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{
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boost::apply_visitor(*this, _expr.expression);
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}
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void operator()(assembly::StackAssignment const&) {}
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void operator()(assembly::Assignment const& _assignment)
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{
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boost::apply_visitor(*this, *_assignment.value);
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}
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void operator()(assembly::VariableDeclaration const& _varDecl)
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{
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if (_varDecl.value)
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boost::apply_visitor(*this, *_varDecl.value);
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}
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void operator()(assembly::FunctionDefinition const& _funDef)
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{
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(*this)(_funDef.body);
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}
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void operator()(assembly::FunctionCall const& _funCall)
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{
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for (auto const& arg: _funCall.arguments)
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boost::apply_visitor(*this, arg);
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}
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void operator()(assembly::If const& _if)
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{
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boost::apply_visitor(*this, *_if.condition);
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(*this)(_if.body);
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}
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void operator()(assembly::Switch const& _switch)
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{
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boost::apply_visitor(*this, *_switch.expression);
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for (auto const& _case: _switch.cases)
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{
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if (_case.value)
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(*this)(*_case.value);
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(*this)(_case.body);
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}
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}
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void operator()(assembly::ForLoop const& _for)
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{
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(*this)(_for.pre);
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boost::apply_visitor(*this, *_for.condition);
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(*this)(_for.body);
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(*this)(_for.post);
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}
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void operator()(assembly::Block const& _block)
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{
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for (auto const& s: _block.statements)
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boost::apply_visitor(*this, s);
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}
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private:
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std::function<void(StateMutability, SourceLocation const&)> m_reportMutability;
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void checkInstruction(SourceLocation _location, solidity::Instruction _instruction)
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{
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if (eth::SemanticInformation::invalidInViewFunctions(_instruction))
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m_reportMutability(StateMutability::NonPayable, _location);
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else if (eth::SemanticInformation::invalidInPureFunctions(_instruction))
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m_reportMutability(StateMutability::View, _location);
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}
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};
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}
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bool ViewPureChecker::check()
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{
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vector<ContractDefinition const*> contracts;
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for (auto const& node: m_ast)
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{
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SourceUnit const* source = dynamic_cast<SourceUnit const*>(node.get());
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solAssert(source, "");
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contracts += source->filteredNodes<ContractDefinition>(source->nodes());
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}
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// Check modifiers first to infer their state mutability.
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for (auto const& contract: contracts)
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for (ModifierDefinition const* mod: contract->functionModifiers())
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mod->accept(*this);
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for (auto const& contract: contracts)
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contract->accept(*this);
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return !m_errors;
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}
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bool ViewPureChecker::visit(FunctionDefinition const& _funDef)
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{
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solAssert(!m_currentFunction, "");
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m_currentFunction = &_funDef;
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m_bestMutabilityAndLocation = {StateMutability::Pure, _funDef.location()};
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return true;
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}
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void ViewPureChecker::endVisit(FunctionDefinition const& _funDef)
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{
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solAssert(m_currentFunction == &_funDef, "");
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if (
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m_bestMutabilityAndLocation.mutability < _funDef.stateMutability() &&
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_funDef.stateMutability() != StateMutability::Payable &&
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_funDef.isImplemented() &&
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!_funDef.isConstructor() &&
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!_funDef.isFallback() &&
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!_funDef.annotation().superFunction
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)
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m_errorReporter.warning(
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_funDef.location(),
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"Function state mutability can be restricted to " + stateMutabilityToString(m_bestMutabilityAndLocation.mutability)
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);
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m_currentFunction = nullptr;
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}
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bool ViewPureChecker::visit(ModifierDefinition const& _modifier)
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{
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solAssert(m_currentFunction == nullptr, "");
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m_bestMutabilityAndLocation = {StateMutability::Pure, _modifier.location()};
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return true;
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}
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void ViewPureChecker::endVisit(ModifierDefinition const& _modifierDef)
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{
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solAssert(m_currentFunction == nullptr, "");
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m_inferredMutability[&_modifierDef] = std::move(m_bestMutabilityAndLocation);
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}
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void ViewPureChecker::endVisit(Identifier const& _identifier)
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{
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Declaration const* declaration = _identifier.annotation().referencedDeclaration;
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solAssert(declaration, "");
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StateMutability mutability = StateMutability::Pure;
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bool writes = _identifier.annotation().lValueRequested;
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if (VariableDeclaration const* varDecl = dynamic_cast<VariableDeclaration const*>(declaration))
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{
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if (varDecl->isStateVariable() && !varDecl->isConstant())
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mutability = writes ? StateMutability::NonPayable : StateMutability::View;
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}
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else if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
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{
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switch (magicVar->type()->category())
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{
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case Type::Category::Contract:
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solAssert(_identifier.name() == "this" || _identifier.name() == "super", "");
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if (!dynamic_cast<ContractType const&>(*magicVar->type()).isSuper())
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// reads the address
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mutability = StateMutability::View;
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break;
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case Type::Category::Integer:
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solAssert(_identifier.name() == "now", "");
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mutability = StateMutability::View;
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break;
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default:
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break;
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}
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}
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reportMutability(mutability, _identifier.location());
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}
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void ViewPureChecker::endVisit(InlineAssembly const& _inlineAssembly)
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{
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AssemblyViewPureChecker{
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[=](StateMutability _mutability, SourceLocation const& _location) { reportMutability(_mutability, _location); }
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}(_inlineAssembly.operations());
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}
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void ViewPureChecker::reportMutability(
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StateMutability _mutability,
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SourceLocation const& _location,
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boost::optional<SourceLocation> const& _nestedLocation
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)
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{
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if (_mutability > m_bestMutabilityAndLocation.mutability)
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m_bestMutabilityAndLocation = MutabilityAndLocation{_mutability, _location};
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if (!m_currentFunction || _mutability <= m_currentFunction->stateMutability())
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return;
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// Check for payable here, because any occurrence of `msg.value`
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// will set mutability to payable.
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if (_mutability == StateMutability::View || (
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_mutability == StateMutability::Payable &&
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m_currentFunction->stateMutability() == StateMutability::Pure
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))
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{
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m_errorReporter.typeError(
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_location,
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"Function declared as pure, but this expression (potentially) reads from the "
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"environment or state and thus requires \"view\"."
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);
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m_errors = true;
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}
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else if (_mutability == StateMutability::NonPayable)
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{
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m_errorReporter.typeError(
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_location,
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"Function declared as " +
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stateMutabilityToString(m_currentFunction->stateMutability()) +
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", but this expression (potentially) modifies the state and thus "
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"requires non-payable (the default) or payable."
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);
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m_errors = true;
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}
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else if (_mutability == StateMutability::Payable)
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{
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// We do not warn for library functions because they cannot be payable anyway.
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// Also internal functions should be allowed to use `msg.value`.
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if (m_currentFunction->isPublic() && m_currentFunction->inContractKind() != ContractDefinition::ContractKind::Library)
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{
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if (_nestedLocation)
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m_errorReporter.typeError(
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_location,
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SecondarySourceLocation().append("\"msg.value\" appears here inside the modifier.", *_nestedLocation),
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"This modifier uses \"msg.value\" and thus the function has to be payable or internal."
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);
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else
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m_errorReporter.typeError(
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_location,
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"\"msg.value\" can only be used in payable public functions. Make the function "
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"\"payable\" or use an internal function to avoid this error."
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);
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m_errors = true;
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}
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}
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else
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solAssert(false, "");
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solAssert(
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m_currentFunction->stateMutability() == StateMutability::View ||
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m_currentFunction->stateMutability() == StateMutability::Pure ||
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m_currentFunction->stateMutability() == StateMutability::NonPayable,
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""
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);
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}
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void ViewPureChecker::endVisit(FunctionCall const& _functionCall)
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{
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if (_functionCall.annotation().kind != FunctionCallKind::FunctionCall)
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return;
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StateMutability mutability = dynamic_cast<FunctionType const&>(*_functionCall.expression().annotation().type).stateMutability();
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// We only require "nonpayable" to call a payble function.
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if (mutability == StateMutability::Payable)
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mutability = StateMutability::NonPayable;
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reportMutability(mutability, _functionCall.location());
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}
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bool ViewPureChecker::visit(MemberAccess const& _memberAccess)
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{
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// Catch the special case of `this.f.selector` which is a pure expression.
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ASTString const& member = _memberAccess.memberName();
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if (
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_memberAccess.expression().annotation().type->category() == Type::Category::Function &&
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member == "selector"
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)
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if (auto const* expr = dynamic_cast<MemberAccess const*>(&_memberAccess.expression()))
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if (auto const* exprInt = dynamic_cast<Identifier const*>(&expr->expression()))
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if (exprInt->name() == "this")
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// Do not continue visiting.
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return false;
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return true;
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}
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void ViewPureChecker::endVisit(MemberAccess const& _memberAccess)
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{
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StateMutability mutability = StateMutability::Pure;
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bool writes = _memberAccess.annotation().lValueRequested;
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ASTString const& member = _memberAccess.memberName();
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switch (_memberAccess.expression().annotation().type->category())
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{
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case Type::Category::Address:
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if (member == "balance")
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mutability = StateMutability::View;
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break;
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case Type::Category::Magic:
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{
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using MagicMember = pair<MagicType::Kind, string>;
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set<MagicMember> static const pureMembers{
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{MagicType::Kind::ABI, "decode"},
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{MagicType::Kind::ABI, "encode"},
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{MagicType::Kind::ABI, "encodePacked"},
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{MagicType::Kind::ABI, "encodeWithSelector"},
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{MagicType::Kind::ABI, "encodeWithSignature"},
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{MagicType::Kind::Block, "blockhash"},
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{MagicType::Kind::Message, "data"},
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{MagicType::Kind::Message, "sig"}
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};
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set<MagicMember> static const payableMembers{
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{MagicType::Kind::Message, "value"}
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};
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auto const& type = dynamic_cast<MagicType const&>(*_memberAccess.expression().annotation().type);
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MagicMember magicMember(type.kind(), member);
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if (!pureMembers.count(magicMember))
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mutability = StateMutability::View;
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if (payableMembers.count(magicMember))
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mutability = StateMutability::Payable;
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break;
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}
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case Type::Category::Struct:
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{
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if (_memberAccess.expression().annotation().type->dataStoredIn(DataLocation::Storage))
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mutability = writes ? StateMutability::NonPayable : StateMutability::View;
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break;
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}
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case Type::Category::Array:
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{
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auto const& type = dynamic_cast<ArrayType const&>(*_memberAccess.expression().annotation().type);
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if (member == "length" && type.isDynamicallySized() && type.dataStoredIn(DataLocation::Storage))
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mutability = writes ? StateMutability::NonPayable : StateMutability::View;
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break;
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}
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default:
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break;
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}
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reportMutability(mutability, _memberAccess.location());
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}
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void ViewPureChecker::endVisit(IndexAccess const& _indexAccess)
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{
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if (!_indexAccess.indexExpression())
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solAssert(_indexAccess.annotation().type->category() == Type::Category::TypeType, "");
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else
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{
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bool writes = _indexAccess.annotation().lValueRequested;
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if (_indexAccess.baseExpression().annotation().type->dataStoredIn(DataLocation::Storage))
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reportMutability(writes ? StateMutability::NonPayable : StateMutability::View, _indexAccess.location());
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}
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}
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void ViewPureChecker::endVisit(ModifierInvocation const& _modifier)
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{
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solAssert(_modifier.name(), "");
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if (ModifierDefinition const* mod = dynamic_cast<decltype(mod)>(_modifier.name()->annotation().referencedDeclaration))
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{
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solAssert(m_inferredMutability.count(mod), "");
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auto const& mutAndLocation = m_inferredMutability.at(mod);
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reportMutability(mutAndLocation.mutability, _modifier.location(), mutAndLocation.location);
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}
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else
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solAssert(dynamic_cast<ContractDefinition const*>(_modifier.name()->annotation().referencedDeclaration), "");
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}
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