/*
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 verifies overloads, abstract contracts, function clashes and others
* checks at contract or function level.
*/
#include <libsolidity/analysis/ContractLevelChecker.h>
#include <libsolidity/ast/AST.h>
#include <liblangutil/ErrorReporter.h>
#include <boost/range/adaptor/reversed.hpp>
using namespace std;
using namespace dev;
using namespace langutil;
using namespace dev::solidity;
bool ContractLevelChecker::check(ContractDefinition const& _contract)
{
checkDuplicateFunctions(_contract);
checkDuplicateEvents(_contract);
checkIllegalOverrides(_contract);
checkAbstractFunctions(_contract);
checkBaseConstructorArguments(_contract);
checkConstructor(_contract);
checkFallbackFunction(_contract);
checkExternalTypeClashes(_contract);
checkHashCollisions(_contract);
checkLibraryRequirements(_contract);
return Error::containsOnlyWarnings(m_errorReporter.errors());
}
void ContractLevelChecker::checkDuplicateFunctions(ContractDefinition const& _contract)
{
/// Checks that two functions with the same name defined in this contract have different
/// argument types and that there is at most one constructor.
map<string, vector<FunctionDefinition const*>> functions;
FunctionDefinition const* constructor = nullptr;
FunctionDefinition const* fallback = nullptr;
for (FunctionDefinition const* function: _contract.definedFunctions())
if (function->isConstructor())
{
if (constructor)
m_errorReporter.declarationError(
function->location(),
SecondarySourceLocation().append("Another declaration is here:", constructor->location()),
"More than one constructor defined."
);
constructor = function;
}
else if (function->isFallback())
{
if (fallback)
m_errorReporter.declarationError(
function->location(),
SecondarySourceLocation().append("Another declaration is here:", fallback->location()),
"Only one fallback function is allowed."
);
fallback = function;
}
else
{
solAssert(!function->name().empty(), "");
functions[function->name()].push_back(function);
}
findDuplicateDefinitions(functions, "Function with same name and arguments defined twice.");
}
void ContractLevelChecker::checkDuplicateEvents(ContractDefinition const& _contract)
{
/// Checks that two events with the same name defined in this contract have different
/// argument types
map<string, vector<EventDefinition const*>> events;
for (EventDefinition const* event: _contract.events())
events[event->name()].push_back(event);
findDuplicateDefinitions(events, "Event with same name and arguments defined twice.");
}
template <class T>
void ContractLevelChecker::findDuplicateDefinitions(map<string, vector<T>> const& _definitions, string _message)
{
for (auto const& it: _definitions)
{
vector<T> const& overloads = it.second;
set<size_t> reported;
for (size_t i = 0; i < overloads.size() && !reported.count(i); ++i)
{
SecondarySourceLocation ssl;
for (size_t j = i + 1; j < overloads.size(); ++j)
if (FunctionType(*overloads[i]).asCallableFunction(false)->hasEqualParameterTypes(
*FunctionType(*overloads[j]).asCallableFunction(false))
)
{
ssl.append("Other declaration is here:", overloads[j]->location());
reported.insert(j);
}
if (ssl.infos.size() > 0)
{
ssl.limitSize(_message);
m_errorReporter.declarationError(
overloads[i]->location(),
ssl,
_message
);
}
}
}
}
void ContractLevelChecker::checkIllegalOverrides(ContractDefinition const& _contract)
{
// TODO unify this at a later point. for this we need to put the constness and the access specifier
// into the types
map<string, vector<FunctionDefinition const*>> functions;
map<string, ModifierDefinition const*> modifiers;
// We search from derived to base, so the stored item causes the error.
for (ContractDefinition const* contract: _contract.annotation().linearizedBaseContracts)
{
for (FunctionDefinition const* function: contract->definedFunctions())
{
if (function->isConstructor())
continue; // constructors can neither be overridden nor override anything
string const& name = function->name();
if (modifiers.count(name))
m_errorReporter.typeError(modifiers[name]->location(), "Override changes function to modifier.");
for (FunctionDefinition const* overriding: functions[name])
checkFunctionOverride(*overriding, *function);
functions[name].push_back(function);
}
for (ModifierDefinition const* modifier: contract->functionModifiers())
{
string const& name = modifier->name();
ModifierDefinition const*& override = modifiers[name];
if (!override)
override = modifier;
else if (ModifierType(*override) != ModifierType(*modifier))
m_errorReporter.typeError(override->location(), "Override changes modifier signature.");
if (!functions[name].empty())
m_errorReporter.typeError(override->location(), "Override changes modifier to function.");
}
}
}
void ContractLevelChecker::checkFunctionOverride(FunctionDefinition const& _function, FunctionDefinition const& _super)
{
FunctionTypePointer functionType = FunctionType(_function).asCallableFunction(false);
FunctionTypePointer superType = FunctionType(_super).asCallableFunction(false);
if (!functionType->hasEqualParameterTypes(*superType))
return;
if (!functionType->hasEqualReturnTypes(*superType))
overrideError(_function, _super, "Overriding function return types differ.");
if (!_function.annotation().superFunction)
_function.annotation().superFunction = &_super;
if (_function.visibility() != _super.visibility())
{
// Visibility change from external to public is fine.
// Any other change is disallowed.
if (!(
_super.visibility() == FunctionDefinition::Visibility::External &&
_function.visibility() == FunctionDefinition::Visibility::Public
))
overrideError(_function, _super, "Overriding function visibility differs.");
}
if (_function.stateMutability() != _super.stateMutability())
overrideError(
_function,
_super,
"Overriding function changes state mutability from \"" +
stateMutabilityToString(_super.stateMutability()) +
"\" to \"" +
stateMutabilityToString(_function.stateMutability()) +
"\"."
);
}
void ContractLevelChecker::overrideError(FunctionDefinition const& function, FunctionDefinition const& super, string message)
{
m_errorReporter.typeError(
function.location(),
SecondarySourceLocation().append("Overridden function is here:", super.location()),
message
);
}
void ContractLevelChecker::checkAbstractFunctions(ContractDefinition const& _contract)
{
// Mapping from name to function definition (exactly one per argument type equality class) and
// flag to indicate whether it is fully implemented.
using FunTypeAndFlag = std::pair<FunctionTypePointer, bool>;
map<string, vector<FunTypeAndFlag>> functions;
auto registerFunction = [&](Declaration const& _declaration, FunctionTypePointer const& _type, bool _implemented)
{
auto& overloads = functions[_declaration.name()];
auto it = find_if(overloads.begin(), overloads.end(), [&](FunTypeAndFlag const& _funAndFlag)
{
return _type->hasEqualParameterTypes(*_funAndFlag.first);
});
if (it == overloads.end())
overloads.push_back(make_pair(_type, _implemented));
else if (it->second)
{
if (!_implemented)
m_errorReporter.typeError(_declaration.location(), "Redeclaring an already implemented function as abstract");
}
else if (_implemented)
it->second = true;
};
// Search from base to derived, collect all functions and update
// the 'implemented' flag.
for (ContractDefinition const* contract: boost::adaptors::reverse(_contract.annotation().linearizedBaseContracts))
{
for (VariableDeclaration const* v: contract->stateVariables())
if (v->isPartOfExternalInterface())
registerFunction(*v, make_shared<FunctionType>(*v), true);
for (FunctionDefinition const* function: contract->definedFunctions())
if (!function->isConstructor())
registerFunction(
*function,
make_shared<FunctionType>(*function)->asCallableFunction(false),
function->isImplemented()
);
}
// Set to not fully implemented if at least one flag is false.
for (auto const& it: functions)
for (auto const& funAndFlag: it.second)
if (!funAndFlag.second)
{
FunctionDefinition const* function = dynamic_cast<FunctionDefinition const*>(&funAndFlag.first->declaration());
solAssert(function, "");
_contract.annotation().unimplementedFunctions.push_back(function);
break;
}
}
void ContractLevelChecker::checkBaseConstructorArguments(ContractDefinition const& _contract)
{
vector<ContractDefinition const*> const& bases = _contract.annotation().linearizedBaseContracts;
// Determine the arguments that are used for the base constructors.
for (ContractDefinition const* contract: bases)
{
if (FunctionDefinition const* constructor = contract->constructor())
for (auto const& modifier: constructor->modifiers())
if (auto baseContract = dynamic_cast<ContractDefinition const*>(
modifier->name()->annotation().referencedDeclaration
))
{
if (modifier->arguments())
{
if (baseContract->constructor())
annotateBaseConstructorArguments(_contract, baseContract->constructor(), modifier.get());
}
else
m_errorReporter.declarationError(
modifier->location(),
"Modifier-style base constructor call without arguments."
);
}
for (ASTPointer<InheritanceSpecifier> const& base: contract->baseContracts())
{
ContractDefinition const* baseContract = dynamic_cast<ContractDefinition const*>(
base->name().annotation().referencedDeclaration
);
solAssert(baseContract, "");
if (baseContract->constructor() && base->arguments() && !base->arguments()->empty())
annotateBaseConstructorArguments(_contract, baseContract->constructor(), base.get());
}
}
// check that we get arguments for all base constructors that need it.
// If not mark the contract as abstract (not fully implemented)
for (ContractDefinition const* contract: bases)
if (FunctionDefinition const* constructor = contract->constructor())
if (contract != &_contract && !constructor->parameters().empty())
if (!_contract.annotation().baseConstructorArguments.count(constructor))
_contract.annotation().unimplementedFunctions.push_back(constructor);
}
void ContractLevelChecker::annotateBaseConstructorArguments(
ContractDefinition const& _currentContract,
FunctionDefinition const* _baseConstructor,
ASTNode const* _argumentNode
)
{
solAssert(_baseConstructor, "");
solAssert(_argumentNode, "");
auto insertionResult = _currentContract.annotation().baseConstructorArguments.insert(
std::make_pair(_baseConstructor, _argumentNode)
);
if (!insertionResult.second)
{
ASTNode const* previousNode = insertionResult.first->second;
SourceLocation const* mainLocation = nullptr;
SecondarySourceLocation ssl;
if (
_currentContract.location().contains(previousNode->location()) ||
_currentContract.location().contains(_argumentNode->location())
)
{
mainLocation = &previousNode->location();
ssl.append("Second constructor call is here:", _argumentNode->location());
}
else
{
mainLocation = &_currentContract.location();
ssl.append("First constructor call is here: ", _argumentNode->location());
ssl.append("Second constructor call is here: ", previousNode->location());
}
m_errorReporter.declarationError(
*mainLocation,
ssl,
"Base constructor arguments given twice."
);
}
}
void ContractLevelChecker::checkConstructor(ContractDefinition const& _contract)
{
FunctionDefinition const* constructor = _contract.constructor();
if (!constructor)
return;
if (!constructor->returnParameters().empty())
m_errorReporter.typeError(constructor->returnParameterList()->location(), "Non-empty \"returns\" directive for constructor.");
if (constructor->stateMutability() != StateMutability::NonPayable && constructor->stateMutability() != StateMutability::Payable)
m_errorReporter.typeError(
constructor->location(),
"Constructor must be payable or non-payable, but is \"" +
stateMutabilityToString(constructor->stateMutability()) +
"\"."
);
if (constructor->visibility() != FunctionDefinition::Visibility::Public && constructor->visibility() != FunctionDefinition::Visibility::Internal)
m_errorReporter.typeError(constructor->location(), "Constructor must be public or internal.");
}
void ContractLevelChecker::checkFallbackFunction(ContractDefinition const& _contract)
{
FunctionDefinition const* fallback = _contract.fallbackFunction();
if (!fallback)
return;
if (_contract.isLibrary())
m_errorReporter.typeError(fallback->location(), "Libraries cannot have fallback functions.");
if (fallback->stateMutability() != StateMutability::NonPayable && fallback->stateMutability() != StateMutability::Payable)
m_errorReporter.typeError(
fallback->location(),
"Fallback function must be payable or non-payable, but is \"" +
stateMutabilityToString(fallback->stateMutability()) +
"\"."
);
if (!fallback->parameters().empty())
m_errorReporter.typeError(fallback->parameterList().location(), "Fallback function cannot take parameters.");
if (!fallback->returnParameters().empty())
m_errorReporter.typeError(fallback->returnParameterList()->location(), "Fallback function cannot return values.");
if (fallback->visibility() != FunctionDefinition::Visibility::External)
m_errorReporter.typeError(fallback->location(), "Fallback function must be defined as \"external\".");
}
void ContractLevelChecker::checkExternalTypeClashes(ContractDefinition const& _contract)
{
map<string, vector<pair<Declaration const*, FunctionTypePointer>>> externalDeclarations;
for (ContractDefinition const* contract: _contract.annotation().linearizedBaseContracts)
{
for (FunctionDefinition const* f: contract->definedFunctions())
if (f->isPartOfExternalInterface())
{
auto functionType = make_shared<FunctionType>(*f);
// under non error circumstances this should be true
if (functionType->interfaceFunctionType())
externalDeclarations[functionType->externalSignature()].push_back(
make_pair(f, functionType->asCallableFunction(false))
);
}
for (VariableDeclaration const* v: contract->stateVariables())
if (v->isPartOfExternalInterface())
{
auto functionType = make_shared<FunctionType>(*v);
// under non error circumstances this should be true
if (functionType->interfaceFunctionType())
externalDeclarations[functionType->externalSignature()].push_back(
make_pair(v, functionType->asCallableFunction(false))
);
}
}
for (auto const& it: externalDeclarations)
for (size_t i = 0; i < it.second.size(); ++i)
for (size_t j = i + 1; j < it.second.size(); ++j)
if (!it.second[i].second->hasEqualParameterTypes(*it.second[j].second))
m_errorReporter.typeError(
it.second[j].first->location(),
"Function overload clash during conversion to external types for arguments."
);
}
void ContractLevelChecker::checkHashCollisions(ContractDefinition const& _contract)
{
set<FixedHash<4>> hashes;
for (auto const& it: _contract.interfaceFunctionList())
{
FixedHash<4> const& hash = it.first;
if (hashes.count(hash))
m_errorReporter.typeError(
_contract.location(),
string("Function signature hash collision for ") + it.second->externalSignature()
);
hashes.insert(hash);
}
}
void ContractLevelChecker::checkLibraryRequirements(ContractDefinition const& _contract)
{
if (!_contract.isLibrary())
return;
if (!_contract.baseContracts().empty())
m_errorReporter.typeError(_contract.location(), "Library is not allowed to inherit.");
for (auto const& var: _contract.stateVariables())
if (!var->isConstant())
m_errorReporter.typeError(var->location(), "Library cannot have non-constant state variables");
}
