solidity/NameAndTypeResolver.cpp
2015-01-26 10:20:46 +01:00

329 lines
11 KiB
C++

/*
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
* Parser part that determines the declarations corresponding to names and the types of expressions.
*/
#include <libsolidity/NameAndTypeResolver.h>
#include <libsolidity/AST.h>
#include <libsolidity/Exceptions.h>
using namespace std;
namespace dev
{
namespace solidity
{
NameAndTypeResolver::NameAndTypeResolver(std::vector<Declaration const*> const& _globals)
{
for (Declaration const* declaration: _globals)
m_scopes[nullptr].registerDeclaration(*declaration);
}
void NameAndTypeResolver::registerDeclarations(SourceUnit& _sourceUnit)
{
// The helper registers all declarations in m_scopes as a side-effect of its construction.
DeclarationRegistrationHelper registrar(m_scopes, _sourceUnit);
}
void NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
{
m_currentScope = &m_scopes[nullptr];
for (ASTPointer<InheritanceSpecifier> const& baseContract: _contract.getBaseContracts())
ReferencesResolver resolver(*baseContract, *this, &_contract, nullptr);
m_currentScope = &m_scopes[&_contract];
linearizeBaseContracts(_contract);
for (ContractDefinition const* base: _contract.getLinearizedBaseContracts())
importInheritedScope(*base);
for (ASTPointer<StructDefinition> const& structDef: _contract.getDefinedStructs())
ReferencesResolver resolver(*structDef, *this, &_contract, nullptr);
for (ASTPointer<VariableDeclaration> const& variable: _contract.getStateVariables())
ReferencesResolver resolver(*variable, *this, &_contract, nullptr);
for (ASTPointer<FunctionDefinition> const& function: _contract.getDefinedFunctions())
{
m_currentScope = &m_scopes[function.get()];
ReferencesResolver referencesResolver(*function, *this, &_contract,
function->getReturnParameterList().get());
}
}
void NameAndTypeResolver::checkTypeRequirements(ContractDefinition& _contract)
{
for (ASTPointer<StructDefinition> const& structDef: _contract.getDefinedStructs())
structDef->checkValidityOfMembers();
_contract.checkTypeRequirements();
}
void NameAndTypeResolver::updateDeclaration(Declaration const& _declaration)
{
m_scopes[nullptr].registerDeclaration(_declaration, true);
solAssert(_declaration.getScope() == nullptr, "Updated declaration outside global scope.");
}
Declaration const* NameAndTypeResolver::resolveName(ASTString const& _name, Declaration const* _scope) const
{
auto iterator = m_scopes.find(_scope);
if (iterator == end(m_scopes))
return nullptr;
return iterator->second.resolveName(_name, false);
}
Declaration const* NameAndTypeResolver::getNameFromCurrentScope(ASTString const& _name, bool _recursive)
{
return m_currentScope->resolveName(_name, _recursive);
}
void NameAndTypeResolver::importInheritedScope(ContractDefinition const& _base)
{
auto iterator = m_scopes.find(&_base);
solAssert(iterator != end(m_scopes), "");
for (auto const& nameAndDeclaration: iterator->second.getDeclarations())
{
Declaration const* declaration = nameAndDeclaration.second;
// Import if it was declared in the base and is not the constructor
if (declaration->getScope() == &_base && declaration->getName() != _base.getName())
m_currentScope->registerDeclaration(*declaration);
}
}
void NameAndTypeResolver::linearizeBaseContracts(ContractDefinition& _contract) const
{
// order in the lists is from derived to base
// list of lists to linearize, the last element is the list of direct bases
list<list<ContractDefinition const*>> input(1, {});
for (ASTPointer<InheritanceSpecifier> const& baseSpecifier: _contract.getBaseContracts())
{
ASTPointer<Identifier> baseName = baseSpecifier->getName();
ContractDefinition const* base = dynamic_cast<ContractDefinition const*>(
baseName->getReferencedDeclaration());
if (!base)
BOOST_THROW_EXCEPTION(baseName->createTypeError("Contract expected."));
// "push_front" has the effect that bases mentioned later can overwrite members of bases
// mentioned earlier
input.back().push_front(base);
vector<ContractDefinition const*> const& basesBases = base->getLinearizedBaseContracts();
if (basesBases.empty())
BOOST_THROW_EXCEPTION(baseName->createTypeError("Definition of base has to precede definition of derived contract"));
input.push_front(list<ContractDefinition const*>(basesBases.begin(), basesBases.end()));
}
input.back().push_front(&_contract);
vector<ContractDefinition const*> result = cThreeMerge(input);
if (result.empty())
BOOST_THROW_EXCEPTION(_contract.createTypeError("Linearization of inheritance graph impossible"));
_contract.setLinearizedBaseContracts(result);
}
template <class _T>
vector<_T const*> NameAndTypeResolver::cThreeMerge(list<list<_T const*>>& _toMerge)
{
// returns true iff _candidate appears only as last element of the lists
auto appearsOnlyAtHead = [&](_T const* _candidate) -> bool
{
for (list<_T const*> const& bases: _toMerge)
{
solAssert(!bases.empty(), "");
if (find(++bases.begin(), bases.end(), _candidate) != bases.end())
return false;
}
return true;
};
// returns the next candidate to append to the linearized list or nullptr on failure
auto nextCandidate = [&]() -> _T const*
{
for (list<_T const*> const& bases: _toMerge)
{
solAssert(!bases.empty(), "");
if (appearsOnlyAtHead(bases.front()))
return bases.front();
}
return nullptr;
};
// removes the given contract from all lists
auto removeCandidate = [&](_T const* _candidate)
{
for (auto it = _toMerge.begin(); it != _toMerge.end();)
{
it->remove(_candidate);
if (it->empty())
it = _toMerge.erase(it);
else
++it;
}
};
_toMerge.remove_if([](list<_T const*> const& _bases) { return _bases.empty(); });
vector<_T const*> result;
while (!_toMerge.empty())
{
_T const* candidate = nextCandidate();
if (!candidate)
return vector<_T const*>();
result.push_back(candidate);
removeCandidate(candidate);
}
return result;
}
DeclarationRegistrationHelper::DeclarationRegistrationHelper(map<ASTNode const*, DeclarationContainer>& _scopes,
ASTNode& _astRoot):
m_scopes(_scopes), m_currentScope(nullptr)
{
_astRoot.accept(*this);
}
bool DeclarationRegistrationHelper::visit(ContractDefinition& _contract)
{
registerDeclaration(_contract, true);
return true;
}
void DeclarationRegistrationHelper::endVisit(ContractDefinition&)
{
closeCurrentScope();
}
bool DeclarationRegistrationHelper::visit(StructDefinition& _struct)
{
registerDeclaration(_struct, true);
return true;
}
void DeclarationRegistrationHelper::endVisit(StructDefinition&)
{
closeCurrentScope();
}
bool DeclarationRegistrationHelper::visit(FunctionDefinition& _function)
{
registerDeclaration(_function, true);
m_currentFunction = &_function;
return true;
}
void DeclarationRegistrationHelper::endVisit(FunctionDefinition&)
{
m_currentFunction = nullptr;
closeCurrentScope();
}
void DeclarationRegistrationHelper::endVisit(VariableDefinition& _variableDefinition)
{
// Register the local variables with the function
// This does not fit here perfectly, but it saves us another AST visit.
solAssert(m_currentFunction, "Variable definition without function.");
m_currentFunction->addLocalVariable(_variableDefinition.getDeclaration());
}
bool DeclarationRegistrationHelper::visit(VariableDeclaration& _declaration)
{
registerDeclaration(_declaration, false);
return true;
}
void DeclarationRegistrationHelper::enterNewSubScope(Declaration const& _declaration)
{
map<ASTNode const*, DeclarationContainer>::iterator iter;
bool newlyAdded;
tie(iter, newlyAdded) = m_scopes.emplace(&_declaration, DeclarationContainer(m_currentScope, &m_scopes[m_currentScope]));
solAssert(newlyAdded, "Unable to add new scope.");
m_currentScope = &_declaration;
}
void DeclarationRegistrationHelper::closeCurrentScope()
{
solAssert(m_currentScope, "Closed non-existing scope.");
m_currentScope = m_scopes[m_currentScope].getEnclosingDeclaration();
}
void DeclarationRegistrationHelper::registerDeclaration(Declaration& _declaration, bool _opensScope)
{
if (!m_scopes[m_currentScope].registerDeclaration(_declaration))
BOOST_THROW_EXCEPTION(DeclarationError() << errinfo_sourceLocation(_declaration.getLocation())
<< errinfo_comment("Identifier already declared."));
//@todo the exception should also contain the location of the first declaration
_declaration.setScope(m_currentScope);
if (_opensScope)
enterNewSubScope(_declaration);
}
ReferencesResolver::ReferencesResolver(ASTNode& _root, NameAndTypeResolver& _resolver,
ContractDefinition const* _currentContract,
ParameterList const* _returnParameters, bool _allowLazyTypes):
m_resolver(_resolver), m_currentContract(_currentContract),
m_returnParameters(_returnParameters), m_allowLazyTypes(_allowLazyTypes)
{
_root.accept(*this);
}
void ReferencesResolver::endVisit(VariableDeclaration& _variable)
{
// endVisit because the internal type needs resolving if it is a user defined type
// or mapping
if (_variable.getTypeName())
{
_variable.setType(_variable.getTypeName()->toType());
if (!_variable.getType())
BOOST_THROW_EXCEPTION(_variable.getTypeName()->createTypeError("Invalid type name"));
}
else if (!m_allowLazyTypes)
BOOST_THROW_EXCEPTION(_variable.createTypeError("Explicit type needed."));
// otherwise we have a "var"-declaration whose type is resolved by the first assignment
}
bool ReferencesResolver::visit(Return& _return)
{
solAssert(m_returnParameters, "Return parameters not set.");
_return.setFunctionReturnParameters(*m_returnParameters);
return true;
}
bool ReferencesResolver::visit(Mapping&)
{
return true;
}
bool ReferencesResolver::visit(UserDefinedTypeName& _typeName)
{
Declaration const* declaration = m_resolver.getNameFromCurrentScope(_typeName.getName());
if (!declaration)
BOOST_THROW_EXCEPTION(DeclarationError() << errinfo_sourceLocation(_typeName.getLocation())
<< errinfo_comment("Undeclared identifier."));
_typeName.setReferencedDeclaration(*declaration);
return false;
}
bool ReferencesResolver::visit(Identifier& _identifier)
{
Declaration const* declaration = m_resolver.getNameFromCurrentScope(_identifier.getName());
if (!declaration)
BOOST_THROW_EXCEPTION(DeclarationError() << errinfo_sourceLocation(_identifier.getLocation())
<< errinfo_comment("Undeclared identifier."));
_identifier.setReferencedDeclaration(*declaration, m_currentContract);
return false;
}
}
}