solidity/libsolidity/analysis/TypeChecker.cpp

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/*
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 2015
* Type analyzer and checker.
*/
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#include <libsolidity/analysis/TypeChecker.h>
#include <memory>
#include <boost/range/adaptor/reversed.hpp>
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#include <libsolidity/ast/AST.h>
using namespace std;
using namespace dev;
using namespace dev::solidity;
bool TypeChecker::checkTypeRequirements(const ContractDefinition& _contract)
{
try
{
visit(_contract);
}
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catch (FatalError const&)
{
// We got a fatal error which required to stop further type checking, but we can
// continue normally from here.
if (m_errors.empty())
throw; // Something is weird here, rather throw again.
}
return Error::containsOnlyWarnings(m_errors);
}
TypePointer const& TypeChecker::type(Expression const& _expression) const
{
solAssert(!!_expression.annotation().type, "Type requested but not present.");
return _expression.annotation().type;
}
TypePointer const& TypeChecker::type(VariableDeclaration const& _variable) const
{
solAssert(!!_variable.annotation().type, "Type requested but not present.");
return _variable.annotation().type;
}
bool TypeChecker::visit(ContractDefinition const& _contract)
{
// We force our own visiting order here.
ASTNode::listAccept(_contract.definedStructs(), *this);
ASTNode::listAccept(_contract.baseContracts(), *this);
checkContractDuplicateFunctions(_contract);
checkContractIllegalOverrides(_contract);
checkContractAbstractFunctions(_contract);
checkContractAbstractConstructors(_contract);
FunctionDefinition const* function = _contract.constructor();
if (function && !function->returnParameters().empty())
typeError(*function->returnParameterList(), "Non-empty \"returns\" directive for constructor.");
FunctionDefinition const* fallbackFunction = nullptr;
for (ASTPointer<FunctionDefinition> const& function: _contract.definedFunctions())
{
if (function->name().empty())
{
if (fallbackFunction)
{
auto err = make_shared<Error>(Error::Type::DeclarationError);
*err << errinfo_comment("Only one fallback function is allowed.");
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m_errors.push_back(err);
}
else
{
fallbackFunction = function.get();
if (!fallbackFunction->parameters().empty())
typeError(fallbackFunction->parameterList(), "Fallback function cannot take parameters.");
}
}
if (!function->isImplemented())
_contract.annotation().isFullyImplemented = false;
}
ASTNode::listAccept(_contract.stateVariables(), *this);
ASTNode::listAccept(_contract.events(), *this);
ASTNode::listAccept(_contract.functionModifiers(), *this);
ASTNode::listAccept(_contract.definedFunctions(), *this);
checkContractExternalTypeClashes(_contract);
// check for hash collisions in function signatures
set<FixedHash<4>> hashes;
for (auto const& it: _contract.interfaceFunctionList())
{
FixedHash<4> const& hash = it.first;
if (hashes.count(hash))
typeError(
_contract,
string("Function signature hash collision for ") + it.second->externalSignature()
);
hashes.insert(hash);
}
if (_contract.isLibrary())
checkLibraryRequirements(_contract);
return false;
}
void TypeChecker::checkContractDuplicateFunctions(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;
for (ASTPointer<FunctionDefinition> const& function: _contract.definedFunctions())
functions[function->name()].push_back(function.get());
// Constructor
if (functions[_contract.name()].size() > 1)
{
SecondarySourceLocation ssl;
auto it = ++functions[_contract.name()].begin();
for (; it != functions[_contract.name()].end(); ++it)
ssl.append("Another declaration is here:", (*it)->location());
auto err = make_shared<Error>(Error(Error::Type::DeclarationError));
*err <<
errinfo_sourceLocation(functions[_contract.name()].front()->location()) <<
errinfo_comment("More than one constructor defined.") <<
errinfo_secondarySourceLocation(ssl);
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m_errors.push_back(err);
}
for (auto const& it: functions)
{
vector<FunctionDefinition const*> const& overloads = it.second;
for (size_t i = 0; i < overloads.size(); ++i)
for (size_t j = i + 1; j < overloads.size(); ++j)
if (FunctionType(*overloads[i]).hasEqualArgumentTypes(FunctionType(*overloads[j])))
{
auto err = make_shared<Error>(Error(Error::Type::DeclarationError));
*err <<
errinfo_sourceLocation(overloads[j]->location()) <<
errinfo_comment("Function with same name and arguments defined twice.") <<
errinfo_secondarySourceLocation(SecondarySourceLocation().append(
"Other declaration is here:", overloads[i]->location()));
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m_errors.push_back(err);
}
}
}
void TypeChecker::checkContractAbstractFunctions(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;
// Search from base to derived
for (ContractDefinition const* contract: boost::adaptors::reverse(_contract.annotation().linearizedBaseContracts))
for (ASTPointer<FunctionDefinition> const& function: contract->definedFunctions())
{
auto& overloads = functions[function->name()];
FunctionTypePointer funType = make_shared<FunctionType>(*function);
auto it = find_if(overloads.begin(), overloads.end(), [&](FunTypeAndFlag const& _funAndFlag)
{
return funType->hasEqualArgumentTypes(*_funAndFlag.first);
});
if (it == overloads.end())
overloads.push_back(make_pair(funType, function->isImplemented()));
else if (it->second)
{
if (!function->isImplemented())
typeError(*function, "Redeclaring an already implemented function as abstract");
}
else if (function->isImplemented())
it->second = true;
}
// 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)
{
_contract.annotation().isFullyImplemented = false;
return;
}
}
void TypeChecker::checkContractAbstractConstructors(ContractDefinition const& _contract)
{
set<ContractDefinition const*> argumentsNeeded;
// check that we get arguments for all base constructors that need it.
// If not mark the contract as abstract (not fully implemented)
vector<ContractDefinition const*> const& bases = _contract.annotation().linearizedBaseContracts;
for (ContractDefinition const* contract: bases)
if (FunctionDefinition const* constructor = contract->constructor())
if (contract != &_contract && !constructor->parameters().empty())
argumentsNeeded.insert(contract);
for (ContractDefinition const* contract: bases)
{
if (FunctionDefinition const* constructor = contract->constructor())
for (auto const& modifier: constructor->modifiers())
{
auto baseContract = dynamic_cast<ContractDefinition const*>(
&dereference(*modifier->name())
);
if (baseContract)
argumentsNeeded.erase(baseContract);
}
for (ASTPointer<InheritanceSpecifier> const& base: contract->baseContracts())
{
auto baseContract = dynamic_cast<ContractDefinition const*>(&dereference(base->name()));
solAssert(baseContract, "");
if (!base->arguments().empty())
argumentsNeeded.erase(baseContract);
}
}
if (!argumentsNeeded.empty())
_contract.annotation().isFullyImplemented = false;
}
void TypeChecker::checkContractIllegalOverrides(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 (ASTPointer<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))
typeError(*modifiers[name], "Override changes function to modifier.");
FunctionType functionType(*function);
// function should not change the return type
for (FunctionDefinition const* overriding: functions[name])
{
FunctionType overridingType(*overriding);
if (!overridingType.hasEqualArgumentTypes(functionType))
continue;
if (
overriding->visibility() != function->visibility() ||
overriding->isDeclaredConst() != function->isDeclaredConst() ||
overridingType != functionType
)
typeError(*overriding, "Override changes extended function signature.");
}
functions[name].push_back(function.get());
}
for (ASTPointer<ModifierDefinition> const& modifier: contract->functionModifiers())
{
string const& name = modifier->name();
ModifierDefinition const*& override = modifiers[name];
if (!override)
override = modifier.get();
else if (ModifierType(*override) != ModifierType(*modifier))
typeError(*override, "Override changes modifier signature.");
if (!functions[name].empty())
typeError(*override, "Override changes modifier to function.");
}
}
}
void TypeChecker::checkContractExternalTypeClashes(ContractDefinition const& _contract)
{
map<string, vector<pair<Declaration const*, FunctionTypePointer>>> externalDeclarations;
for (ContractDefinition const* contract: _contract.annotation().linearizedBaseContracts)
{
for (ASTPointer<FunctionDefinition> const& f: contract->definedFunctions())
if (f->isPartOfExternalInterface())
{
auto functionType = make_shared<FunctionType>(*f);
externalDeclarations[functionType->externalSignature()].push_back(
make_pair(f.get(), functionType)
);
}
for (ASTPointer<VariableDeclaration> const& v: contract->stateVariables())
if (v->isPartOfExternalInterface())
{
auto functionType = make_shared<FunctionType>(*v);
externalDeclarations[functionType->externalSignature()].push_back(
make_pair(v.get(), functionType)
);
}
}
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->hasEqualArgumentTypes(*it.second[j].second))
typeError(
*it.second[j].first,
"Function overload clash during conversion to external types for arguments."
);
}
void TypeChecker::checkLibraryRequirements(ContractDefinition const& _contract)
{
solAssert(_contract.isLibrary(), "");
if (!_contract.baseContracts().empty())
typeError(_contract, "Library is not allowed to inherit.");
for (auto const& var: _contract.stateVariables())
if (!var->isConstant())
typeError(*var, "Library cannot have non-constant state variables");
}
void TypeChecker::endVisit(InheritanceSpecifier const& _inheritance)
{
auto base = dynamic_cast<ContractDefinition const*>(&dereference(_inheritance.name()));
solAssert(base, "Base contract not available.");
if (base->isLibrary())
typeError(_inheritance, "Libraries cannot be inherited from.");
auto const& arguments = _inheritance.arguments();
TypePointers parameterTypes = ContractType(*base).constructorType()->parameterTypes();
if (!arguments.empty() && parameterTypes.size() != arguments.size())
typeError(
_inheritance,
"Wrong argument count for constructor call: " +
toString(arguments.size()) +
" arguments given but expected " +
toString(parameterTypes.size()) +
"."
);
for (size_t i = 0; i < arguments.size(); ++i)
if (!type(*arguments[i])->isImplicitlyConvertibleTo(*parameterTypes[i]))
typeError(
*arguments[i],
"Invalid type for argument in constructor call. "
"Invalid implicit conversion from " +
type(*arguments[i])->toString() +
" to " +
parameterTypes[i]->toString() +
" requested."
);
}
bool TypeChecker::visit(StructDefinition const& _struct)
{
for (ASTPointer<VariableDeclaration> const& member: _struct.members())
if (!type(*member)->canBeStored())
typeError(*member, "Type cannot be used in struct.");
// Check recursion, fatal error if detected.
using StructPointer = StructDefinition const*;
using StructPointersSet = set<StructPointer>;
function<void(StructPointer,StructPointersSet const&)> check = [&](StructPointer _struct, StructPointersSet const& _parents)
{
if (_parents.count(_struct))
fatalTypeError(*_struct, "Recursive struct definition.");
StructPointersSet parents = _parents;
parents.insert(_struct);
for (ASTPointer<VariableDeclaration> const& member: _struct->members())
if (type(*member)->category() == Type::Category::Struct)
{
auto const& typeName = dynamic_cast<UserDefinedTypeName const&>(*member->typeName());
check(&dynamic_cast<StructDefinition const&>(*typeName.annotation().referencedDeclaration), parents);
}
};
check(&_struct, StructPointersSet{});
ASTNode::listAccept(_struct.members(), *this);
return false;
}
bool TypeChecker::visit(FunctionDefinition const& _function)
{
bool isLibraryFunction = dynamic_cast<ContractDefinition const&>(*_function.scope()).isLibrary();
for (ASTPointer<VariableDeclaration> const& var: _function.parameters() + _function.returnParameters())
{
if (!type(*var)->canLiveOutsideStorage())
typeError(*var, "Type is required to live outside storage.");
if (_function.visibility() >= FunctionDefinition::Visibility::Public && !(type(*var)->interfaceType(isLibraryFunction)))
fatalTypeError(*var, "Internal type is not allowed for public or external functions.");
}
for (ASTPointer<ModifierInvocation> const& modifier: _function.modifiers())
visitManually(
*modifier,
_function.isConstructor() ?
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dynamic_cast<ContractDefinition const&>(*_function.scope()).annotation().linearizedBaseContracts :
vector<ContractDefinition const*>()
);
if (_function.isImplemented())
_function.body().accept(*this);
return false;
}
bool TypeChecker::visit(VariableDeclaration const& _variable)
{
// Variables can be declared without type (with "var"), in which case the first assignment
// sets the type.
// Note that assignments before the first declaration are legal because of the special scoping
// rules inherited from JavaScript.
// type is filled either by ReferencesResolver directly from the type name or by
// TypeChecker at the VariableDeclarationStatement level.
TypePointer varType = _variable.annotation().type;
solAssert(!!varType, "Failed to infer variable type.");
if (_variable.isConstant())
{
if (!dynamic_cast<ContractDefinition const*>(_variable.scope()))
typeError(_variable, "Illegal use of \"constant\" specifier.");
if (!_variable.value())
typeError(_variable, "Uninitialized \"constant\" variable.");
if (!varType->isValueType())
{
bool constImplemented = false;
if (auto arrayType = dynamic_cast<ArrayType const*>(varType.get()))
constImplemented = arrayType->isByteArray();
if (!constImplemented)
typeError(
_variable,
"Illegal use of \"constant\" specifier. \"constant\" "
"is not yet implemented for this type."
);
}
}
if (_variable.value())
expectType(*_variable.value(), *varType);
if (!_variable.isStateVariable())
{
if (varType->dataStoredIn(DataLocation::Memory) || varType->dataStoredIn(DataLocation::CallData))
if (!varType->canLiveOutsideStorage())
typeError(_variable, "Type " + varType->toString() + " is only valid in storage.");
}
else if (
_variable.visibility() >= VariableDeclaration::Visibility::Public &&
!FunctionType(_variable).interfaceFunctionType()
)
typeError(_variable, "Internal type is not allowed for public state variables.");
return false;
}
void TypeChecker::visitManually(
ModifierInvocation const& _modifier,
vector<ContractDefinition const*> const& _bases
)
{
std::vector<ASTPointer<Expression>> const& arguments = _modifier.arguments();
for (ASTPointer<Expression> const& argument: arguments)
argument->accept(*this);
_modifier.name()->accept(*this);
auto const* declaration = &dereference(*_modifier.name());
vector<ASTPointer<VariableDeclaration>> emptyParameterList;
vector<ASTPointer<VariableDeclaration>> const* parameters = nullptr;
if (auto modifierDecl = dynamic_cast<ModifierDefinition const*>(declaration))
parameters = &modifierDecl->parameters();
else
// check parameters for Base constructors
for (ContractDefinition const* base: _bases)
if (declaration == base)
{
if (auto referencedConstructor = base->constructor())
parameters = &referencedConstructor->parameters();
else
parameters = &emptyParameterList;
break;
}
if (!parameters)
typeError(_modifier, "Referenced declaration is neither modifier nor base class.");
if (parameters->size() != arguments.size())
typeError(
_modifier,
"Wrong argument count for modifier invocation: " +
toString(arguments.size()) +
" arguments given but expected " +
toString(parameters->size()) +
"."
);
for (size_t i = 0; i < _modifier.arguments().size(); ++i)
if (!type(*arguments[i])->isImplicitlyConvertibleTo(*type(*(*parameters)[i])))
typeError(
*arguments[i],
"Invalid type for argument in modifier invocation. "
"Invalid implicit conversion from " +
type(*arguments[i])->toString() +
" to " +
type(*(*parameters)[i])->toString() +
" requested."
);
}
bool TypeChecker::visit(EventDefinition const& _eventDef)
{
unsigned numIndexed = 0;
for (ASTPointer<VariableDeclaration> const& var: _eventDef.parameters())
{
if (var->isIndexed())
numIndexed++;
if (_eventDef.isAnonymous() && numIndexed > 4)
typeError(_eventDef, "More than 4 indexed arguments for anonymous event.");
else if (!_eventDef.isAnonymous() && numIndexed > 3)
typeError(_eventDef, "More than 3 indexed arguments for event.");
if (!type(*var)->canLiveOutsideStorage())
typeError(*var, "Type is required to live outside storage.");
if (!type(*var)->interfaceType(false))
typeError(*var, "Internal type is not allowed as event parameter type.");
}
return false;
}
bool TypeChecker::visit(IfStatement const& _ifStatement)
{
expectType(_ifStatement.condition(), BoolType());
_ifStatement.trueStatement().accept(*this);
if (_ifStatement.falseStatement())
_ifStatement.falseStatement()->accept(*this);
return false;
}
bool TypeChecker::visit(WhileStatement const& _whileStatement)
{
expectType(_whileStatement.condition(), BoolType());
_whileStatement.body().accept(*this);
return false;
}
bool TypeChecker::visit(ForStatement const& _forStatement)
{
if (_forStatement.initializationExpression())
_forStatement.initializationExpression()->accept(*this);
if (_forStatement.condition())
expectType(*_forStatement.condition(), BoolType());
if (_forStatement.loopExpression())
_forStatement.loopExpression()->accept(*this);
_forStatement.body().accept(*this);
return false;
}
void TypeChecker::endVisit(Return const& _return)
{
if (!_return.expression())
return;
ParameterList const* params = _return.annotation().functionReturnParameters;
if (!params)
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{
typeError(_return, "Return arguments not allowed.");
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return;
}
TypePointers returnTypes;
for (auto const& var: params->parameters())
returnTypes.push_back(type(*var));
if (auto tupleType = dynamic_cast<TupleType const*>(type(*_return.expression()).get()))
{
if (tupleType->components().size() != params->parameters().size())
typeError(_return, "Different number of arguments in return statement than in returns declaration.");
else if (!tupleType->isImplicitlyConvertibleTo(TupleType(returnTypes)))
typeError(
*_return.expression(),
"Return argument type " +
type(*_return.expression())->toString() +
" is not implicitly convertible to expected type " +
TupleType(returnTypes).toString(false) +
"."
);
}
else if (params->parameters().size() != 1)
typeError(_return, "Different number of arguments in return statement than in returns declaration.");
else
{
TypePointer const& expected = type(*params->parameters().front());
if (!type(*_return.expression())->isImplicitlyConvertibleTo(*expected))
typeError(
*_return.expression(),
"Return argument type " +
type(*_return.expression())->toString() +
" is not implicitly convertible to expected type (type of first return variable) " +
expected->toString() +
"."
);
}
}
bool TypeChecker::visit(VariableDeclarationStatement const& _statement)
{
if (!_statement.initialValue())
{
// No initial value is only permitted for single variables with specified type.
if (_statement.declarations().size() != 1 || !_statement.declarations().front())
fatalTypeError(_statement, "Assignment necessary for type detection.");
VariableDeclaration const& varDecl = *_statement.declarations().front();
if (!varDecl.annotation().type)
fatalTypeError(_statement, "Assignment necessary for type detection.");
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if (auto ref = dynamic_cast<ReferenceType const*>(type(varDecl).get()))
{
if (ref->dataStoredIn(DataLocation::Storage))
{
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auto err = make_shared<Error>(Error::Type::Warning);
*err <<
errinfo_sourceLocation(varDecl.location()) <<
errinfo_comment("Uninitialized storage pointer. Did you mean '<type> memory " + varDecl.name() + "'?");
m_errors.push_back(err);
}
}
varDecl.accept(*this);
return false;
}
// Here we have an initial value and might have to derive some types before we can visit
// the variable declaration(s).
_statement.initialValue()->accept(*this);
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TypePointers valueTypes;
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if (auto tupleType = dynamic_cast<TupleType const*>(type(*_statement.initialValue()).get()))
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valueTypes = tupleType->components();
else
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valueTypes = TypePointers{type(*_statement.initialValue())};
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// Determine which component is assigned to which variable.
// If numbers do not match, fill up if variables begin or end empty (not both).
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vector<VariableDeclaration const*>& assignments = _statement.annotation().assignments;
assignments.resize(valueTypes.size(), nullptr);
vector<ASTPointer<VariableDeclaration>> const& variables = _statement.declarations();
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if (variables.empty())
{
if (!valueTypes.empty())
fatalTypeError(
_statement,
"Too many components (" +
toString(valueTypes.size()) +
") in value for variable assignment (0) needed"
);
}
else if (valueTypes.size() != variables.size() && !variables.front() && !variables.back())
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fatalTypeError(
_statement,
"Wildcard both at beginning and end of variable declaration list is only allowed "
"if the number of components is equal."
);
size_t minNumValues = variables.size();
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if (!variables.empty() && (!variables.back() || !variables.front()))
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--minNumValues;
if (valueTypes.size() < minNumValues)
fatalTypeError(
_statement,
"Not enough components (" +
toString(valueTypes.size()) +
") in value to assign all variables (" +
toString(minNumValues) + ")."
);
if (valueTypes.size() > variables.size() && variables.front() && variables.back())
fatalTypeError(
_statement,
"Too many components (" +
toString(valueTypes.size()) +
") in value for variable assignment (" +
toString(minNumValues) +
" needed)."
);
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bool fillRight = !variables.empty() && (!variables.back() || variables.front());
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for (size_t i = 0; i < min(variables.size(), valueTypes.size()); ++i)
if (fillRight)
assignments[i] = variables[i].get();
else
assignments[assignments.size() - i - 1] = variables[variables.size() - i - 1].get();
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for (size_t i = 0; i < assignments.size(); ++i)
{
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if (!assignments[i])
continue;
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VariableDeclaration const& var = *assignments[i];
solAssert(!var.value(), "Value has to be tied to statement.");
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TypePointer const& valueComponentType = valueTypes[i];
solAssert(!!valueComponentType, "");
if (!var.annotation().type)
{
// Infer type from value.
solAssert(!var.typeName(), "");
if (
valueComponentType->category() == Type::Category::IntegerConstant &&
!dynamic_pointer_cast<IntegerConstantType const>(valueComponentType)->integerType()
)
fatalTypeError(*_statement.initialValue(), "Invalid integer constant " + valueComponentType->toString() + ".");
var.annotation().type = valueComponentType->mobileType();
var.accept(*this);
}
else
{
var.accept(*this);
if (!valueComponentType->isImplicitlyConvertibleTo(*var.annotation().type))
typeError(
_statement,
"Type " +
valueComponentType->toString() +
" is not implicitly convertible to expected type " +
var.annotation().type->toString() +
"."
);
}
}
return false;
}
void TypeChecker::endVisit(ExpressionStatement const& _statement)
{
if (type(_statement.expression())->category() == Type::Category::IntegerConstant)
if (!dynamic_pointer_cast<IntegerConstantType const>(type(_statement.expression()))->integerType())
typeError(_statement.expression(), "Invalid integer constant.");
}
bool TypeChecker::visit(Assignment const& _assignment)
{
requireLValue(_assignment.leftHandSide());
TypePointer t = type(_assignment.leftHandSide());
_assignment.annotation().type = t;
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if (TupleType const* tupleType = dynamic_cast<TupleType const*>(t.get()))
{
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// Sequenced assignments of tuples is not valid, make the result a "void" type.
_assignment.annotation().type = make_shared<TupleType>();
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expectType(_assignment.rightHandSide(), *tupleType);
}
else if (t->category() == Type::Category::Mapping)
{
typeError(_assignment, "Mappings cannot be assigned to.");
_assignment.rightHandSide().accept(*this);
}
else if (_assignment.assignmentOperator() == Token::Assign)
expectType(_assignment.rightHandSide(), *t);
else
{
// compound assignment
_assignment.rightHandSide().accept(*this);
TypePointer resultType = t->binaryOperatorResult(
Token::AssignmentToBinaryOp(_assignment.assignmentOperator()),
type(_assignment.rightHandSide())
);
if (!resultType || *resultType != *t)
typeError(
_assignment,
"Operator " +
string(Token::toString(_assignment.assignmentOperator())) +
" not compatible with types " +
t->toString() +
" and " +
type(_assignment.rightHandSide())->toString()
);
}
return false;
}
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bool TypeChecker::visit(TupleExpression const& _tuple)
{
vector<ASTPointer<Expression>> const& components = _tuple.components();
TypePointers types;
if (_tuple.annotation().lValueRequested)
{
for (auto const& component: components)
if (component)
{
requireLValue(*component);
types.push_back(type(*component));
}
else
types.push_back(TypePointer());
_tuple.annotation().type = make_shared<TupleType>(types);
// If some of the components are not LValues, the error is reported above.
_tuple.annotation().isLValue = true;
}
else
{
for (size_t i = 0; i < components.size(); ++i)
{
// Outside of an lvalue-context, the only situation where a component can be empty is (x,).
if (!components[i] && !(i == 1 && components.size() == 2))
fatalTypeError(_tuple, "Tuple component cannot be empty.");
else if (components[i])
{
components[i]->accept(*this);
types.push_back(type(*components[i]));
}
else
types.push_back(TypePointer());
}
if (components.size() == 1)
_tuple.annotation().type = type(*components[0]);
else
{
if (components.size() == 2 && !components[1])
types.pop_back();
_tuple.annotation().type = make_shared<TupleType>(types);
}
}
return false;
}
bool TypeChecker::visit(UnaryOperation const& _operation)
{
// Inc, Dec, Add, Sub, Not, BitNot, Delete
Token::Value op = _operation.getOperator();
if (op == Token::Value::Inc || op == Token::Value::Dec || op == Token::Value::Delete)
requireLValue(_operation.subExpression());
else
_operation.subExpression().accept(*this);
TypePointer const& subExprType = type(_operation.subExpression());
TypePointer t = type(_operation.subExpression())->unaryOperatorResult(op);
if (!t)
{
typeError(
_operation,
"Unary operator " +
string(Token::toString(op)) +
" cannot be applied to type " +
subExprType->toString()
);
t = subExprType;
}
_operation.annotation().type = t;
return false;
}
void TypeChecker::endVisit(BinaryOperation const& _operation)
{
TypePointer const& leftType = type(_operation.leftExpression());
TypePointer const& rightType = type(_operation.rightExpression());
TypePointer commonType = leftType->binaryOperatorResult(_operation.getOperator(), rightType);
if (!commonType)
{
typeError(
_operation,
"Operator " +
string(Token::toString(_operation.getOperator())) +
" not compatible with types " +
leftType->toString() +
" and " +
rightType->toString()
);
commonType = leftType;
}
_operation.annotation().commonType = commonType;
_operation.annotation().type =
Token::isCompareOp(_operation.getOperator()) ?
make_shared<BoolType>() :
commonType;
}
bool TypeChecker::visit(FunctionCall const& _functionCall)
{
bool isPositionalCall = _functionCall.names().empty();
vector<ASTPointer<Expression const>> arguments = _functionCall.arguments();
vector<ASTPointer<ASTString>> const& argumentNames = _functionCall.names();
// We need to check arguments' type first as they will be needed for overload resolution.
shared_ptr<TypePointers> argumentTypes;
if (isPositionalCall)
argumentTypes = make_shared<TypePointers>();
for (ASTPointer<Expression const> const& argument: arguments)
{
argument->accept(*this);
// only store them for positional calls
if (isPositionalCall)
argumentTypes->push_back(type(*argument));
}
if (isPositionalCall)
_functionCall.expression().annotation().argumentTypes = move(argumentTypes);
_functionCall.expression().accept(*this);
TypePointer expressionType = type(_functionCall.expression());
if (auto const* typeType = dynamic_cast<TypeType const*>(expressionType.get()))
{
_functionCall.annotation().isStructConstructorCall = (typeType->actualType()->category() == Type::Category::Struct);
_functionCall.annotation().isTypeConversion = !_functionCall.annotation().isStructConstructorCall;
}
else
_functionCall.annotation().isStructConstructorCall = _functionCall.annotation().isTypeConversion = false;
if (_functionCall.annotation().isTypeConversion)
{
TypeType const& t = dynamic_cast<TypeType const&>(*expressionType);
TypePointer resultType = t.actualType();
if (arguments.size() != 1)
typeError(_functionCall, "Exactly one argument expected for explicit type conversion.");
else if (!isPositionalCall)
typeError(_functionCall, "Type conversion cannot allow named arguments.");
else
{
TypePointer const& argType = type(*arguments.front());
if (auto argRefType = dynamic_cast<ReferenceType const*>(argType.get()))
// do not change the data location when converting
// (data location cannot yet be specified for type conversions)
resultType = ReferenceType::copyForLocationIfReference(argRefType->location(), resultType);
if (!argType->isExplicitlyConvertibleTo(*resultType))
typeError(_functionCall, "Explicit type conversion not allowed.");
}
_functionCall.annotation().type = resultType;
return false;
}
// Actual function call or struct constructor call.
FunctionTypePointer functionType;
/// For error message: Struct members that were removed during conversion to memory.
set<string> membersRemovedForStructConstructor;
if (_functionCall.annotation().isStructConstructorCall)
{
TypeType const& t = dynamic_cast<TypeType const&>(*expressionType);
auto const& structType = dynamic_cast<StructType const&>(*t.actualType());
functionType = structType.constructorType();
membersRemovedForStructConstructor = structType.membersMissingInMemory();
}
else
functionType = dynamic_pointer_cast<FunctionType const>(expressionType);
if (!functionType)
{
typeError(_functionCall, "Type is not callable");
_functionCall.annotation().type = make_shared<TupleType>();
return false;
}
else if (functionType->returnParameterTypes().size() == 1)
_functionCall.annotation().type = functionType->returnParameterTypes().front();
else
_functionCall.annotation().type = make_shared<TupleType>(functionType->returnParameterTypes());
TypePointers const& parameterTypes = functionType->parameterTypes();
if (!functionType->takesArbitraryParameters() && parameterTypes.size() != arguments.size())
{
string msg =
"Wrong argument count for function call: " +
toString(arguments.size()) +
" arguments given but expected " +
toString(parameterTypes.size()) +
".";
// Extend error message in case we try to construct a struct with mapping member.
if (_functionCall.annotation().isStructConstructorCall && !membersRemovedForStructConstructor.empty())
{
msg += " Members that have to be skipped in memory:";
for (auto const& member: membersRemovedForStructConstructor)
msg += " " + member;
}
typeError(_functionCall, msg);
}
else if (isPositionalCall)
{
// call by positional arguments
for (size_t i = 0; i < arguments.size(); ++i)
{
auto const& argType = type(*arguments[i]);
if (functionType->takesArbitraryParameters())
{
if (auto t = dynamic_cast<IntegerConstantType const*>(argType.get()))
if (!t->integerType())
typeError(*arguments[i], "Integer constant too large.");
}
else if (!type(*arguments[i])->isImplicitlyConvertibleTo(*parameterTypes[i]))
typeError(
*arguments[i],
"Invalid type for argument in function call. "
"Invalid implicit conversion from " +
type(*arguments[i])->toString() +
" to " +
parameterTypes[i]->toString() +
" requested."
);
}
}
else
{
// call by named arguments
auto const& parameterNames = functionType->parameterNames();
if (functionType->takesArbitraryParameters())
typeError(
_functionCall,
"Named arguments cannnot be used for functions that take arbitrary parameters."
);
else if (parameterNames.size() > argumentNames.size())
typeError(_functionCall, "Some argument names are missing.");
else if (parameterNames.size() < argumentNames.size())
typeError(_functionCall, "Too many arguments.");
else
{
// check duplicate names
bool duplication = false;
for (size_t i = 0; i < argumentNames.size(); i++)
for (size_t j = i + 1; j < argumentNames.size(); j++)
if (*argumentNames[i] == *argumentNames[j])
{
duplication = true;
typeError(*arguments[i], "Duplicate named argument.");
}
// check actual types
if (!duplication)
for (size_t i = 0; i < argumentNames.size(); i++)
{
bool found = false;
for (size_t j = 0; j < parameterNames.size(); j++)
if (parameterNames[j] == *argumentNames[i])
{
found = true;
// check type convertible
if (!type(*arguments[i])->isImplicitlyConvertibleTo(*parameterTypes[j]))
typeError(
*arguments[i],
"Invalid type for argument in function call. "
"Invalid implicit conversion from " +
type(*arguments[i])->toString() +
" to " +
parameterTypes[i]->toString() +
" requested."
);
break;
}
if (!found)
typeError(
_functionCall,
"Named argument does not match function declaration."
);
}
}
}
return false;
}
void TypeChecker::endVisit(NewExpression const& _newExpression)
{
auto contract = dynamic_cast<ContractDefinition const*>(&dereference(_newExpression.contractName()));
if (!contract)
fatalTypeError(_newExpression, "Identifier is not a contract.");
if (!contract->annotation().isFullyImplemented)
typeError(_newExpression, "Trying to create an instance of an abstract contract.");
auto scopeContract = _newExpression.contractName().annotation().contractScope;
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scopeContract->annotation().contractDependencies.insert(contract);
solAssert(
!contract->annotation().linearizedBaseContracts.empty(),
"Linearized base contracts not yet available."
);
if (contractDependenciesAreCyclic(*scopeContract))
typeError(
_newExpression,
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"Circular reference for contract creation (cannot create instance of derived or same contract)."
);
auto contractType = make_shared<ContractType>(*contract);
TypePointers const& parameterTypes = contractType->constructorType()->parameterTypes();
_newExpression.annotation().type = make_shared<FunctionType>(
parameterTypes,
TypePointers{contractType},
strings(),
strings(),
FunctionType::Location::Creation
);
}
bool TypeChecker::visit(MemberAccess const& _memberAccess)
{
_memberAccess.expression().accept(*this);
TypePointer exprType = type(_memberAccess.expression());
ASTString const& memberName = _memberAccess.memberName();
// Retrieve the types of the arguments if this is used to call a function.
auto const& argumentTypes = _memberAccess.annotation().argumentTypes;
MemberList::MemberMap possibleMembers = exprType->members().membersByName(memberName);
if (possibleMembers.size() > 1 && argumentTypes)
{
// do overload resolution
for (auto it = possibleMembers.begin(); it != possibleMembers.end();)
if (
it->type->category() == Type::Category::Function &&
!dynamic_cast<FunctionType const&>(*it->type).canTakeArguments(*argumentTypes)
)
it = possibleMembers.erase(it);
else
++it;
}
if (possibleMembers.size() == 0)
{
auto storageType = ReferenceType::copyForLocationIfReference(
DataLocation::Storage,
exprType
);
if (!storageType->members().membersByName(memberName).empty())
fatalTypeError(
_memberAccess,
"Member \"" + memberName + "\" is not available in " +
exprType->toString() +
" outside of storage."
);
fatalTypeError(
_memberAccess,
"Member \"" + memberName + "\" not found or not visible "
"after argument-dependent lookup in " + exprType->toString()
);
}
else if (possibleMembers.size() > 1)
fatalTypeError(
_memberAccess,
"Member \"" + memberName + "\" not unique "
"after argument-dependent lookup in " + exprType->toString()
);
auto& annotation = _memberAccess.annotation();
annotation.referencedDeclaration = possibleMembers.front().declaration;
annotation.type = possibleMembers.front().type;
if (exprType->category() == Type::Category::Struct)
annotation.isLValue = true;
else if (exprType->category() == Type::Category::Array)
{
auto const& arrayType(dynamic_cast<ArrayType const&>(*exprType));
annotation.isLValue = (
memberName == "length" &&
arrayType.location() == DataLocation::Storage &&
arrayType.isDynamicallySized()
);
}
return false;
}
bool TypeChecker::visit(IndexAccess const& _access)
{
_access.baseExpression().accept(*this);
TypePointer baseType = type(_access.baseExpression());
TypePointer resultType;
bool isLValue = false;
Expression const* index = _access.indexExpression();
switch (baseType->category())
{
case Type::Category::Array:
{
ArrayType const& actualType = dynamic_cast<ArrayType const&>(*baseType);
if (!index)
typeError(_access, "Index expression cannot be omitted.");
else if (actualType.isString())
{
typeError(_access, "Index access for string is not possible.");
index->accept(*this);
}
else
{
expectType(*index, IntegerType(256));
if (auto integerType = dynamic_cast<IntegerConstantType const*>(type(*index).get()))
if (!actualType.isDynamicallySized() && actualType.length() <= integerType->literalValue(nullptr))
typeError(_access, "Out of bounds array access.");
}
resultType = actualType.baseType();
isLValue = actualType.location() != DataLocation::CallData;
break;
}
case Type::Category::Mapping:
{
MappingType const& actualType = dynamic_cast<MappingType const&>(*baseType);
if (!index)
typeError(_access, "Index expression cannot be omitted.");
else
expectType(*index, *actualType.keyType());
resultType = actualType.valueType();
isLValue = true;
break;
}
case Type::Category::TypeType:
{
TypeType const& typeType = dynamic_cast<TypeType const&>(*baseType);
if (!index)
resultType = make_shared<TypeType>(make_shared<ArrayType>(DataLocation::Memory, typeType.actualType()));
else
{
index->accept(*this);
if (auto length = dynamic_cast<IntegerConstantType const*>(type(*index).get()))
resultType = make_shared<TypeType>(make_shared<ArrayType>(
DataLocation::Memory,
typeType.actualType(),
length->literalValue(nullptr)
));
else
typeError(*index, "Integer constant expected.");
}
break;
}
default:
fatalTypeError(
_access.baseExpression(),
"Indexed expression has to be a type, mapping or array (is " + baseType->toString() + ")"
);
}
_access.annotation().type = move(resultType);
_access.annotation().isLValue = isLValue;
return false;
}
bool TypeChecker::visit(Identifier const& _identifier)
{
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IdentifierAnnotation& annotation = _identifier.annotation();
if (!annotation.referencedDeclaration)
{
if (!annotation.argumentTypes)
fatalTypeError(_identifier, "Unable to determine overloaded type.");
if (annotation.overloadedDeclarations.empty())
fatalTypeError(_identifier, "No candidates for overload resolution found.");
else if (annotation.overloadedDeclarations.size() == 1)
annotation.referencedDeclaration = *annotation.overloadedDeclarations.begin();
else
{
vector<Declaration const*> candidates;
for (Declaration const* declaration: annotation.overloadedDeclarations)
{
TypePointer function = declaration->type(_identifier.annotation().contractScope);
solAssert(!!function, "Requested type not present.");
auto const* functionType = dynamic_cast<FunctionType const*>(function.get());
if (functionType && functionType->canTakeArguments(*annotation.argumentTypes))
candidates.push_back(declaration);
}
if (candidates.empty())
fatalTypeError(_identifier, "No matching declaration found after argument-dependent lookup.");
else if (candidates.size() == 1)
annotation.referencedDeclaration = candidates.front();
else
fatalTypeError(_identifier, "No unique declaration found after argument-dependent lookup.");
}
}
solAssert(
!!annotation.referencedDeclaration,
"Referenced declaration is null after overload resolution."
);
annotation.isLValue = annotation.referencedDeclaration->isLValue();
annotation.type = annotation.referencedDeclaration->type(_identifier.annotation().contractScope);
if (!annotation.type)
fatalTypeError(_identifier, "Declaration referenced before type could be determined.");
return false;
}
void TypeChecker::endVisit(ElementaryTypeNameExpression const& _expr)
{
_expr.annotation().type = make_shared<TypeType>(Type::fromElementaryTypeName(_expr.typeToken()));
}
void TypeChecker::endVisit(Literal const& _literal)
{
_literal.annotation().type = Type::forLiteral(_literal);
if (!_literal.annotation().type)
fatalTypeError(_literal, "Invalid literal value.");
}
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bool TypeChecker::contractDependenciesAreCyclic(
ContractDefinition const& _contract,
std::set<ContractDefinition const*> const& _seenContracts
) const
{
// Naive depth-first search that remembers nodes already seen.
if (_seenContracts.count(&_contract))
return true;
set<ContractDefinition const*> seen(_seenContracts);
seen.insert(&_contract);
for (auto const* c: _contract.annotation().contractDependencies)
if (contractDependenciesAreCyclic(*c, seen))
return true;
return false;
}
Declaration const& TypeChecker::dereference(Identifier const& _identifier)
{
solAssert(!!_identifier.annotation().referencedDeclaration, "Declaration not stored.");
return *_identifier.annotation().referencedDeclaration;
}
void TypeChecker::expectType(Expression const& _expression, Type const& _expectedType)
{
_expression.accept(*this);
if (!type(_expression)->isImplicitlyConvertibleTo(_expectedType))
typeError(
_expression,
"Type " +
type(_expression)->toString() +
" is not implicitly convertible to expected type " +
_expectedType.toString() +
"."
);
}
void TypeChecker::requireLValue(Expression const& _expression)
{
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_expression.annotation().lValueRequested = true;
_expression.accept(*this);
if (!_expression.annotation().isLValue)
typeError(_expression, "Expression has to be an lvalue.");
}
void TypeChecker::typeError(ASTNode const& _node, string const& _description)
{
auto err = make_shared<Error>(Error::Type::TypeError);
*err <<
errinfo_sourceLocation(_node.location()) <<
errinfo_comment(_description);
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m_errors.push_back(err);
}
void TypeChecker::fatalTypeError(ASTNode const& _node, string const& _description)
{
typeError(_node, _description);
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BOOST_THROW_EXCEPTION(FatalError());
}