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Merge pull request #1729 from ethereum/constantvariables

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Only allow pure expressions for constant state variables.
This commit is contained in:
Yoichi Hirai
2017-03-15 10:03:35 +01:00
committed by GitHub
parent 64e00e5371 9f328ff749
commit d134fda0c0
8 changed files with 241 additions and 35 deletions
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libsolidity/analysis/TypeChecker.cpp
+66 -22
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@@ -467,27 +467,29 @@ bool TypeChecker::visit(VariableDeclaration const& _variable)
// 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.location(), "Illegal use of \"constant\" specifier.");
if (!_variable.value())
typeError(_variable.location(), "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.location(),
"Illegal use of \"constant\" specifier. \"constant\" "
"is not yet implemented for this type."
);
}
}
if (_variable.value())
expectType(*_variable.value(), *varType);
if (_variable.isConstant())
{
if (!_variable.isStateVariable())
typeError(_variable.location(), "Illegal use of \"constant\" specifier.");
if (!_variable.type()->isValueType())
{
bool allowed = false;
if (auto arrayType = dynamic_cast<ArrayType const*>(_variable.type().get()))
allowed = arrayType->isString();
if (!allowed)
typeError(_variable.location(), "Constants of non-value type not yet implemented.");
}
if (!_variable.value())
typeError(_variable.location(), "Uninitialized \"constant\" variable.");
else if (!_variable.value()->annotation().isPure)
warning(
_variable.value()->location(),
"Initial value for constant variable has to be compile-time constant. "
"This will fail to compile with the next breaking version change."
);
}
if (!_variable.isStateVariable())
{
if (varType->dataStoredIn(DataLocation::Memory) || varType->dataStoredIn(DataLocation::CallData))
@@ -928,6 +930,10 @@ bool TypeChecker::visit(Conditional const& _conditional)
}
_conditional.annotation().type = commonType;
_conditional.annotation().isPure =
_conditional.condition().annotation().isPure &&
_conditional.trueExpression().annotation().isPure &&
_conditional.falseExpression().annotation().isPure;
if (_conditional.annotation().lValueRequested)
typeError(
@@ -1009,6 +1015,7 @@ bool TypeChecker::visit(TupleExpression const& _tuple)
}
else
{
bool isPure = true;
TypePointer inlineArrayType;
for (size_t i = 0; i < components.size(); ++i)
{
@@ -1031,10 +1038,13 @@ bool TypeChecker::visit(TupleExpression const& _tuple)
else if (inlineArrayType)
inlineArrayType = Type::commonType(inlineArrayType, types[i]);
}
if (!components[i]->annotation().isPure)
isPure = false;
}
else
types.push_back(TypePointer());
}
_tuple.annotation().isPure = isPure;
if (_tuple.isInlineArray())
{
if (!inlineArrayType)
@@ -1061,7 +1071,8 @@ 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)
bool const modifying = (op == Token::Value::Inc || op == Token::Value::Dec || op == Token::Value::Delete);
if (modifying)
requireLValue(_operation.subExpression());
else
_operation.subExpression().accept(*this);
@@ -1079,6 +1090,7 @@ bool TypeChecker::visit(UnaryOperation const& _operation)
t = subExprType;
}
_operation.annotation().type = t;
_operation.annotation().isPure = !modifying && _operation.subExpression().annotation().isPure;
return false;
}
@@ -1105,6 +1117,10 @@ void TypeChecker::endVisit(BinaryOperation const& _operation)
Token::isCompareOp(_operation.getOperator()) ?
make_shared<BoolType>() :
commonType;
_operation.annotation().isPure =
_operation.leftExpression().annotation().isPure &&
_operation.rightExpression().annotation().isPure;
if (_operation.getOperator() == Token::Exp)
{
if (
@@ -1133,6 +1149,8 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
vector<ASTPointer<Expression const>> arguments = _functionCall.arguments();
vector<ASTPointer<ASTString>> const& argumentNames = _functionCall.names();
bool isPure = true;
// We need to check arguments' type first as they will be needed for overload resolution.
shared_ptr<TypePointers> argumentTypes;
if (isPositionalCall)
@@ -1140,6 +1158,8 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
for (ASTPointer<Expression const> const& argument: arguments)
{
argument->accept(*this);
if (!argument->annotation().isPure)
isPure = false;
// only store them for positional calls
if (isPositionalCall)
argumentTypes->push_back(type(*argument));
@@ -1177,6 +1197,7 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
typeError(_functionCall.location(), "Explicit type conversion not allowed.");
}
_functionCall.annotation().type = resultType;
_functionCall.annotation().isPure = isPure;
return false;
}
@@ -1193,9 +1214,16 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
auto const& structType = dynamic_cast<StructType const&>(*t.actualType());
functionType = structType.constructorType();
membersRemovedForStructConstructor = structType.membersMissingInMemory();
_functionCall.annotation().isPure = isPure;
}
else
{
functionType = dynamic_pointer_cast<FunctionType const>(expressionType);
_functionCall.annotation().isPure =
isPure &&
_functionCall.expression().annotation().isPure &&
functionType->isPure();
}
if (!functionType)
{
@@ -1360,6 +1388,7 @@ void TypeChecker::endVisit(NewExpression const& _newExpression)
strings(),
FunctionType::Location::ObjectCreation
);
_newExpression.annotation().isPure = true;
}
else
fatalTypeError(_newExpression.location(), "Contract or array type expected.");
@@ -1445,6 +1474,12 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
annotation.isLValue = annotation.referencedDeclaration->isLValue();
}
// TODO some members might be pure, but for example `address(0x123).balance` is not pure
// although every subexpression is, so leaving this limited for now.
if (auto tt = dynamic_cast<TypeType const*>(exprType.get()))
if (tt->actualType()->category() == Type::Category::Enum)
annotation.isPure = true;
return false;
}
@@ -1454,6 +1489,7 @@ bool TypeChecker::visit(IndexAccess const& _access)
TypePointer baseType = type(_access.baseExpression());
TypePointer resultType;
bool isLValue = false;
bool isPure = _access.baseExpression().annotation().isPure;
Expression const* index = _access.indexExpression();
switch (baseType->category())
{
@@ -1535,6 +1571,9 @@ bool TypeChecker::visit(IndexAccess const& _access)
}
_access.annotation().type = move(resultType);
_access.annotation().isLValue = isLValue;
if (index && !index->annotation().isPure)
isPure = false;
_access.annotation().isPure = isPure;
return false;
}
@@ -1589,18 +1628,22 @@ bool TypeChecker::visit(Identifier const& _identifier)
!!annotation.referencedDeclaration,
"Referenced declaration is null after overload resolution."
);
auto variableDeclaration = dynamic_cast<VariableDeclaration const*>(annotation.referencedDeclaration);
annotation.isConstant = variableDeclaration != nullptr && variableDeclaration->isConstant();
annotation.isLValue = annotation.referencedDeclaration->isLValue();
annotation.type = annotation.referencedDeclaration->type();
if (!annotation.type)
fatalTypeError(_identifier.location(), "Declaration referenced before type could be determined.");
if (auto variableDeclaration = dynamic_cast<VariableDeclaration const*>(annotation.referencedDeclaration))
annotation.isPure = annotation.isConstant = variableDeclaration->isConstant();
else if (dynamic_cast<MagicVariableDeclaration const*>(annotation.referencedDeclaration))
if (auto functionType = dynamic_cast<FunctionType const*>(annotation.type.get()))
annotation.isPure = functionType->isPure();
return false;
}
void TypeChecker::endVisit(ElementaryTypeNameExpression const& _expr)
{
_expr.annotation().type = make_shared<TypeType>(Type::fromElementaryTypeName(_expr.typeName()));
_expr.annotation().isPure = true;
}
void TypeChecker::endVisit(Literal const& _literal)
@@ -1620,6 +1663,7 @@ void TypeChecker::endVisit(Literal const& _literal)
);
}
_literal.annotation().type = Type::forLiteral(_literal);
_literal.annotation().isPure = true;
if (!_literal.annotation().type)
fatalTypeError(_literal.location(), "Invalid literal value.");
}