Disallow assignments to structs and mappings.

This commit is contained in:
Christian 2014-12-01 17:32:10 +01:00
parent 9e91596c8d
commit a2ad47441e
2 changed files with 19 additions and 9 deletions

12
AST.cpp
View File

@ -378,6 +378,9 @@ void Assignment::checkTypeRequirements()
{
m_leftHandSide->checkTypeRequirements();
m_leftHandSide->requireLValue();
//@todo later, assignments to structs might be possible, but not to mappings
if (!m_leftHandSide->getType()->isValueType() && !m_leftHandSide->isLocalLValue())
BOOST_THROW_EXCEPTION(createTypeError("Assignment to non-local non-value lvalue."));
m_rightHandSide->expectType(*m_leftHandSide->getType());
m_type = m_leftHandSide->getType();
if (m_assigmentOperator != Token::ASSIGN)
@ -403,7 +406,7 @@ void Expression::expectType(Type const& _expectedType)
void Expression::requireLValue()
{
if (!isLvalue())
if (!isLValue())
BOOST_THROW_EXCEPTION(createTypeError("Expression has to be an lvalue."));
m_lvalueRequested = true;
}
@ -495,7 +498,8 @@ void MemberAccess::checkTypeRequirements()
m_type = type.getMemberType(*m_memberName);
if (!m_type)
BOOST_THROW_EXCEPTION(createTypeError("Member \"" + *m_memberName + "\" not found in " + type.toString()));
m_isLvalue = (type.getCategory() == Type::Category::STRUCT && m_type->getCategory() != Type::Category::MAPPING);
//@todo later, this will not always be STORAGE
m_lvalue = type.getCategory() == Type::Category::STRUCT ? LValueType::STORAGE : LValueType::NONE;
}
void IndexAccess::checkTypeRequirements()
@ -507,7 +511,7 @@ void IndexAccess::checkTypeRequirements()
MappingType const& type = dynamic_cast<MappingType const&>(*m_base->getType());
m_index->expectType(*type.getKeyType());
m_type = type.getValueType();
m_isLvalue = m_type->getCategory() != Type::Category::MAPPING;
m_lvalue = LValueType::STORAGE;
}
void Identifier::checkTypeRequirements()
@ -521,7 +525,7 @@ void Identifier::checkTypeRequirements()
if (!variable->getType())
BOOST_THROW_EXCEPTION(createTypeError("Variable referenced before type could be determined."));
m_type = variable->getType();
m_isLvalue = true;
m_lvalue = variable->isLocalVariable() ? LValueType::LOCAL : LValueType::STORAGE;
return;
}
//@todo can we unify these with TypeName::toType()?

16
AST.h
View File

@ -242,6 +242,8 @@ public:
std::shared_ptr<Type const> const& getType() const { return m_type; }
void setType(std::shared_ptr<Type const> const& _type) { m_type = _type; }
bool isLocalVariable() const { return !!dynamic_cast<FunctionDefinition*>(getScope()); }
private:
ASTPointer<TypeName> m_typeName; ///< can be empty ("var")
@ -526,12 +528,16 @@ private:
*/
class Expression: public ASTNode
{
protected:
enum class LValueType { NONE, LOCAL, STORAGE };
public:
Expression(Location const& _location): ASTNode(_location), m_isLvalue(false), m_lvalueRequested(false) {}
Expression(Location const& _location): ASTNode(_location), m_lvalue(LValueType::NONE), m_lvalueRequested(false) {}
virtual void checkTypeRequirements() = 0;
std::shared_ptr<Type const> const& getType() const { return m_type; }
bool isLvalue() const { return m_isLvalue; }
bool isLValue() const { return m_lvalue != LValueType::NONE; }
bool isLocalLValue() const { return m_lvalue == LValueType::LOCAL; }
/// Helper function, infer the type via @ref checkTypeRequirements and then check that it
/// is implicitly convertible to @a _expectedType. If not, throw exception.
@ -546,9 +552,9 @@ public:
protected:
//! Inferred type of the expression, only filled after a call to checkTypeRequirements().
std::shared_ptr<Type const> m_type;
//! Whether or not this expression is an lvalue, i.e. something that can be assigned to.
//! This is set during calls to @a checkTypeRequirements()
bool m_isLvalue;
//! If this expression is an lvalue (i.e. something that can be assigned to) and is stored
//! locally or in storage. This is set during calls to @a checkTypeRequirements()
LValueType m_lvalue;
//! Whether the outer expression requested the address (true) or the value (false) of this expression.
bool m_lvalueRequested;
};