Contract compiler and also add ExpressionStatement to AST.

ExpressionStatement functions as glue between Statements and Expressions.

This way it is possible to detect when the border between statements and
expressions is crossed while walking the AST. Note that ExpressionStatement is
not the only border, almost every statement can contains expressions.

1 files changed, 28 insertions, 15 deletions

diff --git a/AST.cpp b/AST.cpp
index 099222fa..5391e71b 100644
--- a/AST.cpp
+++ b/AST.cpp
@@ -167,6 +167,14 @@ void Return::accept(ASTVisitor& _visitor)
 	_visitor.endVisit(*this);
 }
 
+void ExpressionStatement::accept(ASTVisitor& _visitor)
+{
+	if (_visitor.visit(*this))
+		if (m_expression)
+			m_expression->accept(_visitor);
+	_visitor.endVisit(*this);
+}
+
 void VariableDefinition::accept(ASTVisitor& _visitor)
 {
 	if (_visitor.visit(*this))
@@ -255,14 +263,6 @@ TypeError ASTNode::createTypeError(string const& _description)
 	return TypeError() << errinfo_sourceLocation(getLocation()) << errinfo_comment(_description);
 }
 
-void Statement::expectType(Expression& _expression, const Type& _expectedType)
-{
-	_expression.checkTypeRequirements();
-	if (!_expression.getType()->isImplicitlyConvertibleTo(_expectedType))
-		BOOST_THROW_EXCEPTION(_expression.createTypeError("Type not implicitly convertible to expected type."));
-	//@todo provide more information to the exception
-}
-
 void Block::checkTypeRequirements()
 {
 	for (shared_ptr<Statement> const& statement: m_statements)
@@ -271,7 +271,7 @@ void Block::checkTypeRequirements()
 
 void IfStatement::checkTypeRequirements()
 {
-	expectType(*m_condition, BoolType());
+	m_condition->expectType(BoolType());
 	m_trueBody->checkTypeRequirements();
 	if (m_falseBody)
 		m_falseBody->checkTypeRequirements();
@@ -279,7 +279,7 @@ void IfStatement::checkTypeRequirements()
 
 void WhileStatement::checkTypeRequirements()
 {
-	expectType(*m_condition, BoolType());
+	m_condition->expectType(BoolType());
 	m_body->checkTypeRequirements();
 }
 
@@ -301,7 +301,7 @@ void Return::checkTypeRequirements()
 											  "than in returns declaration."));
 	// this could later be changed such that the paramaters type is an anonymous struct type,
 	// but for now, we only allow one return parameter
-	expectType(*m_expression, *m_returnParameters->getParameters().front()->getType());
+	m_expression->expectType(*m_returnParameters->getParameters().front()->getType());
 }
 
 void VariableDefinition::checkTypeRequirements()
@@ -313,7 +313,7 @@ void VariableDefinition::checkTypeRequirements()
 	if (m_value)
 	{
 		if (m_variable->getType())
-			expectType(*m_value, *m_variable->getType());
+			m_value->expectType(*m_variable->getType());
 		else
 		{
 			// no type declared and no previous assignment, infer the type
@@ -330,7 +330,7 @@ void Assignment::checkTypeRequirements()
 	m_leftHandSide->checkTypeRequirements();
 	if (!m_leftHandSide->isLvalue())
 		BOOST_THROW_EXCEPTION(createTypeError("Expression has to be an lvalue."));
-	expectType(*m_rightHandSide, *m_leftHandSide->getType());
+	m_rightHandSide->expectType(*m_leftHandSide->getType());
 	m_type = m_leftHandSide->getType();
 	if (m_assigmentOperator != Token::ASSIGN)
 	{
@@ -340,6 +340,19 @@ void Assignment::checkTypeRequirements()
 	}
 }
 
+void ExpressionStatement::checkTypeRequirements()
+{
+	m_expression->checkTypeRequirements();
+}
+
+void Expression::expectType(const Type& _expectedType)
+{
+	checkTypeRequirements();
+	if (!getType()->isImplicitlyConvertibleTo(_expectedType))
+		BOOST_THROW_EXCEPTION(createTypeError("Type not implicitly convertible to expected type."));
+	//@todo provide more information to the exception
+}
+
 void UnaryOperation::checkTypeRequirements()
 {
 	// INC, DEC, ADD, SUB, NOT, BIT_NOT, DELETE
@@ -411,10 +424,10 @@ void FunctionCall::checkTypeRequirements()
 				BOOST_THROW_EXCEPTION(createTypeError("Invalid type for argument in function call."));
 		// @todo actually the return type should be an anonymous struct,
 		// but we change it to the type of the first return value until we have structs
-		if (fun.getReturnParameterList()->getParameters().empty())
+		if (fun.getReturnParameters().empty())
 			m_type = make_shared<VoidType>();
 		else
-			m_type = fun.getReturnParameterList()->getParameters().front()->getType();
+			m_type = fun.getReturnParameters().front()->getType();
 	}
 }