Merge pull request #2554 from ethereum/minMaxValue

Some helper functions.

libsolidity/ast/AST.cpp

@@ -416,6 +416,23 @@ bool VariableDeclaration::isCallableParameter() const
 	return false;
 }
 
+bool VariableDeclaration::isLocalOrReturn() const
+{
+	return isReturnParameter() || (isLocalVariable() && !isCallableParameter());
+}
+
+bool VariableDeclaration::isReturnParameter() const
+{
+	auto const* callable = dynamic_cast<CallableDeclaration const*>(scope());
+	if (!callable)
+		return false;
+	if (callable->returnParameterList())
+		for (auto const& variable: callable->returnParameterList()->parameters())
+			if (variable.get() == this)
+				return true;
+	return false;
+}
+
 bool VariableDeclaration::isExternalCallableParameter() const
 {
 	auto const* callable = dynamic_cast<CallableDeclaration const*>(scope());

libsolidity/ast/AST.h

@@ -650,6 +650,10 @@ public:
 	bool isLocalVariable() const { return !!dynamic_cast<CallableDeclaration const*>(scope()); }
 	/// @returns true if this variable is a parameter or return parameter of a function.
 	bool isCallableParameter() const;
+	/// @returns true if this variable is a return parameter of a function.
+	bool isReturnParameter() const;
+	/// @returns true if this variable is a local variable or return parameter.
+	bool isLocalOrReturn() const;
 	/// @returns true if this variable is a parameter (not return parameter) of an external function.
 	bool isExternalCallableParameter() const;
 	/// @returns true if the type of the variable does not need to be specified, i.e. it is declared

libsolidity/ast/Types.cpp

@@ -413,6 +413,22 @@ u256 IntegerType::literalValue(Literal const* _literal) const
 	return u256(_literal->value());
 }
 
+bigint IntegerType::minValue() const
+{
+	if (isSigned())
+		return -(bigint(1) << (m_bits - 1));
+	else
+		return bigint(0);
+}
+
+bigint IntegerType::maxValue() const
+{
+	if (isSigned())
+		return (bigint(1) << (m_bits - 1)) - 1;
+	else
+		return (bigint(1) << m_bits) - 1;
+}
+
 TypePointer IntegerType::binaryOperatorResult(Token::Value _operator, TypePointer const& _other) const
 {
 	if (

libsolidity/ast/Types.h

@@ -323,6 +323,9 @@ public:
 	bool isAddress() const { return m_modifier == Modifier::Address; }
 	bool isSigned() const { return m_modifier == Modifier::Signed; }
 
+	bigint minValue() const;
+	bigint maxValue() const;
+
 private:
 	int m_bits;
 	Modifier m_modifier;