5 files changed, 33 insertions, 30 deletions

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index ca848dd0..0764bf67 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -84,8 +84,13 @@ bool TypeChecker::visit(ContractDefinition const& _contract)
 	{
 		if (!function->returnParameters().empty())
 			m_errorReporter.typeError(function->returnParameterList()->location(), "Non-empty \"returns\" directive for constructor.");
-		if (function->isDeclaredConst())
-			m_errorReporter.typeError(function->location(), "Constructor cannot be defined as constant.");
+		if (function->stateMutability() != StateMutability::NonPayable && function->stateMutability() != StateMutability::Payable)
+			m_errorReporter.typeError(
+				function->location(),
+				"Constructor must be payable or non-payable, but is \"" +
+				stateMutabilityToString(function->stateMutability()) +
+				"\"."
+			);
 		if (function->visibility() != FunctionDefinition::Visibility::Public && function->visibility() != FunctionDefinition::Visibility::Internal)
 			m_errorReporter.typeError(function->location(), "Constructor must be public or internal.");
 	}
@@ -104,8 +109,13 @@ bool TypeChecker::visit(ContractDefinition const& _contract)
 				fallbackFunction = function;
 				if (_contract.isLibrary())
 					m_errorReporter.typeError(fallbackFunction->location(), "Libraries cannot have fallback functions.");
-				if (fallbackFunction->isDeclaredConst())
-					m_errorReporter.typeError(fallbackFunction->location(), "Fallback function cannot be declared constant.");
+				if (function->stateMutability() != StateMutability::NonPayable && function->stateMutability() != StateMutability::Payable)
+					m_errorReporter.typeError(
+						function->location(),
+						"Fallback function must be payable or non-payable, but is \"" +
+						stateMutabilityToString(function->stateMutability()) +
+						"\"."
+				);
 				if (!fallbackFunction->parameters().empty())
 					m_errorReporter.typeError(fallbackFunction->parameterList().location(), "Fallback function cannot take parameters.");
 				if (!fallbackFunction->returnParameters().empty())
@@ -308,17 +318,16 @@ void TypeChecker::checkFunctionOverride(FunctionDefinition const& function, Func
 	if (function.visibility() != super.visibility())
 		overrideError(function, super, "Overriding function visibility differs.");
 
-	else if (function.isDeclaredConst() && !super.isDeclaredConst())
-		overrideError(function, super, "Overriding function should not be declared constant.");
-
-	else if (!function.isDeclaredConst() && super.isDeclaredConst())
-		overrideError(function, super, "Overriding function should be declared constant.");
-
-	else if (function.isPayable() && !super.isPayable())
-		overrideError(function, super, "Overriding function should not be declared payable.");
-
-	else if (!function.isPayable() && super.isPayable())
-		overrideError(function, super, "Overriding function should be declared payable.");
+	else if (function.stateMutability() != super.stateMutability())
+		overrideError(
+			function,
+			super,
+			"Overriding function changes state mutability from \"" +
+			stateMutabilityToString(super.stateMutability()) +
+			"\" to \"" +
+			stateMutabilityToString(function.stateMutability()) +
+			"\"."
+		);
 
 	else if (functionType != superType)
 		overrideError(function, super, "Overriding function return types differ.");
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index 8a577c0c..53a34d32 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -608,7 +608,6 @@ public:
 	StateMutability stateMutability() const { return m_stateMutability; }
 	bool isConstructor() const { return m_isConstructor; }
 	bool isFallback() const { return name().empty(); }
-	bool isDeclaredConst() const { return m_stateMutability == StateMutability::View; }
 	bool isPayable() const { return m_stateMutability == StateMutability::Payable; }
 	std::vector<ASTPointer<ModifierInvocation>> const& modifiers() const { return m_functionModifiers; }
 	std::vector<ASTPointer<VariableDeclaration>> const& returnParameters() const { return m_returnParameters->parameters(); }
@@ -913,7 +912,6 @@ public:
 		return m_visibility == Declaration::Visibility::Default ? Declaration::Visibility::Internal : m_visibility;
 	}
 	StateMutability stateMutability() const { return m_stateMutability; }
-	bool isDeclaredConst() const { return m_stateMutability == StateMutability::View; }
 	bool isPayable() const { return m_stateMutability == StateMutability::Payable; }
 
 private:
diff --git a/libsolidity/ast/ASTJsonConverter.cpp b/libsolidity/ast/ASTJsonConverter.cpp
index abee55ee..3f16db23 100644
--- a/libsolidity/ast/ASTJsonConverter.cpp
+++ b/libsolidity/ast/ASTJsonConverter.cpp
@@ -323,8 +323,9 @@ bool ASTJsonConverter::visit(FunctionDefinition const& _node)
 {
 	std::vector<pair<string, Json::Value>> attributes = {
 		make_pair("name", _node.name()),
-		make_pair(m_legacy ? "constant" : "isDeclaredConst", _node.isDeclaredConst()),
+		make_pair(m_legacy ? "constant" : "isDeclaredConst", _node.stateMutability() == StateMutability::View),
 		make_pair("payable", _node.isPayable()),
+		make_pair("statemutability", stateMutabilityToString(_node.stateMutability())),
 		make_pair("visibility", Declaration::visibilityToString(_node.visibility())),
 		make_pair("parameters", toJson(_node.parameterList())),
 		make_pair("isConstructor", _node.isConstructor()),
@@ -419,7 +420,8 @@ bool ASTJsonConverter::visit(FunctionTypeName const& _node)
 	setJsonNode(_node, "FunctionTypeName", {
 		make_pair("payable", _node.isPayable()),
 		make_pair("visibility", Declaration::visibilityToString(_node.visibility())),
-		make_pair(m_legacy ? "constant" : "isDeclaredConst", _node.isDeclaredConst()),
+		make_pair("statemutability", stateMutabilityToString(_node.stateMutability())),
+		make_pair(m_legacy ? "constant" : "isDeclaredConst", _node.stateMutability() == StateMutability::View),
 		make_pair("parameterTypes", toJson(*_node.parameterTypeList())),
 		make_pair("returnParameterTypes", toJson(*_node.returnParameterTypeList())),
 		make_pair("typeDescriptions", typePointerToJson(_node.annotation().type))
diff --git a/libsolidity/ast/ASTPrinter.cpp b/libsolidity/ast/ASTPrinter.cpp
index 23eb3b64..bcb5e3b9 100644
--- a/libsolidity/ast/ASTPrinter.cpp
+++ b/libsolidity/ast/ASTPrinter.cpp
@@ -105,7 +105,7 @@ bool ASTPrinter::visit(FunctionDefinition const& _node)
 {
 	writeLine("FunctionDefinition \"" + _node.name() + "\"" +
 			  (_node.isPublic() ? " - public" : "") +
-			  (_node.isDeclaredConst() ? " - const" : ""));
+			  (_node.stateMutability() == StateMutability::View ? " - const" : ""));
 	printSourcePart(_node);
 	return goDeeper();
 }
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 302f1022..e6664895 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -2215,10 +2215,7 @@ string FunctionType::identifier() const
 	case Kind::Require: id += "require";break;
 	default: solAssert(false, "Unknown function location."); break;
 	}
-	if (isConstant())
-		id += "_constant";
-	if (isPayable())
-		id += "_payable";
+	id += "_" + stateMutabilityToString(m_stateMutability);
 	id += identifierList(m_parameterTypes) + "returns" + identifierList(m_returnParameterTypes);
 	if (m_gasSet)
 		id += "gas";
@@ -2237,8 +2234,7 @@ bool FunctionType::operator==(Type const& _other) const
 	FunctionType const& other = dynamic_cast<FunctionType const&>(_other);
 	if (
 		m_kind != other.m_kind ||
-		isConstant() != other.isConstant() ||
-		isPayable() != other.isPayable() ||
+		m_stateMutability != other.stateMutability() ||
 		m_parameterTypes.size() != other.m_parameterTypes.size() ||
 		m_returnParameterTypes.size() != other.m_returnParameterTypes.size()
 	)
@@ -2300,10 +2296,8 @@ string FunctionType::toString(bool _short) const
 	for (auto it = m_parameterTypes.begin(); it != m_parameterTypes.end(); ++it)
 		name += (*it)->toString(_short) + (it + 1 == m_parameterTypes.end() ? "" : ",");
 	name += ")";
-	if (isConstant())
-		name += " constant";
-	if (isPayable())
-		name += " payable";
+	if (m_stateMutability != StateMutability::NonPayable)
+		name += " " + stateMutabilityToString(m_stateMutability);
 	if (m_kind == Kind::External)
 		name += " external";
 	if (!m_returnParameterTypes.empty())