8 files changed, 111 insertions, 74 deletions
diff --git a/libsolidity/analysis/ControlFlowAnalyzer.cpp b/libsolidity/analysis/ControlFlowAnalyzer.cpp
index 483d08c8..ab6569be 100644
--- a/libsolidity/analysis/ControlFlowAnalyzer.cpp
+++ b/libsolidity/analysis/ControlFlowAnalyzer.cpp
@@ -75,7 +75,10 @@ void ControlFlowAnalyzer::checkUnassignedStorageReturnValues(
 	{
 		auto& unassignedAtFunctionEntry = unassigned[_functionEntry];
 		for (auto const& returnParameter: _function.returnParameterList()->parameters())
-			if (returnParameter->type()->dataStoredIn(DataLocation::Storage))
+			if (
+				returnParameter->type()->dataStoredIn(DataLocation::Storage) ||
+				returnParameter->type()->category() == Type::Category::Mapping
+			)
 				unassignedAtFunctionEntry.insert(returnParameter.get());
 	}
 
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index bcc3757a..601a5e7c 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -580,9 +580,6 @@ void TypeChecker::endVisit(UsingForDirective const& _usingFor)
 
 bool TypeChecker::visit(StructDefinition const& _struct)
 {
-	if (m_scope->contractKind() == ContractDefinition::ContractKind::Interface)
-		m_errorReporter.typeError(_struct.location(), "Structs cannot be defined in interfaces.");
-
 	for (ASTPointer<VariableDeclaration> const& member: _struct.members())
 		if (!type(*member)->canBeStored())
 			m_errorReporter.typeError(member->location(), "Type cannot be used in struct.");
@@ -610,7 +607,10 @@ bool TypeChecker::visit(StructDefinition const& _struct)
 	if (CycleDetector<StructDefinition>(visitor).run(_struct) != nullptr)
 		m_errorReporter.fatalTypeError(_struct.location(), "Recursive struct definition.");
 
+	bool insideStruct = true;
+	swap(insideStruct, m_insideStruct);
 	ASTNode::listAccept(_struct.members(), *this);
+	m_insideStruct = insideStruct;
 
 	return false;
 }
@@ -629,7 +629,10 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 	}
 	for (ASTPointer<VariableDeclaration> const& var: _function.parameters() + _function.returnParameters())
 	{
-		if (!type(*var)->canLiveOutsideStorage())
+		if (
+			!type(*var)->canLiveOutsideStorage() &&
+			!(_function.visibility() <= FunctionDefinition::Visibility::Internal)
+		)
 			m_errorReporter.typeError(var->location(), "Type is required to live outside storage.");
 		if (_function.visibility() >= FunctionDefinition::Visibility::Public && !(type(*var)->interfaceType(isLibraryFunction)))
 			m_errorReporter.fatalTypeError(var->location(), "Internal or recursive type is not allowed for public or external functions.");
@@ -690,10 +693,12 @@ bool TypeChecker::visit(FunctionDefinition const& _function)
 bool TypeChecker::visit(VariableDeclaration const& _variable)
 {
 	// Forbid any variable declarations inside interfaces unless they are part of
-	// a function's input/output parameters.
+	// * a function's input/output parameters,
+	// * or inside of a struct definition.
 	if (
 		m_scope->contractKind() == ContractDefinition::ContractKind::Interface
 		&& !_variable.isCallableParameter()
+		&& !m_insideStruct
 	)
 		m_errorReporter.typeError(_variable.location(), "Variables cannot be declared in interfaces.");
 
@@ -1626,10 +1631,13 @@ bool TypeChecker::visit(FunctionCall const& _functionCall)
 		else
 		{
 			TypePointer const& argType = type(*arguments.front());
+			// Resulting data location is memory unless we are converting from a reference
+			// type with a different data location.
+			// (data location cannot yet be specified for type conversions)
+			DataLocation dataLoc = DataLocation::Memory;
 			if (auto argRefType = dynamic_cast<ReferenceType const*>(argType.get()))
-				// do not change the data location when converting
-				// (data location cannot yet be specified for type conversions)
-				resultType = ReferenceType::copyForLocationIfReference(argRefType->location(), resultType);
+				dataLoc = argRefType->location();
+			resultType = ReferenceType::copyForLocationIfReference(dataLoc, resultType);
 			if (!argType->isExplicitlyConvertibleTo(*resultType))
 				m_errorReporter.typeError(
 					_functionCall.location(),
@@ -2348,22 +2356,6 @@ void TypeChecker::expectType(Expression const& _expression, Type const& _expecte
 				"."
 			);
 	}
-
-	if (
-		type(_expression)->category() == Type::Category::RationalNumber &&
-		_expectedType.category() == Type::Category::FixedBytes
-	)
-	{
-		auto literal = dynamic_cast<Literal const*>(&_expression);
-
-		if (literal && !literal->isHexNumber())
-			m_errorReporter.warning(
-				_expression.location(),
-				"Decimal literal assigned to bytesXX variable will be left-aligned. "
-				"Use an explicit conversion to silence this warning."
-			);
-	}
-
 }
 
 void TypeChecker::requireLValue(Expression const& _expression)
diff --git a/libsolidity/analysis/TypeChecker.h b/libsolidity/analysis/TypeChecker.h
index b696de85..ed316f9c 100644
--- a/libsolidity/analysis/TypeChecker.h
+++ b/libsolidity/analysis/TypeChecker.h
@@ -149,6 +149,9 @@ private:
 	/// Flag indicating whether we are currently inside an EmitStatement.
 	bool m_insideEmitStatement = false;
 
+	/// Flag indicating whether we are currently inside a StructDefinition.
+	bool m_insideStruct = false;
+
 	ErrorReporter& m_errorReporter;
 };
 
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 5368e9c2..0d69ae1a 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -355,13 +355,7 @@ TypePointer Type::forLiteral(Literal const& _literal)
 	case Token::FalseLiteral:
 		return make_shared<BoolType>();
 	case Token::Number:
-	{
-		tuple<bool, rational> validLiteral = RationalNumberType::isValidLiteral(_literal);
-		if (get<0>(validLiteral) == true)
-			return make_shared<RationalNumberType>(get<1>(validLiteral));
-		else
-			return TypePointer();
-	}
+		return RationalNumberType::forLiteral(_literal);
 	case Token::StringLiteral:
 		return make_shared<StringLiteralType>(_literal);
 	default:
@@ -779,6 +773,30 @@ tuple<bool, rational> RationalNumberType::parseRational(string const& _value)
 	}
 }
 
+TypePointer RationalNumberType::forLiteral(Literal const& _literal)
+{
+	solAssert(_literal.token() == Token::Number, "");
+	tuple<bool, rational> validLiteral = isValidLiteral(_literal);
+	if (get<0>(validLiteral))
+	{
+		TypePointer compatibleBytesType;
+		if (_literal.isHexNumber())
+		{
+			size_t digitCount = count_if(
+				_literal.value().begin() + 2, // skip "0x"
+				_literal.value().end(),
+				[](unsigned char _c) -> bool { return isxdigit(_c); }
+			);
+			// require even number of digits
+			if (!(digitCount & 1))
+				compatibleBytesType = make_shared<FixedBytesType>(digitCount / 2);
+		}
+
+		return make_shared<RationalNumberType>(get<1>(validLiteral), compatibleBytesType);
+	}
+	return TypePointer();
+}
+
 tuple<bool, rational> RationalNumberType::isValidLiteral(Literal const& _literal)
 {
 	rational value;
@@ -918,14 +936,7 @@ bool RationalNumberType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 		return false;
 	}
 	case Category::FixedBytes:
-	{
-		FixedBytesType const& fixedBytes = dynamic_cast<FixedBytesType const&>(_convertTo);
-		if (isFractional())
-			return false;
-		if (integerType())
-			return fixedBytes.numBytes() * 8 >= integerType()->numBits();
-		return false;
-	}
+		return (m_value == rational(0)) || (m_compatibleBytesType && *m_compatibleBytesType == _convertTo);
 	default:
 		return false;
 	}
@@ -933,11 +944,15 @@ bool RationalNumberType::isImplicitlyConvertibleTo(Type const& _convertTo) const
 
 bool RationalNumberType::isExplicitlyConvertibleTo(Type const& _convertTo) const
 {
-	TypePointer mobType = mobileType();
-	return
-		(mobType && mobType->isExplicitlyConvertibleTo(_convertTo)) ||
-		(!isFractional() && _convertTo.category() == Category::FixedBytes)
-	;
+	if (isImplicitlyConvertibleTo(_convertTo))
+		return true;
+	else if (_convertTo.category() != Category::FixedBytes)
+	{
+		TypePointer mobType = mobileType();
+		return (mobType && mobType->isExplicitlyConvertibleTo(_convertTo));
+	}
+	else
+		return false;
 }
 
 TypePointer RationalNumberType::unaryOperatorResult(Token::Value _operator) const
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index 3b57109d..8bae3d41 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -423,12 +423,12 @@ public:
 
 	virtual Category category() const override { return Category::RationalNumber; }
 
-	/// @returns true if the literal is a valid integer.
-	static std::tuple<bool, rational> isValidLiteral(Literal const& _literal);
+	static TypePointer forLiteral(Literal const& _literal);
 
-	explicit RationalNumberType(rational const& _value):
-		m_value(_value)
+	explicit RationalNumberType(rational const& _value, TypePointer const& _compatibleBytesType = TypePointer()):
+		m_value(_value), m_compatibleBytesType(_compatibleBytesType)
 	{}
+
 	virtual bool isImplicitlyConvertibleTo(Type const& _convertTo) const override;
 	virtual bool isExplicitlyConvertibleTo(Type const& _convertTo) const override;
 	virtual TypePointer unaryOperatorResult(Token::Value _operator) const override;
@@ -462,6 +462,13 @@ public:
 private:
 	rational m_value;
 
+	/// Bytes type to which the rational can be explicitly converted.
+	/// Empty for all rationals that are not directly parsed from hex literals.
+	TypePointer m_compatibleBytesType;
+
+	/// @returns true if the literal is a valid integer.
+	static std::tuple<bool, rational> isValidLiteral(Literal const& _literal);
+
 	/// @returns true if the literal is a valid rational number.
 	static std::tuple<bool, rational> parseRational(std::string const& _value);
 
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 836e30d2..e800b278 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -58,22 +58,31 @@ using namespace std;
 using namespace dev;
 using namespace dev::solidity;
 
-void CompilerStack::setRemappings(vector<string> const& _remappings)
+boost::optional<CompilerStack::Remapping> CompilerStack::parseRemapping(string const& _remapping)
+{
+	auto eq = find(_remapping.begin(), _remapping.end(), '=');
+	if (eq == _remapping.end())
+		return {};
+
+	auto colon = find(_remapping.begin(), eq, ':');
+
+	Remapping r;
+
+	r.context = colon == eq ? string() : string(_remapping.begin(), colon);
+	r.prefix = colon == eq ? string(_remapping.begin(), eq) : string(colon + 1, eq);
+	r.target = string(eq + 1, _remapping.end());
+
+	if (r.prefix.empty())
+		return {};
+
+	return r;
+}
+
+void CompilerStack::setRemappings(vector<Remapping> const& _remappings)
 {
-	vector<Remapping> remappings;
 	for (auto const& remapping: _remappings)
-	{
-		auto eq = find(remapping.begin(), remapping.end(), '=');
-		if (eq == remapping.end())
-			continue; // ignore
-		auto colon = find(remapping.begin(), eq, ':');
-		Remapping r;
-		r.context = colon == eq ? string() : string(remapping.begin(), colon);
-		r.prefix = colon == eq ? string(remapping.begin(), eq) : string(colon + 1, eq);
-		r.target = string(eq + 1, remapping.end());
-		remappings.push_back(r);
-	}
-	swap(m_remappings, remappings);
+		solAssert(!remapping.prefix.empty(), "");
+	m_remappings = _remappings;
 }
 
 void CompilerStack::setEVMVersion(EVMVersion _version)
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index 2234a8c9..9a15fbf0 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -84,6 +84,13 @@ public:
 		CompilationSuccessful
 	};
 
+	struct Remapping
+	{
+		std::string context;
+		std::string prefix;
+		std::string target;
+	};
+
 	/// Creates a new compiler stack.
 	/// @param _readFile callback to used to read files for import statements. Must return
 	/// and must not emit exceptions.
@@ -103,8 +110,11 @@ public:
 	/// All settings, with the exception of remappings, are reset.
 	void reset(bool _keepSources = false);
 
-	/// Sets path remappings in the format "context:prefix=target"
-	void setRemappings(std::vector<std::string> const& _remappings);
+	// Parses a remapping of the format "context:prefix=target".
+	static boost::optional<Remapping> parseRemapping(std::string const& _remapping);
+
+	/// Sets path remappings.
+	void setRemappings(std::vector<Remapping> const& _remappings);
 
 	/// Sets library addresses. Addresses are cleared iff @a _libraries is missing.
 	/// Will not take effect before running compile.
@@ -319,13 +329,6 @@ private:
 		FunctionDefinition const& _function
 	) const;
 
-	struct Remapping
-	{
-		std::string context;
-		std::string prefix;
-		std::string target;
-	};
-
 	ReadCallback::Callback m_readFile;
 	ReadCallback::Callback m_smtQuery;
 	bool m_optimize = false;
diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index 58b84163..c1996777 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -326,9 +326,14 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 		m_compilerStack.setEVMVersion(*version);
 	}
 
-	vector<string> remappings;
+	vector<CompilerStack::Remapping> remappings;
 	for (auto const& remapping: settings.get("remappings", Json::Value()))
-		remappings.push_back(remapping.asString());
+	{
+		if (auto r = CompilerStack::parseRemapping(remapping.asString()))
+			remappings.emplace_back(std::move(*r));
+		else
+			return formatFatalError("JSONError", "Invalid remapping: \"" + remapping.asString() + "\"");
+	}
 	m_compilerStack.setRemappings(remappings);
 
 	Json::Value optimizerSettings = settings.get("optimizer", Json::Value());