5 files changed, 34 insertions, 8 deletions

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index b276a2d4..1563467c 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1886,7 +1886,7 @@ void TypeChecker::expectType(Expression const& _expression, Type const& _expecte
 	{
 		auto literal = dynamic_cast<Literal const*>(&_expression);
 
-		if (literal && !boost::starts_with(literal->value(), "0x"))
+		if (literal && !literal->isHexNumber())
 			m_errorReporter.warning(
 				_expression.location(),
 				"Decimal literal assigned to bytesXX variable will be left-aligned. "
diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index b929b6fe..403f4b79 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -530,20 +530,26 @@ IdentifierAnnotation& Identifier::annotation() const
 	return dynamic_cast<IdentifierAnnotation&>(*m_annotation);
 }
 
+bool Literal::isHexNumber() const
+{
+	if (token() != Token::Number)
+		return false;
+	return boost::starts_with(value(), "0x");
+}
+
 bool Literal::looksLikeAddress() const
 {
 	if (subDenomination() != SubDenomination::None)
 		return false;
-	if (token() != Token::Number)
+
+	if (!isHexNumber())
 		return false;
 
-	string lit = value();
-	return lit.substr(0, 2) == "0x" && abs(int(lit.length()) - 42) <= 1;
+	return abs(int(value().length()) - 42) <= 1;
 }
 
 bool Literal::passesAddressChecksum() const
 {
-	string lit = value();
-	solAssert(lit.substr(0, 2) == "0x", "Expected hex prefix");
-	return dev::passesAddressChecksum(lit, true);
+	solAssert(isHexNumber(), "Expected hex number");
+	return dev::passesAddressChecksum(value(), true);
 }
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index 83572692..e8831dc0 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -1590,6 +1590,9 @@ public:
 
 	SubDenomination subDenomination() const { return m_subDenomination; }
 
+	/// @returns true if this is a number with a hex prefix.
+	bool isHexNumber() const;
+
 	/// @returns true if this looks like a checksummed address.
 	bool looksLikeAddress() const;
 	/// @returns true if it passes the address checksum test.
diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp
index 977a2c7c..74b07d4d 100644
--- a/libsolidity/codegen/ContractCompiler.cpp
+++ b/libsolidity/codegen/ContractCompiler.cpp
@@ -267,13 +267,19 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac
 	m_context << notFound;
 	if (fallback)
 	{
+		m_context.setStackOffset(0);
 		if (!fallback->isPayable())
 			appendCallValueCheck();
 
+		// Return tag is used to jump out of the function.
 		eth::AssemblyItem returnTag = m_context.pushNewTag();
 		fallback->accept(*this);
 		m_context << returnTag;
-		appendReturnValuePacker(FunctionType(*fallback).returnParameterTypes(), _contract.isLibrary());
+		solAssert(FunctionType(*fallback).parameterTypes().empty(), "");
+		solAssert(FunctionType(*fallback).returnParameterTypes().empty(), "");
+		// Return tag gets consumed.
+		m_context.adjustStackOffset(-1);
+		m_context << Instruction::STOP;
 	}
 	else
 		m_context.appendRevert();
@@ -285,16 +291,26 @@ void ContractCompiler::appendFunctionSelector(ContractDefinition const& _contrac
 		CompilerContext::LocationSetter locationSetter(m_context, functionType->declaration());
 
 		m_context << callDataUnpackerEntryPoints.at(it.first);
+		m_context.setStackOffset(0);
 		// We have to allow this for libraries, because value of the previous
 		// call is still visible in the delegatecall.
 		if (!functionType->isPayable() && !_contract.isLibrary())
 			appendCallValueCheck();
 
+		// Return tag is used to jump out of the function.
 		eth::AssemblyItem returnTag = m_context.pushNewTag();
+		// Parameter for calldataUnpacker
 		m_context << CompilerUtils::dataStartOffset;
 		appendCalldataUnpacker(functionType->parameterTypes());
 		m_context.appendJumpTo(m_context.functionEntryLabel(functionType->declaration()));
 		m_context << returnTag;
+		// Return tag and input parameters get consumed.
+		m_context.adjustStackOffset(
+			CompilerUtils(m_context).sizeOnStack(functionType->returnParameterTypes()) -
+			CompilerUtils(m_context).sizeOnStack(functionType->parameterTypes()) -
+			1
+		);
+		// Consumes the return parameters.
 		appendReturnValuePacker(functionType->returnParameterTypes(), _contract.isLibrary());
 	}
 }
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index a65549fd..9d4024c9 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -88,6 +88,7 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 	FunctionType accessorType(_varDecl);
 
 	TypePointers paramTypes = accessorType.parameterTypes();
+	m_context.adjustStackOffset(1 + CompilerUtils::sizeOnStack(paramTypes));
 
 	// retrieve the position of the variable
 	auto const& location = m_context.storageLocationOfVariable(_varDecl);