Implementation of index access.

4 files changed, 74 insertions, 27 deletions

diff --git a/CompilerContext.cpp b/CompilerContext.cpp
index 01a71d7c..8d32a1a5 100644
--- a/CompilerContext.cpp
+++ b/CompilerContext.cpp
@@ -40,7 +40,12 @@ void CompilerContext::addMagicGlobal(MagicVariableDeclaration const& _declaratio
 void CompilerContext::addStateVariable(VariableDeclaration const& _declaration)
 {
 	m_stateVariables[&_declaration] = m_stateVariablesSize;
-	m_stateVariablesSize += _declaration.getType()->getStorageSize();
+	bigint newSize = bigint(m_stateVariablesSize) + _declaration.getType()->getStorageSize();
+	if (newSize >= bigint(1) << 256)
+		BOOST_THROW_EXCEPTION(TypeError()
+			<< errinfo_comment("State variable does not fit in storage.")
+			<< errinfo_sourceLocation(_declaration.getLocation()));
+	m_stateVariablesSize = u256(newSize);
 }
 
 void CompilerContext::startFunction(Declaration const& _function)
diff --git a/ExpressionCompiler.cpp b/ExpressionCompiler.cpp
index 94f65b93..dcd411c3 100644
--- a/ExpressionCompiler.cpp
+++ b/ExpressionCompiler.cpp
@@ -534,19 +534,24 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 	{
 		solAssert(member == "length", "Illegal array member.");
 		auto const& type = dynamic_cast<ArrayType const&>(*_memberAccess.getExpression().getType());
-		solAssert(type.isByteArray(), "Non byte arrays not yet implemented here.");
-		switch (type.getLocation())
+		if (!type.isDynamicallySized())
 		{
-		case ArrayType::Location::CallData:
-			m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
-			break;
-		case ArrayType::Location::Storage:
-			m_context << eth::Instruction::SLOAD;
-			break;
-		default:
-			solAssert(false, "Unsupported array location.");
-			break;
+			CompilerUtils(m_context).popStackElement(type);
+			m_context << type.getLength();
 		}
+		else
+			switch (type.getLocation())
+			{
+			case ArrayType::Location::CallData:
+				m_context << eth::Instruction::SWAP1 << eth::Instruction::POP;
+				break;
+			case ArrayType::Location::Storage:
+				m_context << eth::Instruction::SLOAD;
+				break;
+			default:
+				solAssert(false, "Unsupported array location.");
+				break;
+			}
 		break;
 	}
 	default:
@@ -559,19 +564,40 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
 	_indexAccess.getBaseExpression().accept(*this);
 
 	Type const& baseType = *_indexAccess.getBaseExpression().getType();
-	solAssert(baseType.getCategory() == Type::Category::Mapping, "");
-	Type const& keyType = *dynamic_cast<MappingType const&>(baseType).getKeyType();
-	m_context << u256(0);
-	solAssert(_indexAccess.getIndexExpression(), "Index expression expected.");
-	appendExpressionCopyToMemory(keyType, *_indexAccess.getIndexExpression());
-	solAssert(baseType.getSizeOnStack() == 1,
-			  "Unexpected: Not exactly one stack slot taken by subscriptable expression.");
-	m_context << eth::Instruction::SWAP1;
-	appendTypeMoveToMemory(IntegerType(256));
-	m_context << u256(0) << eth::Instruction::SHA3;
-
-	m_currentLValue = LValue(m_context, LValue::LValueType::Storage, _indexAccess.getType());
-	m_currentLValue.retrieveValueIfLValueNotRequested(_indexAccess);
+	if (baseType.getCategory() == Type::Category::Mapping)
+	{
+		Type const& keyType = *dynamic_cast<MappingType const&>(baseType).getKeyType();
+		m_context << u256(0);
+		solAssert(_indexAccess.getIndexExpression(), "Index expression expected.");
+		appendExpressionCopyToMemory(keyType, *_indexAccess.getIndexExpression());
+		solAssert(baseType.getSizeOnStack() == 1,
+				  "Unexpected: Not exactly one stack slot taken by subscriptable expression.");
+		m_context << eth::Instruction::SWAP1;
+		appendTypeMoveToMemory(IntegerType(256));
+		m_context << u256(0) << eth::Instruction::SHA3;
+		m_currentLValue = LValue(m_context, LValue::LValueType::Storage, _indexAccess.getType());
+		m_currentLValue.retrieveValueIfLValueNotRequested(_indexAccess);
+	}
+	else if (baseType.getCategory() == Type::Category::Array)
+	{
+		ArrayType const& arrayType = dynamic_cast<ArrayType const&>(baseType);
+		solAssert(arrayType.getLocation() == ArrayType::Location::Storage,
+			"TODO: Index acces only implemented for storage arrays.");
+		solAssert(!arrayType.isDynamicallySized(),
+			"TODO: Index acces only implemented for fixed-size arrays.");
+		solAssert(!arrayType.isByteArray(),
+			"TODO: Index acces not implemented for byte arrays.");
+		solAssert(_indexAccess.getIndexExpression(), "Index expression expected.");
+		// TODO: for dynamically-sized arrays, update the length for each write
+		// TODO: do we want to check the index?
+		_indexAccess.getIndexExpression()->accept(*this);
+		m_context << arrayType.getBaseType()->getStorageSize() << eth::Instruction::MUL
+			<< eth::Instruction::ADD;
+		m_currentLValue = LValue(m_context, LValue::LValueType::Storage, _indexAccess.getType());
+		m_currentLValue.retrieveValueIfLValueNotRequested(_indexAccess);
+	}
+	else
+		solAssert(false, "Index access only allowed for mappings or arrays.");
 
 	return false;
 }
diff --git a/Types.cpp b/Types.cpp
index c0be0d93..adcd2e54 100644
--- a/Types.cpp
+++ b/Types.cpp
@@ -555,6 +555,19 @@ bool ArrayType::operator==(Type const& _other) const
 	return other.m_location == m_location;
 }
 
+u256 ArrayType::getStorageSize() const
+{
+	if (isDynamicallySized())
+		return 1;
+	else
+	{
+		bigint size = bigint(getLength()) * getBaseType()->getStorageSize();
+		if (size >= bigint(1) << 256)
+			BOOST_THROW_EXCEPTION(TypeError() << errinfo_comment("Array too large for storage."));
+		return max<u256>(1, u256(size));
+	}
+}
+
 unsigned ArrayType::getSizeOnStack() const
 {
 	if (m_location == Location::CallData)
@@ -665,10 +678,12 @@ bool StructType::operator==(Type const& _other) const
 
 u256 StructType::getStorageSize() const
 {
-	u256 size = 0;
+	bigint size = 0;
 	for (pair<string, TypePointer> const& member: getMembers())
 		size += member.second->getStorageSize();
-	return max<u256>(1, size);
+	if (size >= bigint(1) << 256)
+		BOOST_THROW_EXCEPTION(TypeError() << errinfo_comment("Struct too large for storage."));
+	return max<u256>(1, u256(size));
 }
 
 bool StructType::canLiveOutsideStorage() const
diff --git a/Types.h b/Types.h
index 0d24b722..9961f03a 100644
--- a/Types.h
+++ b/Types.h
@@ -303,6 +303,7 @@ public:
 	virtual TypePointer unaryOperatorResult(Token::Value _operator) const override;
 	virtual bool operator==(const Type& _other) const override;
 	virtual bool isDynamicallySized() const { return m_hasDynamicLength; }
+	virtual u256 getStorageSize() const override;
 	virtual unsigned getSizeOnStack() const override;
 	virtual std::string toString() const override;
 	virtual MemberList const& getMembers() const override { return s_arrayTypeMemberList; }