added compile time check for out of bounds access for ordinary arrays

todo: check for dynamicaly sized arrays

Conflicts:
	libsolidity/ExpressionCompiler.cpp

1 files changed, 14 insertions, 0 deletions

diff --git a/libsolidity/ExpressionCompiler.cpp b/libsolidity/ExpressionCompiler.cpp
index b22a78dc..06cccc24 100644
--- a/libsolidity/ExpressionCompiler.cpp
+++ b/libsolidity/ExpressionCompiler.cpp
@@ -821,6 +821,8 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
 	_indexAccess.baseExpression().accept(*this);
 
 	Type const& baseType = *_indexAccess.baseExpression().type();
+	Type const& indexType = *_indexAccess.indexExpression()->type();
+
 	if (baseType.category() == Type::Category::Mapping)
 	{
 		// stack: storage_base_ref
@@ -861,8 +863,20 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
 		solAssert(_indexAccess.indexExpression(), "Index expression expected.");
 
 		_indexAccess.indexExpression()->accept(*this);
+
+		// check for dynamically sized arrays should be done after memberAccess visit to have length
+		if (
+			(indexType.category() == Type::Category::IntegerConstant) &&
+				((arrayType.isDynamicallySized() && arrayType.length()) || !arrayType.isDynamicallySized()))
+		{
+			IntegerConstantType const& constant = dynamic_cast<IntegerConstantType const&>(indexType);
+			if (arrayType.length() < constant.literalValue(nullptr))
+				BOOST_THROW_EXCEPTION(CompilerError() << errinfo_comment("Out of bounds access."));
+		}
+
 		// stack layout: <base_ref> [<length>] <index>
 		ArrayUtils(m_context).accessIndex(arrayType);
+
 		switch (arrayType.location())
 		{
 		case DataLocation::Storage: