Index access for bytesXX.

4 files changed, 50 insertions, 0 deletions

diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index 0d74ddba..756f0e4f 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -1253,6 +1253,8 @@ bool TypeChecker::visit(MemberAccess const& _memberAccess)
 			arrayType.isDynamicallySized()
 		);
 	}
+	else if (exprType->category() == Type::Category::FixedBytes)
+		annotation.isLValue = false;
 
 	return false;
 }
@@ -1317,6 +1319,22 @@ bool TypeChecker::visit(IndexAccess const& _access)
 		}
 		break;
 	}
+	case Type::Category::FixedBytes:
+	{
+		FixedBytesType const& bytesType = dynamic_cast<FixedBytesType const&>(*baseType);
+		if (!index)
+			typeError(_access.location(), "Index expression cannot be omitted.");
+		else
+		{
+			expectType(*index, IntegerType(256));
+			if (auto integerType = dynamic_cast<IntegerConstantType const*>(type(*index).get()))
+				if (bytesType.numBytes() <= integerType->literalValue(nullptr))
+					typeError(_access.location(), "Out of bounds array access.");
+		}
+		resultType = make_shared<FixedBytesType>(1);
+		isLValue = false; // @todo this heavily depends on how it is embedded
+		break;
+	}
 	default:
 		fatalTypeError(
 			_access.baseExpression().location(),
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 79e5bb02..01d1cb37 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -638,6 +638,11 @@ TypePointer FixedBytesType::binaryOperatorResult(Token::Value _operator, TypePoi
 	return TypePointer();
 }
 
+MemberList::MemberMap FixedBytesType::nativeMembers(const ContractDefinition*) const
+{
+	return MemberList::MemberMap{MemberList::Member{"length", make_shared<IntegerType>(8)}};
+}
+
 bool FixedBytesType::operator==(Type const& _other) const
 {
 	if (_other.category() != category())
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index 723d633b..90a0509b 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -399,6 +399,7 @@ public:
 	virtual bool isValueType() const override { return true; }
 
 	virtual std::string toString(bool) const override { return "bytes" + dev::toString(m_bytes); }
+	virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
 	virtual TypePointer encodingType() const override { return shared_from_this(); }
 	virtual TypePointer interfaceType(bool) const override { return shared_from_this(); }
 
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 9536c727..58db07b1 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -1004,6 +1004,16 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 			solAssert(false, "Illegal array member.");
 		break;
 	}
+	case Type::Category::FixedBytes:
+	{
+		auto const& type = dynamic_cast<FixedBytesType const&>(*_memberAccess.expression().annotation().type);
+		utils().popStackElement(type);
+		if (member == "length")
+			m_context << u256(type.numBytes());
+		else
+			solAssert(false, "Illegal fixed bytes member.");
+		break;
+	}
 	default:
 		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Member access to unknown type."));
 	}
@@ -1085,6 +1095,22 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
 			break;
 		}
 	}
+	else if (baseType.category() == Type::Category::FixedBytes)
+	{
+		FixedBytesType const& fixedBytesType = dynamic_cast<FixedBytesType const&>(baseType);
+		solAssert(_indexAccess.indexExpression(), "Index expression expected.");
+
+		_indexAccess.indexExpression()->accept(*this);
+		// stack layout: <value> <index>
+		// check out-of-bounds access
+		m_context << u256(fixedBytesType.numBytes());
+		m_context << eth::Instruction::DUP2 << eth::Instruction::LT << eth::Instruction::ISZERO;
+		// out-of-bounds access throws exception
+		m_context.appendConditionalJumpTo(m_context.errorTag());
+
+		m_context << eth::Instruction::BYTE;
+		m_context << (u256(1) << (256 - 8)) << eth::Instruction::MUL;
+	}
 	else if (baseType.category() == Type::Category::TypeType)
 	{
 		solAssert(baseType.sizeOnStack() == 0, "");