1 files changed, 15 insertions, 0 deletions
diff --git a/libsolidity/codegen/CompilerContext.cpp b/libsolidity/codegen/CompilerContext.cpp
index 9d0d6d37..6875bda1 100644
--- a/libsolidity/codegen/CompilerContext.cpp
+++ b/libsolidity/codegen/CompilerContext.cpp
@@ -124,6 +124,7 @@ void CompilerContext::addVariable(VariableDeclaration const& _declaration,
 								  unsigned _offsetToCurrent)
 {
 	solAssert(m_asm->deposit() >= 0 && unsigned(m_asm->deposit()) >= _offsetToCurrent, "");
+	solAssert(m_localVariables.count(&_declaration) == 0, "Variable already present");
 	m_localVariables[&_declaration] = unsigned(m_asm->deposit()) - _offsetToCurrent;
 }
 
@@ -244,6 +245,20 @@ CompilerContext& CompilerContext::appendConditionalInvalid()
 	return *this;
 }
 
+CompilerContext& CompilerContext::appendRevert()
+{
+	return *this << u256(0) << u256(0) << Instruction::REVERT;
+}
+
+CompilerContext& CompilerContext::appendConditionalRevert()
+{
+	*this << Instruction::ISZERO;
+	eth::AssemblyItem afterTag = appendConditionalJump();
+	appendRevert();
+	*this << afterTag;
+	return *this;
+}
+
 void CompilerContext::resetVisitedNodes(ASTNode const* _node)
 {
 	stack<ASTNode const*> newStack;