Handle externally supplied variables correctly in disambiguator.

2 files changed, 12 insertions, 3 deletions

diff --git a/libyul/optimiser/Disambiguator.cpp b/libyul/optimiser/Disambiguator.cpp
index af3507e1..dcba97c9 100644
--- a/libyul/optimiser/Disambiguator.cpp
+++ b/libyul/optimiser/Disambiguator.cpp
@@ -34,6 +34,9 @@ using Scope = dev::solidity::assembly::Scope;
 
 string Disambiguator::translateIdentifier(string const& _originalName)
 {
+	if ((m_externallyUsedIdentifiers.count(_originalName)))
+		return _originalName;
+
 	assertThrow(!m_scopes.empty() && m_scopes.back(), OptimizerException, "");
 	Scope::Identifier const* id = m_scopes.back()->lookup(_originalName);
 	assertThrow(id, OptimizerException, "");
diff --git a/libyul/optimiser/Disambiguator.h b/libyul/optimiser/Disambiguator.h
index 0829fd58..e16ebfbf 100644
--- a/libyul/optimiser/Disambiguator.h
+++ b/libyul/optimiser/Disambiguator.h
@@ -43,9 +43,14 @@ namespace yul
 class Disambiguator: public ASTCopier
 {
 public:
-	Disambiguator(solidity::assembly::AsmAnalysisInfo const& _analysisInfo):
-		m_info(_analysisInfo)
-	{}
+	explicit Disambiguator(
+		solidity::assembly::AsmAnalysisInfo const& _analysisInfo,
+		std::set<std::string> const& _externallyUsedIdentifiers = {}
+	):
+		m_info(_analysisInfo), m_externallyUsedIdentifiers(_externallyUsedIdentifiers)
+	{
+		m_nameDispenser.m_usedNames = m_externallyUsedIdentifiers;
+	}
 
 protected:
 	virtual void enterScope(Block const& _block) override;
@@ -58,6 +63,7 @@ protected:
 	void leaveScopeInternal(solidity::assembly::Scope& _scope);
 
 	solidity::assembly::AsmAnalysisInfo const& m_info;
+	std::set<std::string> const& m_externallyUsedIdentifiers;
 
 	std::vector<solidity::assembly::Scope*> m_scopes;
 	std::map<void const*, std::string> m_translations;