From 89a1e97e7dd8a9af5a5fe2c5530cf4217c79f43b Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Thu, 13 Jul 2017 01:07:23 +0100
Subject: Avoid cyclic imports in referencedSourceUnits

---
 libsolidity/ast/AST.cpp | 15 ++++++++++-----
 libsolidity/ast/AST.h   |  2 +-
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index a126e6ed..f4ab6491 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -84,16 +84,21 @@ SourceUnitAnnotation& SourceUnit::annotation() const
 	return dynamic_cast<SourceUnitAnnotation&>(*m_annotation);
 }
 
-set<SourceUnit const*> SourceUnit::referencedSourceUnits(bool _recurse) const
+set<SourceUnit const*> SourceUnit::referencedSourceUnits(bool _recurse, set<SourceUnit const*> _skipList) const
 {
 	set<SourceUnit const*> sourceUnits;
 	for (ImportDirective const* importDirective: filteredNodes<ImportDirective>(nodes()))
 	{
-		sourceUnits.insert(importDirective->annotation().sourceUnit);
-		if (_recurse)
+		auto const& sourceUnit = importDirective->annotation().sourceUnit;
+		if (!_skipList.count(sourceUnit))
 		{
-			set<SourceUnit const*> referencedSourceUnits = importDirective->annotation().sourceUnit->referencedSourceUnits(true);
-			sourceUnits.insert(referencedSourceUnits.begin(), referencedSourceUnits.end());
+			_skipList.insert(sourceUnit);
+			sourceUnits.insert(sourceUnit);
+			if (_recurse)
+			{
+				set<SourceUnit const*> referencedSourceUnits = sourceUnit->referencedSourceUnits(true, _skipList);
+				sourceUnits.insert(referencedSourceUnits.begin(), referencedSourceUnits.end());
+			}
 		}
 	}
 	return sourceUnits;
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index 2522867b..8012bcb4 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -137,7 +137,7 @@ public:
 	std::vector<ASTPointer<ASTNode>> nodes() const { return m_nodes; }
 
 	/// @returns a set of referenced SourceUnits. Recursively if @a _recurse is true.
-	std::set<SourceUnit const*> referencedSourceUnits(bool _recurse = false) const;
+	std::set<SourceUnit const*> referencedSourceUnits(bool _recurse = false, std::set<SourceUnit const*> _skipList = std::set<SourceUnit const*>()) const;
 
 private:
 	std::vector<ASTPointer<ASTNode>> m_nodes;
-- 
cgit