Limit size of generated names and add convenience constructors.

1 files changed, 24 insertions, 2 deletions

diff --git a/libyul/optimiser/NameDispenser.h b/libyul/optimiser/NameDispenser.h
index 64ec318f..5fbf5f8e 100644
--- a/libyul/optimiser/NameDispenser.h
+++ b/libyul/optimiser/NameDispenser.h
@@ -19,6 +19,8 @@
  */
 #pragma once
 
+#include <libyul/ASTDataForward.h>
+
 #include <set>
 #include <string>
 
@@ -27,9 +29,29 @@ namespace dev
 namespace yul
 {
 
-struct NameDispenser
+/**
+ * Optimizer component that can be used to generate new names that
+ * do not conflict with existing names.
+ *
+ * Tries to keep names short and appends decimals to disambiguate.
+ */
+class NameDispenser
 {
-	std::string newName(std::string const& _prefix);
+public:
+	/// Initialize the name dispenser with all the names used in the given AST.
+	explicit NameDispenser(Block const& _ast);
+	/// Initialize the name dispenser with the given used names.
+	explicit NameDispenser(std::set<std::string> _usedNames);
+
+	/// @returns a currently unused name that should be similar to _nameHint
+	/// and prefixed by _context if present.
+	/// If the resulting name would be too long, trims the context at the end
+	/// and the name hint at the start.
+	std::string newName(std::string const& _nameHint, std::string const& _context = {});
+
+private:
+	std::string newNameInternal(std::string const& _nameHint);
+
 	std::set<std::string> m_usedNames;
 };