Merge pull request #5416 from ethereum/develop

Merge develop into release for 0.5.0

1 files changed, 86 insertions, 0 deletions

diff --git a/libyul/optimiser/NameCollector.h b/libyul/optimiser/NameCollector.h
new file mode 100644
index 00000000..b76eec30
--- /dev/null
+++ b/libyul/optimiser/NameCollector.h
@@ -0,0 +1,86 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Specific AST walkers that collect facts about identifiers and definitions.
+ */
+
+#pragma once
+
+#include <libyul/optimiser/ASTWalker.h>
+
+#include <map>
+#include <set>
+
+namespace dev
+{
+namespace yul
+{
+
+/**
+ * Specific AST walker that collects all defined names.
+ */
+class NameCollector: public ASTWalker
+{
+public:
+	explicit NameCollector(Block const& _block)
+	{
+		(*this)(_block);
+	}
+
+	using ASTWalker::operator ();
+	virtual void operator()(VariableDeclaration const& _varDecl) override;
+	virtual void operator()(FunctionDefinition const& _funDef) override;
+
+	std::set<YulString> names() const { return m_names; }
+private:
+	std::set<YulString> m_names;
+};
+
+/**
+ * Specific AST walker that counts all references to all declarations.
+ */
+class ReferencesCounter: public ASTWalker
+{
+public:
+	using ASTWalker::operator ();
+	virtual void operator()(Identifier const& _identifier);
+	virtual void operator()(FunctionCall const& _funCall);
+
+	static std::map<YulString, size_t> countReferences(Block const& _block);
+	static std::map<YulString, size_t> countReferences(Expression const& _expression);
+
+	std::map<YulString, size_t> const& references() const { return m_references; }
+private:
+	std::map<YulString, size_t> m_references;
+};
+
+/**
+ * Specific AST walker that finds all variables that are assigned to.
+ */
+class Assignments: public ASTWalker
+{
+public:
+	using ASTWalker::operator ();
+	virtual void operator()(Assignment const& _assignment) override;
+
+	std::set<YulString> const& names() const { return m_names; }
+private:
+	std::set<YulString> m_names;
+};
+
+}
+}