Introduce JumpdestRemover optimisation step

1 files changed, 50 insertions, 0 deletions

diff --git a/libevmasm/JumpdestRemover.h b/libevmasm/JumpdestRemover.h
new file mode 100644
index 00000000..2dad0927
--- /dev/null
+++ b/libevmasm/JumpdestRemover.h
@@ -0,0 +1,50 @@
+/*
+	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/>.
+*/
+/**
+ * @author Alex Beregszaszi
+ * Removes unused JUMPDESTs.
+ */
+#pragma once
+
+#include <vector>
+#include <cstddef>
+#include <set>
+
+namespace dev
+{
+namespace eth
+{
+class AssemblyItem;
+using AssemblyItems = std::vector<AssemblyItem>;
+
+class JumpdestRemover
+{
+public:
+	explicit JumpdestRemover(AssemblyItems& _items): m_items(_items) {}
+
+	bool optimise(std::set<size_t> const& _tagsReferencedFromOutside);
+
+	/// @returns a set of all tags from the given sub-assembly that are referenced
+	/// from the given list of items.
+	static std::set<size_t> referencedTags(AssemblyItems const& _items, size_t _subId);
+
+private:
+	AssemblyItems& m_items;
+};
+
+}
+}