Yul: Introduces a block flattening pass + tests

libyul/optimiser/BlockFlattener.cpp

@@ -0,0 +1,41 @@
+/*
+	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/>.
+*/
+#include <libyul/optimiser/BlockFlattener.h>
+#include <libsolidity/inlineasm/AsmData.h>
+#include <libdevcore/Visitor.h>
+#include <libdevcore/CommonData.h>
+#include <functional>
+
+using namespace std;
+using namespace dev;
+using namespace dev::yul;
+
+void BlockFlattener::operator()(Block& _block)
+{
+	ASTModifier::operator()(_block);
+
+	iterateReplacing(
+		_block.statements,
+		[](Statement& _s) -> boost::optional<vector<Statement>>
+		{
+			if (_s.type() == typeid(Block))
+				return std::move(boost::get<Block>(_s).statements);
+			else
+				return {};
+		}
+	);
+}