Name displacer.

libyul/optimiser/NameDisplacer.cpp

@@ -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/>.
+*/
+/**
+ * Optimiser component that renames identifiers to free up certain names.
+ */
+
+#include <libyul/optimiser/NameDisplacer.h>
+
+#include <libyul/AsmData.h>
+
+
+using namespace std;
+using namespace dev;
+using namespace yul;
+
+void NameDisplacer::operator()(Identifier& _identifier)
+{
+	checkAndReplace(_identifier.name);
+}
+
+void NameDisplacer::operator()(VariableDeclaration& _varDecl)
+{
+	for (TypedName& var: _varDecl.variables)
+		checkAndReplaceNew(var.name);
+
+	ASTModifier::operator()(_varDecl);
+}
+
+void NameDisplacer::operator()(FunctionDefinition& _function)
+{
+	// Should have been done in the block already.
+	yulAssert(!m_namesToFree.count(_function.name), "");
+
+	for (auto& param: _function.parameters)
+		checkAndReplaceNew(param.name);
+	for (auto& retVar: _function.returnVariables)
+		checkAndReplaceNew(retVar.name);
+
+	ASTModifier::operator()(_function);
+}
+
+void NameDisplacer::operator()(FunctionCall& _funCall)
+{
+	checkAndReplace(_funCall.functionName.name);
+	ASTModifier::operator()(_funCall);
+}
+
+void NameDisplacer::operator()(Block& _block)
+{
+	// First replace all the names of function definitions
+	// because of scoping.
+	for (auto& st: _block.statements)
+		if (st.type() == typeid(FunctionDefinition))
+			checkAndReplaceNew(boost::get<FunctionDefinition>(st).name);
+
+	ASTModifier::operator()(_block);
+}
+
+void NameDisplacer::checkAndReplaceNew(YulString& _name)
+{
+	yulAssert(!m_translations.count(_name), "");
+	if (m_namesToFree.count(_name))
+		_name = (m_translations[_name] = m_nameDispenser.newName(_name));
+}
+
+void NameDisplacer::checkAndReplace(YulString& _name) const
+{
+	if (m_translations.count(_name))
+		_name = m_translations.at(_name);
+	yulAssert(!m_namesToFree.count(_name), "");
+}
+