1 files changed, 156 insertions, 37 deletions
diff --git a/libyul/optimiser/SyntacticalEquality.cpp b/libyul/optimiser/SyntacticalEquality.cpp
index 99ce06e5..ba8cc793 100644
--- a/libyul/optimiser/SyntacticalEquality.cpp
+++ b/libyul/optimiser/SyntacticalEquality.cpp
@@ -22,6 +22,7 @@
 
 #include <libyul/Exceptions.h>
 #include <libyul/AsmData.h>
+#include <libyul/Utilities.h>
 
 #include <libdevcore/CommonData.h>
 
@@ -29,48 +30,166 @@ using namespace std;
 using namespace dev;
 using namespace yul;
 
-bool SyntacticalEqualityChecker::equal(Expression const& _e1, Expression const& _e2)
+bool SyntacticallyEqual::operator()(Expression const& _lhs, Expression const& _rhs)
 {
-	if (_e1.type() != _e2.type())
+	return boost::apply_visitor([this](auto&& _lhsExpr, auto&& _rhsExpr) -> bool {
+		// ``this->`` is redundant, but required to work around a bug present in gcc 6.x.
+		return this->expressionEqual(_lhsExpr, _rhsExpr);
+	}, _lhs, _rhs);
+}
+
+bool SyntacticallyEqual::operator()(Statement const& _lhs, Statement const& _rhs)
+{
+	return boost::apply_visitor([this](auto&& _lhsStmt, auto&& _rhsStmt) -> bool {
+		// ``this->`` is redundant, but required to work around a bug present in gcc 6.x.
+		return this->statementEqual(_lhsStmt, _rhsStmt);
+	}, _lhs, _rhs);
+}
+
+bool SyntacticallyEqual::expressionEqual(FunctionalInstruction const& _lhs, FunctionalInstruction const& _rhs)
+{
+	return
+		_lhs.instruction == _rhs.instruction &&
+		containerEqual(_lhs.arguments, _rhs.arguments, [this](Expression const& _lhsExpr, Expression const& _rhsExpr) -> bool {
+			return (*this)(_lhsExpr, _rhsExpr);
+		});
+}
+
+bool SyntacticallyEqual::expressionEqual(FunctionCall const& _lhs, FunctionCall const& _rhs)
+{
+	return
+		expressionEqual(_lhs.functionName, _rhs.functionName) &&
+		containerEqual(_lhs.arguments, _rhs.arguments, [this](Expression const& _lhsExpr, Expression const& _rhsExpr) -> bool {
+			return (*this)(_lhsExpr, _rhsExpr);
+		});
+}
+
+bool SyntacticallyEqual::expressionEqual(Identifier const& _lhs, Identifier const& _rhs)
+{
+	auto lhsIt = m_identifiersLHS.find(_lhs.name);
+	auto rhsIt = m_identifiersRHS.find(_rhs.name);
+	return
+		(lhsIt == m_identifiersLHS.end() && rhsIt == m_identifiersRHS.end() && _lhs.name == _rhs.name) ||
+		(lhsIt != m_identifiersLHS.end() && rhsIt != m_identifiersRHS.end() && lhsIt->second == rhsIt->second);
+}
+bool SyntacticallyEqual::expressionEqual(Literal const& _lhs, Literal const& _rhs)
+{
+	if (_lhs.kind != _rhs.kind || _lhs.type != _rhs.type)
 		return false;
-	// TODO This somehow calls strcmp - WHERE?
-
-	// TODO This should be replaced by some kind of AST walker as soon as it gets
-	// more complex.
-	if (_e1.type() == typeid(FunctionalInstruction))
-	{
-		auto const& e1 = boost::get<FunctionalInstruction>(_e1);
-		auto const& e2 = boost::get<FunctionalInstruction>(_e2);
-		return
-			e1.instruction == e2.instruction &&
-			equalVector(e1.arguments, e2.arguments);
-	}
-	else if (_e1.type() == typeid(FunctionCall))
-	{
-		auto const& e1 = boost::get<FunctionCall>(_e1);
-		auto const& e2 = boost::get<FunctionCall>(_e2);
-		return
-			equal(e1.functionName, e2.functionName) &&
-			equalVector(e1.arguments, e2.arguments);
-	}
-	else if (_e1.type() == typeid(Identifier))
-		return boost::get<Identifier>(_e1).name == boost::get<Identifier>(_e2).name;
-	else if (_e1.type() == typeid(Literal))
-	{
-		auto const& e1 = boost::get<Literal>(_e1);
-		auto const& e2 = boost::get<Literal>(_e2);
-		return e1.kind == e2.kind && e1.value == e2.value && e1.type == e2.type;
-	}
+	if (_lhs.kind == LiteralKind::Number)
+		return valueOfNumberLiteral(_lhs) == valueOfNumberLiteral(_rhs);
 	else
-	{
-		assertThrow(false, OptimizerException, "Invalid expression");
-	}
-	return false;
+		return _lhs.value == _rhs.value;
 }
 
-bool SyntacticalEqualityChecker::equalVector(vector<Expression> const& _e1, vector<Expression> const& _e2)
+bool SyntacticallyEqual::statementEqual(ExpressionStatement const& _lhs, ExpressionStatement const& _rhs)
 {
-	return _e1.size() == _e2.size() &&
-		std::equal(begin(_e1), end(_e1), begin(_e2), SyntacticalEqualityChecker::equal);
+	return (*this)(_lhs.expression, _rhs.expression);
+}
+bool SyntacticallyEqual::statementEqual(Assignment const& _lhs, Assignment const& _rhs)
+{
+	return containerEqual(
+		_lhs.variableNames,
+		_rhs.variableNames,
+		[this](Identifier const& _lhsVarName, Identifier const& _rhsVarName) -> bool {
+			return this->expressionEqual(_lhsVarName, _rhsVarName);
+		}
+	) && (*this)(*_lhs.value, *_rhs.value);
+}
+
+bool SyntacticallyEqual::statementEqual(VariableDeclaration const& _lhs, VariableDeclaration const& _rhs)
+{
+	// first visit expression, then variable declarations
+	if (!compareSharedPtr<Expression, &SyntacticallyEqual::operator()>(_lhs.value, _rhs.value))
+		return false;
+	return containerEqual(_lhs.variables, _rhs.variables, [this](TypedName const& _lhsVarName, TypedName const& _rhsVarName) -> bool {
+		return this->visitDeclaration(_lhsVarName, _rhsVarName);
+	});
+}
 
+bool SyntacticallyEqual::statementEqual(FunctionDefinition const& _lhs, FunctionDefinition const& _rhs)
+{
+	auto compare = [this](TypedName const& _lhsVarName, TypedName const& _rhsVarName) -> bool {
+		return this->visitDeclaration(_lhsVarName, _rhsVarName);
+	};
+	// first visit parameter declarations, then body
+	if (!containerEqual(_lhs.parameters, _rhs.parameters, compare))
+		return false;
+	if (!containerEqual(_lhs.returnVariables, _rhs.returnVariables, compare))
+		return false;
+	return statementEqual(_lhs.body, _rhs.body);
+}
+
+bool SyntacticallyEqual::statementEqual(If const& _lhs, If const& _rhs)
+{
+	return
+		compareSharedPtr<Expression, &SyntacticallyEqual::operator()>(_lhs.condition, _rhs.condition) &&
+		statementEqual(_lhs.body, _rhs.body);
+}
+
+bool SyntacticallyEqual::statementEqual(Switch const& _lhs, Switch const& _rhs)
+{
+	static auto const sortCasesByValue = [](Case const* _lhsCase, Case const* _rhsCase) -> bool {
+		return Less<Literal*>{}(_lhsCase->value.get(), _rhsCase->value.get());
+	};
+	std::set<Case const*, decltype(sortCasesByValue)> lhsCases(sortCasesByValue);
+	std::set<Case const*, decltype(sortCasesByValue)> rhsCases(sortCasesByValue);
+	for (auto const& lhsCase: _lhs.cases)
+		lhsCases.insert(&lhsCase);
+	for (auto const& rhsCase: _rhs.cases)
+		rhsCases.insert(&rhsCase);
+	return
+		compareSharedPtr<Expression, &SyntacticallyEqual::operator()>(_lhs.expression, _rhs.expression) &&
+		containerEqual(lhsCases, rhsCases, [this](Case const* _lhsCase, Case const* _rhsCase) -> bool {
+			return this->switchCaseEqual(*_lhsCase, *_rhsCase);
+		});
+}
+
+
+bool SyntacticallyEqual::switchCaseEqual(Case const& _lhs, Case const& _rhs)
+{
+	return
+		compareSharedPtr<Literal, &SyntacticallyEqual::expressionEqual>(_lhs.value, _rhs.value) &&
+		statementEqual(_lhs.body, _rhs.body);
+}
+
+bool SyntacticallyEqual::statementEqual(ForLoop const& _lhs, ForLoop const& _rhs)
+{
+	return
+		statementEqual(_lhs.pre, _rhs.pre) &&
+		compareSharedPtr<Expression, &SyntacticallyEqual::operator()>(_lhs.condition, _rhs.condition) &&
+		statementEqual(_lhs.body, _rhs.body) &&
+		statementEqual(_lhs.post, _rhs.post);
+}
+
+bool SyntacticallyEqual::statementEqual(Instruction const&, Instruction const&)
+{
+	assertThrow(false, OptimizerException, "");
+}
+
+bool SyntacticallyEqual::statementEqual(Label const&, Label const&)
+{
+	assertThrow(false, OptimizerException, "");
+}
+
+bool SyntacticallyEqual::statementEqual(StackAssignment const&, StackAssignment const&)
+{
+	assertThrow(false, OptimizerException, "");
+}
+
+bool SyntacticallyEqual::statementEqual(Block const& _lhs, Block const& _rhs)
+{
+	return containerEqual(_lhs.statements, _rhs.statements, [this](Statement const& _lhsStmt, Statement const& _rhsStmt) -> bool {
+		return (*this)(_lhsStmt, _rhsStmt);
+	});
+}
+
+bool SyntacticallyEqual::visitDeclaration(TypedName const& _lhs, TypedName const& _rhs)
+{
+	if (_lhs.type != _rhs.type)
+		return false;
+	std::size_t id = m_idsUsed++;
+	m_identifiersLHS[_lhs.name] = id;
+	m_identifiersRHS[_rhs.name] = id;
+	return true;
 }