libyul: Adds Comment as new AST node type, to be used for pretty printing (and preserving) comments in yul-format.

libyul/optimiser/ASTCopier.cpp

@@ -153,6 +153,11 @@ Statement ASTCopier::operator ()(Block const& _block)
 	return translate(_block);
 }
 
+Statement ASTCopier::operator()(Comment const& _comment)
+{
+	return Comment{_comment.location, _comment.text};
+}
+
 Expression ASTCopier::translate(Expression const& _expression)
 {
 	return _expression.apply_visitor(static_cast<ExpressionCopier&>(*this));

libyul/optimiser/ASTCopier.h

@@ -61,6 +61,7 @@ public:
 	virtual Statement operator()(Break const&) = 0;
 	virtual Statement operator()(Continue const&) = 0;
 	virtual Statement operator()(Block const& _block) = 0;
+	virtual Statement operator()(Comment const& _comment) = 0;
 };
 
 /**
@@ -88,6 +89,7 @@ public:
 	Statement operator()(Break const&) override;
 	Statement operator()(Continue const&) override;
 	Statement operator()(Block const& _block) override;
+	Statement operator()(Comment const& _comment) override;
 
 	virtual Expression translate(Expression const& _expression);
 	virtual Statement translate(Statement const& _statement);

libyul/optimiser/ASTWalker.h

@@ -59,6 +59,7 @@ public:
 	virtual void operator()(Break const&) {}
 	virtual void operator()(Continue const&) {}
 	virtual void operator()(Block const& _block);
+	virtual void operator()(Comment const&) {}
 
 	virtual void visit(Statement const& _st);
 	virtual void visit(Expression const& _e);
@@ -96,6 +97,7 @@ public:
 	virtual void operator()(Break&);
 	virtual void operator()(Continue&);
 	virtual void operator()(Block& _block);
+	virtual void operator()(Comment&) {}
 
 	virtual void visit(Statement& _st);
 	virtual void visit(Expression& _e);

libyul/optimiser/SyntacticalEquality.cpp

@@ -181,6 +181,11 @@ bool SyntacticallyEqual::statementEqual(Block const& _lhs, Block const& _rhs)
 	});
 }
 
+bool SyntacticallyEqual::statementEqual(Comment const& _lhs, Comment const& _rhs)
+{
+	return _lhs.text == _rhs.text;
+}
+
 bool SyntacticallyEqual::visitDeclaration(TypedName const& _lhs, TypedName const& _rhs)
 {
 	if (_lhs.type != _rhs.type)

libyul/optimiser/SyntacticalEquality.h

@@ -58,6 +58,7 @@ public:
 	bool statementEqual(Break const&, Break const&) { return true; }
 	bool statementEqual(Continue const&, Continue const&) { return true; }
 	bool statementEqual(Block const& _lhs, Block const& _rhs);
+	bool statementEqual(Comment const& _lhs, Comment const& _rhs);
 private:
 	bool statementEqual(Instruction const& _lhs, Instruction const& _rhs);
 	bool statementEqual(Label const& _lhs, Label const& _rhs);