Merge pull request #356 from guanqun/break-not-in-loop

check whether break/continue is in the loop

2 files changed, 141 insertions, 0 deletions

diff --git a/libsolidity/analysis/SyntaxChecker.cpp b/libsolidity/analysis/SyntaxChecker.cpp
new file mode 100644
index 00000000..e94ce9fe
--- /dev/null
+++ b/libsolidity/analysis/SyntaxChecker.cpp
@@ -0,0 +1,80 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum 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.
+
+	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <memory>
+#include <libsolidity/ast/AST.h>
+#include <libsolidity/analysis/SyntaxChecker.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+
+
+bool SyntaxChecker::checkSyntax(SourceUnit const& _sourceUnit)
+{
+	_sourceUnit.accept(*this);
+	return m_errors.empty();
+}
+
+void SyntaxChecker::syntaxError(SourceLocation const& _location, std::string const& _description)
+{
+	auto err = make_shared<Error>(Error::Type::SyntaxError);
+	*err <<
+		errinfo_sourceLocation(_location) <<
+		errinfo_comment(_description);
+
+	m_errors.push_back(err);
+}
+
+bool SyntaxChecker::visit(WhileStatement const&)
+{
+	m_inLoopDepth++;
+	return true;
+}
+
+void SyntaxChecker::endVisit(WhileStatement const&)
+{
+	m_inLoopDepth--;
+}
+
+bool SyntaxChecker::visit(ForStatement const&)
+{
+	m_inLoopDepth++;
+	return true;
+}
+
+void SyntaxChecker::endVisit(ForStatement const&)
+{
+	m_inLoopDepth--;
+}
+
+bool SyntaxChecker::visit(Continue const& _continueStatement)
+{
+	if (m_inLoopDepth <= 0)
+		// we're not in a for/while loop, report syntax error
+		syntaxError(_continueStatement.location(), "\"continue\" has to be in a \"for\" or \"while\" loop.");
+	return true;
+}
+
+bool SyntaxChecker::visit(Break const& _breakStatement)
+{
+	if (m_inLoopDepth <= 0)
+		// we're not in a for/while loop, report syntax error
+		syntaxError(_breakStatement.location(), "\"break\" has to be in a \"for\" or \"while\" loop.");
+	return true;
+}
+
diff --git a/libsolidity/analysis/SyntaxChecker.h b/libsolidity/analysis/SyntaxChecker.h
new file mode 100644
index 00000000..c836d49f
--- /dev/null
+++ b/libsolidity/analysis/SyntaxChecker.h
@@ -0,0 +1,61 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum 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.
+
+	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include <libsolidity/analysis/TypeChecker.h>
+#include <libsolidity/ast/Types.h>
+#include <libsolidity/ast/ASTAnnotations.h>
+#include <libsolidity/ast/ASTForward.h>
+#include <libsolidity/ast/ASTVisitor.h>
+
+namespace dev
+{
+namespace solidity
+{
+
+/**
+ * The module that performs syntax analysis on the AST:
+ *  - whether continue/break is in a for/while loop.
+ */
+class SyntaxChecker: private ASTConstVisitor
+{
+public:
+	/// @param _errors the reference to the list of errors and warnings to add them found during type checking.
+	SyntaxChecker(ErrorList& _errors): m_errors(_errors) {}
+
+	bool checkSyntax(SourceUnit const& _sourceUnit);
+
+private:
+	/// Adds a new error to the list of errors.
+	void syntaxError(SourceLocation const& _location, std::string const& _description);
+
+	virtual bool visit(WhileStatement const& _whileStatement) override;
+	virtual void endVisit(WhileStatement const& _whileStatement) override;
+	virtual bool visit(ForStatement const& _forStatement) override;
+	virtual void endVisit(ForStatement const& _forStatement) override;
+
+	virtual bool visit(Continue const& _continueStatement) override;
+	virtual bool visit(Break const& _breakStatement) override;
+
+	ErrorList& m_errors;
+
+	int m_inLoopDepth = 0;
+};
+
+}
+}