Warn about using msg.value in non-payable function

2 files changed, 150 insertions, 0 deletions

diff --git a/libsolidity/analysis/StaticAnalyzer.cpp b/libsolidity/analysis/StaticAnalyzer.cpp
new file mode 100644
index 00000000..c39f874e
--- /dev/null
+++ b/libsolidity/analysis/StaticAnalyzer.cpp
@@ -0,0 +1,78 @@
+/*
+	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/>.
+*/
+/**
+ * @author Federico Bond <federicobond@gmail.com>
+ * @date 2016
+ * Static analyzer and checker.
+ */
+
+#include <libsolidity/analysis/StaticAnalyzer.h>
+#include <memory>
+#include <libsolidity/ast/AST.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+
+
+bool StaticAnalyzer::analyze(SourceUnit const& _sourceUnit)
+{
+	_sourceUnit.accept(*this);
+	return Error::containsOnlyWarnings(m_errors);
+}
+
+bool StaticAnalyzer::visit(ContractDefinition const& _contract)
+{
+	m_library = _contract.isLibrary();
+	return true;
+}
+
+void StaticAnalyzer::endVisit(ContractDefinition const&)
+{
+	m_library = false;
+}
+
+bool StaticAnalyzer::visit(FunctionDefinition const& _function)
+{
+	m_nonPayablePublic = _function.isPublic() && !_function.isPayable();
+	return true;
+}
+
+void StaticAnalyzer::endVisit(FunctionDefinition const&)
+{
+	m_nonPayablePublic = false;
+}
+
+bool StaticAnalyzer::visit(MemberAccess const& _memberAccess)
+{
+	if (m_nonPayablePublic && !m_library)
+		if (MagicType const* type = dynamic_cast<MagicType const*>(_memberAccess.expression().annotation().type.get()))
+			if (type->kind() == MagicType::Kind::Message && _memberAccess.memberName() == "value")
+				warning(_memberAccess.location(), "\"msg.value\" used in non-payable function. Do you want to add the \"payable\" modifier to this function?");
+
+	return true;
+}
+
+void StaticAnalyzer::warning(SourceLocation const& _location, string const& _description)
+{
+	auto err = make_shared<Error>(Error::Type::Warning);
+	*err <<
+		errinfo_sourceLocation(_location) <<
+		errinfo_comment(_description);
+
+	m_errors.push_back(err);
+}
diff --git a/libsolidity/analysis/StaticAnalyzer.h b/libsolidity/analysis/StaticAnalyzer.h
new file mode 100644
index 00000000..b6cf783e
--- /dev/null
+++ b/libsolidity/analysis/StaticAnalyzer.h
@@ -0,0 +1,72 @@
+/*
+	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/>.
+*/
+/**
+ * @author Federico Bond <federicobond@gmail.com>
+ * @date 2016
+ * Static analyzer and checker.
+ */
+
+#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 static analysis on the AST.
+ */
+class StaticAnalyzer: private ASTConstVisitor
+{
+public:
+	/// @param _errors the reference to the list of errors and warnings to add them found during static analysis.
+	explicit StaticAnalyzer(ErrorList& _errors): m_errors(_errors) {}
+
+	/// Performs static analysis on the given source unit and all of its sub-nodes.
+	/// @returns true iff all checks passed. Note even if all checks passed, errors() can still contain warnings
+	bool analyze(SourceUnit const& _sourceUnit);
+
+private:
+	/// Adds a new warning to the list of errors.
+	void warning(SourceLocation const& _location, std::string const& _description);
+
+	virtual bool visit(ContractDefinition const& _contract) override;
+	virtual void endVisit(ContractDefinition const& _contract) override;
+
+	virtual bool visit(FunctionDefinition const& _function) override;
+	virtual void endVisit(FunctionDefinition const& _function) override;
+
+	virtual bool visit(MemberAccess const& _memberAccess) override;
+
+	ErrorList& m_errors;
+
+	/// Flag that indicates whether the current contract definition is a library.
+	bool m_library = false;
+
+	/// Flag that indicates whether a public function does not contain the "payable" modifier.
+	bool m_nonPayablePublic = false;
+};
+
+}
+}