1 files changed, 153 insertions, 0 deletions
diff --git a/libsolidity/analysis/StaticAnalyzer.cpp b/libsolidity/analysis/StaticAnalyzer.cpp
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+/*
+	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 <libsolidity/ast/AST.h>
+#include <libsolidity/interface/ErrorReporter.h>
+#include <memory>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+
+bool StaticAnalyzer::analyze(SourceUnit const& _sourceUnit)
+{
+	_sourceUnit.accept(*this);
+	return Error::containsOnlyWarnings(m_errorReporter.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)
+{
+	if (_function.isImplemented())
+		m_currentFunction = &_function;
+	else
+		solAssert(!m_currentFunction, "");
+	solAssert(m_localVarUseCount.empty(), "");
+	m_nonPayablePublic = _function.isPublic() && !_function.isPayable();
+	return true;
+}
+
+void StaticAnalyzer::endVisit(FunctionDefinition const&)
+{
+	m_currentFunction = nullptr;
+	m_nonPayablePublic = false;
+	for (auto const& var: m_localVarUseCount)
+		if (var.second == 0)
+			m_errorReporter.warning(var.first->location(), "Unused local variable");
+	m_localVarUseCount.clear();
+}
+
+bool StaticAnalyzer::visit(Identifier const& _identifier)
+{
+	if (m_currentFunction)
+		if (auto var = dynamic_cast<VariableDeclaration const*>(_identifier.annotation().referencedDeclaration))
+		{
+			solAssert(!var->name().empty(), "");
+			if (var->isLocalVariable())
+				m_localVarUseCount[var] += 1;
+		}
+	return true;
+}
+
+bool StaticAnalyzer::visit(VariableDeclaration const& _variable)
+{
+	if (m_currentFunction)
+	{
+		solAssert(_variable.isLocalVariable(), "");
+		if (_variable.name() != "")
+			// This is not a no-op, the entry might pre-exist.
+			m_localVarUseCount[&_variable] += 0;
+	}
+	return true;
+}
+
+bool StaticAnalyzer::visit(Return const& _return)
+{
+	// If the return has an expression, it counts as
+	// a "use" of the return parameters.
+	if (m_currentFunction && _return.expression())
+		for (auto const& var: m_currentFunction->returnParameters())
+			if (!var->name().empty())
+				m_localVarUseCount[var.get()] += 1;
+	return true;
+}
+
+bool StaticAnalyzer::visit(ExpressionStatement const& _statement)
+{
+	if (_statement.expression().annotation().isPure)
+		m_errorReporter.warning(
+			_statement.location(),
+			"Statement has no effect."
+		);
+
+	return true;
+}
+
+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")
+				m_errorReporter.warning(
+					_memberAccess.location(),
+					"\"msg.value\" used in non-payable function. Do you want to add the \"payable\" modifier to this function?"
+				);
+
+	if (_memberAccess.memberName() == "callcode")
+		if (auto const* type = dynamic_cast<FunctionType const*>(_memberAccess.annotation().type.get()))
+			if (type->kind() == FunctionType::Kind::BareCallCode)
+				m_errorReporter.warning(
+					_memberAccess.location(),
+					"\"callcode\" has been deprecated in favour of \"delegatecall\"."
+				);
+
+	return true;
+}
+
+bool StaticAnalyzer::visit(InlineAssembly const& _inlineAssembly)
+{
+	if (!m_currentFunction)
+		return true;
+
+	for (auto const& ref: _inlineAssembly.annotation().externalReferences)
+	{
+		if (auto var = dynamic_cast<VariableDeclaration const*>(ref.second.declaration))
+		{
+			solAssert(!var->name().empty(), "");
+			if (var->isLocalVariable())
+				m_localVarUseCount[var] += 1;
+		}
+	}
+
+	return true;
+}