1 files changed, 298 insertions, 77 deletions

diff --git a/libsolidity/inlineasm/AsmAnalysis.cpp b/libsolidity/inlineasm/AsmAnalysis.cpp
index a3ddb61d..e03eea2e 100644
--- a/libsolidity/inlineasm/AsmAnalysis.cpp
+++ b/libsolidity/inlineasm/AsmAnalysis.cpp
@@ -21,6 +21,9 @@
 #include <libsolidity/inlineasm/AsmAnalysis.h>
 
 #include <libsolidity/inlineasm/AsmData.h>
+#include <libsolidity/inlineasm/AsmScopeFiller.h>
+#include <libsolidity/inlineasm/AsmScope.h>
+#include <libsolidity/inlineasm/AsmAnalysisInfo.h>
 
 #include <libsolidity/interface/Exceptions.h>
 #include <libsolidity/interface/Utils.h>
@@ -35,146 +38,364 @@ using namespace dev;
 using namespace dev::solidity;
 using namespace dev::solidity::assembly;
 
-
-bool Scope::registerLabel(string const& _name)
+AsmAnalyzer::AsmAnalyzer(
+	AsmAnalysisInfo& _analysisInfo,
+	ErrorList& _errors,
+	ExternalIdentifierAccess::Resolver const& _resolver
+):
+	m_resolver(_resolver), m_info(_analysisInfo), m_errors(_errors)
 {
-	if (exists(_name))
-		return false;
-	identifiers[_name] = Label();
-	return true;
 }
 
-bool Scope::registerVariable(string const& _name)
+bool AsmAnalyzer::analyze(Block const& _block)
 {
-	if (exists(_name))
+	if (!(ScopeFiller(m_info.scopes, m_errors))(_block))
 		return false;
-	identifiers[_name] = Variable();
-	return true;
-}
 
-bool Scope::registerFunction(string const& _name, size_t _arguments, size_t _returns)
-{
-	if (exists(_name))
-		return false;
-	identifiers[_name] = Function(_arguments, _returns);
-	return true;
+	return (*this)(_block);
 }
 
-Scope::Identifier* Scope::lookup(string const& _name)
+bool AsmAnalyzer::operator()(Label const& _label)
 {
-	if (identifiers.count(_name))
-		return &identifiers[_name];
-	else if (superScope && !closedScope)
-		return superScope->lookup(_name);
-	else
-		return nullptr;
-}
-
-bool Scope::exists(string const& _name)
-{
-	if (identifiers.count(_name))
-		return true;
-	else if (superScope)
-		return superScope->exists(_name);
-	else
-		return false;
+	m_info.stackHeightInfo[&_label] = m_stackHeight;
+	return true;
 }
 
-AsmAnalyzer::AsmAnalyzer(AsmAnalyzer::Scopes& _scopes, ErrorList& _errors):
-	m_scopes(_scopes), m_errors(_errors)
+bool AsmAnalyzer::operator()(assembly::Instruction const& _instruction)
 {
-	// Make the Solidity ErrorTag available to inline assembly
-	m_scopes[nullptr] = make_shared<Scope>();
-	Scope::Label errorLabel;
-	errorLabel.id = Scope::Label::errorLabelId;
-	m_scopes[nullptr]->identifiers["invalidJumpLabel"] = errorLabel;
-	m_currentScope = m_scopes[nullptr].get();
+	auto const& info = instructionInfo(_instruction.instruction);
+	m_stackHeight += info.ret - info.args;
+	m_info.stackHeightInfo[&_instruction] = m_stackHeight;
+	return true;
 }
 
 bool AsmAnalyzer::operator()(assembly::Literal const& _literal)
 {
-	if (!_literal.isNumber && _literal.value.size() > 32)
+	++m_stackHeight;
+	if (_literal.kind == assembly::LiteralKind::String && _literal.value.size() > 32)
 	{
 		m_errors.push_back(make_shared<Error>(
 			Error::Type::TypeError,
-			"String literal too long (" + boost::lexical_cast<std::string>(_literal.value.size()) + " > 32)"
+			"String literal too long (" + boost::lexical_cast<std::string>(_literal.value.size()) + " > 32)",
+			_literal.location
 		));
 		return false;
 	}
+	m_info.stackHeightInfo[&_literal] = m_stackHeight;
 	return true;
 }
 
+bool AsmAnalyzer::operator()(assembly::Identifier const& _identifier)
+{
+	size_t numErrorsBefore = m_errors.size();
+	bool success = true;
+	if (m_currentScope->lookup(_identifier.name, Scope::Visitor(
+		[&](Scope::Variable const& _var)
+		{
+			if (!_var.active)
+			{
+				m_errors.push_back(make_shared<Error>(
+					Error::Type::DeclarationError,
+					"Variable " + _identifier.name + " used before it was declared.",
+					_identifier.location
+				));
+				success = false;
+			}
+			++m_stackHeight;
+		},
+		[&](Scope::Label const&)
+		{
+			++m_stackHeight;
+		},
+		[&](Scope::Function const&)
+		{
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::TypeError,
+				"Function " + _identifier.name + " used without being called.",
+				_identifier.location
+			));
+			success = false;
+		}
+	)))
+	{
+	}
+	else
+	{
+		size_t stackSize(-1);
+		if (m_resolver)
+			stackSize = m_resolver(_identifier, IdentifierContext::RValue);
+		if (stackSize == size_t(-1))
+		{
+			// Only add an error message if the callback did not do it.
+			if (numErrorsBefore == m_errors.size())
+				m_errors.push_back(make_shared<Error>(
+					Error::Type::DeclarationError,
+					"Identifier not found.",
+					_identifier.location
+				));
+			success = false;
+		}
+		m_stackHeight += stackSize == size_t(-1) ? 1 : stackSize;
+	}
+	m_info.stackHeightInfo[&_identifier] = m_stackHeight;
+	return success;
+}
+
 bool AsmAnalyzer::operator()(FunctionalInstruction const& _instr)
 {
 	bool success = true;
 	for (auto const& arg: _instr.arguments | boost::adaptors::reversed)
+	{
+		int const stackHeight = m_stackHeight;
 		if (!boost::apply_visitor(*this, arg))
 			success = false;
+		if (!expectDeposit(1, stackHeight, locationOf(arg)))
+			success = false;
+	}
+	// Parser already checks that the number of arguments is correct.
+	solAssert(instructionInfo(_instr.instruction.instruction).args == int(_instr.arguments.size()), "");
 	if (!(*this)(_instr.instruction))
 		success = false;
+	m_info.stackHeightInfo[&_instr] = m_stackHeight;
 	return success;
 }
 
-bool AsmAnalyzer::operator()(Label const& _item)
+bool AsmAnalyzer::operator()(assembly::Assignment const& _assignment)
 {
-	if (!m_currentScope->registerLabel(_item.name))
-	{
-		//@TODO secondary location
-		m_errors.push_back(make_shared<Error>(
-			Error::Type::DeclarationError,
-			"Label name " + _item.name + " already taken in this scope.",
-			_item.location
-		));
-		return false;
-	}
-	return true;
+	bool success = checkAssignment(_assignment.variableName, size_t(-1));
+	m_info.stackHeightInfo[&_assignment] = m_stackHeight;
+	return success;
 }
 
+
 bool AsmAnalyzer::operator()(FunctionalAssignment const& _assignment)
 {
-	return boost::apply_visitor(*this, *_assignment.value);
+	int const stackHeight = m_stackHeight;
+	bool success = boost::apply_visitor(*this, *_assignment.value);
+	solAssert(m_stackHeight >= stackHeight, "Negative value size.");
+	if (!checkAssignment(_assignment.variableName, m_stackHeight - stackHeight))
+		success = false;
+	m_info.stackHeightInfo[&_assignment] = m_stackHeight;
+	return success;
 }
 
 bool AsmAnalyzer::operator()(assembly::VariableDeclaration const& _varDecl)
 {
+	int const stackHeight = m_stackHeight;
 	bool success = boost::apply_visitor(*this, *_varDecl.value);
-	if (!m_currentScope->registerVariable(_varDecl.name))
-	{
-		//@TODO secondary location
-		m_errors.push_back(make_shared<Error>(
-			Error::Type::DeclarationError,
-			"Variable name " + _varDecl.name + " already taken in this scope.",
-			_varDecl.location
-		));
-		success = false;
-	}
+	solAssert(m_stackHeight - stackHeight == 1, "Invalid value size.");
+	boost::get<Scope::Variable>(m_currentScope->identifiers.at(_varDecl.variable.name)).active = true;
+	m_info.stackHeightInfo[&_varDecl] = m_stackHeight;
 	return success;
 }
 
-bool AsmAnalyzer::operator()(assembly::FunctionDefinition const&)
+bool AsmAnalyzer::operator()(assembly::FunctionDefinition const& _funDef)
 {
-	// TODO - we cannot throw an exception here because of some tests.
-	return true;
+	Scope& bodyScope = scope(&_funDef.body);
+	for (auto const& var: _funDef.arguments + _funDef.returns)
+		boost::get<Scope::Variable>(bodyScope.identifiers.at(var.name)).active = true;
+
+	int const stackHeight = m_stackHeight;
+	m_stackHeight = _funDef.arguments.size() + _funDef.returns.size();
+	m_virtualVariablesInNextBlock = m_stackHeight;
+
+	bool success = (*this)(_funDef.body);
+
+	m_stackHeight = stackHeight;
+	m_info.stackHeightInfo[&_funDef] = m_stackHeight;
+	return success;
 }
 
-bool AsmAnalyzer::operator()(assembly::FunctionCall const&)
+bool AsmAnalyzer::operator()(assembly::FunctionCall const& _funCall)
 {
-	// TODO - we cannot throw an exception here because of some tests.
-	return true;
+	bool success = true;
+	size_t arguments = 0;
+	size_t returns = 0;
+	if (!m_currentScope->lookup(_funCall.functionName.name, Scope::Visitor(
+		[&](Scope::Variable const&)
+		{
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::TypeError,
+				"Attempt to call variable instead of function.",
+				_funCall.functionName.location
+			));
+			success = false;
+		},
+		[&](Scope::Label const&)
+		{
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::TypeError,
+				"Attempt to call label instead of function.",
+				_funCall.functionName.location
+				));
+			success = false;
+		},
+		[&](Scope::Function const& _fun)
+		{
+			/// TODO: compare types too
+			arguments = _fun.arguments.size();
+			returns = _fun.returns.size();
+		}
+	)))
+	{
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::DeclarationError,
+			"Function not found.",
+			_funCall.functionName.location
+		));
+		success = false;
+	}
+	if (success)
+	{
+		if (_funCall.arguments.size() != arguments)
+		{
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::TypeError,
+				"Expected " +
+				boost::lexical_cast<string>(arguments) +
+				" arguments but got " +
+				boost::lexical_cast<string>(_funCall.arguments.size()) +
+				".",
+				_funCall.functionName.location
+				));
+			success = false;
+		}
+	}
+	for (auto const& arg: _funCall.arguments | boost::adaptors::reversed)
+	{
+		int const stackHeight = m_stackHeight;
+		if (!boost::apply_visitor(*this, arg))
+			success = false;
+		if (!expectDeposit(1, stackHeight, locationOf(arg)))
+			success = false;
+	}
+	m_stackHeight += int(returns) - int(arguments);
+	m_info.stackHeightInfo[&_funCall] = m_stackHeight;
+	return success;
 }
 
 bool AsmAnalyzer::operator()(Block const& _block)
 {
 	bool success = true;
-	auto scope = make_shared<Scope>();
-	scope->superScope = m_currentScope;
-	m_scopes[&_block] = scope;
-	m_currentScope = scope.get();
+	m_currentScope = &scope(&_block);
+
+	int const initialStackHeight = m_stackHeight - m_virtualVariablesInNextBlock;
+	m_virtualVariablesInNextBlock = 0;
 
 	for (auto const& s: _block.statements)
 		if (!boost::apply_visitor(*this, s))
 			success = false;
 
+	for (auto const& identifier: scope(&_block).identifiers)
+		if (identifier.second.type() == typeid(Scope::Variable))
+			--m_stackHeight;
+
+	int const stackDiff = m_stackHeight - initialStackHeight;
+	if (stackDiff != 0)
+	{
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::DeclarationError,
+			"Unbalanced stack at the end of a block: " +
+			(
+				stackDiff > 0 ?
+				to_string(stackDiff) + string(" surplus item(s).") :
+				to_string(-stackDiff) + string(" missing item(s).")
+			),
+			_block.location
+		));
+		success = false;
+	}
+
 	m_currentScope = m_currentScope->superScope;
+	m_info.stackHeightInfo[&_block] = m_stackHeight;
+	return success;
+}
+
+bool AsmAnalyzer::checkAssignment(assembly::Identifier const& _variable, size_t _valueSize)
+{
+	bool success = true;
+	size_t numErrorsBefore = m_errors.size();
+	size_t variableSize(-1);
+	if (Scope::Identifier const* var = m_currentScope->lookup(_variable.name))
+	{
+		// Check that it is a variable
+		if (var->type() != typeid(Scope::Variable))
+		{
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::TypeError,
+				"Assignment requires variable.",
+				_variable.location
+			));
+			success = false;
+		}
+		else if (!boost::get<Scope::Variable>(*var).active)
+		{
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::DeclarationError,
+				"Variable " + _variable.name + " used before it was declared.",
+				_variable.location
+			));
+			success = false;
+		}
+		variableSize = 1;
+	}
+	else if (m_resolver)
+		variableSize = m_resolver(_variable, IdentifierContext::LValue);
+	if (variableSize == size_t(-1))
+	{
+		// Only add message if the callback did not.
+		if (numErrorsBefore == m_errors.size())
+			m_errors.push_back(make_shared<Error>(
+				Error::Type::DeclarationError,
+				"Variable not found or variable not lvalue.",
+				_variable.location
+			));
+		success = false;
+	}
+	if (_valueSize == size_t(-1))
+		_valueSize = variableSize == size_t(-1) ? 1 : variableSize;
+
+	m_stackHeight -= _valueSize;
+
+	if (_valueSize != variableSize && variableSize != size_t(-1))
+	{
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::TypeError,
+			"Variable size (" +
+			to_string(variableSize) +
+			") and value size (" +
+			to_string(_valueSize) +
+			") do not match.",
+			_variable.location
+		));
+		success = false;
+	}
 	return success;
 }
+
+bool AsmAnalyzer::expectDeposit(int const _deposit, int const _oldHeight, SourceLocation const& _location)
+{
+	int stackDiff = m_stackHeight - _oldHeight;
+	if (stackDiff != _deposit)
+	{
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::TypeError,
+			"Expected instruction(s) to deposit " +
+			boost::lexical_cast<string>(_deposit) +
+			" item(s) to the stack, but did deposit " +
+			boost::lexical_cast<string>(stackDiff) +
+			" item(s).",
+			_location
+		));
+		return false;
+	}
+	else
+		return true;
+}
+
+Scope& AsmAnalyzer::scope(Block const* _block)
+{
+	auto scopePtr = m_info.scopes.at(_block);
+	solAssert(scopePtr, "Scope requested but not present.");
+	return *scopePtr;
+}