Merge pull request #288 from chriseth/import_contexts

Do not clutter importee when importing.
2023-10-03 13:03:40 +00:00 · 2015-12-15 11:43:59 +01:00 · 2015-12-15 11:43:59 +01:00 · 591a4f1ff4
commit 591a4f1ff4
parent 98684cca90 53da78e609
12 changed files with 288 additions and 75 deletions
--- a/libsolidity/analysis/DeclarationContainer.cpp
+++ b/libsolidity/analysis/DeclarationContainer.cpp
@ -28,15 +28,19 @@ using namespace std;
 using namespace dev;
 using namespace dev::solidity;

-Declaration const* DeclarationContainer::conflictingDeclaration(Declaration const& _declaration) const
+Declaration const* DeclarationContainer::conflictingDeclaration(
+	Declaration const& _declaration,
+	ASTString const* _name
+) const
 {
-	ASTString const& declarationName(_declaration.name());
-	solAssert(!declarationName.empty(), "");
+	if (!_name)
+		_name = &_declaration.name();
+	solAssert(!_name->empty(), "");
 	vector<Declaration const*> declarations;
-	if (m_declarations.count(declarationName))
-		declarations += m_declarations.at(declarationName);
-	if (m_invisibleDeclarations.count(declarationName))
-		declarations += m_invisibleDeclarations.at(declarationName);
+	if (m_declarations.count(*_name))
+		declarations += m_declarations.at(*_name);
+	if (m_invisibleDeclarations.count(*_name))
+		declarations += m_invisibleDeclarations.at(*_name);

 	if (dynamic_cast<FunctionDefinition const*>(&_declaration))
 	{
@ -51,25 +55,31 @@ Declaration const* DeclarationContainer::conflictingDeclaration(Declaration cons
 	return nullptr;
 }

-bool DeclarationContainer::registerDeclaration(Declaration const& _declaration, bool _invisible, bool _update)
+bool DeclarationContainer::registerDeclaration(
+	Declaration const& _declaration,
+	ASTString const* _name,
+	bool _invisible,
+	bool _update
+)
 {
-	ASTString const& declarationName(_declaration.name());
-	if (declarationName.empty())
+	if (!_name)
+		_name = &_declaration.name();
+	if (_name->empty())
 		return true;

 	if (_update)
 	{
 		solAssert(!dynamic_cast<FunctionDefinition const*>(&_declaration), "Attempt to update function definition.");
-		m_declarations.erase(declarationName);
-		m_invisibleDeclarations.erase(declarationName);
+		m_declarations.erase(*_name);
+		m_invisibleDeclarations.erase(*_name);
 	}
 	else if (conflictingDeclaration(_declaration))
 		return false;

 	if (_invisible)
-		m_invisibleDeclarations[declarationName].push_back(&_declaration);
+		m_invisibleDeclarations[*_name].push_back(&_declaration);
 	else
-		m_declarations[declarationName].push_back(&_declaration);
+		m_declarations[*_name].push_back(&_declaration);
 	return true;
 }

--- a/libsolidity/analysis/DeclarationContainer.h
+++ b/libsolidity/analysis/DeclarationContainer.h
@ -41,23 +41,24 @@ class DeclarationContainer
 {
 public:
 	explicit DeclarationContainer(
-		Declaration const* _enclosingDeclaration = nullptr,
+		ASTNode const* _enclosingNode = nullptr,
 		DeclarationContainer const* _enclosingContainer = nullptr
 	):
-		m_enclosingDeclaration(_enclosingDeclaration), m_enclosingContainer(_enclosingContainer) {}
+		m_enclosingNode(_enclosingNode), m_enclosingContainer(_enclosingContainer) {}
 	/// Registers the declaration in the scope unless its name is already declared or the name is empty.
+	/// @param _name the name to register, if nullptr the intrinsic name of @a _declaration is used.
 	/// @param _invisible if true, registers the declaration, reports name clashes but does not return it in @a resolveName
 	/// @param _update if true, replaces a potential declaration that is already present
 	/// @returns false if the name was already declared.
-	bool registerDeclaration(Declaration const& _declaration, bool _invisible = false, bool _update = false);
+	bool registerDeclaration(Declaration const& _declaration, ASTString const* _name = nullptr, bool _invisible = false, bool _update = false);
 	std::vector<Declaration const*> resolveName(ASTString const& _name, bool _recursive = false) const;
-	Declaration const* enclosingDeclaration() const { return m_enclosingDeclaration; }
+	ASTNode const* enclosingNode() const { return m_enclosingNode; }
 	std::map<ASTString, std::vector<Declaration const*>> const& declarations() const { return m_declarations; }
 	/// @returns whether declaration is valid, and if not also returns previous declaration.
-	Declaration const* conflictingDeclaration(Declaration const& _declaration) const;
+	Declaration const* conflictingDeclaration(Declaration const& _declaration, ASTString const* _name = nullptr) const;

 private:
-	Declaration const* m_enclosingDeclaration;
+	ASTNode const* m_enclosingNode;
 	DeclarationContainer const* m_enclosingContainer;
 	std::map<ASTString, std::vector<Declaration const*>> m_declarations;
 	std::map<ASTString, std::vector<Declaration const*>> m_invisibleDeclarations;
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@ -38,12 +38,18 @@ NameAndTypeResolver::NameAndTypeResolver(
 ) :
 	m_errors(_errors)
 {
+	if (!m_scopes[nullptr])
+		m_scopes[nullptr].reset(new DeclarationContainer());
 	for (Declaration const* declaration: _globals)
-		m_scopes[nullptr].registerDeclaration(*declaration);
+		m_scopes[nullptr]->registerDeclaration(*declaration);
 }

 bool NameAndTypeResolver::registerDeclarations(SourceUnit& _sourceUnit)
 {
+	solAssert(!m_scopes[&_sourceUnit], "");
+	m_scopes[&_sourceUnit].reset(new DeclarationContainer(nullptr, m_scopes[nullptr].get()));
+	m_currentScope = m_scopes[&_sourceUnit].get();
+
 	// The helper registers all declarations in m_scopes as a side-effect of its construction.
 	try
 	{
@ -58,11 +64,43 @@ bool NameAndTypeResolver::registerDeclarations(SourceUnit& _sourceUnit)
 	return true;
 }

+bool NameAndTypeResolver::performImports(SourceUnit& _sourceUnit, map<string, SourceUnit const*> const& _sourceUnits)
+{
+	DeclarationContainer& target = *m_scopes.at(&_sourceUnit);
+	bool error = false;
+	for (auto const& node: _sourceUnit.nodes())
+		if (auto imp = dynamic_cast<ImportDirective const*>(node.get()))
+		{
+			string const& path = imp->annotation().absolutePath;
+			if (!_sourceUnits.count(path))
+			{
+				reportDeclarationError( node->location(),
+					"Import \"" +
+					path +
+					"\" (referenced as \"" +
+					imp->identifier() +
+					"\") not found."
+				);
+				error = true;
+			}
+			else
+			{
+				auto scope = m_scopes.find(_sourceUnits.at(path));
+				solAssert(scope != end(m_scopes), "");
+				for (auto const& nameAndDeclaration: scope->second->declarations())
+					for (auto const& declaration: nameAndDeclaration.second)
+						target.registerDeclaration(*declaration, &nameAndDeclaration.first);
+			}
+		}
+	return !error;
+}
+
 bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 {
 	try
 	{
-		m_currentScope = &m_scopes[nullptr];
+		m_currentScope = m_scopes[_contract.scope()].get();
+		solAssert(!!m_currentScope, "");

 		ReferencesResolver resolver(m_errors, *this, nullptr);
 		bool success = true;
@ -70,12 +108,12 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 			if (!resolver.resolve(*baseContract))
 				success = false;

-		m_currentScope = &m_scopes[&_contract];
+		m_currentScope = m_scopes[&_contract].get();

 		if (success)
 		{
 			linearizeBaseContracts(_contract);
-			std::vector<ContractDefinition const*> properBases(
+			vector<ContractDefinition const*> properBases(
 				++_contract.annotation().linearizedBaseContracts.begin(),
 				_contract.annotation().linearizedBaseContracts.end()
 			);
@ -87,7 +125,7 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 		// these can contain code, only resolve parameters for now
 		for (ASTPointer<ASTNode> const& node: _contract.subNodes())
 		{
-			m_currentScope = &m_scopes[m_scopes.count(node.get()) ? node.get() : &_contract];
+			m_currentScope = m_scopes[m_scopes.count(node.get()) ? node.get() : &_contract].get();
 			if (!resolver.resolve(*node))
 				success = false;
 		}
@ -95,12 +133,12 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
 		if (!success)
 			return false;

-		m_currentScope = &m_scopes[&_contract];
+		m_currentScope = m_scopes[&_contract].get();

 		// now resolve references inside the code
 		for (ModifierDefinition const* modifier: _contract.functionModifiers())
 		{
-			m_currentScope = &m_scopes[modifier];
+			m_currentScope = m_scopes[modifier].get();
 			ReferencesResolver resolver(m_errors, *this, nullptr, true);
 			if (!resolver.resolve(*modifier))
 				success = false;
@ -108,7 +146,7 @@ bool NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)

 		for (FunctionDefinition const* function: _contract.definedFunctions())
 		{
-			m_currentScope = &m_scopes[function];
+			m_currentScope = m_scopes[function].get();
 			if (!ReferencesResolver(
 				m_errors,
 				*this,
@ -133,7 +171,7 @@ bool NameAndTypeResolver::updateDeclaration(Declaration const& _declaration)
 {
 	try
 	{
-		m_scopes[nullptr].registerDeclaration(_declaration, false, true);
+		m_scopes[nullptr]->registerDeclaration(_declaration, nullptr, false, true);
 		solAssert(_declaration.scope() == nullptr, "Updated declaration outside global scope.");
 	}
 	catch (FatalError const&)
@ -145,12 +183,12 @@ bool NameAndTypeResolver::updateDeclaration(Declaration const& _declaration)
 	return true;
 }

-vector<Declaration const*> NameAndTypeResolver::resolveName(ASTString const& _name, Declaration const* _scope) const
+vector<Declaration const*> NameAndTypeResolver::resolveName(ASTString const& _name, ASTNode const* _scope) const
 {
 	auto iterator = m_scopes.find(_scope);
 	if (iterator == end(m_scopes))
 		return vector<Declaration const*>({});
-	return iterator->second.resolveName(_name, false);
+	return iterator->second->resolveName(_name, false);
 }

 vector<Declaration const*> NameAndTypeResolver::nameFromCurrentScope(ASTString const& _name, bool _recursive) const
@ -166,7 +204,7 @@ Declaration const* NameAndTypeResolver::pathFromCurrentScope(vector<ASTString> c
 	{
 		if (!m_scopes.count(candidates.front()))
 			return nullptr;
-		candidates = m_scopes.at(candidates.front()).resolveName(_path[i], false);
+		candidates = m_scopes.at(candidates.front())->resolveName(_path[i], false);
 	}
 	if (candidates.size() == 1)
 		return candidates.front();
@ -210,7 +248,7 @@ void NameAndTypeResolver::importInheritedScope(ContractDefinition const& _base)
 {
 	auto iterator = m_scopes.find(&_base);
 	solAssert(iterator != end(m_scopes), "");
-	for (auto const& nameAndDeclaration: iterator->second.declarations())
+	for (auto const& nameAndDeclaration: iterator->second->declarations())
 		for (auto const& declaration: nameAndDeclaration.second)
 			// Import if it was declared in the base, is not the constructor and is visible in derived classes
 			if (declaration->scope() == &_base && declaration->isVisibleInDerivedContracts())
@ -342,14 +380,15 @@ void NameAndTypeResolver::reportFatalTypeError(Error const& _e)
 }

 DeclarationRegistrationHelper::DeclarationRegistrationHelper(
-	map<ASTNode const*, DeclarationContainer>& _scopes,
+	map<ASTNode const*, unique_ptr<DeclarationContainer>>& _scopes,
 	ASTNode& _astRoot,
 	ErrorList& _errors
 ):
 	m_scopes(_scopes),
-	m_currentScope(nullptr),
+	m_currentScope(&_astRoot),
 	m_errors(_errors)
 {
+	solAssert(!!m_scopes.at(m_currentScope), "");
 	_astRoot.accept(*this);
 }

@ -450,9 +489,10 @@ void DeclarationRegistrationHelper::endVisit(EventDefinition&)

 void DeclarationRegistrationHelper::enterNewSubScope(Declaration const& _declaration)
 {
-	map<ASTNode const*, DeclarationContainer>::iterator iter;
+	map<ASTNode const*, unique_ptr<DeclarationContainer>>::iterator iter;
 	bool newlyAdded;
-	tie(iter, newlyAdded) = m_scopes.emplace(&_declaration, DeclarationContainer(m_currentScope, &m_scopes[m_currentScope]));
+	unique_ptr<DeclarationContainer> container(new DeclarationContainer(m_currentScope, m_scopes[m_currentScope].get()));
+	tie(iter, newlyAdded) = m_scopes.emplace(&_declaration, move(container));
 	solAssert(newlyAdded, "Unable to add new scope.");
 	m_currentScope = &_declaration;
 }
@ -460,16 +500,16 @@ void DeclarationRegistrationHelper::enterNewSubScope(Declaration const& _declara
 void DeclarationRegistrationHelper::closeCurrentScope()
 {
 	solAssert(m_currentScope, "Closed non-existing scope.");
-	m_currentScope = m_scopes[m_currentScope].enclosingDeclaration();
+	m_currentScope = m_scopes[m_currentScope]->enclosingNode();
 }

 void DeclarationRegistrationHelper::registerDeclaration(Declaration& _declaration, bool _opensScope)
 {
-	if (!m_scopes[m_currentScope].registerDeclaration(_declaration, !_declaration.isVisibleInContract()))
+	if (!m_scopes[m_currentScope]->registerDeclaration(_declaration, nullptr, !_declaration.isVisibleInContract()))
 	{
 		SourceLocation firstDeclarationLocation;
 		SourceLocation secondDeclarationLocation;
-		Declaration const* conflictingDeclaration = m_scopes[m_currentScope].conflictingDeclaration(_declaration);
+		Declaration const* conflictingDeclaration = m_scopes[m_currentScope]->conflictingDeclaration(_declaration);
 		solAssert(conflictingDeclaration, "");

 		if (_declaration.location().start < conflictingDeclaration->location().start)
@ -500,14 +540,17 @@ string DeclarationRegistrationHelper::currentCanonicalName() const
 {
 	string ret;
 	for (
-		Declaration const* scope = m_currentScope;
+		ASTNode const* scope = m_currentScope;
 		scope != nullptr;
-		scope = m_scopes[scope].enclosingDeclaration()
+		scope = m_scopes[scope]->enclosingNode()
 	)
 	{
-		if (!ret.empty())
-			ret = "." + ret;
-		ret = scope->name() + ret;
+		if (auto decl = dynamic_cast<Declaration const*>(scope))
+		{
+			if (!ret.empty())
+				ret = "." + ret;
+			ret = decl->name() + ret;
+		}
 	}
 	return ret;
 }
--- a/libsolidity/analysis/NameAndTypeResolver.h
+++ b/libsolidity/analysis/NameAndTypeResolver.h
@ -46,6 +46,8 @@ public:
 	/// Registers all declarations found in the source unit.
 	/// @returns false in case of error.
 	bool registerDeclarations(SourceUnit& _sourceUnit);
+	/// Applies the effect of import directives.
+	bool performImports(SourceUnit& _sourceUnit, std::map<std::string, SourceUnit const*> const& _sourceUnits);
 	/// Resolves all names and types referenced from the given contract.
 	/// @returns false in case of error.
 	bool resolveNamesAndTypes(ContractDefinition& _contract);
@ -55,9 +57,9 @@ public:
 	bool updateDeclaration(Declaration const& _declaration);

 	/// Resolves the given @a _name inside the scope @a _scope. If @a _scope is omitted,
-	/// the global scope is used (i.e. the one containing only the contract).
+	/// the global scope is used (i.e. the one containing only the pre-defined global variables).
 	/// @returns a pointer to the declaration on success or nullptr on failure.
-	std::vector<Declaration const*> resolveName(ASTString const& _name, Declaration const* _scope = nullptr) const;
+	std::vector<Declaration const*> resolveName(ASTString const& _name, ASTNode const* _scope = nullptr) const;

 	/// Resolves a name in the "current" scope. Should only be called during the initial
 	/// resolving phase.
@ -88,11 +90,6 @@ private:
 	template <class _T>
 	static std::vector<_T const*> cThreeMerge(std::list<std::list<_T const*>>& _toMerge);

-	/// Maps nodes declaring a scope to scopes, i.e. ContractDefinition and FunctionDeclaration,
-	/// where nullptr denotes the global scope. Note that structs are not scope since they do
-	/// not contain code.
-	std::map<ASTNode const*, DeclarationContainer> m_scopes;
-
 	// creates the Declaration error and adds it in the errors list
 	void reportDeclarationError(
 		SourceLocation _sourceLoction,
@ -110,6 +107,12 @@ private:
 	// creates the Declaration error and adds it in the errors list and throws FatalError
 	void reportFatalTypeError(Error const& _e);

+
+	/// Maps nodes declaring a scope to scopes, i.e. ContractDefinition and FunctionDeclaration,
+	/// where nullptr denotes the global scope. Note that structs are not scope since they do
+	/// not contain code.
+	std::map<ASTNode const*, std::unique_ptr<DeclarationContainer>> m_scopes;
+
 	DeclarationContainer* m_currentScope = nullptr;
 	ErrorList& m_errors;
 };
@ -121,7 +124,11 @@ private:
 class DeclarationRegistrationHelper: private ASTVisitor
 {
 public:
-	DeclarationRegistrationHelper(std::map<ASTNode const*, DeclarationContainer>& _scopes, ASTNode& _astRoot, ErrorList& _errors);
+	DeclarationRegistrationHelper(
+		std::map<ASTNode const*, std::unique_ptr<DeclarationContainer>>& _scopes,
+		ASTNode& _astRoot,
+		ErrorList& _errors
+	);

 private:
 	bool visit(ContractDefinition& _contract) override;
@ -159,8 +166,8 @@ private:
 	// creates the Declaration error and adds it in the errors list and throws FatalError
 	void fatalDeclarationError(SourceLocation _sourceLocation, std::string const& _description);

-	std::map<ASTNode const*, DeclarationContainer>& m_scopes;
-	Declaration const* m_currentScope = nullptr;
+	std::map<ASTNode const*, std::unique_ptr<DeclarationContainer>>& m_scopes;
+	ASTNode const* m_currentScope = nullptr;
 	VariableScope* m_currentFunction = nullptr;
 	ErrorList& m_errors;
 };
--- a/libsolidity/analysis/ReferencesResolver.cpp
+++ b/libsolidity/analysis/ReferencesResolver.cpp
@ -139,7 +139,9 @@ void ReferencesResolver::endVisit(VariableDeclaration const& _variable)
 			bool isPointer = true;
 			if (_variable.isExternalCallableParameter())
 			{
-				auto const& contract = dynamic_cast<ContractDefinition const&>(*_variable.scope()->scope());
+				auto const& contract = dynamic_cast<ContractDefinition const&>(
+					*dynamic_cast<Declaration const&>(*_variable.scope()).scope()
+				);
 				if (contract.isLibrary())
 				{
 					if (varLoc == Location::Memory)
@ -162,9 +164,11 @@ void ReferencesResolver::endVisit(VariableDeclaration const& _variable)
 				else
 					typeLoc = varLoc == Location::Memory ? DataLocation::Memory : DataLocation::Storage;
 			}
-			else if (_variable.isCallableParameter() && _variable.scope()->isPublic())
+			else if (_variable.isCallableParameter() && dynamic_cast<Declaration const&>(*_variable.scope()).isPublic())
 			{
-				auto const& contract = dynamic_cast<ContractDefinition const&>(*_variable.scope()->scope());
+				auto const& contract = dynamic_cast<ContractDefinition const&>(
+					*dynamic_cast<Declaration const&>(*_variable.scope()).scope()
+				);
 				// force locations of public or external function (return) parameters to memory
 				if (varLoc == Location::Storage && !contract.isLibrary())
 					fatalTypeError(_variable.location(),
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@ -56,6 +56,13 @@ Error ASTNode::createTypeError(string const& _description) const
 	return Error(Error::Type::TypeError) << errinfo_sourceLocation(location()) << errinfo_comment(_description);
 }

+ImportAnnotation& ImportDirective::annotation() const
+{
+	if (!m_annotation)
+		m_annotation = new ImportAnnotation();
+	return static_cast<ImportAnnotation&>(*m_annotation);
+}
+
 map<FixedHash<4>, FunctionTypePointer> ContractDefinition::interfaceFunctions() const
 {
 	auto exportedFunctionList = interfaceFunctionList();
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@ -142,6 +142,7 @@ public:
 	virtual void accept(ASTConstVisitor& _visitor) const override;

 	ASTString const& identifier() const { return *m_identifier; }
+	virtual ImportAnnotation& annotation() const override;

 private:
 	ASTPointer<ASTString> m_identifier;
@ -172,8 +173,8 @@ public:

 	/// @returns the scope this declaration resides in. Can be nullptr if it is the global scope.
 	/// Available only after name and type resolution step.
-	Declaration const* scope() const { return m_scope; }
-	void setScope(Declaration const* _scope) { m_scope = _scope; }
+	ASTNode const* scope() const { return m_scope; }
+	void setScope(ASTNode const* _scope) { m_scope = _scope; }

 	virtual bool isLValue() const { return false; }
 	virtual bool isPartOfExternalInterface() const { return false; }
@ -190,7 +191,7 @@ protected:
 private:
 	ASTPointer<ASTString> m_name;
 	Visibility m_visibility;
-	Declaration const* m_scope;
+	ASTNode const* m_scope;
 };

 /**
--- a/libsolidity/ast/ASTAnnotations.h
+++ b/libsolidity/ast/ASTAnnotations.h
@ -54,6 +54,12 @@ struct DocumentedAnnotation
 	std::multimap<std::string, DocTag> docTags;
 };

+struct ImportAnnotation: ASTAnnotation
+{
+	/// The absolute path of the source unit to import.
+	std::string absolutePath;
+};
+
 struct TypeDeclarationAnnotation: ASTAnnotation
 {
 	/// The name of this type, prefixed by proper namespaces if globally accessible.
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@ -22,6 +22,7 @@
 */

 #include <boost/algorithm/string.hpp>
+#include <boost/filesystem.hpp>
 #include <libsolidity/ast/AST.h>
 #include <libsolidity/parsing/Scanner.h>
 #include <libsolidity/parsing/Parser.h>
@ -103,12 +104,14 @@ bool CompilerStack::parse()
 	m_errors.clear();
 	m_parseSuccessful = false;

+	map<string, SourceUnit const*> sourceUnitsByName;
 	for (auto& sourcePair: m_sources)
 	{
 		sourcePair.second.scanner->reset();
 		sourcePair.second.ast = Parser(m_errors).parse(sourcePair.second.scanner);
 		if (!sourcePair.second.ast)
 			solAssert(!Error::containsOnlyWarnings(m_errors), "Parser returned null but did not report error.");
+		sourceUnitsByName[sourcePair.first] = sourcePair.second.ast.get();
 	}
 	if (!Error::containsOnlyWarnings(m_errors))
 		// errors while parsing. sould stop before type checking
@ -128,6 +131,10 @@ bool CompilerStack::parse()
 		if (!resolver.registerDeclarations(*source->ast))
 			return false;

+	for (Source const* source: m_sourceOrder)
+		if (!resolver.performImports(*source->ast, sourceUnitsByName))
+			return false;
+
 	for (Source const* source: m_sourceOrder)
 		for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 			if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
@ -361,7 +368,7 @@ void CompilerStack::resolveImports()
 	vector<Source const*> sourceOrder;
 	set<Source const*> sourcesSeen;

-	function<void(Source const*)> toposort = [&](Source const* _source)
+	function<void(string const&, Source const*)> toposort = [&](string const& _sourceName, Source const* _source)
 	{
 		if (sourcesSeen.count(_source))
 			return;
@ -369,26 +376,44 @@ void CompilerStack::resolveImports()
 		for (ASTPointer<ASTNode> const& node: _source->ast->nodes())
 			if (ImportDirective const* import = dynamic_cast<ImportDirective*>(node.get()))
 			{
-				string const& id = import->identifier();
-				if (!m_sources.count(id))
+				string path = absolutePath(import->identifier(), _sourceName);
+				import->annotation().absolutePath = path;
+				if (!m_sources.count(path))
 					BOOST_THROW_EXCEPTION(
 						Error(Error::Type::ParserError)
 							<< errinfo_sourceLocation(import->location())
 							<< errinfo_comment("Source not found.")
 					);

-				toposort(&m_sources[id]);
+				toposort(path, &m_sources[path]);
 			}
 		sourceOrder.push_back(_source);
 	};

 	for (auto const& sourcePair: m_sources)
 		if (!sourcePair.second.isLibrary)
-			toposort(&sourcePair.second);
+			toposort(sourcePair.first, &sourcePair.second);

 	swap(m_sourceOrder, sourceOrder);
 }

+string CompilerStack::absolutePath(string const& _path, string const& _reference) const
+{
+	// Anything that does not start with `.` is an absolute path.
+	if (_path.empty() || _path.front() != '.')
+		return _path;
+	using path = boost::filesystem::path;
+	path p(_path);
+	path result(_reference);
+	result.remove_filename();
+	for (path::iterator it = p.begin(); it != p.end(); ++it)
+		if (*it == "..")
+			result = result.parent_path();
+		else if (*it != ".")
+			result /= *it;
+	return result.string();
+}
+
 void CompilerStack::compileContract(
 	bool _optimize,
 	unsigned _runs,
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@ -199,6 +199,8 @@ private:
 	};

 	void resolveImports();
+	/// @returns the absolute path corresponding to @a _path relative to @a _reference.
+	std::string absolutePath(std::string const& _path, std::string const& _reference) const;
 	/// Compile a single contract and put the result in @a _compiledContracts.
 	void compileContract(
 		bool _optimize,
--- a/test/libsolidity/Imports.cpp
+++ b/test/libsolidity/Imports.cpp
@ -0,0 +1,100 @@
+/*
+	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/>.
+*/
+/**
+ * @author Christian <c@ethdev.com>
+ * @date 2015
+ * Tests for high level features like import.
+ */
+
+#include <string>
+#include <boost/test/unit_test.hpp>
+#include <libsolidity/interface/Exceptions.h>
+#include <libsolidity/interface/CompilerStack.h>
+
+using namespace std;
+
+namespace dev
+{
+namespace solidity
+{
+namespace test
+{
+
+BOOST_AUTO_TEST_SUITE(SolidityImports)
+
+BOOST_AUTO_TEST_CASE(smoke_test)
+{
+	CompilerStack c;
+	c.addSource("a", "contract C {}");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(regular_import)
+{
+	CompilerStack c;
+	c.addSource("a", "contract C {}");
+	c.addSource("b", "import \"a\"; contract D is C {}");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(import_does_not_clutter_importee)
+{
+	CompilerStack c;
+	c.addSource("a", "contract C { D d; }");
+	c.addSource("b", "import \"a\"; contract D is C {}");
+	BOOST_CHECK(!c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(import_is_transitive)
+{
+	CompilerStack c;
+	c.addSource("a", "contract C { }");
+	c.addSource("b", "import \"a\";");
+	c.addSource("c", "import \"b\"; contract D is C {}");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(circular_import)
+{
+	CompilerStack c;
+	c.addSource("a", "import \"b\"; contract C { D d; }");
+	c.addSource("b", "import \"a\"; contract D { C c; }");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(relative_import)
+{
+	CompilerStack c;
+	c.addSource("a", "import \"./dir/b\"; contract A is B {}");
+	c.addSource("dir/b", "contract B {}");
+	c.addSource("dir/c", "import \"../a\"; contract C is A {}");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_CASE(relative_import_multiplex)
+{
+	CompilerStack c;
+	c.addSource("a", "contract A {}");
+	c.addSource("dir/a/b/c", "import \"../../.././a\"; contract B is A {}");
+	BOOST_CHECK(c.compile());
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+
+}
+}
+} // end namespaces
--- a/test/libsolidity/SolidityExpressionCompiler.cpp
+++ b/test/libsolidity/SolidityExpressionCompiler.cpp
@ -71,18 +71,21 @@ private:
 };

 Declaration const& resolveDeclaration(
-	vector<string> const& _namespacedName, NameAndTypeResolver const& _resolver)
+	SourceUnit const& _sourceUnit,
+	vector<string> const& _namespacedName,
+	NameAndTypeResolver const& _resolver
+)
 {
-	Declaration const* declaration = nullptr;
+	ASTNode const* scope = &_sourceUnit;
 	// bracers are required, cause msvc couldnt handle this macro in for statement
 	for (string const& namePart: _namespacedName)
 	{
-		auto declarations = _resolver.resolveName(namePart, declaration);
+		auto declarations = _resolver.resolveName(namePart, scope);
 		BOOST_REQUIRE(!declarations.empty());
-		BOOST_REQUIRE(declaration = *declarations.begin());
+		BOOST_REQUIRE(scope = *declarations.begin());
 	}
-	BOOST_REQUIRE(declaration);
-	return *declaration;
+	BOOST_REQUIRE(scope);
+	return dynamic_cast<Declaration const&>(*scope);
 }

 bytes compileFirstExpression(
@ -140,13 +143,17 @@ bytes compileFirstExpression(
 			unsigned parametersSize = _localVariables.size(); // assume they are all one slot on the stack
 			context.adjustStackOffset(parametersSize);
 			for (vector<string> const& variable: _localVariables)
-				context.addVariable(dynamic_cast<VariableDeclaration const&>(resolveDeclaration(variable, resolver)),
-									parametersSize--);
+				context.addVariable(
+					dynamic_cast<VariableDeclaration const&>(resolveDeclaration(*sourceUnit, variable, resolver)),
+					parametersSize--
+				);

 			ExpressionCompiler(context).compile(*extractor.expression());

 			for (vector<string> const& function: _functions)
-				context << context.functionEntryLabel(dynamic_cast<FunctionDefinition const&>(resolveDeclaration(function, resolver)));
+				context << context.functionEntryLabel(dynamic_cast<FunctionDefinition const&>(
+					resolveDeclaration(*sourceUnit, function, resolver)
+				));
 			bytes instructions = context.assembledObject().bytecode;
 			// debug
 			// cout << eth::disassemble(instructions) << endl;