Source units are independent scopes.

9 files changed, 204 insertions, 55 deletions

diff --git a/libsolidity/analysis/DeclarationContainer.cpp b/libsolidity/analysis/DeclarationContainer.cpp
index 7339ad5d..ac56562e 100644
--- 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;
 }
 
diff --git a/libsolidity/analysis/DeclarationContainer.h b/libsolidity/analysis/DeclarationContainer.h
index 064724d1..5862f7a5 100644
--- 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;
diff --git a/libsolidity/analysis/NameAndTypeResolver.cpp b/libsolidity/analysis/NameAndTypeResolver.cpp
index fb3e9305..907d703c 100644
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@@ -38,13 +38,18 @@ NameAndTypeResolver::NameAndTypeResolver(
 ) :
 	m_errors(_errors)
 {
-	m_scopes[nullptr].reset(new DeclarationContainer());
+	if (!m_scopes[nullptr])
+		m_scopes[nullptr].reset(new DeclarationContainer());
 	for (Declaration const* declaration: _globals)
 		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
 	{
@@ -59,11 +64,37 @@ 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()))
+		{
+			if (!_sourceUnits.count(imp->identifier()))
+			{
+				reportDeclarationError(node->location(), "Import \"" + imp->identifier() + "\" not found.");
+				error = true;
+			}
+			else
+			{
+				auto scope = m_scopes.find(_sourceUnits.at(imp->identifier()));
+				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].get();
+		m_currentScope = m_scopes[_contract.scope()].get();
+		solAssert(!!m_currentScope, "");
 
 		ReferencesResolver resolver(m_errors, *this, nullptr);
 		bool success = true;
@@ -134,7 +165,7 @@ 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&)
@@ -146,7 +177,7 @@ 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))
@@ -348,9 +379,10 @@ DeclarationRegistrationHelper::DeclarationRegistrationHelper(
 	ErrorList& _errors
 ):
 	m_scopes(_scopes),
-	m_currentScope(nullptr),
+	m_currentScope(&_astRoot),
 	m_errors(_errors)
 {
+	solAssert(!!m_scopes.at(m_currentScope), "");
 	_astRoot.accept(*this);
 }
 
@@ -462,12 +494,12 @@ 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;
@@ -502,14 +534,17 @@ 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;
 }
diff --git a/libsolidity/analysis/NameAndTypeResolver.h b/libsolidity/analysis/NameAndTypeResolver.h
index 805a5596..3c444aba 100644
--- 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*, std::unique_ptr<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;
 };
@@ -164,7 +167,7 @@ private:
 	void fatalDeclarationError(SourceLocation _sourceLocation, std::string const& _description);
 
 	std::map<ASTNode const*, std::unique_ptr<DeclarationContainer>>& m_scopes;
-	Declaration const* m_currentScope = nullptr;
+	ASTNode const* m_currentScope = nullptr;
 	VariableScope* m_currentFunction = nullptr;
 	ErrorList& m_errors;
 };
diff --git a/libsolidity/analysis/ReferencesResolver.cpp b/libsolidity/analysis/ReferencesResolver.cpp
index 2fe53e8b..ca002f58 100644
--- 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(),
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index 1217d945..446088ad 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -172,8 +172,8 @@ 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 +190,7 @@ protected:
 private:
 	ASTPointer<ASTString> m_name;
 	Visibility m_visibility;
-	Declaration const* m_scope;
+	ASTNode const* m_scope;
 };
 
 /**
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 18eec0a2..38fe5956 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -103,12 +103,14 @@ 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
@@ -129,6 +131,10 @@ bool CompilerStack::parse()
 			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()))
 			{
diff --git a/test/libsolidity/Imports.cpp b/test/libsolidity/Imports.cpp
new file mode 100644
index 00000000..b5ff0c54
--- /dev/null
+++ b/test/libsolidity/Imports.cpp
@@ -0,0 +1,83 @@
+/*
+	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_SUITE_END()
+
+}
+}
+} // end namespaces
diff --git a/test/libsolidity/SolidityExpressionCompiler.cpp b/test/libsolidity/SolidityExpressionCompiler.cpp
index a622c738..0e814e56 100644
--- 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;