Name resolution.

10 files changed, 318 insertions, 64 deletions

diff --git a/AST.h b/AST.h
index bedb5f10..cbb78087 100644
--- a/AST.h
+++ b/AST.h
@@ -72,6 +72,9 @@ public:
 	virtual void accept(ASTVisitor& _visitor) override;
 
 	const ASTString& getName() const { return *m_name; }
+	vecptr<StructDefinition> const& getDefinedStructs() { return m_definedStructs; }
+	vecptr<VariableDeclaration> const& getStateVariables() { return m_stateVariables; }
+	vecptr<FunctionDefinition> const& getDefinedFunctions() { return m_definedFunctions; }
 private:
 	ptr<ASTString> m_name;
 	vecptr<StructDefinition> m_definedStructs;
@@ -105,6 +108,8 @@ public:
 		: ASTNode(_location), m_parameters(_parameters)
 	{}
 	virtual void accept(ASTVisitor& _visitor) override;
+
+	vecptr<VariableDeclaration> const& getParameters() { return m_parameters; }
 private:
 	vecptr<VariableDeclaration> m_parameters;
 };
@@ -126,12 +131,16 @@ public:
 	const ASTString& getName() const { return *m_name; }
 	bool isPublic() const { return m_isPublic; }
 	bool isDeclaredConst() const { return m_isDeclaredConst; }
+	vecptr<VariableDeclaration> const& getParameters() { return m_parameters->getParameters(); }
+	bool hasReturnParameters() const { return m_returnParameters.get() != nullptr; }
+	vecptr<VariableDeclaration> const& getReturnParameters() { return m_returnParameters->getParameters(); }
+	Block& getBody() { return *m_body; }
 private:
 	ptr<ASTString> m_name;
 	bool m_isPublic;
 	ptr<ParameterList> m_parameters;
 	bool m_isDeclaredConst;
-	ptr<ParameterList> m_returnParameters;
+	ptr<ParameterList> m_returnParameters; //< either "null"pointer or pointer to non-empty parameter list
 	ptr<Block> m_body;
 };
 
@@ -145,6 +154,7 @@ public:
 	{}
 	virtual void accept(ASTVisitor& _visitor) override;
 
+	TypeName* getTypeName() const { return m_type.get(); }
 	const ASTString& getName() const { return *m_name; }
 private:
 	ptr<TypeName> m_type; ///< can be empty ("var")
@@ -416,8 +426,13 @@ public:
 	virtual void accept(ASTVisitor& _visitor) override;
 
 	ASTString const& getName() const { return *m_name; }
+	void setReferencedObject(ASTNode& _referencedObject) { m_referencedObject = &_referencedObject; }
+	ASTNode* getReferencedVariable() { return m_referencedObject; }
 private:
 	ptr<ASTString> m_name;
+
+	//! Node the name refers to. Has to be a declaration of some sort.
+	ASTNode* m_referencedObject;
 };
 
 class ElementaryTypeNameExpression : public PrimaryExpression
diff --git a/ASTForward.h b/ASTForward.h
index b930a223..963e3d47 100644
--- a/ASTForward.h
+++ b/ASTForward.h
@@ -36,6 +36,7 @@ class FunctionCall;
 class MemberAccess;
 class IndexAccess;
 class PrimaryExpression;
+class Identifier;
 class ElementaryTypeNameExpression;
 class Literal;
 
diff --git a/ASTPrinter.cpp b/ASTPrinter.cpp
index a5fcf959..12969621 100644
--- a/ASTPrinter.cpp
+++ b/ASTPrinter.cpp
@@ -202,6 +202,13 @@ bool ASTPrinter::visit(PrimaryExpression& _node)
 	return goDeeper();
 }
 
+bool ASTPrinter::visit(Identifier& _node)
+{
+	writeLine(std::string("Identifier ") + _node.getName());
+	printSourcePart(_node);
+	return goDeeper();
+}
+
 bool ASTPrinter::visit(ElementaryTypeNameExpression& _node)
 {
 	writeLine(std::string("ElementaryTypeNameExpression ") + Token::String(_node.getType()));
@@ -356,6 +363,11 @@ void ASTPrinter::endVisit(PrimaryExpression&)
 	m_indentation--;
 }
 
+void ASTPrinter::endVisit(Identifier&)
+{
+	m_indentation--;
+}
+
 void ASTPrinter::endVisit(ElementaryTypeNameExpression&)
 {
 	m_indentation--;
diff --git a/ASTPrinter.h b/ASTPrinter.h
index d3cad11c..8e908a84 100644
--- a/ASTPrinter.h
+++ b/ASTPrinter.h
@@ -15,64 +15,66 @@ public:
 	/// Output the string representation of the AST to _stream.
 	void print(std::ostream& _stream);
 
-	bool visit(ContractDefinition& _node);
-	bool visit(StructDefinition& _node);
-	bool visit(ParameterList& _node);
-	bool visit(FunctionDefinition& _node);
-	bool visit(VariableDeclaration& _node);
-	bool visit(TypeName& _node);
-	bool visit(ElementaryTypeName& _node);
-	bool visit(UserDefinedTypeName& _node);
-	bool visit(Mapping& _node);
-	bool visit(Statement& _node);
-	bool visit(Block& _node);
-	bool visit(IfStatement& _node);
-	bool visit(BreakableStatement& _node);
-	bool visit(WhileStatement& _node);
-	bool visit(Continue& _node);
-	bool visit(Break& _node);
-	bool visit(Return& _node);
-	bool visit(VariableDefinition& _node);
-	bool visit(Expression& _node);
-	bool visit(Assignment& _node);
-	bool visit(UnaryOperation& _node);
-	bool visit(BinaryOperation& _node);
-	bool visit(FunctionCall& _node);
-	bool visit(MemberAccess& _node);
-	bool visit(IndexAccess& _node);
-	bool visit(PrimaryExpression& _node);
-	bool visit(ElementaryTypeNameExpression& _node);
-	bool visit(Literal& _node);
+	bool visit(ContractDefinition& _node) override;
+	bool visit(StructDefinition& _node) override;
+	bool visit(ParameterList& _node) override;
+	bool visit(FunctionDefinition& _node) override;
+	bool visit(VariableDeclaration& _node) override;
+	bool visit(TypeName& _node) override;
+	bool visit(ElementaryTypeName& _node) override;
+	bool visit(UserDefinedTypeName& _node) override;
+	bool visit(Mapping& _node) override;
+	bool visit(Statement& _node) override;
+	bool visit(Block& _node) override;
+	bool visit(IfStatement& _node) override;
+	bool visit(BreakableStatement& _node) override;
+	bool visit(WhileStatement& _node) override;
+	bool visit(Continue& _node) override;
+	bool visit(Break& _node) override;
+	bool visit(Return& _node) override;
+	bool visit(VariableDefinition& _node) override;
+	bool visit(Expression& _node) override;
+	bool visit(Assignment& _node) override;
+	bool visit(UnaryOperation& _node) override;
+	bool visit(BinaryOperation& _node) override;
+	bool visit(FunctionCall& _node) override;
+	bool visit(MemberAccess& _node) override;
+	bool visit(IndexAccess& _node) override;
+	bool visit(PrimaryExpression& _node) override;
+	bool visit(Identifier& _node) override;
+	bool visit(ElementaryTypeNameExpression& _node) override;
+	bool visit(Literal& _node) override;
 
-	void endVisit(ASTNode & _node);
-	void endVisit(ContractDefinition&);
-	void endVisit(StructDefinition&);
-	void endVisit(ParameterList&);
-	void endVisit(FunctionDefinition&);
-	void endVisit(VariableDeclaration&);
-	void endVisit(TypeName&);
-	void endVisit(ElementaryTypeName&);
-	void endVisit(UserDefinedTypeName&);
-	void endVisit(Mapping&);
-	void endVisit(Statement&);
-	void endVisit(Block&);
-	void endVisit(IfStatement&);
-	void endVisit(BreakableStatement&);
-	void endVisit(WhileStatement&);
-	void endVisit(Continue&);
-	void endVisit(Break&);
-	void endVisit(Return&);
-	void endVisit(VariableDefinition&);
-	void endVisit(Expression&);
-	void endVisit(Assignment&);
-	void endVisit(UnaryOperation&);
-	void endVisit(BinaryOperation&);
-	void endVisit(FunctionCall&);
-	void endVisit(MemberAccess&);
-	void endVisit(IndexAccess&);
-	void endVisit(PrimaryExpression&);
-	void endVisit(ElementaryTypeNameExpression&);
-	void endVisit(Literal&);
+	void endVisit(ASTNode & _node) override;
+	void endVisit(ContractDefinition&) override;
+	void endVisit(StructDefinition&) override;
+	void endVisit(ParameterList&) override;
+	void endVisit(FunctionDefinition&) override;
+	void endVisit(VariableDeclaration&) override;
+	void endVisit(TypeName&) override;
+	void endVisit(ElementaryTypeName&) override;
+	void endVisit(UserDefinedTypeName&) override;
+	void endVisit(Mapping&) override;
+	void endVisit(Statement&) override;
+	void endVisit(Block&) override;
+	void endVisit(IfStatement&) override;
+	void endVisit(BreakableStatement&) override;
+	void endVisit(WhileStatement&) override;
+	void endVisit(Continue&) override;
+	void endVisit(Break&) override;
+	void endVisit(Return&) override;
+	void endVisit(VariableDefinition&) override;
+	void endVisit(Expression&) override;
+	void endVisit(Assignment&) override;
+	void endVisit(UnaryOperation&) override;
+	void endVisit(BinaryOperation&) override;
+	void endVisit(FunctionCall&) override;
+	void endVisit(MemberAccess&) override;
+	void endVisit(IndexAccess&) override;
+	void endVisit(PrimaryExpression&) override;
+	void endVisit(Identifier&) override;
+	void endVisit(ElementaryTypeNameExpression&) override;
+	void endVisit(Literal&) override;
 
 private:
 	void printSourcePart(ASTNode const& _node);
diff --git a/ASTVisitor.h b/ASTVisitor.h
index a68d76ae..f3ae3be7 100644
--- a/ASTVisitor.h
+++ b/ASTVisitor.h
@@ -39,6 +39,7 @@ public:
 	virtual bool visit(MemberAccess&) { return true; }
 	virtual bool visit(IndexAccess&) { return true; }
 	virtual bool visit(PrimaryExpression&) { return true; }
+	virtual bool visit(Identifier&) { return true; }
 	virtual bool visit(ElementaryTypeNameExpression&) { return true; }
 	virtual bool visit(Literal&) { return true; }
 
@@ -69,6 +70,7 @@ public:
 	virtual void endVisit(MemberAccess&) { }
 	virtual void endVisit(IndexAccess&) { }
 	virtual void endVisit(PrimaryExpression&) { }
+	virtual void endVisit(Identifier&) { }
 	virtual void endVisit(ElementaryTypeNameExpression&) { }
 	virtual void endVisit(Literal&) { }
 };
diff --git a/NameAndTypeResolver.cpp b/NameAndTypeResolver.cpp
new file mode 100644
index 00000000..c4f0612b
--- /dev/null
+++ b/NameAndTypeResolver.cpp
@@ -0,0 +1,142 @@
+#include <libsolidity/NameAndTypeResolver.h>
+
+#include <libsolidity/AST.h>
+#include <boost/assert.hpp>
+
+namespace dev {
+namespace solidity {
+
+
+class NameAndTypeResolver::ScopeHelper {
+public:
+	ScopeHelper(NameAndTypeResolver& _resolver, ASTString const& _name, ASTNode& _declaration)
+		: m_resolver(_resolver)
+	{
+		m_resolver.registerName(_name, _declaration);
+		m_resolver.enterNewSubScope(_declaration);
+	}
+	~ScopeHelper()
+	{
+		m_resolver.closeCurrentScope();
+	}
+
+private:
+	NameAndTypeResolver& m_resolver;
+};
+
+
+NameAndTypeResolver::NameAndTypeResolver()
+{
+}
+
+void NameAndTypeResolver::resolveNamesAndTypes(ContractDefinition& _contract)
+{
+	reset();
+
+	handleContract(_contract);
+}
+
+void NameAndTypeResolver::handleContract(ContractDefinition& _contract)
+{
+	ScopeHelper scopeHelper(*this, _contract.getName(), _contract);
+
+	for (ptr<VariableDeclaration> const& variable : _contract.getStateVariables())
+		registerName(variable->getName(), *variable);
+	// @todo structs
+
+	for (ptr<FunctionDefinition> const& function : _contract.getDefinedFunctions())
+		handleFunction(*function);
+
+	// @todo resolve names used in mappings
+}
+
+void NameAndTypeResolver::reset()
+{
+	m_scopes.clear();
+	m_globalScope = Scope();
+	m_currentScope = &m_globalScope;
+}
+
+void NameAndTypeResolver::handleFunction(FunctionDefinition& _function)
+{
+	ScopeHelper scopeHelper(*this, _function.getName(), _function);
+
+	// @todo resolve names used in mappings
+	for (ptr<VariableDeclaration> const& variable  : _function.getParameters())
+		registerName(variable->getName(), *variable);
+	if (_function.hasReturnParameters())
+		for (ptr<VariableDeclaration> const& variable  : _function.getReturnParameters())
+			registerName(variable->getName(), *variable);
+	handleFunctionBody(_function.getBody());
+}
+
+void NameAndTypeResolver::handleFunctionBody(Block& _functionBody)
+{
+	registerVariablesInFunction(_functionBody);
+	resolveReferencesInFunction(_functionBody);
+}
+
+void NameAndTypeResolver::registerVariablesInFunction(Block& _functionBody)
+{
+	class VariableDeclarationFinder : public ASTVisitor {
+	public:
+		VariableDeclarationFinder(NameAndTypeResolver& _resolver) : m_resolver(_resolver) {}
+		virtual bool visit(VariableDeclaration& _variable) override {
+			m_resolver.registerName(_variable.getName(), _variable);
+			return false;
+		}
+	private:
+		NameAndTypeResolver& m_resolver;
+	};
+
+	VariableDeclarationFinder declarationFinder(*this);
+	_functionBody.accept(declarationFinder);
+}
+
+void NameAndTypeResolver::resolveReferencesInFunction(Block& _functionBody)
+{
+	class ReferencesResolver : public ASTVisitor {
+	public:
+		ReferencesResolver(NameAndTypeResolver& _resolver) : m_resolver(_resolver) {}
+		virtual bool visit(Identifier& _identifier) override {
+			ASTNode* node = m_resolver.getNameFromCurrentScope(_identifier.getName());
+			if (node == nullptr)
+				throw std::exception(); // @todo
+			_identifier.setReferencedObject(*node);
+			return false;
+		}
+	private:
+		NameAndTypeResolver& m_resolver;
+	};
+
+	ReferencesResolver referencesResolver(*this);
+	_functionBody.accept(referencesResolver);
+}
+
+
+void NameAndTypeResolver::registerName(ASTString const& _name, ASTNode& _declaration)
+{
+	if (!m_currentScope->registerName(_name, _declaration))
+		throw std::exception(); // @todo
+}
+
+ASTNode* NameAndTypeResolver::getNameFromCurrentScope(ASTString const& _name, bool _recursive)
+{
+	return m_currentScope->resolveName(_name, _recursive);
+}
+
+void NameAndTypeResolver::enterNewSubScope(ASTNode& _node)
+{
+	decltype(m_scopes)::iterator iter;
+	bool newlyAdded;
+	std::tie(iter, newlyAdded) = m_scopes.emplace(&_node, Scope(m_currentScope));
+	BOOST_ASSERT(newlyAdded);
+	m_currentScope = &iter->second;
+}
+
+void NameAndTypeResolver::closeCurrentScope()
+{
+	m_currentScope = m_currentScope->getOuterScope();
+}
+
+} }
diff --git a/NameAndTypeResolver.h b/NameAndTypeResolver.h
new file mode 100644
index 00000000..ca714ac2
--- /dev/null
+++ b/NameAndTypeResolver.h
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <map>
+
+#include <libsolidity/Scope.h>
+#include <libsolidity/ASTVisitor.h>
+
+namespace dev {
+namespace solidity {
+
+class NameAndTypeResolver
+{
+public:
+	NameAndTypeResolver();
+
+	void resolveNamesAndTypes(ContractDefinition& _contract);
+private:
+	class ScopeHelper; //< RIIA helper to open and close scopes
+
+	void reset();
+
+	void handleContract(ContractDefinition& _contract);
+	void handleFunction(FunctionDefinition& _function);
+	void handleFunctionBody(Block& _functionBody);
+	void registerVariablesInFunction(Block& _functionBody);
+	void resolveReferencesInFunction(Block& _functionBody);
+
+	void registerName(ASTString const& _name, ASTNode& _declaration);
+	ASTNode* getNameFromCurrentScope(ASTString const& _name, bool _recursive = true);
+
+	void enterNewSubScope(ASTNode& _node);
+	void closeCurrentScope();
+
+	Scope m_globalScope; // not part of the map
+	std::map<ASTNode*, Scope> m_scopes;
+
+	Scope* m_currentScope;
+};
+
+} }
diff --git a/Parser.cpp b/Parser.cpp
index 3ccd0930..eb171cbc 100644
--- a/Parser.cpp
+++ b/Parser.cpp
@@ -28,7 +28,7 @@
 namespace dev {
 namespace solidity {
 
-ptr<ASTNode> Parser::parse(std::shared_ptr<Scanner> const& _scanner)
+ptr<ContractDefinition> Parser::parse(std::shared_ptr<Scanner> const& _scanner)
 {
 	m_scanner = _scanner;
 
@@ -132,8 +132,9 @@ ptr<FunctionDefinition> Parser::parseFunctionDefinition(bool _isPublic)
 	}
 	ptr<ParameterList> returnParameters;
 	if (m_scanner->getCurrentToken() == Token::RETURNS) {
+		const bool permitEmptyParameterList = false;
 		m_scanner->next();
-		returnParameters = parseParameterList();
+		returnParameters = parseParameterList(permitEmptyParameterList);
 	}
 	ptr<Block> block = parseBlock();
 	nodeFactory.setEndPositionFromNode(block);
@@ -212,13 +213,13 @@ ptr<Mapping> Parser::parseMapping()
 	return nodeFactory.createNode<Mapping>(keyType, valueType);
 }
 
-ptr<ParameterList> Parser::parseParameterList()
+ptr<ParameterList> Parser::parseParameterList(bool _permitEmpty)
 {
 	ASTNodeFactory nodeFactory(*this);
 
 	vecptr<VariableDeclaration> parameters;
 	expectToken(Token::LPAREN);
-	if (m_scanner->getCurrentToken() != Token::RPAREN) {
+	if (!_permitEmpty || m_scanner->getCurrentToken() != Token::RPAREN) {
 		parameters.push_back(parseVariableDeclaration());
 		while (m_scanner->getCurrentToken() != Token::RPAREN) {
 			expectToken(Token::COMMA);
diff --git a/Parser.h b/Parser.h
index f8940d1a..88369052 100644
--- a/Parser.h
+++ b/Parser.h
@@ -32,7 +32,7 @@ class Scanner;
 class Parser
 {
 public:
-	ptr<ASTNode> parse(std::shared_ptr<Scanner> const& _scanner);
+	ptr<ContractDefinition> parse(std::shared_ptr<Scanner> const& _scanner);
 
 private:
 	class ASTNodeFactory;
@@ -50,7 +50,7 @@ private:
 	ptr<VariableDeclaration> parseVariableDeclaration();
 	ptr<TypeName> parseTypeName();
 	ptr<Mapping> parseMapping();
-	ptr<ParameterList> parseParameterList();
+	ptr<ParameterList> parseParameterList(bool _permitEmpty = true);
 	ptr<Block> parseBlock();
 	ptr<Statement> parseStatement();
 	ptr<IfStatement> parseIfStatement();
diff --git a/Scope.h b/Scope.h
new file mode 100644
index 00000000..c0aede94
--- /dev/null
+++ b/Scope.h
@@ -0,0 +1,39 @@
+#pragma once
+
+#include <map>
+
+#include <libsolidity/ASTForward.h>
+
+namespace dev {
+namespace solidity {
+
+class Scope
+{
+public:
+	explicit Scope(Scope* _outerScope = nullptr) : m_outerScope(_outerScope) {}
+	/// Registers the name _name in the scope unless it is already declared. Returns true iff
+	/// it was not yet declared.
+	bool registerName(ASTString const& _name, ASTNode& _declaration)
+	{
+		if (m_declaredNames.find(_name) != m_declaredNames.end())
+			return false;
+		m_declaredNames[_name] = &_declaration;
+		return true;
+	}
+	ASTNode* resolveName(ASTString const& _name, bool _recursive = false) const
+	{
+		auto result = m_declaredNames.find(_name);
+		if (result != m_declaredNames.end())
+			return result->second;
+		if (_recursive && m_outerScope != nullptr)
+			return m_outerScope->resolveName(_name, true);
+		return nullptr;
+	}
+	Scope* getOuterScope() const { return m_outerScope; }
+
+private:
+	Scope* m_outerScope;
+	std::map<ASTString, ASTNode*> m_declaredNames;
+};
+
+} }