Store docstrings in AST annotations.

11 files changed, 509 insertions, 335 deletions

diff --git a/libsolidity/analysis/DocStringAnalyser.cpp b/libsolidity/analysis/DocStringAnalyser.cpp
new file mode 100644
index 00000000..96cb5692
--- /dev/null
+++ b/libsolidity/analysis/DocStringAnalyser.cpp
@@ -0,0 +1,117 @@
+/*
+    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
+ * Parses and analyses the doc strings.
+ * Stores the parsing results in the AST annotations and reports errors.
+ */
+
+#include <libsolidity/analysis/DocStringAnalyser.h>
+#include <libsolidity/ast/AST.h>
+#include <libsolidity/parsing/DocStringParser.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+
+bool DocStringAnalyser::analyseDocStrings(SourceUnit const& _sourceUnit)
+{
+	m_errorOccured = false;
+	_sourceUnit.accept(*this);
+
+	return !m_errorOccured;
+}
+
+bool DocStringAnalyser::visit(ContractDefinition const& _node)
+{
+	parseDocStrings(_node, _node.annotation());
+
+	static const set<string> validTags = set<string>{"author", "title", "dev", "notice"};
+	for (auto const& docTag: _node.annotation().docTags)
+		if (!validTags.count(docTag.first))
+			appendError("Doc tag @" + docTag.first + " not valid for contracts.");
+
+	return true;
+}
+
+bool DocStringAnalyser::visit(FunctionDefinition const& _node)
+{
+	handleCallable(_node, _node, _node.annotation());
+	return true;
+}
+
+bool DocStringAnalyser::visit(ModifierDefinition const& _node)
+{
+	handleCallable(_node, _node, _node.annotation());
+
+	return true;
+}
+
+bool DocStringAnalyser::visit(EventDefinition const& _node)
+{
+	handleCallable(_node, _node, _node.annotation());
+
+	return true;
+}
+
+void DocStringAnalyser::handleCallable(
+		CallableDeclaration const& _callable,
+		Documented const& _node,
+		DocumentedAnnotation& _annotation
+)
+{
+	parseDocStrings(_node, _annotation);
+	static const set<string> validTags = set<string>{"author", "dev", "notice", "return", "param", "why3"};
+	for (auto const& docTag: _annotation.docTags)
+		if (!validTags.count(docTag.first))
+			appendError("Doc tag @" + docTag.first + " not valid for functions.");
+
+	set<string> validParams;
+	for (auto const& p: _callable.parameters())
+		validParams.insert(p->name());
+	if (_callable.returnParameterList())
+		for (auto const& p: _callable.returnParameterList()->parameters())
+			validParams.insert(p->name());
+	auto paramRange = _annotation.docTags.equal_range("param");
+	for (auto i = paramRange.first; i != paramRange.second; ++i)
+		if (!validParams.count(i->second.paramName))
+			appendError(
+				"Documented parameter \"" +
+				i->second.paramName +
+				"\" not found in the parameter list of the function."
+			);
+}
+
+void DocStringAnalyser::parseDocStrings(Documented const& _node, DocumentedAnnotation& _annotation)
+{
+	DocStringParser parser;
+	if (_node.documentation() && !_node.documentation()->empty())
+	{
+		if (!parser.parse(*_node.documentation(), m_errors))
+			m_errorOccured = true;
+		_annotation.docTags = parser.tags();
+	}
+}
+
+void DocStringAnalyser::appendError(string const& _description)
+{
+	auto err = make_shared<Error>(Error::Type::DocstringParsingError);
+	*err << errinfo_comment(_description);
+	m_errors.push_back(err);
+	m_errorOccured = true;
+}
diff --git a/libsolidity/analysis/DocStringAnalyser.h b/libsolidity/analysis/DocStringAnalyser.h
new file mode 100644
index 00000000..06384c8d
--- /dev/null
+++ b/libsolidity/analysis/DocStringAnalyser.h
@@ -0,0 +1,64 @@
+/*
+    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
+ * Parses and analyses the doc strings.
+ * Stores the parsing results in the AST annotations and reports errors.
+ */
+
+#pragma once
+
+#include <libsolidity/ast/ASTVisitor.h>
+
+namespace dev
+{
+namespace solidity
+{
+
+/**
+ * Parses and analyses the doc strings.
+ * Stores the parsing results in the AST annotations and reports errors.
+ */
+class DocStringAnalyser: private ASTConstVisitor
+{
+public:
+	DocStringAnalyser(ErrorList& _errors): m_errors(_errors) {}
+	bool analyseDocStrings(SourceUnit const& _sourceUnit);
+
+private:
+	virtual bool visit(ContractDefinition const& _contract) override;
+	virtual bool visit(FunctionDefinition const& _function) override;
+	virtual bool visit(ModifierDefinition const& _modifier) override;
+	virtual bool visit(EventDefinition const& _event) override;
+
+	void handleCallable(
+		CallableDeclaration const& _callable,
+		Documented const& _node,
+		DocumentedAnnotation& _annotation
+	);
+
+	void parseDocStrings(Documented const& _node, DocumentedAnnotation& _annotation);
+
+	void appendError(std::string const& _description);
+
+	bool m_errorOccured = false;
+	ErrorList& m_errors;
+};
+
+}
+}
diff --git a/libsolidity/ast/AST.cpp b/libsolidity/ast/AST.cpp
index 71d80a36..9d1fb811 100644
--- a/libsolidity/ast/AST.cpp
+++ b/libsolidity/ast/AST.cpp
@@ -248,16 +248,37 @@ string FunctionDefinition::externalSignature() const
 	return FunctionType(*this).externalSignature();
 }
 
+FunctionDefinitionAnnotation& FunctionDefinition::annotation() const
+{
+	if (!m_annotation)
+		m_annotation = new FunctionDefinitionAnnotation();
+	return static_cast<FunctionDefinitionAnnotation&>(*m_annotation);
+}
+
 TypePointer ModifierDefinition::type(ContractDefinition const*) const
 {
 	return make_shared<ModifierType>(*this);
 }
 
+ModifierDefinitionAnnotation& ModifierDefinition::annotation() const
+{
+	if (!m_annotation)
+		m_annotation = new ModifierDefinitionAnnotation();
+	return static_cast<ModifierDefinitionAnnotation&>(*m_annotation);
+}
+
 TypePointer EventDefinition::type(ContractDefinition const*) const
 {
 	return make_shared<FunctionType>(*this);
 }
 
+EventDefinitionAnnotation& EventDefinition::annotation() const
+{
+	if (!m_annotation)
+		m_annotation = new EventDefinitionAnnotation();
+	return static_cast<EventDefinitionAnnotation&>(*m_annotation);
+}
+
 UserDefinedTypeNameAnnotation& UserDefinedTypeName::annotation() const
 {
 	if (!m_annotation)
diff --git a/libsolidity/ast/AST.h b/libsolidity/ast/AST.h
index 3fe447eb..6a593d3e 100644
--- a/libsolidity/ast/AST.h
+++ b/libsolidity/ast/AST.h
@@ -492,6 +492,8 @@ public:
 
 	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
 
+	virtual FunctionDefinitionAnnotation& annotation() const override;
+
 private:
 	bool m_isConstructor;
 	bool m_isDeclaredConst;
@@ -593,6 +595,8 @@ public:
 
 	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
 
+	virtual ModifierDefinitionAnnotation& annotation() const override;
+
 private:
 	ASTPointer<Block> m_body;
 };
@@ -647,6 +651,8 @@ public:
 
 	virtual TypePointer type(ContractDefinition const* m_currentContract) const override;
 
+	virtual EventDefinitionAnnotation& annotation() const override;
+
 private:
 	bool m_anonymous = false;
 };
diff --git a/libsolidity/ast/ASTAnnotations.h b/libsolidity/ast/ASTAnnotations.h
index d112b1ef..094a178e 100644
--- a/libsolidity/ast/ASTAnnotations.h
+++ b/libsolidity/ast/ASTAnnotations.h
@@ -41,13 +41,26 @@ struct ASTAnnotation
 	virtual ~ASTAnnotation() {}
 };
 
+struct DocTag
+{
+	std::string content;	///< The text content of the tag.
+	std::string paramName;	///< Only used for @param, stores the parameter name.
+};
+
+struct DocumentedAnnotation
+{
+	virtual ~DocumentedAnnotation() {}
+	/// Mapping docstring tag name -> content.
+	std::multimap<std::string, DocTag> docTags;
+};
+
 struct TypeDeclarationAnnotation: ASTAnnotation
 {
 	/// The name of this type, prefixed by proper namespaces if globally accessible.
 	std::string canonicalName;
 };
 
-struct ContractDefinitionAnnotation: TypeDeclarationAnnotation
+struct ContractDefinitionAnnotation: TypeDeclarationAnnotation, DocumentedAnnotation
 {
 	/// Whether all functions are implemented.
 	bool isFullyImplemented = true;
@@ -59,6 +72,18 @@ struct ContractDefinitionAnnotation: TypeDeclarationAnnotation
 	std::set<ContractDefinition const*> contractDependencies;
 };
 
+struct FunctionDefinitionAnnotation: ASTAnnotation, DocumentedAnnotation
+{
+};
+
+struct EventDefinitionAnnotation: ASTAnnotation, DocumentedAnnotation
+{
+};
+
+struct ModifierDefinitionAnnotation: ASTAnnotation, DocumentedAnnotation
+{
+};
+
 struct VariableDeclarationAnnotation: ASTAnnotation
 {
 	/// Type of variable (type of identifier referencing this variable).
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 775c7eb6..6b55b408 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -28,6 +28,7 @@
 #include <libsolidity/analysis/GlobalContext.h>
 #include <libsolidity/analysis/NameAndTypeResolver.h>
 #include <libsolidity/analysis/TypeChecker.h>
+#include <libsolidity/analysis/DocStringAnalyser.h>
 #include <libsolidity/codegen/Compiler.h>
 #include <libsolidity/interface/CompilerStack.h>
 #include <libsolidity/interface/InterfaceHandler.h>
@@ -114,6 +115,12 @@ bool CompilerStack::parse()
 
 	resolveImports();
 
+	bool noErrors = true;
+	DocStringAnalyser docStringAnalyser(m_errors);
+	for (Source const* source: m_sourceOrder)
+		if (!docStringAnalyser.analyseDocStrings(*source->ast))
+			noErrors = false;
+
 	m_globalContext = make_shared<GlobalContext>();
 	NameAndTypeResolver resolver(m_globalContext->declarations(), m_errors);
 	for (Source const* source: m_sourceOrder)
@@ -131,8 +138,6 @@ bool CompilerStack::parse()
 				m_contracts[contract->name()].contract = contract;
 			}
 
-	InterfaceHandler interfaceHandler;
-	bool typesFine = true;
 	for (Source const* source: m_sourceOrder)
 		for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 			if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
@@ -142,15 +147,15 @@ bool CompilerStack::parse()
 				TypeChecker typeChecker(m_errors);
 				if (typeChecker.checkTypeRequirements(*contract))
 				{
-					contract->setDevDocumentation(interfaceHandler.devDocumentation(*contract));
-					contract->setUserDocumentation(interfaceHandler.userDocumentation(*contract));
+					contract->setDevDocumentation(InterfaceHandler::devDocumentation(*contract));
+					contract->setUserDocumentation(InterfaceHandler::userDocumentation(*contract));
 				}
 				else
-					typesFine = false;
+					noErrors = false;
 
 				m_contracts[contract->name()].contract = contract;
 			}
-	m_parseSuccessful = typesFine;
+	m_parseSuccessful = noErrors;
 	return m_parseSuccessful;
 }
 
@@ -287,7 +292,7 @@ string const& CompilerStack::metadata(string const& _contractName, Documentation
 
 	// caches the result
 	if (!*doc)
-		doc->reset(new string(currentContract.interfaceHandler->documentation(*currentContract.contract, _type)));
+		doc->reset(new string(InterfaceHandler::documentation(*currentContract.contract, _type)));
 
 	return *(*doc);
 }
@@ -428,8 +433,5 @@ CompilerStack::Source const& CompilerStack::source(string const& _sourceName) co
 	return it->second;
 }
 
-CompilerStack::Contract::Contract(): interfaceHandler(make_shared<InterfaceHandler>()) {}
-
-
 }
 }
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index 1f1b74f5..ac71da2e 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -188,13 +188,10 @@ private:
 		eth::LinkerObject object;
 		eth::LinkerObject runtimeObject;
 		eth::LinkerObject cloneObject;
-		std::shared_ptr<InterfaceHandler> interfaceHandler;
 		mutable std::unique_ptr<std::string const> interface;
 		mutable std::unique_ptr<std::string const> solidityInterface;
 		mutable std::unique_ptr<std::string const> userDocumentation;
 		mutable std::unique_ptr<std::string const> devDocumentation;
-
-		Contract();
 	};
 
 	void resolveImports();
diff --git a/libsolidity/interface/InterfaceHandler.cpp b/libsolidity/interface/InterfaceHandler.cpp
index 136136e6..30cd9724 100644
--- a/libsolidity/interface/InterfaceHandler.cpp
+++ b/libsolidity/interface/InterfaceHandler.cpp
@@ -3,19 +3,10 @@
 #include <boost/range/irange.hpp>
 #include <libsolidity/ast/AST.h>
 #include <libsolidity/interface/CompilerStack.h>
-using namespace std;
-
-namespace dev
-{
-namespace solidity
-{
-
-/* -- public -- */
 
-InterfaceHandler::InterfaceHandler()
-{
-	m_lastTag = DocTagType::None;
-}
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
 
 string InterfaceHandler::documentation(
 	ContractDefinition const& _contractDef,
@@ -181,20 +172,18 @@ string InterfaceHandler::userDocumentation(ContractDefinition const& _contractDe
 	Json::Value methods(Json::objectValue);
 
 	for (auto const& it: _contractDef.interfaceFunctions())
-	{
-		Json::Value user;
-		auto strPtr = it.second->documentation();
-		if (strPtr)
-		{
-			resetUser();
-			parseDocString(*strPtr, CommentOwner::Function);
-			if (!m_notice.empty())
-			{// since @notice is the only user tag if missing function should not appear
-				user["notice"] = Json::Value(m_notice);
-				methods[it.second->externalSignature()] = user;
+		if (it.second->hasDeclaration())
+			if (auto const* f = dynamic_cast<FunctionDefinition const*>(&it.second->declaration()))
+			{
+				string value = extractDoc(f->annotation().docTags, "notice");
+				if (!value.empty())
+				{
+					Json::Value user;
+					// since @notice is the only user tag if missing function should not appear
+					user["notice"] = Json::Value(value);
+					methods[it.second->externalSignature()] = user;
+				}
 			}
-		}
-	}
 	doc["methods"] = methods;
 
 	return Json::StyledWriter().write(doc);
@@ -202,60 +191,45 @@ string InterfaceHandler::userDocumentation(ContractDefinition const& _contractDe
 
 string InterfaceHandler::devDocumentation(ContractDefinition const& _contractDef)
 {
-	// LTODO: Somewhere in this function warnings for mismatch of param names
-	// should be thrown
 	Json::Value doc;
 	Json::Value methods(Json::objectValue);
 
-	auto contractDoc = _contractDef.documentation();
-	if (contractDoc)
-	{
-		m_contractAuthor.clear();
-		m_title.clear();
-		parseDocString(*contractDoc, CommentOwner::Contract);
-
-		if (!m_contractAuthor.empty())
-			doc["author"] = m_contractAuthor;
-
-		if (!m_title.empty())
-			doc["title"] = m_title;
-	}
+	auto author = extractDoc(_contractDef.annotation().docTags, "author");
+	if (!author.empty())
+		doc["author"] = author;
+	auto title = extractDoc(_contractDef.annotation().docTags, "title");
+	if (!title.empty())
+		doc["title"] = title;
 
 	for (auto const& it: _contractDef.interfaceFunctions())
 	{
+		if (!it.second->hasDeclaration())
+			continue;
 		Json::Value method;
-		auto strPtr = it.second->documentation();
-		if (strPtr)
+		if (auto fun = dynamic_cast<FunctionDefinition const*>(&it.second->declaration()))
 		{
-			resetDev();
-			parseDocString(*strPtr, CommentOwner::Function);
+			auto dev = extractDoc(fun->annotation().docTags, "dev");
+			if (!dev.empty())
+				method["details"] = Json::Value(dev);
 
-			if (!m_dev.empty())
-				method["details"] = Json::Value(m_dev);
+			auto author = extractDoc(fun->annotation().docTags, "author");
+			if (!author.empty())
+				method["author"] = author;
 
-			if (!m_author.empty())
-				method["author"] = m_author;
+			auto ret = extractDoc(fun->annotation().docTags, "return");
+			if (!ret.empty())
+				method["return"] = ret;
 
 			Json::Value params(Json::objectValue);
-			vector<string> paramNames = it.second->parameterNames();
-			for (auto const& pair: m_params)
-			{
-				if (find(paramNames.begin(), paramNames.end(), pair.first) == paramNames.end())
-					// LTODO: mismatching parameter name, throw some form of warning and not just an exception
-					BOOST_THROW_EXCEPTION(
-						Error(Error::Type::DocstringParsingError) <<
-						errinfo_comment("documented parameter \"" + pair.first + "\" not found in the parameter list of the function.")
-					);					
-				params[pair.first] = pair.second;
-			}
+			auto paramRange = fun->annotation().docTags.equal_range("param");
+			for (auto i = paramRange.first; i != paramRange.second; ++i)
+				params[i->second.paramName] = Json::Value(i->second.content);
 
-			if (!m_params.empty())
+			if (!params.empty())
 				method["params"] = params;
 
-			if (!m_return.empty())
-				method["return"] = m_return;
-
-			if (!method.empty()) // add the function, only if we have any documentation to add
+			if (!method.empty())
+				// add the function, only if we have any documentation to add
 				methods[it.second->externalSignature()] = method;
 		}
 	}
@@ -264,215 +238,11 @@ string InterfaceHandler::devDocumentation(ContractDefinition const& _contractDef
 	return Json::StyledWriter().write(doc);
 }
 
-/* -- private -- */
-void InterfaceHandler::resetUser()
+string InterfaceHandler::extractDoc(multimap<string, DocTag> const& _tags, string const& _name)
 {
-	m_notice.clear();
+	string value;
+	auto range = _tags.equal_range(_name);
+	for (auto i = range.first; i != range.second; i++)
+		value += i->second.content;
+	return value;
 }
-
-void InterfaceHandler::resetDev()
-{
-	m_dev.clear();
-	m_author.clear();
-	m_return.clear();
-	m_params.clear();
-}
-
-static inline string::const_iterator skipLineOrEOS(
-	string::const_iterator _nlPos,
-	string::const_iterator _end
-)
-{
-	return (_nlPos == _end) ? _end : ++_nlPos;
-}
-
-string::const_iterator InterfaceHandler::parseDocTagLine(
-	string::const_iterator _pos,
-	string::const_iterator _end,
-	string& _tagString,
-	DocTagType _tagType,
-	bool _appending
-)
-{
-	auto nlPos = find(_pos, _end, '\n');
-	if (_appending && _pos < _end && *_pos != ' ')
-		_tagString += " ";
-	copy(_pos, nlPos, back_inserter(_tagString));
-	m_lastTag = _tagType;
-	return skipLineOrEOS(nlPos, _end);
-}
-
-string::const_iterator InterfaceHandler::parseDocTagParam(
-	string::const_iterator _pos,
-	string::const_iterator _end
-)
-{
-	// find param name
-	auto currPos = find(_pos, _end, ' ');
-	if (currPos == _end)
-		BOOST_THROW_EXCEPTION(Error(Error::Type::DocstringParsingError) << errinfo_comment("End of param name not found" + string(_pos, _end)));
-
-
-	auto paramName = string(_pos, currPos);
-
-	currPos += 1;
-	auto nlPos = find(currPos, _end, '\n');
-	auto paramDesc = string(currPos, nlPos);
-	m_params.push_back(make_pair(paramName, paramDesc));
-
-	m_lastTag = DocTagType::Param;
-	return skipLineOrEOS(nlPos, _end);
-}
-
-string::const_iterator InterfaceHandler::appendDocTagParam(
-	string::const_iterator _pos,
-	string::const_iterator _end
-)
-{
-	// Should never be called with an empty vector
-	solAssert(!m_params.empty(), "Internal: Tried to append to empty parameter");
-
-	auto pair = m_params.back();
-	if (_pos < _end && *_pos != ' ')
-		pair.second += " ";
-	auto nlPos = find(_pos, _end, '\n');
-	copy(_pos, nlPos, back_inserter(pair.second));
-
-	m_params.at(m_params.size() - 1) = pair;
-
-	return skipLineOrEOS(nlPos, _end);
-}
-
-string::const_iterator InterfaceHandler::parseDocTag(
-	string::const_iterator _pos,
-	string::const_iterator _end,
-	string const& _tag,
-	CommentOwner _owner
-)
-{
-	// LTODO: need to check for @(start of a tag) between here and the end of line
-	// for all cases. Also somehow automate list of acceptable tags for each
-	// language construct since current way does not scale well.
-	if (m_lastTag == DocTagType::None || _tag != "")
-	{
-		if (_tag == "dev")
-			return parseDocTagLine(_pos, _end, m_dev, DocTagType::Dev, false);
-		else if (_tag == "notice")
-			return parseDocTagLine(_pos, _end, m_notice, DocTagType::Notice, false);
-		else if (_tag == "return")
-			return parseDocTagLine(_pos, _end, m_return, DocTagType::Return, false);
-		else if (_tag == "author")
-		{
-			if (_owner == CommentOwner::Contract)
-				return parseDocTagLine(_pos, _end, m_contractAuthor, DocTagType::Author, false);
-			else if (_owner == CommentOwner::Function)
-				return parseDocTagLine(_pos, _end, m_author, DocTagType::Author, false);
-			else
-				// LTODO: for now this else makes no sense but later comments will go to more language constructs
-				BOOST_THROW_EXCEPTION(Error(Error::Type::DocstringParsingError) << errinfo_comment("@author tag is legal only for contracts"));
-		}
-		else if (_tag == "title")
-		{
-			if (_owner == CommentOwner::Contract)
-				return parseDocTagLine(_pos, _end, m_title, DocTagType::Title, false);
-			else
-				// LTODO: Unknown tag, throw some form of warning and not just an exception
-				BOOST_THROW_EXCEPTION(Error(Error::Type::DocstringParsingError) << errinfo_comment("@title tag is legal only for contracts"));
-		}
-		else if (_tag == "param")
-			return parseDocTagParam(_pos, _end);
-		else
-			// LTODO: Unknown tag, throw some form of warning and not just an exception
-			BOOST_THROW_EXCEPTION(Error(Error::Type::DocstringParsingError) << errinfo_comment("Unknown tag " + _tag + " encountered"));
-	}
-	else
-		return appendDocTag(_pos, _end, _owner);
-}
-
-string::const_iterator InterfaceHandler::appendDocTag(
-	string::const_iterator _pos,
-	string::const_iterator _end,
-	CommentOwner _owner
-)
-{
-	switch (m_lastTag)
-	{
-	case DocTagType::Dev:
-		return parseDocTagLine(_pos, _end, m_dev, DocTagType::Dev, true);
-	case DocTagType::Notice:
-		return parseDocTagLine(_pos, _end, m_notice, DocTagType::Notice, true);
-	case DocTagType::Return:
-		return parseDocTagLine(_pos, _end, m_return, DocTagType::Return, true);
-	case DocTagType::Author:
-		if (_owner == CommentOwner::Contract)
-			return parseDocTagLine(_pos, _end, m_contractAuthor, DocTagType::Author, true);
-		else if (_owner == CommentOwner::Function)
-			return parseDocTagLine(_pos, _end, m_author, DocTagType::Author, true);
-		else
-			// LTODO: Unknown tag, throw some form of warning and not just an exception
-			BOOST_THROW_EXCEPTION(Error(Error::Type::DocstringParsingError) << errinfo_comment("@author tag in illegal comment"));
-	case DocTagType::Title:
-		if (_owner == CommentOwner::Contract)
-			return parseDocTagLine(_pos, _end, m_title, DocTagType::Title, true);
-		else
-			// LTODO: Unknown tag, throw some form of warning and not just an exception
-			BOOST_THROW_EXCEPTION(Error(Error::Type::DocstringParsingError) << errinfo_comment("@title tag in illegal comment"));
-	case DocTagType::Param:
-		return appendDocTagParam(_pos, _end);
-	default:
-		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Internal: Illegal documentation tag type"));
-		break;
-	}
-}
-
-static inline string::const_iterator firstSpaceOrNl(
-	string::const_iterator _pos,
-	string::const_iterator _end
-)
-{
-	auto spacePos = find(_pos, _end, ' ');
-	auto nlPos = find(_pos, _end, '\n');
-	return (spacePos < nlPos) ? spacePos : nlPos;
-}
-
-void InterfaceHandler::parseDocString(string const& _string, CommentOwner _owner)
-{
-	auto currPos = _string.begin();
-	auto end = _string.end();
-
-	while (currPos != end)
-	{
-		auto tagPos = find(currPos, end, '@');
-		auto nlPos = find(currPos, end, '\n');
-
-		if (tagPos != end && tagPos < nlPos)
-		{
-			// we found a tag
-			auto tagNameEndPos = firstSpaceOrNl(tagPos, end);
-			if (tagNameEndPos == end)
-				BOOST_THROW_EXCEPTION(
-					Error(Error::Type::DocstringParsingError) <<
-					errinfo_comment("End of tag " + string(tagPos, tagNameEndPos) + "not found"));
-
-			currPos = parseDocTag(tagNameEndPos + 1, end, string(tagPos + 1, tagNameEndPos), _owner);
-		}
-		else if (m_lastTag != DocTagType::None) // continuation of the previous tag
-			currPos = appendDocTag(currPos, end, _owner);
-		else if (currPos != end)
-		{
-			// if it begins without a tag then consider it as @notice
-			if (currPos == _string.begin())
-			{
-				currPos = parseDocTag(currPos, end, "notice", CommentOwner::Function);
-				continue;
-			}
-			else if (nlPos == end) //end of text
-				return;
-			// else skip the line if a newline was found and we get here
-			currPos = nlPos + 1;
-		}
-	}
-}
-
-} //solidity NS
-} // dev NS
diff --git a/libsolidity/interface/InterfaceHandler.h b/libsolidity/interface/InterfaceHandler.h
index 62164517..30b8f520 100644
--- a/libsolidity/interface/InterfaceHandler.h
+++ b/libsolidity/interface/InterfaceHandler.h
@@ -37,6 +37,7 @@ namespace solidity
 
 // Forward declarations
 class ContractDefinition;
+struct DocTag;
 enum class DocumentationType: uint8_t;
 
 enum class DocTagType: uint8_t
@@ -59,73 +60,33 @@ enum class CommentOwner
 class InterfaceHandler
 {
 public:
-	InterfaceHandler();
-
 	/// Get the given type of documentation
 	/// @param _contractDef The contract definition
 	/// @param _type        The type of the documentation. Can be one of the
 	///                     types provided by @c DocumentationType
 	/// @return             A string with the json representation of provided type
-	std::string documentation(
+	static std::string documentation(
 		ContractDefinition const& _contractDef,
 		DocumentationType _type
 	);
 	/// Get the ABI Interface of the contract
 	/// @param _contractDef The contract definition
 	/// @return             A string with the json representation of the contract's ABI Interface
-	std::string abiInterface(ContractDefinition const& _contractDef);
-	std::string ABISolidityInterface(ContractDefinition const& _contractDef);
+	static std::string abiInterface(ContractDefinition const& _contractDef);
+	static std::string ABISolidityInterface(ContractDefinition const& _contractDef);
 	/// Get the User documentation of the contract
 	/// @param _contractDef The contract definition
 	/// @return             A string with the json representation of the contract's user documentation
-	std::string userDocumentation(ContractDefinition const& _contractDef);
+	static std::string userDocumentation(ContractDefinition const& _contractDef);
 	/// Genereates the Developer's documentation of the contract
 	/// @param _contractDef The contract definition
 	/// @return             A string with the json representation
 	///                     of the contract's developer documentation
-	std::string devDocumentation(ContractDefinition const& _contractDef);
+	static std::string devDocumentation(ContractDefinition const& _contractDef);
 
 private:
-	void resetUser();
-	void resetDev();
-
-	std::string::const_iterator parseDocTagLine(
-		std::string::const_iterator _pos,
-		std::string::const_iterator _end,
-		std::string& _tagString,
-		DocTagType _tagType,
-		bool _appending
-	);
-	std::string::const_iterator parseDocTagParam(
-		std::string::const_iterator _pos,
-		std::string::const_iterator _end
-	);
-	std::string::const_iterator appendDocTagParam(
-		std::string::const_iterator _pos,
-		std::string::const_iterator _end
-	);
-	void parseDocString(std::string const& _string, CommentOwner _owner);
-	std::string::const_iterator appendDocTag(
-		std::string::const_iterator _pos,
-		std::string::const_iterator _end,
-		CommentOwner _owner
-	);
-	std::string::const_iterator parseDocTag(
-		std::string::const_iterator _pos,
-		std::string::const_iterator _end,
-		std::string const& _tag,
-		CommentOwner _owner
-	);
-
-	// internal state
-	DocTagType m_lastTag;
-	std::string m_notice;
-	std::string m_dev;
-	std::string m_return;
-	std::string m_contractAuthor;
-	std::string m_author;
-	std::string m_title;
-	std::vector<std::pair<std::string, std::string>> m_params;
+	/// Returns concatenation of all content under the given tag name.
+	static std::string extractDoc(std::multimap<std::string, DocTag> const& _tags, std::string const& _name);
 };
 
 } //solidity NS
diff --git a/libsolidity/parsing/DocStringParser.cpp b/libsolidity/parsing/DocStringParser.cpp
new file mode 100644
index 00000000..bbee35f5
--- /dev/null
+++ b/libsolidity/parsing/DocStringParser.cpp
@@ -0,0 +1,141 @@
+
+#include <libsolidity/parsing/DocStringParser.h>
+#include <boost/range/irange.hpp>
+#include <libsolidity/interface/Utils.h>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+
+
+static inline string::const_iterator skipLineOrEOS(
+	string::const_iterator _nlPos,
+	string::const_iterator _end
+)
+{
+	return (_nlPos == _end) ? _end : ++_nlPos;
+}
+
+static inline string::const_iterator firstSpaceOrNl(
+	string::const_iterator _pos,
+	string::const_iterator _end
+)
+{
+	auto spacePos = find(_pos, _end, ' ');
+	auto nlPos = find(_pos, _end, '\n');
+	return (spacePos < nlPos) ? spacePos : nlPos;
+}
+
+bool DocStringParser::parse(string const& _docString, ErrorList& _errors)
+{
+	m_errors = &_errors;
+	m_errorsOccurred = false;
+	m_lastTag = nullptr;
+
+	auto currPos = _docString.begin();
+	auto end = _docString.end();
+
+	while (currPos != end)
+	{
+		auto tagPos = find(currPos, end, '@');
+		auto nlPos = find(currPos, end, '\n');
+
+		if (tagPos != end && tagPos < nlPos)
+		{
+			// we found a tag
+			auto tagNameEndPos = firstSpaceOrNl(tagPos, end);
+			if (tagNameEndPos == end)
+			{
+				appendError("End of tag " + string(tagPos, tagNameEndPos) + "not found");
+				break;
+			}
+
+			currPos = parseDocTag(tagNameEndPos + 1, end, string(tagPos + 1, tagNameEndPos));
+		}
+		else if (!!m_lastTag) // continuation of the previous tag
+			currPos = appendDocTag(currPos, end);
+		else if (currPos != end)
+		{
+			// if it begins without a tag then consider it as @notice
+			if (currPos == _docString.begin())
+			{
+				currPos = parseDocTag(currPos, end, "notice");
+				continue;
+			}
+			else if (nlPos == end) //end of text
+				break;
+			// else skip the line if a newline was found and we get here
+			currPos = nlPos + 1;
+		}
+	}
+	return !m_errorsOccurred;
+}
+
+DocStringParser::iter DocStringParser::parseDocTagLine(iter _pos, iter _end, bool _appending)
+{
+	solAssert(!!m_lastTag, "");
+	auto nlPos = find(_pos, _end, '\n');
+	if (_appending && _pos < _end && *_pos != ' ')
+		m_lastTag->content += " ";
+	copy(_pos, nlPos, back_inserter(m_lastTag->content));
+	return skipLineOrEOS(nlPos, _end);
+}
+
+DocStringParser::iter DocStringParser::parseDocTagParam(iter _pos, iter _end)
+{
+	// find param name
+	auto currPos = find(_pos, _end, ' ');
+	if (currPos == _end)
+	{
+		appendError("End of param name not found" + string(_pos, _end));
+		return _end;
+	}
+
+	auto paramName = string(_pos, currPos);
+
+	currPos += 1;
+	auto nlPos = find(currPos, _end, '\n');
+	auto paramDesc = string(currPos, nlPos);
+	newTag("param");
+	m_lastTag->paramName = paramName;
+	m_lastTag->content = paramDesc;
+
+	return skipLineOrEOS(nlPos, _end);
+}
+
+DocStringParser::iter DocStringParser::parseDocTag(iter _pos, iter _end, string const& _tag)
+{
+	// LTODO: need to check for @(start of a tag) between here and the end of line
+	// for all cases.
+	if (!m_lastTag || _tag != "")
+	{
+		if (_tag == "param")
+			return parseDocTagParam(_pos, _end);
+		else
+		{
+			newTag(_tag);
+			return parseDocTagLine(_pos, _end, false);
+		}
+	}
+	else
+		return appendDocTag(_pos, _end);
+}
+
+DocStringParser::iter DocStringParser::appendDocTag(iter _pos, iter _end)
+{
+	solAssert(!!m_lastTag, "");
+	return parseDocTagLine(_pos, _end, true);
+}
+
+void DocStringParser::newTag(string const& _tagName)
+{
+	m_lastTag = &m_docTags.insert(make_pair(_tagName, DocTag()))->second;
+}
+
+void DocStringParser::appendError(string const& _description)
+{
+	auto err = make_shared<Error>(Error::Type::DocstringParsingError);
+	*err << errinfo_comment(_description);
+	m_errors->push_back(err);
+	m_errorsOccurred = true;
+}
diff --git a/libsolidity/parsing/DocStringParser.h b/libsolidity/parsing/DocStringParser.h
new file mode 100644
index 00000000..f67b8bbd
--- /dev/null
+++ b/libsolidity/parsing/DocStringParser.h
@@ -0,0 +1,70 @@
+/*
+	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 Lefteris <lefteris@ethdev.com>
+ * @date 2014, 2015
+ * Parses a given docstring into pieces introduced by tags.
+ */
+
+#pragma once
+
+#include <string>
+#include <libsolidity/interface/Exceptions.h>
+#include <libsolidity/ast/ASTAnnotations.h>
+
+namespace dev
+{
+namespace solidity
+{
+
+class DocStringParser
+{
+public:
+	/// Parse the given @a _docString and stores the parsed components internally.
+	/// @returns false on error and appends the error to @a _errors.
+	bool parse(std::string const& _docString, ErrorList& _errors);
+
+	std::multimap<std::string, DocTag> const& tags() const { return m_docTags; }
+
+private:
+	using iter = std::string::const_iterator;
+	void resetUser();
+	void resetDev();
+
+	iter parseDocTagLine(iter _pos, iter _end, bool _appending);
+	iter parseDocTagParam(iter _pos, iter _end);
+	iter appendDocTagParam(iter _pos, iter _end);
+	void parseDocString(std::string const& _string);
+	iter appendDocTag(iter _pos, iter _end);
+	/// Parses the doc tag named @a _tag, adds it to m_docTags and returns the position
+	/// after the tag.
+	iter parseDocTag(iter _pos, iter _end, std::string const& _tag);
+
+	/// Creates and inserts a new tag and adjusts m_lastTag.
+	void newTag(std::string const& _tagName);
+
+	void appendError(std::string const& _description);
+
+	/// Mapping tag name -> content.
+	std::multimap<std::string, DocTag> m_docTags;
+	DocTag* m_lastTag = nullptr;
+	ErrorList* m_errors = nullptr;
+	bool m_errorsOccurred = false;
+};
+
+} //solidity NS
+} // dev NS