Analysis refactoring.

7 files changed, 466 insertions, 115 deletions

diff --git a/libsolidity/inlineasm/AsmAnalysis.cpp b/libsolidity/inlineasm/AsmAnalysis.cpp
new file mode 100644
index 00000000..ef620b84
--- /dev/null
+++ b/libsolidity/inlineasm/AsmAnalysis.cpp
@@ -0,0 +1,179 @@
+/*
+	This file is part of solidity.
+
+	solidity 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.
+
+	solidity 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 solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Analyzer part of inline assembly.
+ */
+
+#include <libsolidity/inlineasm/AsmAnalysis.h>
+
+#include <libsolidity/inlineasm/AsmData.h>
+
+#include <libsolidity/interface/Exceptions.h>
+#include <libsolidity/interface/Utils.h>
+
+#include <boost/range/adaptor/reversed.hpp>
+
+#include <memory>
+#include <functional>
+
+using namespace std;
+using namespace dev;
+using namespace dev::solidity;
+using namespace dev::solidity::assembly;
+
+
+bool Scope::registerLabel(const string& _name, size_t _id)
+{
+	if (lookup(_name))
+		return false;
+	identifiers[_name] = Scope::Label(_id);
+	return true;
+}
+
+
+bool Scope::registerVariable(const string& _name)
+{
+	if (lookup(_name))
+		return false;
+	identifiers[_name] = Variable();
+	return true;
+}
+
+Scope::Identifier* Scope::lookup(string const& _name)
+{
+	if (identifiers.count(_name))
+		return &identifiers[_name];
+	else if (superScope)
+		return superScope->lookup(_name);
+	else
+		return nullptr;
+}
+
+AsmAnalyzer::AsmAnalyzer(AsmAnalyzer::Scopes& _scopes, ErrorList& _errors):
+	m_scopes(_scopes), m_errors(_errors)
+{
+	// Make the Solidity ErrorTag available to inline assembly
+	m_scopes[nullptr] = make_shared<Scope>();
+	m_scopes[nullptr]->identifiers["invalidJumpLabel"] = Scope::Label(Scope::Label::errorLabelId);
+	m_currentScope = m_scopes[nullptr].get();
+}
+
+bool AsmAnalyzer::operator()(assembly::Literal const& _literal)
+{
+	if (!_literal.isNumber && _literal.value.size() > 32)
+	{
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::TypeError,
+			"string literal too long (" + boost::lexical_cast<std::string>(_literal.value.size()) + " > 32)"
+		));
+		return false;
+	}
+	return true;
+}
+
+bool AsmAnalyzer::operator()(FunctionalInstruction const& _instr)
+{
+	bool success = true;
+	for (auto const& arg: _instr.arguments | boost::adaptors::reversed)
+		if (!boost::apply_visitor(*this, arg))
+			success = false;
+	if (!(*this)(_instr.instruction))
+		success = false;
+	return success;
+}
+
+bool AsmAnalyzer::operator()(Label const& _item)
+{
+	if (!m_currentScope->registerLabel(_item.name, Scope::Label::unassignedLabelId))
+	{
+		//@TODO secondary location
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::DeclarationError,
+			"Label name " + _item.name + " already taken in this scope.",
+			_item.location
+		));
+		return false;
+	}
+	bool success = true;
+	if (!_item.stackInfo.empty())
+	{
+		Scope::Label& label = boost::get<Scope::Label>(m_currentScope->identifiers[_item.name]);
+		if (_item.stackInfo.size() == 1)
+			try
+			{
+				label.stackAdjustment = boost::lexical_cast<int>(_item.stackInfo[0]);
+				label.resetStackHeight = false;
+				return true;
+			}
+			catch (boost::bad_lexical_cast const&)
+			{
+				// Interpret as variable name
+			}
+		label.resetStackHeight = true;
+		for (auto const& stackItem: _item.stackInfo)
+		{
+			if (!m_currentScope->registerVariable(stackItem))
+			{
+				//@TODO secondary location
+				m_errors.push_back(make_shared<Error>(
+					Error::Type::DeclarationError,
+					"Variable name " + stackItem + " already taken in this scope.",
+					_item.location
+				));
+				success = false;
+			}
+		}
+	}
+	return success;
+}
+
+bool AsmAnalyzer::operator()(const FunctionalAssignment& _assignment)
+{
+	return boost::apply_visitor(*this, *_assignment.value);
+}
+
+bool AsmAnalyzer::operator()(assembly::VariableDeclaration const& _varDecl)
+{
+	bool success = boost::apply_visitor(*this, *_varDecl.value);
+	if (!m_currentScope->registerVariable(_varDecl.name))
+	{
+		//@TODO secondary location
+		m_errors.push_back(make_shared<Error>(
+			Error::Type::DeclarationError,
+			"Variable name " + _varDecl.name + " already taken in this scope.",
+			_varDecl.location
+		));
+		success = false;
+	}
+	return success;
+}
+
+bool AsmAnalyzer::operator()(Block const& _block)
+{
+	bool success = true;
+	auto scope = make_shared<Scope>();
+	scope->superScope = m_currentScope;
+	m_scopes[&_block] = scope;
+	m_currentScope = scope.get();
+
+	for (auto const& s: _block.statements)
+		if (!boost::apply_visitor(*this, s))
+			success = false;
+
+	m_currentScope = m_currentScope->superScope;
+	return success;
+}
diff --git a/libsolidity/inlineasm/AsmAnalysis.h b/libsolidity/inlineasm/AsmAnalysis.h
new file mode 100644
index 00000000..6b79ca67
--- /dev/null
+++ b/libsolidity/inlineasm/AsmAnalysis.h
@@ -0,0 +1,152 @@
+/*
+	This file is part of solidity.
+
+	solidity 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.
+
+	solidity 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 solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Analysis part of inline assembly.
+ */
+
+#pragma once
+
+#include <libsolidity/interface/Exceptions.h>
+
+#include <boost/variant.hpp>
+
+#include <functional>
+#include <memory>
+
+namespace dev
+{
+namespace solidity
+{
+namespace assembly
+{
+
+struct Literal;
+struct Block;
+struct Label;
+struct FunctionalInstruction;
+struct FunctionalAssignment;
+struct VariableDeclaration;
+struct Instruction;
+struct Identifier;
+struct Assignment;
+
+struct Scope
+{
+	struct Variable
+	{
+		int stackHeight = 0;
+		bool active = false;
+	};
+
+	struct Label
+	{
+		Label(size_t _id): id(_id) {}
+		size_t id = 0;
+		int stackAdjustment = 0;
+		bool resetStackHeight = false;
+		static const size_t errorLabelId = -1;
+		static const size_t unassignedLabelId = 0;
+	};
+
+	using Identifier = boost::variant<Variable, Label>;
+
+	struct Visitor: public boost::static_visitor<>
+	{
+		Visitor(
+			std::function<void(Variable const&)> _varVisitor,
+			std::function<void(Label const&)> _labelVisitor
+		):
+			m_varVisitor(std::move(_varVisitor)),
+			m_labelVisitor(std::move(_labelVisitor))
+		{}
+
+		void operator()(Variable const& _var) const { m_varVisitor(_var); }
+		void operator()(Label const& _label) const { m_labelVisitor(_label); }
+
+		std::function<void(Variable const&)> m_varVisitor;
+		std::function<void(Label const&)> m_labelVisitor;
+	};
+	struct NonconstVisitor: public boost::static_visitor<>
+	{
+		NonconstVisitor(
+			std::function<void(Variable&)> _varVisitor,
+			std::function<void(Label&)> _labelVisitor
+		):
+			m_varVisitor(std::move(_varVisitor)),
+			m_labelVisitor(std::move(_labelVisitor))
+		{}
+
+		void operator()(Variable& _var) const { m_varVisitor(_var); }
+		void operator()(Label& _label) const { m_labelVisitor(_label); }
+
+		std::function<void(Variable&)> m_varVisitor;
+		std::function<void(Label&)> m_labelVisitor;
+	};
+
+	bool registerLabel(std::string const& _name, size_t _id);
+
+	bool registerVariable(std::string const& _name);
+
+	/// Looks up the identifier in this or super scopes and returns a valid pointer if
+	/// found or a nullptr if not found.
+	/// The pointer will be invalidated if the scope is modified.
+	Identifier* lookup(std::string const& _name);
+	/// Looks up the identifier in this and super scopes and calls the visitor, returns false if not found.
+	template <class V>
+	bool lookup(std::string const& _name, V const& _visitor)
+	{
+		if (Identifier* id = lookup(_name))
+		{
+			boost::apply_visitor(_visitor, *id);
+			return true;
+		}
+		else
+			return false;
+	}
+
+
+
+	Scope* superScope = nullptr;
+	std::map<std::string, Identifier> identifiers;
+};
+
+
+class AsmAnalyzer: public boost::static_visitor<bool>
+{
+public:
+	using Scopes = std::map<assembly::Block const*, std::shared_ptr<Scope>>;
+	AsmAnalyzer(Scopes& _scopes, ErrorList& _errors);
+
+	bool operator()(assembly::Instruction const&) { return true; }
+	bool operator()(assembly::Literal const& _literal);
+	bool operator()(assembly::Identifier const&) { return true; }
+	bool operator()(assembly::FunctionalInstruction const& _functionalInstruction);
+	bool operator()(assembly::Label const& _label);
+	bool operator()(assembly::Assignment const&) { return true; }
+	bool operator()(assembly::FunctionalAssignment const& _functionalAssignment);
+	bool operator()(assembly::VariableDeclaration const& _variableDeclaration);
+	bool operator()(assembly::Block const& _block);
+
+private:
+	Scope* m_currentScope = nullptr;
+	Scopes& m_scopes;
+	ErrorList& m_errors;
+};
+
+}
+}
+}
diff --git a/libsolidity/inlineasm/AsmCodeGen.cpp b/libsolidity/inlineasm/AsmCodeGen.cpp
index abc0ca01..0c802310 100644
--- a/libsolidity/inlineasm/AsmCodeGen.cpp
+++ b/libsolidity/inlineasm/AsmCodeGen.cpp
@@ -21,14 +21,21 @@
  */
 
 #include <libsolidity/inlineasm/AsmCodeGen.h>
-#include <memory>
-#include <functional>
-#include <libdevcore/CommonIO.h>
+
+#include <libsolidity/inlineasm/AsmParser.h>
+#include <libsolidity/inlineasm/AsmData.h>
+#include <libsolidity/inlineasm/AsmAnalysis.h>
+
 #include <libevmasm/Assembly.h>
 #include <libevmasm/SourceLocation.h>
 #include <libevmasm/Instruction.h>
-#include <libsolidity/inlineasm/AsmParser.h>
-#include <libsolidity/inlineasm/AsmData.h>
+
+#include <libdevcore/CommonIO.h>
+
+#include <boost/range/adaptor/reversed.hpp>
+
+#include <memory>
+#include <functional>
 
 using namespace std;
 using namespace dev;
@@ -42,74 +49,26 @@ struct GeneratorState
 
 	void addError(Error::Type _type, std::string const& _description, SourceLocation const& _location = SourceLocation())
 	{
-		auto err = make_shared<Error>(_type);
-		if (!_location.isEmpty())
-			*err << errinfo_sourceLocation(_location);
-		*err << errinfo_comment(_description);
-		errors.push_back(err);
+		errors.push_back(make_shared<Error>(_type, _description, _location));
 	}
 
-	int const* findVariable(string const& _variableName) const
+	size_t newLabelId()
 	{
-		auto localVariable = find_if(
-			variables.rbegin(),
-			variables.rend(),
-			[&](pair<string, int> const& _var) { return _var.first == _variableName; }
-		);
-		return localVariable != variables.rend() ? &localVariable->second : nullptr;
+		return assemblyTagToIdentifier(assembly.newTag());
 	}
-	eth::AssemblyItem const* findLabel(string const& _labelName) const
+
+	size_t assemblyTagToIdentifier(eth::AssemblyItem const& _tag) const
 	{
-		auto label = find_if(
-			labels.begin(),
-			labels.end(),
-			[&](pair<string, eth::AssemblyItem> const& _label) { return _label.first == _labelName; }
-		);
-		return label != labels.end() ? &label->second : nullptr;
+		u256 id = _tag.data();
+		solAssert(id <= std::numeric_limits<size_t>::max(), "Tag id too large.");
+		return size_t(id);
 	}
 
-	map<string, eth::AssemblyItem> labels;
-	vector<pair<string, int>> variables; ///< name plus stack height
+	std::map<assembly::Block const*, shared_ptr<Scope>> scopes;
 	ErrorList& errors;
 	eth::Assembly& assembly;
 };
 
-/**
- * Scans the inline assembly data for labels, creates tags in the assembly and searches for
- * duplicate labels.
- */
-class LabelOrganizer: public boost::static_visitor<>
-{
-public:
-	LabelOrganizer(GeneratorState& _state): m_state(_state)
-	{
-		// Make the Solidity ErrorTag available to inline assembly
-		m_state.labels.insert(make_pair("invalidJumpLabel", m_state.assembly.errorTag()));
-	}
-
-	template <class T>
-	void operator()(T const& /*_item*/) { }
-	void operator()(Label const& _item)
-	{
-		solAssert(_item.stackInfo.empty(), "Labels with stack info not yet supported.");
-		if (m_state.labels.count(_item.name))
-			//@TODO secondary location
-			m_state.addError(
-				Error::Type::DeclarationError,
-				"Label " + _item.name + " declared twice.",
-				_item.location
-			);
-		m_state.labels.insert(make_pair(_item.name, m_state.assembly.newTag()));
-	}
-	void operator()(assembly::Block const& _block)
-	{
-		std::for_each(_block.statements.begin(), _block.statements.end(), boost::apply_visitor(*this));
-	}
-
-private:
-	GeneratorState& m_state;
-};
-
 class CodeTransform: public boost::static_visitor<>
 {
 public:
@@ -126,6 +85,7 @@ public:
 			m_identifierAccess = _identifierAccess;
 		else
 			m_identifierAccess = [](assembly::Identifier const&, eth::Assembly&, CodeGenerator::IdentifierContext) { return false; };
+		m_currentScope = m_state.scopes[nullptr].get();
 	}
 
 	void operator()(assembly::Instruction const& _instruction)
@@ -138,40 +98,49 @@ public:
 		m_state.assembly.setSourceLocation(_literal.location);
 		if (_literal.isNumber)
 			m_state.assembly.append(u256(_literal.value));
-		else if (_literal.value.size() > 32)
-		{
-			m_state.addError(
-				Error::Type::TypeError,
-				"String literal too long (" + boost::lexical_cast<string>(_literal.value.size()) + " > 32)"
-			);
-			m_state.assembly.append(u256(0));
-		}
 		else
+		{
+			solAssert(_literal.value.size() <= 32, "");
 			m_state.assembly.append(_literal.value);
+		}
 	}
 	void operator()(assembly::Identifier const& _identifier)
 	{
 		m_state.assembly.setSourceLocation(_identifier.location);
-		// First search local variables, then labels, then externals.
-		if (int const* stackHeight = m_state.findVariable(_identifier.name))
-		{
-			int heightDiff = m_state.assembly.deposit() - *stackHeight;
-			if (heightDiff <= 0 || heightDiff > 16)
+		// First search internals, then externals.
+		if (!m_currentScope->lookup(_identifier.name, Scope::NonconstVisitor(
+			[=](Scope::Variable& _var)
 			{
-				m_state.addError(
-					Error::Type::TypeError,
-					"Variable inaccessible, too deep inside stack (" + boost::lexical_cast<string>(heightDiff) + ")",
-					_identifier.location
-				);
-				m_state.assembly.append(u256(0));
+				if (!_var.active)
+				{
+					m_state.addError(
+						Error::Type::TypeError,
+						"Variable used before it was declared",
+						_identifier.location
+					);
+					m_state.assembly.append(u256(0));
+					return;
+				}
+				int heightDiff = m_state.assembly.deposit() - _var.stackHeight;
+				if (heightDiff <= 0 || heightDiff > 16)
+				{
+					m_state.addError(
+						Error::Type::TypeError,
+						"Variable inaccessible, too deep inside stack (" + boost::lexical_cast<string>(heightDiff) + ")",
+						_identifier.location
+					);
+					m_state.assembly.append(u256(0));
+				}
+				else
+					m_state.assembly.append(solidity::dupInstruction(heightDiff));
+			},
+			[=](Scope::Label& _label)
+			{
+				if (_label.id == Scope::Label::unassignedLabelId)
+					_label.id = m_state.newLabelId();
+				m_state.assembly.append(eth::AssemblyItem(eth::PushTag, _label.id));
 			}
-			else
-				m_state.assembly.append(solidity::dupInstruction(heightDiff));
-			return;
-		}
-		else if (eth::AssemblyItem const* label = m_state.findLabel(_identifier.name))
-			m_state.assembly.append(label->pushTag());
-		else if (!m_identifierAccess(_identifier, m_state.assembly, CodeGenerator::IdentifierContext::RValue))
+		)))
 		{
 			m_state.addError(
 				Error::Type::DeclarationError,
@@ -197,8 +166,13 @@ public:
 	}
 	void operator()(Label const& _label)
 	{
+		solAssert(_label.stackInfo.empty(), "Labels with stack info not yet supported.");
 		m_state.assembly.setSourceLocation(_label.location);
-		m_state.assembly.append(m_state.labels.at(_label.name));
+		solAssert(m_currentScope->identifiers.count(_label.name), "");
+		Scope::Label& label = boost::get<Scope::Label>(m_currentScope->identifiers[_label.name]);
+		if (label.id == Scope::Label::unassignedLabelId)
+			label.id = m_state.newLabelId();
+		m_state.assembly.append(eth::AssemblyItem(eth::PushTag, label.id));
 	}
 	void operator()(assembly::Assignment const& _assignment)
 	{
@@ -218,23 +192,25 @@ public:
 		int height = m_state.assembly.deposit();
 		boost::apply_visitor(*this, *_varDecl.value);
 		expectDeposit(1, height, locationOf(*_varDecl.value));
-		m_state.variables.push_back(make_pair(_varDecl.name, height));
+		solAssert(m_currentScope && m_currentScope->identifiers.count(_varDecl.name), "");
+		auto& var = boost::get<Scope::Variable>(m_currentScope->identifiers[_varDecl.name]);
+		var.stackHeight = height;
+		var.active = true;
 	}
 	void operator()(assembly::Block const& _block)
 	{
-		size_t numVariables = m_state.variables.size();
+		solAssert(m_state.scopes.count(&_block), "Scope for block not defined.");
+		m_currentScope = m_state.scopes[&_block].get();
 		int deposit = m_state.assembly.deposit();
 		std::for_each(_block.statements.begin(), _block.statements.end(), boost::apply_visitor(*this));
 
-		// pop variables
-		while (m_state.variables.size() > numVariables)
-		{
-			m_state.assembly.append(solidity::Instruction::POP);
-			m_state.variables.pop_back();
-		}
-
 		m_state.assembly.setSourceLocation(_block.location);
 
+		// pop variables
+		for (auto const& identifier: m_currentScope->identifiers)
+			if (identifier.second.type() == typeid(Scope::Variable))
+				m_state.assembly.append(solidity::Instruction::POP);
+
 		deposit = m_state.assembly.deposit() - deposit;
 
 		// issue warnings for stack height discrepancies
@@ -254,6 +230,8 @@ public:
 				_block.location
 			);
 		}
+
+		m_currentScope = m_currentScope->superScope;
 	}
 	void operator()(assembly::FunctionDefinition const&)
 	{
@@ -263,21 +241,38 @@ public:
 private:
 	void generateAssignment(assembly::Identifier const& _variableName, SourceLocation const& _location)
 	{
-		if (int const* stackHeight = m_state.findVariable(_variableName.name))
-		{
-			int heightDiff = m_state.assembly.deposit() - *stackHeight - 1;
-			if (heightDiff <= 0 || heightDiff > 16)
+		if (!m_currentScope->lookup(_variableName.name, Scope::Visitor(
+			[=](Scope::Variable const& _var)
+			{
+				if (!_var.active)
+				{
+					m_state.addError(
+						Error::Type::TypeError,
+						"Variable used before it was declared",
+						_location
+					);
+					m_state.assembly.append(u256(0));
+					return;
+				}
+				int heightDiff = m_state.assembly.deposit() - _var.stackHeight - 1;
+				if (heightDiff <= 0 || heightDiff > 16)
+					m_state.addError(
+						Error::Type::TypeError,
+						"Variable inaccessible, too deep inside stack (" + boost::lexical_cast<string>(heightDiff) + ")",
+						_location
+					);
+				else
+					m_state.assembly.append(solidity::swapInstruction(heightDiff));
+				m_state.assembly.append(solidity::Instruction::POP);
+			},
+			[=](Scope::Label const&)
+			{
 				m_state.addError(
-					Error::Type::TypeError,
-					"Variable inaccessible, too deep inside stack (" + boost::lexical_cast<string>(heightDiff) + ")",
-					_location
+					Error::Type::DeclarationError,
+					"Label \"" + string(_variableName.name) + "\" used as variable."
 				);
-			else
-				m_state.assembly.append(solidity::swapInstruction(heightDiff));
-			m_state.assembly.append(solidity::Instruction::POP);
-			return;
-		}
-		else if (!m_identifierAccess(_variableName, m_state.assembly, CodeGenerator::IdentifierContext::LValue))
+			}
+		)) && !m_identifierAccess(_variableName, m_state.assembly, CodeGenerator::IdentifierContext::LValue))
 			m_state.addError(
 				Error::Type::DeclarationError,
 				"Identifier \"" + string(_variableName.name) + "\" not found, not unique or not lvalue."
@@ -298,6 +293,7 @@ private:
 	}
 
 	GeneratorState& m_state;
+	Scope* m_currentScope;
 	assembly::CodeGenerator::IdentifierAccess m_identifierAccess;
 };
 
@@ -306,24 +302,31 @@ bool assembly::CodeGenerator::typeCheck(assembly::CodeGenerator::IdentifierAcces
 	size_t initialErrorLen = m_errors.size();
 	eth::Assembly assembly;
 	GeneratorState state(m_errors, assembly);
-	(LabelOrganizer(state))(m_parsedData);
+	if (!(AsmAnalyzer(state.scopes, m_errors))(m_parsedData))
+		return false;
 	(CodeTransform(state, _identifierAccess))(m_parsedData);
 	return m_errors.size() == initialErrorLen;
 }
 
 eth::Assembly assembly::CodeGenerator::assemble(assembly::CodeGenerator::IdentifierAccess const& _identifierAccess)
 {
+	size_t initialErrorLen = m_errors.size();
 	eth::Assembly assembly;
 	GeneratorState state(m_errors, assembly);
-	(LabelOrganizer(state))(m_parsedData);
+	if (!(AsmAnalyzer(state.scopes, m_errors))(m_parsedData))
+		solAssert(false, "Assembly error");
 	(CodeTransform(state, _identifierAccess))(m_parsedData);
+	solAssert(m_errors.size() == initialErrorLen, "Assembly error");
 	return assembly;
 }
 
 void assembly::CodeGenerator::assemble(eth::Assembly& _assembly, assembly::CodeGenerator::IdentifierAccess const& _identifierAccess)
 {
+	size_t initialErrorLen = m_errors.size();
 	GeneratorState state(m_errors, _assembly);
-	(LabelOrganizer(state))(m_parsedData);
+	if (!(AsmAnalyzer(state.scopes, m_errors))(m_parsedData))
+		solAssert(false, "Assembly error");
 	(CodeTransform(state, _identifierAccess))(m_parsedData);
+	solAssert(m_errors.size() == initialErrorLen, "Assembly error");
 }
 
diff --git a/libsolidity/inlineasm/AsmParser.cpp b/libsolidity/inlineasm/AsmParser.cpp
index 5d439b2f..779646b8 100644
--- a/libsolidity/inlineasm/AsmParser.cpp
+++ b/libsolidity/inlineasm/AsmParser.cpp
@@ -148,6 +148,10 @@ assembly::Statement Parser::parseStatement()
 					break;
 				expectToken(Token::Comma);
 			}
+		// Push an empty string to signify that there were brackets, like in
+		// "name[]:", which just resets the stack height to the height of the local variables.
+		if (label.stackInfo.empty())
+			label.stackInfo.push_back("");
 		expectToken(Token::RBrack);
 		label.location.end = endPosition();
 		expectToken(Token::Colon);
diff --git a/libsolidity/inlineasm/AsmStack.cpp b/libsolidity/inlineasm/AsmStack.cpp
index 38d688c1..266136a1 100644
--- a/libsolidity/inlineasm/AsmStack.cpp
+++ b/libsolidity/inlineasm/AsmStack.cpp
@@ -25,6 +25,7 @@
 #include <libsolidity/inlineasm/AsmParser.h>
 #include <libsolidity/inlineasm/AsmCodeGen.h>
 #include <libsolidity/inlineasm/AsmPrinter.h>
+#include <libsolidity/inlineasm/AsmAnalysis.h>
 
 #include <libsolidity/parsing/Scanner.h>
 
@@ -45,8 +46,10 @@ bool InlineAssemblyStack::parse(shared_ptr<Scanner> const& _scanner)
 	auto result = parser.parse(_scanner);
 	if (!result)
 		return false;
+
 	*m_parserResult = std::move(*result);
-	return true;
+	AsmAnalyzer::Scopes scopes;
+	return (AsmAnalyzer(scopes, m_errors))(*m_parserResult);
 }
 
 string InlineAssemblyStack::toString()
diff --git a/libsolidity/interface/Exceptions.cpp b/libsolidity/interface/Exceptions.cpp
index 41890b91..20f9dd75 100644
--- a/libsolidity/interface/Exceptions.cpp
+++ b/libsolidity/interface/Exceptions.cpp
@@ -58,6 +58,14 @@ Error::Error(Type _type): m_type(_type)
 	}
 }
 
+Error::Error(Error::Type _type, const std::string& _description, const SourceLocation& _location):
+	Error(_type)
+{
+	if (!_location.isEmpty())
+		*this << errinfo_sourceLocation(_location);
+	*this << errinfo_comment(_description);
+}
+
 string Exception::lineInfo() const
 {
 	char const* const* file = boost::get_error_info<boost::throw_file>(*this);
diff --git a/libsolidity/interface/Exceptions.h b/libsolidity/interface/Exceptions.h
index 81716c41..71699da8 100644
--- a/libsolidity/interface/Exceptions.h
+++ b/libsolidity/interface/Exceptions.h
@@ -55,6 +55,8 @@ public:
 
 	explicit Error(Type _type);
 
+	Error(Type _type, std::string const& _description, SourceLocation const& _location = SourceLocation());
+
 	Type type() const { return m_type; }
 	std::string const& typeName() const { return m_typeName; }