Merge pull request #5537 from ethereum/cp-SourceLocation-related-refactoring

[1/3] SourceLocation related refactoring.

28 files changed, 215 insertions, 208 deletions

diff --git a/libevmasm/Assembly.cpp b/libevmasm/Assembly.cpp
index d80f97c4..29d9846d 100644
--- a/libevmasm/Assembly.cpp
+++ b/libevmasm/Assembly.cpp
@@ -114,10 +114,10 @@ namespace
 
 string locationFromSources(StringMap const& _sourceCodes, SourceLocation const& _location)
 {
-	if (_location.isEmpty() || _sourceCodes.empty() || _location.start >= _location.end || _location.start < 0)
+	if (_location.isEmpty() || !_location.source.get() || _sourceCodes.empty() || _location.start >= _location.end || _location.start < 0)
 		return "";
 
-	auto it = _sourceCodes.find(*_location.sourceName);
+	auto it = _sourceCodes.find(_location.source->name());
 	if (it == _sourceCodes.end())
 		return "";
 
@@ -186,11 +186,11 @@ public:
 
 	void printLocation()
 	{
-		if (!m_location.sourceName && m_location.isEmpty())
+		if (!m_location.source && m_location.isEmpty())
 			return;
 		m_out << m_prefix << "    /*";
-		if (m_location.sourceName)
-			m_out << " \"" + *m_location.sourceName + "\"";
+		if (m_location.source)
+			m_out << " \"" + m_location.source->name() + "\"";
 		if (!m_location.isEmpty())
 			m_out << ":" << to_string(m_location.start) + ":" + to_string(m_location.end);
 		m_out << "  " << locationFromSources(m_sourceCodes, m_location);
diff --git a/liblangutil/CharStream.h b/liblangutil/CharStream.h
index 72aacacf..f92beb30 100644
--- a/liblangutil/CharStream.h
+++ b/liblangutil/CharStream.h
@@ -68,7 +68,8 @@ class CharStream
 {
 public:
 	CharStream(): m_position(0) {}
-	explicit CharStream(std::string const& _source): m_source(_source), m_position(0) {}
+	explicit CharStream(std::string const& _source, std::string const& name):
+		m_source(_source), m_name(name), m_position(0) {}
 
 	int position() const { return m_position; }
 	bool isPastEndOfInput(size_t _charsForward = 0) const { return (m_position + _charsForward) >= m_source.size(); }
@@ -79,7 +80,8 @@ public:
 
 	void reset() { m_position = 0; }
 
-	std::string const& source() const { return m_source; }
+	std::string const& source() const noexcept { return m_source; }
+	std::string const& name() const noexcept { return m_name; }
 
 	///@{
 	///@name Error printing helper functions
@@ -91,6 +93,7 @@ public:
 
 private:
 	std::string m_source;
+	std::string m_name;
 	size_t m_position;
 };
 
diff --git a/liblangutil/ParserBase.cpp b/liblangutil/ParserBase.cpp
index 8156f9b9..391af291 100644
--- a/liblangutil/ParserBase.cpp
+++ b/liblangutil/ParserBase.cpp
@@ -27,11 +27,6 @@
 using namespace std;
 using namespace langutil;
 
-std::shared_ptr<string const> const& ParserBase::sourceName() const
-{
-	return m_scanner->sourceName();
-}
-
 int ParserBase::position() const
 {
 	return m_scanner->currentLocation().start;
@@ -105,10 +100,10 @@ void ParserBase::decreaseRecursionDepth()
 
 void ParserBase::parserError(string const& _description)
 {
-	m_errorReporter.parserError(SourceLocation(position(), endPosition(), sourceName()), _description);
+	m_errorReporter.parserError(SourceLocation(position(), endPosition(), source()), _description);
 }
 
 void ParserBase::fatalParserError(string const& _description)
 {
-	m_errorReporter.fatalParserError(SourceLocation(position(), endPosition(), sourceName()), _description);
+	m_errorReporter.fatalParserError(SourceLocation(position(), endPosition(), source()), _description);
 }
diff --git a/liblangutil/ParserBase.h b/liblangutil/ParserBase.h
index 3ecabed5..855201e2 100644
--- a/liblangutil/ParserBase.h
+++ b/liblangutil/ParserBase.h
@@ -23,6 +23,7 @@
 #pragma once
 
 #include <liblangutil/Token.h>
+#include <liblangutil/Scanner.h>
 #include <memory>
 #include <string>
 
@@ -37,7 +38,7 @@ class ParserBase
 public:
 	explicit ParserBase(ErrorReporter& errorReporter): m_errorReporter(errorReporter) {}
 
-	std::shared_ptr<std::string const> const& sourceName() const;
+	std::shared_ptr<CharStream> source() const { return m_scanner->charStream(); }
 
 protected:
 	/// Utility class that creates an error and throws an exception if the
diff --git a/liblangutil/Scanner.cpp b/liblangutil/Scanner.cpp
index 215171b3..ac298bd5 100644
--- a/liblangutil/Scanner.cpp
+++ b/liblangutil/Scanner.cpp
@@ -167,17 +167,23 @@ private:
 }; // end of LiteralScope class
 
 
-void Scanner::reset(CharStream _source, string _sourceName)
+void Scanner::reset(CharStream _source)
 {
-	m_source = std::move(_source);
-	m_sourceName = make_shared<string const>(std::move(_sourceName));
+	m_source = make_shared<CharStream>(std::move(_source));
+	reset();
+}
+
+void Scanner::reset(std::shared_ptr<CharStream> _source)
+{
+	solAssert(_source.get() != nullptr, "You MUST provide a CharStream when resetting.");
+	m_source = _source;
 	reset();
 }
 
 void Scanner::reset()
 {
-	m_source.reset();
-	m_char = m_source.get();
+	m_source->reset();
+	m_char = m_source->get();
 	skipWhitespace();
 	scanToken();
 	next();
@@ -296,13 +302,13 @@ Token Scanner::scanSingleLineDocComment()
 		{
 			// check if next line is also a documentation comment
 			skipWhitespace();
-			if (!m_source.isPastEndOfInput(3) &&
-				m_source.get(0) == '/' &&
-				m_source.get(1) == '/' &&
-				m_source.get(2) == '/')
+			if (!m_source->isPastEndOfInput(3) &&
+				m_source->get(0) == '/' &&
+				m_source->get(1) == '/' &&
+				m_source->get(2) == '/')
 			{
 				addCommentLiteralChar('\n');
-				m_char = m_source.advanceAndGet(3);
+				m_char = m_source->advanceAndGet(3);
 			}
 			else
 				break; // next line is not a documentation comment, we are done
@@ -355,20 +361,20 @@ Token Scanner::scanMultiLineDocComment()
 		if (isLineTerminator(m_char))
 		{
 			skipWhitespace();
-			if (!m_source.isPastEndOfInput(1) && m_source.get(0) == '*' && m_source.get(1) == '*')
+			if (!m_source->isPastEndOfInput(1) && m_source->get(0) == '*' && m_source->get(1) == '*')
 			{ // it is unknown if this leads to the end of the comment
 				addCommentLiteralChar('*');
 				advance();
 			}
-			else if (!m_source.isPastEndOfInput(1) && m_source.get(0) == '*' && m_source.get(1) != '/')
+			else if (!m_source->isPastEndOfInput(1) && m_source->get(0) == '*' && m_source->get(1) != '/')
 			{ // skip first '*' in subsequent lines
 				if (charsAdded)
 					addCommentLiteralChar('\n');
-				m_char = m_source.advanceAndGet(2);
+				m_char = m_source->advanceAndGet(2);
 			}
-			else if (!m_source.isPastEndOfInput(1) && m_source.get(0) == '*' && m_source.get(1) == '/')
+			else if (!m_source->isPastEndOfInput(1) && m_source->get(0) == '*' && m_source->get(1) == '/')
 			{ // if after newline the comment ends, don't insert the newline
-				m_char = m_source.advanceAndGet(2);
+				m_char = m_source->advanceAndGet(2);
 				endFound = true;
 				break;
 			}
@@ -376,9 +382,9 @@ Token Scanner::scanMultiLineDocComment()
 				addCommentLiteralChar('\n');
 		}
 
-		if (!m_source.isPastEndOfInput(1) && m_source.get(0) == '*' && m_source.get(1) == '/')
+		if (!m_source->isPastEndOfInput(1) && m_source->get(0) == '*' && m_source->get(1) == '/')
 		{
-			m_char = m_source.advanceAndGet(2);
+			m_char = m_source->advanceAndGet(2);
 			endFound = true;
 			break;
 		}
@@ -715,11 +721,11 @@ bool Scanner::isUnicodeLinebreak()
 	if (0x0a <= m_char && m_char <= 0x0d)
 		// line feed, vertical tab, form feed, carriage return
 		return true;
-	else if (!m_source.isPastEndOfInput(1) && uint8_t(m_source.get(0)) == 0xc2 && uint8_t(m_source.get(1)) == 0x85)
+	else if (!m_source->isPastEndOfInput(1) && uint8_t(m_source->get(0)) == 0xc2 && uint8_t(m_source->get(1)) == 0x85)
 		// NEL - U+0085, C2 85 in utf8
 		return true;
-	else if (!m_source.isPastEndOfInput(2) && uint8_t(m_source.get(0)) == 0xe2 && uint8_t(m_source.get(1)) == 0x80 && (
-		uint8_t(m_source.get(2)) == 0xa8 || uint8_t(m_source.get(2)) == 0xa9
+	else if (!m_source->isPastEndOfInput(2) && uint8_t(m_source->get(0)) == 0xe2 && uint8_t(m_source->get(1)) == 0x80 && (
+		uint8_t(m_source->get(2)) == 0xa8 || uint8_t(m_source->get(2)) == 0xa9
 	))
 		// LS - U+2028, E2 80 A8  in utf8
 		// PS - U+2029, E2 80 A9  in utf8
@@ -783,7 +789,7 @@ void Scanner::scanDecimalDigits()
 
 	// May continue with decimal digit or underscore for grouping.
 	do addLiteralCharAndAdvance();
-	while (!m_source.isPastEndOfInput() && (isDecimalDigit(m_char) || m_char == '_'));
+	while (!m_source->isPastEndOfInput() && (isDecimalDigit(m_char) || m_char == '_'));
 
 	// Defer further validation of underscore to SyntaxChecker.
 }
@@ -829,7 +835,7 @@ Token Scanner::scanNumber(char _charSeen)
 			scanDecimalDigits();  // optional
 			if (m_char == '.')
 			{
-				if (!m_source.isPastEndOfInput(1) && m_source.get(1) == '_')
+				if (!m_source->isPastEndOfInput(1) && m_source->get(1) == '_')
 				{
 					// Assume the input may be a floating point number with leading '_' in fraction part.
 					// Recover by consuming it all but returning `Illegal` right away.
@@ -837,7 +843,7 @@ Token Scanner::scanNumber(char _charSeen)
 					addLiteralCharAndAdvance(); // '_'
 					scanDecimalDigits();
 				}
-				if (m_source.isPastEndOfInput() || !isDecimalDigit(m_source.get(1)))
+				if (m_source->isPastEndOfInput() || !isDecimalDigit(m_source->get(1)))
 				{
 					// A '.' has to be followed by a number.
 					literal.complete();
@@ -854,7 +860,7 @@ Token Scanner::scanNumber(char _charSeen)
 		solAssert(kind != HEX, "'e'/'E' must be scanned as part of the hex number");
 		if (kind != DECIMAL)
 			return setError(ScannerError::IllegalExponent);
-		else if (!m_source.isPastEndOfInput(1) && m_source.get(1) == '_')
+		else if (!m_source->isPastEndOfInput(1) && m_source->get(1) == '_')
 		{
 			// Recover from wrongly placed underscore as delimiter in literal with scientific
 			// notation by consuming until the end.
diff --git a/liblangutil/Scanner.h b/liblangutil/Scanner.h
index d01e71e2..72d0072f 100644
--- a/liblangutil/Scanner.h
+++ b/liblangutil/Scanner.h
@@ -90,12 +90,16 @@ class Scanner
 {
 	friend class LiteralScope;
 public:
-	explicit Scanner(CharStream _source = CharStream(), std::string _sourceName = "") { reset(std::move(_source), std::move(_sourceName)); }
+	explicit Scanner(std::shared_ptr<CharStream> _source) { reset(std::move(_source)); }
+	explicit Scanner(CharStream _source = CharStream()) { reset(std::move(_source)); }
 
-	std::string source() const { return m_source.source(); }
+	std::string const& source() const noexcept { return m_source->source(); }
 
-	/// Resets the scanner as if newly constructed with _source and _sourceName as input.
-	void reset(CharStream _source, std::string _sourceName);
+	std::shared_ptr<CharStream> charStream() noexcept { return m_source; }
+
+	/// Resets the scanner as if newly constructed with _source as input.
+	void reset(CharStream _source);
+	void reset(std::shared_ptr<CharStream> _source);
 	/// Resets scanner to the start of input.
 	void reset();
 
@@ -146,20 +150,17 @@ public:
 	std::string const& peekLiteral() const { return m_nextToken.literal; }
 	///@}
 
-	std::shared_ptr<std::string const> const& sourceName() const { return m_sourceName; }
-
 	///@{
 	///@name Error printing helper functions
 	/// Functions that help pretty-printing parse errors
 	/// Do only use in error cases, they are quite expensive.
-	std::string lineAtPosition(int _position) const { return m_source.lineAtPosition(_position); }
-	std::tuple<int, int> translatePositionToLineColumn(int _position) const { return m_source.translatePositionToLineColumn(_position); }
+	std::string lineAtPosition(int _position) const { return m_source->lineAtPosition(_position); }
+	std::tuple<int, int> translatePositionToLineColumn(int _position) const { return m_source->translatePositionToLineColumn(_position); }
 	std::string sourceAt(SourceLocation const& _location) const
 	{
 		solAssert(!_location.isEmpty(), "");
-		solAssert(m_sourceName && _location.sourceName, "");
-		solAssert(*m_sourceName == *_location.sourceName, "");
-		return m_source.source().substr(_location.start, _location.end - _location.start);
+		solAssert(m_source.get() == _location.source.get(), "CharStream memory locations must match.");
+		return m_source->source().substr(_location.start, _location.end - _location.start);
 	}
 	///@}
 
@@ -188,8 +189,8 @@ private:
 	void addUnicodeAsUTF8(unsigned codepoint);
 	///@}
 
-	bool advance() { m_char = m_source.advanceAndGet(); return !m_source.isPastEndOfInput(); }
-	void rollback(int _amount) { m_char = m_source.rollback(_amount); }
+	bool advance() { m_char = m_source->advanceAndGet(); return !m_source->isPastEndOfInput(); }
+	void rollback(int _amount) { m_char = m_source->rollback(_amount); }
 
 	inline Token selectErrorToken(ScannerError _err) { advance(); return setError(_err); }
 	inline Token selectToken(Token _tok) { advance(); return _tok; }
@@ -229,8 +230,8 @@ private:
 	bool isUnicodeLinebreak();
 
 	/// Return the current source position.
-	int sourcePos() const { return m_source.position(); }
-	bool isSourcePastEndOfInput() const { return m_source.isPastEndOfInput(); }
+	int sourcePos() const { return m_source->position(); }
+	bool isSourcePastEndOfInput() const { return m_source->isPastEndOfInput(); }
 
 	TokenDesc m_skippedComment;  // desc for current skipped comment
 	TokenDesc m_nextSkippedComment; // desc for next skipped comment
@@ -238,8 +239,7 @@ private:
 	TokenDesc m_currentToken;  // desc for current token (as returned by Next())
 	TokenDesc m_nextToken;     // desc for next token (one token look-ahead)
 
-	CharStream m_source;
-	std::shared_ptr<std::string const> m_sourceName;
+	std::shared_ptr<CharStream> m_source;
 
 	/// one character look-ahead, equals 0 at end of input
 	char m_char;
diff --git a/liblangutil/SourceLocation.h b/liblangutil/SourceLocation.h
index eeb81e94..2d18a7d1 100644
--- a/liblangutil/SourceLocation.h
+++ b/liblangutil/SourceLocation.h
@@ -23,6 +23,7 @@
 #pragma once
 
 #include <libdevcore/Common.h> // defines noexcept macro for MSVC
+#include <liblangutil/CharStream.h>
 #include <memory>
 #include <string>
 #include <ostream>
@@ -37,28 +38,13 @@ namespace langutil
  */
 struct SourceLocation
 {
-	SourceLocation(): start(-1), end(-1) { }
-	SourceLocation(int _start, int _end, std::shared_ptr<std::string const> _sourceName):
-		start(_start), end(_end), sourceName(_sourceName) { }
-	SourceLocation(SourceLocation&& _other) noexcept:
-		start(_other.start),
-		end(_other.end),
-		sourceName(std::move(_other.sourceName))
-	{}
-	SourceLocation(SourceLocation const&) = default;
-	SourceLocation& operator=(SourceLocation const&) = default;
-	SourceLocation& operator=(SourceLocation&& _other) noexcept
-	{
-		start = _other.start;
-		end = _other.end;
-		sourceName = std::move(_other.sourceName);
-		return *this;
-	}
+	SourceLocation(): start(-1), end(-1), source{nullptr} { }
+	SourceLocation(int _start, int _end, std::shared_ptr<CharStream> _source):
+		start(_start), end(_end), source{std::move(_source)} { }
 
 	bool operator==(SourceLocation const& _other) const
 	{
-		return start == _other.start && end == _other.end &&
-			((!sourceName && !_other.sourceName) || (sourceName && _other.sourceName && *sourceName == *_other.sourceName));
+		return source.get() == _other.source.get() && start == _other.start && end == _other.end;
 	}
 	bool operator!=(SourceLocation const& _other) const { return !operator==(_other); }
 	inline bool operator<(SourceLocation const& _other) const;
@@ -69,7 +55,7 @@ struct SourceLocation
 
 	int start;
 	int end;
-	std::shared_ptr<std::string const> sourceName;
+	std::shared_ptr<CharStream> source;
 };
 
 /// Stream output for Location (used e.g. in boost exceptions).
@@ -77,27 +63,33 @@ inline std::ostream& operator<<(std::ostream& _out, SourceLocation const& _locat
 {
 	if (_location.isEmpty())
 		return _out << "NO_LOCATION_SPECIFIED";
-	return _out << *_location.sourceName << "[" << _location.start << "," << _location.end << ")";
+
+	if (_location.source)
+		_out << _location.source->name();
+
+	_out << "[" << _location.start << "," << _location.end << ")";
+
+	return _out;
 }
 
 bool SourceLocation::operator<(SourceLocation const& _other) const
 {
-	if (!sourceName || !_other.sourceName)
-		return std::make_tuple(int(!!sourceName), start, end) < std::make_tuple(int(!!_other.sourceName), _other.start, _other.end);
+	if (!source|| !_other.source)
+		return std::make_tuple(int(!!source), start, end) < std::make_tuple(int(!!_other.source), _other.start, _other.end);
 	else
-		return std::make_tuple(*sourceName, start, end) < std::make_tuple(*_other.sourceName, _other.start, _other.end);
+		return std::make_tuple(source->name(), start, end) < std::make_tuple(_other.source->name(), _other.start, _other.end);
 }
 
 bool SourceLocation::contains(SourceLocation const& _other) const
 {
-	if (isEmpty() || _other.isEmpty() || ((!sourceName || !_other.sourceName || *sourceName != *_other.sourceName) && (sourceName || _other.sourceName)))
+	if (isEmpty() || _other.isEmpty() || source.get() != _other.source.get())
 		return false;
 	return start <= _other.start && _other.end <= end;
 }
 
 bool SourceLocation::intersects(SourceLocation const& _other) const
 {
-	if (isEmpty() || _other.isEmpty() || ((!sourceName || !_other.sourceName || *sourceName != *_other.sourceName) && (sourceName || _other.sourceName)))
+	if (isEmpty() || _other.isEmpty() || source.get() != _other.source.get())
 		return false;
 	return _other.start < end && start < _other.end;
 }
diff --git a/liblangutil/SourceReferenceFormatter.cpp b/liblangutil/SourceReferenceFormatter.cpp
index 58a65521..8ac05b4e 100644
--- a/liblangutil/SourceReferenceFormatter.cpp
+++ b/liblangutil/SourceReferenceFormatter.cpp
@@ -30,9 +30,9 @@ using namespace langutil;
 
 void SourceReferenceFormatter::printSourceLocation(SourceLocation const* _location)
 {
-	if (!_location || !_location->sourceName)
+	if (!_location || !_location->source)
 		return; // Nothing we can print here
-	auto const& scanner = m_scannerFromSourceName(*_location->sourceName);
+	auto const& scanner = m_scannerFromSourceName(_location->source->name());
 	int startLine;
 	int startColumn;
 	tie(startLine, startColumn) = scanner.translatePositionToLineColumn(_location->start);
@@ -89,13 +89,13 @@ void SourceReferenceFormatter::printSourceLocation(SourceLocation const* _locati
 
 void SourceReferenceFormatter::printSourceName(SourceLocation const* _location)
 {
-	if (!_location || !_location->sourceName)
+	if (!_location || !_location->source)
 		return; // Nothing we can print here
-	auto const& scanner = m_scannerFromSourceName(*_location->sourceName);
+	auto const& scanner = m_scannerFromSourceName(_location->source->name());
 	int startLine;
 	int startColumn;
 	tie(startLine, startColumn) = scanner.translatePositionToLineColumn(_location->start);
-	m_stream << *_location->sourceName << ":" << (startLine + 1) << ":" << (startColumn + 1) << ": ";
+	m_stream << _location->source->name() << ":" << (startLine + 1) << ":" << (startColumn + 1) << ": ";
 }
 
 void SourceReferenceFormatter::printExceptionInformation(
diff --git a/libsolidity/analysis/NameAndTypeResolver.cpp b/libsolidity/analysis/NameAndTypeResolver.cpp
index e40a2c97..0528a200 100644
--- a/libsolidity/analysis/NameAndTypeResolver.cpp
+++ b/libsolidity/analysis/NameAndTypeResolver.cpp
@@ -492,9 +492,9 @@ bool DeclarationRegistrationHelper::registerDeclaration(
 		Declaration const* conflictingDeclaration = _container.conflictingDeclaration(_declaration, _name);
 		solAssert(conflictingDeclaration, "");
 		bool const comparable =
-			_errorLocation->sourceName &&
-			conflictingDeclaration->location().sourceName &&
-			*_errorLocation->sourceName == *conflictingDeclaration->location().sourceName;
+			_errorLocation->source &&
+			conflictingDeclaration->location().source &&
+			_errorLocation->source->name() == conflictingDeclaration->location().source->name();
 		if (comparable && _errorLocation->start < conflictingDeclaration->location().start)
 		{
 			firstDeclarationLocation = *_errorLocation;
diff --git a/libsolidity/ast/ASTJsonConverter.cpp b/libsolidity/ast/ASTJsonConverter.cpp
index b9054692..cfb13271 100644
--- a/libsolidity/ast/ASTJsonConverter.cpp
+++ b/libsolidity/ast/ASTJsonConverter.cpp
@@ -122,8 +122,8 @@ void ASTJsonConverter::setJsonNode(
 string ASTJsonConverter::sourceLocationToString(SourceLocation const& _location) const
 {
 	int sourceIndex{-1};
-	if (_location.sourceName && m_sourceIndices.count(*_location.sourceName))
-		sourceIndex = m_sourceIndices.at(*_location.sourceName);
+	if (_location.source && m_sourceIndices.count(_location.source->name()))
+		sourceIndex = m_sourceIndices.at(_location.source->name());
 	int length = -1;
 	if (_location.start >= 0 && _location.end >= 0)
 		length = _location.end - _location.start;
diff --git a/libsolidity/codegen/CompilerContext.cpp b/libsolidity/codegen/CompilerContext.cpp
index 2fd62de2..5a3a233c 100644
--- a/libsolidity/codegen/CompilerContext.cpp
+++ b/libsolidity/codegen/CompilerContext.cpp
@@ -360,7 +360,7 @@ void CompilerContext::appendInlineAssembly(
 
 	ErrorList errors;
 	ErrorReporter errorReporter(errors);
-	auto scanner = make_shared<langutil::Scanner>(langutil::CharStream(_assembly), "--CODEGEN--");
+	auto scanner = make_shared<langutil::Scanner>(langutil::CharStream(_assembly, "--CODEGEN--"));
 	auto parserResult = yul::Parser(errorReporter, yul::AsmFlavour::Strict).parse(scanner, false);
 #ifdef SOL_OUTPUT_ASM
 	cout << yul::AsmPrinter()(*parserResult) << endl;
diff --git a/libsolidity/interface/AssemblyStack.cpp b/libsolidity/interface/AssemblyStack.cpp
index 24e190b3..66ba42ee 100644
--- a/libsolidity/interface/AssemblyStack.cpp
+++ b/libsolidity/interface/AssemblyStack.cpp
@@ -69,7 +69,7 @@ bool AssemblyStack::parseAndAnalyze(std::string const& _sourceName, std::string
 {
 	m_errors.clear();
 	m_analysisSuccessful = false;
-	m_scanner = make_shared<Scanner>(CharStream(_source), _sourceName);
+	m_scanner = make_shared<Scanner>(CharStream(_source, _sourceName));
 	m_parserResult = yul::ObjectParser(m_errorReporter, languageToAsmFlavour(m_language)).parse(m_scanner, false);
 	if (!m_errorReporter.errors().empty())
 		return false;
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 623ccca8..610caea1 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -126,7 +126,7 @@ bool CompilerStack::addSource(string const& _name, string const& _content, bool
 {
 	bool existed = m_sources.count(_name) != 0;
 	reset(true);
-	m_sources[_name].scanner = make_shared<Scanner>(CharStream(_content), _name);
+	m_sources[_name].scanner = make_shared<Scanner>(CharStream(_content, _name));
 	m_sources[_name].isLibrary = _isLibrary;
 	m_stackState = SourcesSet;
 	return existed;
@@ -161,7 +161,7 @@ bool CompilerStack::parse()
 			{
 				string const& newPath = newSource.first;
 				string const& newContents = newSource.second;
-				m_sources[newPath].scanner = make_shared<Scanner>(CharStream(newContents), newPath);
+				m_sources[newPath].scanner = make_shared<Scanner>(CharStream(newContents, newPath));
 				sourcesToParse.push_back(newPath);
 			}
 		}
@@ -612,8 +612,8 @@ tuple<int, int, int, int> CompilerStack::positionFromSourceLocation(SourceLocati
 	int startColumn;
 	int endLine;
 	int endColumn;
-	tie(startLine, startColumn) = scanner(*_sourceLocation.sourceName).translatePositionToLineColumn(_sourceLocation.start);
-	tie(endLine, endColumn) = scanner(*_sourceLocation.sourceName).translatePositionToLineColumn(_sourceLocation.end);
+	tie(startLine, startColumn) = scanner(_sourceLocation.source->name()).translatePositionToLineColumn(_sourceLocation.start);
+	tie(endLine, endColumn) = scanner(_sourceLocation.source->name()).translatePositionToLineColumn(_sourceLocation.end);
 
 	return make_tuple(++startLine, ++startColumn, ++endLine, ++endColumn);
 }
@@ -936,8 +936,8 @@ string CompilerStack::computeSourceMapping(eth::AssemblyItems const& _items) con
 		SourceLocation const& location = item.location();
 		int length = location.start != -1 && location.end != -1 ? location.end - location.start : -1;
 		int sourceIndex =
-			location.sourceName && sourceIndicesMap.count(*location.sourceName) ?
-			sourceIndicesMap.at(*location.sourceName) :
+			location.source && sourceIndicesMap.count(location.source->name()) ?
+			sourceIndicesMap.at(location.source->name()) :
 			-1;
 		char jump = '-';
 		if (item.getJumpType() == eth::AssemblyItem::JumpType::IntoFunction)
diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index 4a32d9f3..0eef50d2 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -85,9 +85,9 @@ Json::Value formatErrorWithException(
 		message = _message;
 
 	Json::Value sourceLocation;
-	if (location && location->sourceName)
+	if (location && location->source && location->source->name() != "")
 	{
-		sourceLocation["file"] = *location->sourceName;
+		sourceLocation["file"] = location->source->name();
 		sourceLocation["start"] = location->start;
 		sourceLocation["end"] = location->end;
 	}
diff --git a/libsolidity/parsing/Parser.cpp b/libsolidity/parsing/Parser.cpp
index 3f4a015b..6cab7be3 100644
--- a/libsolidity/parsing/Parser.cpp
+++ b/libsolidity/parsing/Parser.cpp
@@ -42,7 +42,7 @@ class Parser::ASTNodeFactory
 {
 public:
 	explicit ASTNodeFactory(Parser const& _parser):
-		m_parser(_parser), m_location(_parser.position(), -1, _parser.sourceName()) {}
+		m_parser(_parser), m_location(_parser.position(), -1, _parser.source()) {}
 	ASTNodeFactory(Parser const& _parser, ASTPointer<ASTNode> const& _childNode):
 		m_parser(_parser), m_location(_childNode->location()) {}
 
@@ -55,7 +55,7 @@ public:
 	template <class NodeType, typename... Args>
 	ASTPointer<NodeType> createNode(Args&& ... _args)
 	{
-		solAssert(m_location.sourceName, "");
+		solAssert(m_location.source, "");
 		if (m_location.end < 0)
 			markEndPosition();
 		return make_shared<NodeType>(m_location, std::forward<Args>(_args)...);
diff --git a/libyul/AsmParser.h b/libyul/AsmParser.h
index cea3b667..52166a20 100644
--- a/libyul/AsmParser.h
+++ b/libyul/AsmParser.h
@@ -56,11 +56,11 @@ protected:
 			r.location.start = position();
 			r.location.end = endPosition();
 		}
-		if (!r.location.sourceName)
-			r.location.sourceName = sourceName();
+		if (!r.location.source)
+			r.location.source = m_scanner->charStream();
 		return r;
 	}
-	langutil::SourceLocation location() const { return {position(), endPosition(), sourceName()}; }
+	langutil::SourceLocation location() const { return {position(), endPosition(), m_scanner->charStream()}; }
 
 	Block parseBlock();
 	Statement parseStatement();
diff --git a/test/libevmasm/Assembler.cpp b/test/libevmasm/Assembler.cpp
index 5ad01594..bece2be4 100644
--- a/test/libevmasm/Assembler.cpp
+++ b/test/libevmasm/Assembler.cpp
@@ -55,10 +55,12 @@ BOOST_AUTO_TEST_SUITE(Assembler)
 BOOST_AUTO_TEST_CASE(all_assembly_items)
 {
 	Assembly _assembly;
-	_assembly.setSourceLocation(SourceLocation(1, 3, make_shared<string>("root.asm")));
+	auto root_asm = make_shared<CharStream>("", "root.asm");
+	_assembly.setSourceLocation(SourceLocation(1, 3, root_asm));
 
 	Assembly _subAsm;
-	_subAsm.setSourceLocation(SourceLocation(6, 8, make_shared<string>("sub.asm")));
+	auto sub_asm = make_shared<CharStream>("", "sub.asm");
+	_subAsm.setSourceLocation(SourceLocation(6, 8, sub_asm));
 	_subAsm.append(Instruction::INVALID);
 	shared_ptr<Assembly> _subAsmPtr = make_shared<Assembly>(_subAsm);
 
diff --git a/test/libevmasm/Optimiser.cpp b/test/libevmasm/Optimiser.cpp
index c061b783..7d102948 100644
--- a/test/libevmasm/Optimiser.cpp
+++ b/test/libevmasm/Optimiser.cpp
@@ -53,7 +53,7 @@ namespace
 		// add dummy locations to each item so that we can check that they are not deleted
 		AssemblyItems input = _input;
 		for (AssemblyItem& item: input)
-			item.setLocation(SourceLocation(1, 3, make_shared<string>("")));
+			item.setLocation(SourceLocation(1, 3, nullptr));
 		return input;
 	}
 
diff --git a/test/liblangutil/SourceLocation.cpp b/test/liblangutil/SourceLocation.cpp
index ac7a2173..ef4103da 100644
--- a/test/liblangutil/SourceLocation.cpp
+++ b/test/liblangutil/SourceLocation.cpp
@@ -33,12 +33,16 @@ BOOST_AUTO_TEST_SUITE(SourceLocationTest)
 
 BOOST_AUTO_TEST_CASE(test_fail)
 {
+	auto const source = std::make_shared<CharStream>("", "source");
+	auto const sourceA = std::make_shared<CharStream>("", "sourceA");
+	auto const sourceB = std::make_shared<CharStream>("", "sourceB");
+
 	BOOST_CHECK(SourceLocation() == SourceLocation());
-	BOOST_CHECK(SourceLocation(0, 3, std::make_shared<std::string>("sourceA")) != SourceLocation(0, 3, std::make_shared<std::string>("sourceB")));
-	BOOST_CHECK(SourceLocation(0, 3, std::make_shared<std::string>("source")) == SourceLocation(0, 3, std::make_shared<std::string>("source")));
-	BOOST_CHECK(SourceLocation(3, 7, std::make_shared<std::string>("source")).contains(SourceLocation(4, 6, std::make_shared<std::string>("source"))));
-	BOOST_CHECK(!SourceLocation(3, 7, std::make_shared<std::string>("sourceA")).contains(SourceLocation(4, 6, std::make_shared<std::string>("sourceB"))));
-	BOOST_CHECK(SourceLocation(3, 7, std::make_shared<std::string>("sourceA")) < SourceLocation(4, 6, std::make_shared<std::string>("sourceB")));
+	BOOST_CHECK(SourceLocation(0, 3, sourceA) != SourceLocation(0, 3, sourceB));
+	BOOST_CHECK(SourceLocation(0, 3, source) == SourceLocation(0, 3, source));
+	BOOST_CHECK(SourceLocation(3, 7, source).contains(SourceLocation(4, 6, source)));
+	BOOST_CHECK(!SourceLocation(3, 7, sourceA).contains(SourceLocation(4, 6, sourceB)));
+	BOOST_CHECK(SourceLocation(3, 7, sourceA) < SourceLocation(4, 6, sourceB));
 }
 
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/test/libsolidity/Assembly.cpp b/test/libsolidity/Assembly.cpp
index 926e29fe..aa10147c 100644
--- a/test/libsolidity/Assembly.cpp
+++ b/test/libsolidity/Assembly.cpp
@@ -52,13 +52,13 @@ namespace test
 namespace
 {
 
-eth::AssemblyItems compileContract(string const& _sourceCode)
+eth::AssemblyItems compileContract(std::shared_ptr<CharStream> _sourceCode)
 {
 	ErrorList errors;
 	ErrorReporter errorReporter(errors);
 	Parser parser(errorReporter);
 	ASTPointer<SourceUnit> sourceUnit;
-	BOOST_REQUIRE_NO_THROW(sourceUnit = parser.parse(make_shared<Scanner>(CharStream(_sourceCode))));
+	BOOST_REQUIRE_NO_THROW(sourceUnit = parser.parse(make_shared<Scanner>(_sourceCode)));
 	BOOST_CHECK(!!sourceUnit);
 
 	map<ASTNode const*, shared_ptr<DeclarationContainer>> scopes;
@@ -104,7 +104,7 @@ void printAssemblyLocations(AssemblyItems const& _items)
 			", " <<
 			_loc.end <<
 			", make_shared<string>(\"" <<
-			*_loc.sourceName <<
+			_loc.source->name() <<
 			"\"))) +" << endl;
 	};
 
@@ -135,7 +135,8 @@ void checkAssemblyLocations(AssemblyItems const& _items, vector<SourceLocation>
 	BOOST_CHECK_EQUAL(_items.size(), _locations.size());
 	for (size_t i = 0; i < min(_items.size(), _locations.size()); ++i)
 	{
-		if (_items[i].location() != _locations[i])
+		if (_items[i].location().start != _locations[i].start ||
+			_items[i].location().end != _locations[i].end)
 		{
 			BOOST_CHECK_MESSAGE(false, "Location mismatch for item " + to_string(i) + ". Found the following locations:");
 			printAssemblyLocations(_items);
@@ -151,29 +152,32 @@ BOOST_AUTO_TEST_SUITE(Assembly)
 
 BOOST_AUTO_TEST_CASE(location_test)
 {
-	char const* sourceCode = R"(
+	auto sourceCode = make_shared<CharStream>(R"(
 	contract test {
 		function f() public returns (uint256 a) {
 			return 16;
 		}
 	}
-	)";
+	)", "");
 	AssemblyItems items = compileContract(sourceCode);
 	bool hasShifts = dev::test::Options::get().evmVersion().hasBitwiseShifting();
+
+	auto codegenCharStream = make_shared<CharStream>("", "--CODEGEN--");
+
 	vector<SourceLocation> locations =
-		vector<SourceLocation>(hasShifts ? 21 : 22, SourceLocation(2, 82, make_shared<string>(""))) +
-		vector<SourceLocation>(2, SourceLocation(20, 79, make_shared<string>(""))) +
-		vector<SourceLocation>(1, SourceLocation(8, 17, make_shared<string>("--CODEGEN--"))) +
-		vector<SourceLocation>(3, SourceLocation(5, 7, make_shared<string>("--CODEGEN--"))) +
-		vector<SourceLocation>(1, SourceLocation(30, 31, make_shared<string>("--CODEGEN--"))) +
-		vector<SourceLocation>(1, SourceLocation(27, 28, make_shared<string>("--CODEGEN--"))) +
-		vector<SourceLocation>(1, SourceLocation(20, 32, make_shared<string>("--CODEGEN--"))) +
-		vector<SourceLocation>(1, SourceLocation(5, 7, make_shared<string>("--CODEGEN--"))) +
-		vector<SourceLocation>(24, SourceLocation(20, 79, make_shared<string>(""))) +
-		vector<SourceLocation>(1, SourceLocation(49, 58, make_shared<string>(""))) +
-		vector<SourceLocation>(1, SourceLocation(72, 74, make_shared<string>(""))) +
-		vector<SourceLocation>(2, SourceLocation(65, 74, make_shared<string>(""))) +
-		vector<SourceLocation>(2, SourceLocation(20, 79, make_shared<string>("")));
+		vector<SourceLocation>(hasShifts ? 21 : 22, SourceLocation(2, 82, sourceCode)) +
+		vector<SourceLocation>(2, SourceLocation(20, 79, sourceCode)) +
+		vector<SourceLocation>(1, SourceLocation(8, 17,  codegenCharStream)) +
+		vector<SourceLocation>(3, SourceLocation(5, 7,   codegenCharStream)) +
+		vector<SourceLocation>(1, SourceLocation(30, 31, codegenCharStream)) +
+		vector<SourceLocation>(1, SourceLocation(27, 28, codegenCharStream)) +
+		vector<SourceLocation>(1, SourceLocation(20, 32, codegenCharStream)) +
+		vector<SourceLocation>(1, SourceLocation(5, 7,   codegenCharStream)) +
+		vector<SourceLocation>(24, SourceLocation(20, 79, sourceCode)) +
+		vector<SourceLocation>(1, SourceLocation(49, 58, sourceCode)) +
+		vector<SourceLocation>(1, SourceLocation(72, 74, sourceCode)) +
+		vector<SourceLocation>(2, SourceLocation(65, 74, sourceCode)) +
+		vector<SourceLocation>(2, SourceLocation(20, 79, sourceCode));
 	checkAssemblyLocations(items, locations);
 }
 
diff --git a/test/libsolidity/SemVerMatcher.cpp b/test/libsolidity/SemVerMatcher.cpp
index 2e147847..2980acd1 100644
--- a/test/libsolidity/SemVerMatcher.cpp
+++ b/test/libsolidity/SemVerMatcher.cpp
@@ -41,7 +41,7 @@ BOOST_AUTO_TEST_SUITE(SemVerMatcher)
 
 SemVerMatchExpression parseExpression(string const& _input)
 {
-	Scanner scanner{CharStream(_input)};
+	Scanner scanner{CharStream(_input, "")};
 	vector<string> literals;
 	vector<Token> tokens;
 	while (scanner.currentToken() != Token::EOS)
diff --git a/test/libsolidity/SolidityExpressionCompiler.cpp b/test/libsolidity/SolidityExpressionCompiler.cpp
index a68eb3df..8bce26c1 100644
--- a/test/libsolidity/SolidityExpressionCompiler.cpp
+++ b/test/libsolidity/SolidityExpressionCompiler.cpp
@@ -101,7 +101,7 @@ bytes compileFirstExpression(
 	{
 		ErrorList errors;
 		ErrorReporter errorReporter(errors);
-		sourceUnit = Parser(errorReporter).parse(make_shared<Scanner>(CharStream(_sourceCode)));
+		sourceUnit = Parser(errorReporter).parse(make_shared<Scanner>(CharStream(_sourceCode, "")));
 		if (!sourceUnit)
 			return bytes();
 	}
diff --git a/test/libsolidity/SolidityParser.cpp b/test/libsolidity/SolidityParser.cpp
index 3534dd5b..d86d3d39 100644
--- a/test/libsolidity/SolidityParser.cpp
+++ b/test/libsolidity/SolidityParser.cpp
@@ -43,7 +43,7 @@ namespace
 ASTPointer<ContractDefinition> parseText(std::string const& _source, ErrorList& _errors)
 {
 	ErrorReporter errorReporter(_errors);
-	ASTPointer<SourceUnit> sourceUnit = Parser(errorReporter).parse(std::make_shared<Scanner>(CharStream(_source)));
+	ASTPointer<SourceUnit> sourceUnit = Parser(errorReporter).parse(std::make_shared<Scanner>(CharStream(_source, "")));
 	if (!sourceUnit)
 		return ASTPointer<ContractDefinition>();
 	for (ASTPointer<ASTNode> const& node: sourceUnit->nodes())
diff --git a/test/libsolidity/SolidityScanner.cpp b/test/libsolidity/SolidityScanner.cpp
index 02d91d32..5ce4eda2 100644
--- a/test/libsolidity/SolidityScanner.cpp
+++ b/test/libsolidity/SolidityScanner.cpp
@@ -37,13 +37,13 @@ BOOST_AUTO_TEST_SUITE(SolidityScanner)
 
 BOOST_AUTO_TEST_CASE(test_empty)
 {
-	Scanner scanner(CharStream(""));
+	Scanner scanner(CharStream{});
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 }
 
 BOOST_AUTO_TEST_CASE(smoke_test)
 {
-	Scanner scanner(CharStream("function break;765  \t  \"string1\",'string2'\nidentifier1"));
+	Scanner scanner(CharStream("function break;765  \t  \"string1\",'string2'\nidentifier1", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Function);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Break);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Semicolon);
@@ -61,7 +61,7 @@ BOOST_AUTO_TEST_CASE(smoke_test)
 
 BOOST_AUTO_TEST_CASE(string_escapes)
 {
-	Scanner scanner(CharStream("  { \"a\\x61\""));
+	Scanner scanner(CharStream("  { \"a\\x61\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "aa");
@@ -69,7 +69,7 @@ BOOST_AUTO_TEST_CASE(string_escapes)
 
 BOOST_AUTO_TEST_CASE(string_escapes_all)
 {
-	Scanner scanner(CharStream("  { \"a\\x61\\b\\f\\n\\r\\t\\v\""));
+	Scanner scanner(CharStream("  { \"a\\x61\\b\\f\\n\\r\\t\\v\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "aa\b\f\n\r\t\v");
@@ -77,7 +77,7 @@ BOOST_AUTO_TEST_CASE(string_escapes_all)
 
 BOOST_AUTO_TEST_CASE(string_escapes_with_zero)
 {
-	Scanner scanner(CharStream("  { \"a\\x61\\x00abc\""));
+	Scanner scanner(CharStream("  { \"a\\x61\\x00abc\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), std::string("aa\0abc", 6));
@@ -85,7 +85,7 @@ BOOST_AUTO_TEST_CASE(string_escapes_with_zero)
 
 BOOST_AUTO_TEST_CASE(string_escape_illegal)
 {
-	Scanner scanner(CharStream(" bla \"\\x6rf\" (illegalescape)"));
+	Scanner scanner(CharStream(" bla \"\\x6rf\" (illegalescape)", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalEscapeSequence);
@@ -99,7 +99,7 @@ BOOST_AUTO_TEST_CASE(string_escape_illegal)
 
 BOOST_AUTO_TEST_CASE(hex_numbers)
 {
-	Scanner scanner(CharStream("var x = 0x765432536763762734623472346;"));
+	Scanner scanner(CharStream("var x = 0x765432536763762734623472346;", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Var);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Assign);
@@ -107,34 +107,34 @@ BOOST_AUTO_TEST_CASE(hex_numbers)
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "0x765432536763762734623472346");
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Semicolon);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
-	scanner.reset(CharStream("0x1234"), "");
+	scanner.reset(CharStream("0x1234", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "0x1234");
-	scanner.reset(CharStream("0X1234"), "");
+	scanner.reset(CharStream("0X1234", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 }
 
 BOOST_AUTO_TEST_CASE(octal_numbers)
 {
-	Scanner scanner(CharStream("07"));
+	Scanner scanner(CharStream("07", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
-	scanner.reset(CharStream("007"), "");
+	scanner.reset(CharStream("007", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
-	scanner.reset(CharStream("-07"), "");
+	scanner.reset(CharStream("-07", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Sub);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
-	scanner.reset(CharStream("-.07"), "");
+	scanner.reset(CharStream("-.07", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Sub);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Number);
-	scanner.reset(CharStream("0"), "");
+	scanner.reset(CharStream("0", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
-	scanner.reset(CharStream("0.1"), "");
+	scanner.reset(CharStream("0.1", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 }
 
 BOOST_AUTO_TEST_CASE(scientific_notation)
 {
-	Scanner scanner(CharStream("var x = 2e10;"));
+	Scanner scanner(CharStream("var x = 2e10;", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Var);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Assign);
@@ -146,19 +146,19 @@ BOOST_AUTO_TEST_CASE(scientific_notation)
 
 BOOST_AUTO_TEST_CASE(trailing_dot)
 {
-	Scanner scanner(CharStream("2.5"));
+	Scanner scanner(CharStream("2.5", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
-	scanner.reset(CharStream("2.5e10"), "");
+	scanner.reset(CharStream("2.5e10", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
-	scanner.reset(CharStream(".5"), "");
+	scanner.reset(CharStream(".5", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
-	scanner.reset(CharStream(".5e10"), "");
+	scanner.reset(CharStream(".5e10", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
-	scanner.reset(CharStream("2."), "");
+	scanner.reset(CharStream("2.", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Period);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
@@ -167,7 +167,7 @@ BOOST_AUTO_TEST_CASE(trailing_dot)
 BOOST_AUTO_TEST_CASE(leading_underscore_decimal_is_identifier)
 {
 	// Actual error is cought by SyntaxChecker.
-	Scanner scanner(CharStream("_1.2"));
+	Scanner scanner(CharStream("_1.2", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
@@ -176,11 +176,11 @@ BOOST_AUTO_TEST_CASE(leading_underscore_decimal_is_identifier)
 BOOST_AUTO_TEST_CASE(leading_underscore_decimal_after_dot_illegal)
 {
 	// Actual error is cought by SyntaxChecker.
-	Scanner scanner(CharStream("1._2"));
+	Scanner scanner(CharStream("1._2", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 
-	scanner.reset(CharStream("1._"), "");
+	scanner.reset(CharStream("1._", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
@@ -188,7 +188,7 @@ BOOST_AUTO_TEST_CASE(leading_underscore_decimal_after_dot_illegal)
 BOOST_AUTO_TEST_CASE(leading_underscore_exp_are_identifier)
 {
 	// Actual error is cought by SyntaxChecker.
-	Scanner scanner(CharStream("_1e2"));
+	Scanner scanner(CharStream("_1e2", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
@@ -196,7 +196,7 @@ BOOST_AUTO_TEST_CASE(leading_underscore_exp_are_identifier)
 BOOST_AUTO_TEST_CASE(leading_underscore_exp_after_e_illegal)
 {
 	// Actual error is cought by SyntaxChecker.
-	Scanner scanner(CharStream("1e_2"));
+	Scanner scanner(CharStream("1e_2", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), "1e_2");
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
@@ -204,7 +204,7 @@ BOOST_AUTO_TEST_CASE(leading_underscore_exp_after_e_illegal)
 
 BOOST_AUTO_TEST_CASE(leading_underscore_hex_illegal)
 {
-	Scanner scanner(CharStream("0x_abc"));
+	Scanner scanner(CharStream("0x_abc", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
@@ -213,7 +213,7 @@ BOOST_AUTO_TEST_CASE(leading_underscore_hex_illegal)
 BOOST_AUTO_TEST_CASE(fixed_number_invalid_underscore_front)
 {
 	// Actual error is cought by SyntaxChecker.
-	Scanner scanner(CharStream("12._1234_1234"));
+	Scanner scanner(CharStream("12._1234_1234", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
@@ -221,22 +221,22 @@ BOOST_AUTO_TEST_CASE(fixed_number_invalid_underscore_front)
 BOOST_AUTO_TEST_CASE(number_literals_with_trailing_underscore_at_eos)
 {
 	// Actual error is cought by SyntaxChecker.
-	Scanner scanner(CharStream("0x123_"));
+	Scanner scanner(CharStream("0x123_", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 
-	scanner.reset(CharStream("123_"), "");
+	scanner.reset(CharStream("123_", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 
-	scanner.reset(CharStream("12.34_"), "");
+	scanner.reset(CharStream("12.34_", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Number);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
 
 BOOST_AUTO_TEST_CASE(negative_numbers)
 {
-	Scanner scanner(CharStream("var x = -.2 + -0x78 + -7.3 + 8.9 + 2e-2;"));
+	Scanner scanner(CharStream("var x = -.2 + -0x78 + -7.3 + 8.9 + 2e-2;", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Var);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Assign);
@@ -263,7 +263,7 @@ BOOST_AUTO_TEST_CASE(negative_numbers)
 
 BOOST_AUTO_TEST_CASE(locations)
 {
-	Scanner scanner(CharStream("function_identifier has ; -0x743/*comment*/\n ident //comment"));
+	Scanner scanner(CharStream("function_identifier has ; -0x743/*comment*/\n ident //comment", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.currentLocation().start, 0);
 	BOOST_CHECK_EQUAL(scanner.currentLocation().end, 19);
@@ -286,7 +286,7 @@ BOOST_AUTO_TEST_CASE(locations)
 BOOST_AUTO_TEST_CASE(ambiguities)
 {
 	// test scanning of some operators which need look-ahead
-	Scanner scanner(CharStream("<=" "<" "+ +=a++ =>" "<<" ">>" " >>=" ">>>" ">>>=" " >>>>>=><<="));
+	Scanner scanner(CharStream("<=" "<" "+ +=a++ =>" "<<" ">>" " >>=" ">>>" ">>>=" " >>>>>=><<=", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LessThanOrEqual);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::LessThan);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Add);
@@ -308,21 +308,21 @@ BOOST_AUTO_TEST_CASE(ambiguities)
 
 BOOST_AUTO_TEST_CASE(documentation_comments_parsed_begin)
 {
-	Scanner scanner(CharStream("/// Send $(value / 1000) chocolates to the user"));
+	Scanner scanner(CharStream("/// Send $(value / 1000) chocolates to the user", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "Send $(value / 1000) chocolates to the user");
 }
 
 BOOST_AUTO_TEST_CASE(multiline_documentation_comments_parsed_begin)
 {
-	Scanner scanner(CharStream("/** Send $(value / 1000) chocolates to the user*/"));
+	Scanner scanner(CharStream("/** Send $(value / 1000) chocolates to the user*/", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "Send $(value / 1000) chocolates to the user");
 }
 
 BOOST_AUTO_TEST_CASE(documentation_comments_parsed)
 {
-	Scanner scanner(CharStream("some other tokens /// Send $(value / 1000) chocolates to the user"));
+	Scanner scanner(CharStream("some other tokens /// Send $(value / 1000) chocolates to the user", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
@@ -334,7 +334,7 @@ BOOST_AUTO_TEST_CASE(multiline_documentation_comments_parsed)
 {
 	Scanner scanner(CharStream("some other tokens /**\n"
 							   "* Send $(value / 1000) chocolates to the user\n"
-							   "*/"));
+							   "*/", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
@@ -346,7 +346,7 @@ BOOST_AUTO_TEST_CASE(multiline_documentation_no_stars)
 {
 	Scanner scanner(CharStream("some other tokens /**\n"
 							   " Send $(value / 1000) chocolates to the user\n"
-							   "*/"));
+							   "*/", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
@@ -358,7 +358,7 @@ BOOST_AUTO_TEST_CASE(multiline_documentation_whitespace_hell)
 {
 	Scanner scanner(CharStream("some other tokens /** \t \r \n"
 							   "\t \r  * Send $(value / 1000) chocolates to the user\n"
-							   "*/"));
+							   "*/", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
@@ -368,28 +368,28 @@ BOOST_AUTO_TEST_CASE(multiline_documentation_whitespace_hell)
 
 BOOST_AUTO_TEST_CASE(comment_before_eos)
 {
-	Scanner scanner(CharStream("//"));
+	Scanner scanner(CharStream("//", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 }
 
 BOOST_AUTO_TEST_CASE(documentation_comment_before_eos)
 {
-	Scanner scanner(CharStream("///"));
+	Scanner scanner(CharStream("///", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 }
 
 BOOST_AUTO_TEST_CASE(empty_multiline_comment)
 {
-	Scanner scanner(CharStream("/**/"));
+	Scanner scanner(CharStream("/**/", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 }
 
 BOOST_AUTO_TEST_CASE(empty_multiline_documentation_comment_before_eos)
 {
-	Scanner scanner(CharStream("/***/"));
+	Scanner scanner(CharStream("/***/", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::EOS);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 }
@@ -398,7 +398,7 @@ BOOST_AUTO_TEST_CASE(comments_mixed_in_sequence)
 {
 	Scanner scanner(CharStream("hello_world ///documentation comment \n"
 							   "//simple comment \n"
-							   "<<"));
+							   "<<", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::SHL);
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "documentation comment ");
@@ -406,7 +406,7 @@ BOOST_AUTO_TEST_CASE(comments_mixed_in_sequence)
 
 BOOST_AUTO_TEST_CASE(ether_subdenominations)
 {
-	Scanner scanner(CharStream("wei szabo finney ether"));
+	Scanner scanner(CharStream("wei szabo finney ether", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::SubWei);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::SubSzabo);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::SubFinney);
@@ -415,7 +415,7 @@ BOOST_AUTO_TEST_CASE(ether_subdenominations)
 
 BOOST_AUTO_TEST_CASE(time_subdenominations)
 {
-	Scanner scanner(CharStream("seconds minutes hours days weeks years"));
+	Scanner scanner(CharStream("seconds minutes hours days weeks years", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::SubSecond);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::SubMinute);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::SubHour);
@@ -426,7 +426,7 @@ BOOST_AUTO_TEST_CASE(time_subdenominations)
 
 BOOST_AUTO_TEST_CASE(empty_comment)
 {
-	Scanner scanner(CharStream("//\ncontract{}"));
+	Scanner scanner(CharStream("//\ncontract{}", ""));
 	BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Contract);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::LBrace);
@@ -436,7 +436,7 @@ BOOST_AUTO_TEST_CASE(empty_comment)
 
 BOOST_AUTO_TEST_CASE(valid_unicode_string_escape)
 {
-	Scanner scanner(CharStream("{ \"\\u00DAnicode\""));
+	Scanner scanner(CharStream("{ \"\\u00DAnicode\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), std::string("\xC3\x9Anicode", 8));
@@ -444,7 +444,7 @@ BOOST_AUTO_TEST_CASE(valid_unicode_string_escape)
 
 BOOST_AUTO_TEST_CASE(valid_unicode_string_escape_7f)
 {
-	Scanner scanner(CharStream("{ \"\\u007Fnicode\""));
+	Scanner scanner(CharStream("{ \"\\u007Fnicode\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), std::string("\x7Fnicode", 7));
@@ -452,7 +452,7 @@ BOOST_AUTO_TEST_CASE(valid_unicode_string_escape_7f)
 
 BOOST_AUTO_TEST_CASE(valid_unicode_string_escape_7ff)
 {
-	Scanner scanner(CharStream("{ \"\\u07FFnicode\""));
+	Scanner scanner(CharStream("{ \"\\u07FFnicode\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), std::string("\xDF\xBFnicode", 8));
@@ -460,7 +460,7 @@ BOOST_AUTO_TEST_CASE(valid_unicode_string_escape_7ff)
 
 BOOST_AUTO_TEST_CASE(valid_unicode_string_escape_ffff)
 {
-	Scanner scanner(CharStream("{ \"\\uFFFFnicode\""));
+	Scanner scanner(CharStream("{ \"\\uFFFFnicode\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), std::string("\xEF\xBF\xBFnicode", 9));
@@ -468,7 +468,7 @@ BOOST_AUTO_TEST_CASE(valid_unicode_string_escape_ffff)
 
 BOOST_AUTO_TEST_CASE(invalid_short_unicode_string_escape)
 {
-	Scanner scanner(CharStream("{ \"\\uFFnicode\""));
+	Scanner scanner(CharStream("{ \"\\uFFnicode\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
 }
@@ -477,7 +477,7 @@ BOOST_AUTO_TEST_CASE(invalid_short_unicode_string_escape)
 
 BOOST_AUTO_TEST_CASE(valid_hex_literal)
 {
-	Scanner scanner(CharStream("{ hex\"00112233FF\""));
+	Scanner scanner(CharStream("{ hex\"00112233FF\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::StringLiteral);
 	BOOST_CHECK_EQUAL(scanner.currentLiteral(), std::string("\x00\x11\x22\x33\xFF", 5));
@@ -485,7 +485,7 @@ BOOST_AUTO_TEST_CASE(valid_hex_literal)
 
 BOOST_AUTO_TEST_CASE(invalid_short_hex_literal)
 {
-	Scanner scanner(CharStream("{ hex\"00112233F\""));
+	Scanner scanner(CharStream("{ hex\"00112233F\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalHexString);
@@ -493,7 +493,7 @@ BOOST_AUTO_TEST_CASE(invalid_short_hex_literal)
 
 BOOST_AUTO_TEST_CASE(invalid_hex_literal_with_space)
 {
-	Scanner scanner(CharStream("{ hex\"00112233FF \""));
+	Scanner scanner(CharStream("{ hex\"00112233FF \"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalHexString);
@@ -501,7 +501,7 @@ BOOST_AUTO_TEST_CASE(invalid_hex_literal_with_space)
 
 BOOST_AUTO_TEST_CASE(invalid_hex_literal_with_wrong_quotes)
 {
-	Scanner scanner(CharStream("{ hex\"00112233FF'"));
+	Scanner scanner(CharStream("{ hex\"00112233FF'", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalHexString);
@@ -509,7 +509,7 @@ BOOST_AUTO_TEST_CASE(invalid_hex_literal_with_wrong_quotes)
 
 BOOST_AUTO_TEST_CASE(invalid_hex_literal_nonhex_string)
 {
-	Scanner scanner(CharStream("{ hex\"hello\""));
+	Scanner scanner(CharStream("{ hex\"hello\"", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::LBrace);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.currentError(), ScannerError::IllegalHexString);
@@ -520,7 +520,7 @@ BOOST_AUTO_TEST_CASE(invalid_hex_literal_nonhex_string)
 BOOST_AUTO_TEST_CASE(invalid_multiline_comment_close)
 {
 	// This used to parse as "comment", "identifier"
-	Scanner scanner(CharStream("/** / x"));
+	Scanner scanner(CharStream("/** / x", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
@@ -528,14 +528,14 @@ BOOST_AUTO_TEST_CASE(invalid_multiline_comment_close)
 BOOST_AUTO_TEST_CASE(multiline_doc_comment_at_eos)
 {
 	// This used to parse as "whitespace"
-	Scanner scanner(CharStream("/**"));
+	Scanner scanner(CharStream("/**", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
 
 BOOST_AUTO_TEST_CASE(multiline_comment_at_eos)
 {
-	Scanner scanner(CharStream("/*"));
+	Scanner scanner(CharStream("/*", ""));
 	BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 	BOOST_CHECK_EQUAL(scanner.next(), Token::EOS);
 }
@@ -544,7 +544,7 @@ BOOST_AUTO_TEST_CASE(regular_line_break_in_single_line_comment)
 {
 	for (auto const& nl: {"\r", "\n"})
 	{
-		Scanner scanner(CharStream("// abc " + string(nl) + " def "));
+		Scanner scanner(CharStream("// abc " + string(nl) + " def ", ""));
 		BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 		BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 		BOOST_CHECK_EQUAL(scanner.currentLiteral(), "def");
@@ -556,7 +556,7 @@ BOOST_AUTO_TEST_CASE(irregular_line_breaks_in_single_line_comment)
 {
 	for (auto const& nl: {"\v", "\f", "\xE2\x80\xA8", "\xE2\x80\xA9"})
 	{
-		Scanner scanner(CharStream("// abc " + string(nl) + " def "));
+		Scanner scanner(CharStream("// abc " + string(nl) + " def ", ""));
 		BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "");
 		BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 		for (size_t i = 0; i < string(nl).size() - 1; i++)
@@ -571,7 +571,7 @@ BOOST_AUTO_TEST_CASE(regular_line_breaks_in_single_line_doc_comment)
 {
 	for (auto const& nl: {"\r", "\n"})
 	{
-		Scanner scanner(CharStream("/// abc " + string(nl) + " def "));
+		Scanner scanner(CharStream("/// abc " + string(nl) + " def ", ""));
 		BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "abc ");
 		BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Identifier);
 		BOOST_CHECK_EQUAL(scanner.currentLiteral(), "def");
@@ -583,7 +583,7 @@ BOOST_AUTO_TEST_CASE(irregular_line_breaks_in_single_line_doc_comment)
 {
 	for (auto const& nl: {"\v", "\f", "\xE2\x80\xA8", "\xE2\x80\xA9"})
 	{
-		Scanner scanner(CharStream("/// abc " + string(nl) + " def "));
+		Scanner scanner(CharStream("/// abc " + string(nl) + " def ", ""));
 		BOOST_CHECK_EQUAL(scanner.currentCommentLiteral(), "abc ");
 		BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 		for (size_t i = 0; i < string(nl).size() - 1; i++)
@@ -598,7 +598,7 @@ BOOST_AUTO_TEST_CASE(regular_line_breaks_in_strings)
 {
 	for (auto const& nl: {"\n", "\r"})
 	{
-		Scanner scanner(CharStream("\"abc " + string(nl) + " def\""));
+		Scanner scanner(CharStream("\"abc " + string(nl) + " def\"", ""));
 		BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 		BOOST_CHECK_EQUAL(scanner.next(), Token::Identifier);
 		BOOST_CHECK_EQUAL(scanner.currentLiteral(), "def");
@@ -611,7 +611,7 @@ BOOST_AUTO_TEST_CASE(irregular_line_breaks_in_strings)
 {
 	for (auto const& nl: {"\v", "\f", "\xE2\x80\xA8", "\xE2\x80\xA9"})
 	{
-		Scanner scanner(CharStream("\"abc " + string(nl) + " def\""));
+		Scanner scanner(CharStream("\"abc " + string(nl) + " def\"", ""));
 		BOOST_CHECK_EQUAL(scanner.currentToken(), Token::Illegal);
 		for (size_t i = 0; i < string(nl).size(); i++)
 			BOOST_CHECK_EQUAL(scanner.next(), Token::Illegal);
diff --git a/test/libyul/Common.cpp b/test/libyul/Common.cpp
index 2e70d086..a247a169 100644
--- a/test/libyul/Common.cpp
+++ b/test/libyul/Common.cpp
@@ -57,7 +57,7 @@ pair<shared_ptr<Block>, shared_ptr<yul::AsmAnalysisInfo>> yul::test::parse(strin
 	auto flavour = _yul ? yul::AsmFlavour::Yul : yul::AsmFlavour::Strict;
 	ErrorList errors;
 	ErrorReporter errorReporter(errors);
-	auto scanner = make_shared<Scanner>(CharStream(_source), "");
+	auto scanner = make_shared<Scanner>(CharStream(_source, ""));
 	auto parserResult = yul::Parser(errorReporter, flavour).parse(scanner, false);
 	if (parserResult)
 	{
diff --git a/test/libyul/Parser.cpp b/test/libyul/Parser.cpp
index 6f946362..caaf2719 100644
--- a/test/libyul/Parser.cpp
+++ b/test/libyul/Parser.cpp
@@ -51,7 +51,7 @@ bool parse(string const& _source, ErrorReporter& errorReporter)
 {
 	try
 	{
-		auto scanner = make_shared<Scanner>(CharStream(_source));
+		auto scanner = make_shared<Scanner>(CharStream(_source, ""));
 		auto parserResult = yul::Parser(errorReporter, yul::AsmFlavour::Yul).parse(scanner, false);
 		if (parserResult)
 		{
diff --git a/test/libyul/YulOptimizerTest.cpp b/test/libyul/YulOptimizerTest.cpp
index c857d8a5..15d70faa 100644
--- a/test/libyul/YulOptimizerTest.cpp
+++ b/test/libyul/YulOptimizerTest.cpp
@@ -259,7 +259,7 @@ bool YulOptimizerTest::parse(ostream& _stream, string const& _linePrefix, bool c
 	yul::AsmFlavour flavour = m_yul ? yul::AsmFlavour::Yul : yul::AsmFlavour::Strict;
 	ErrorList errors;
 	ErrorReporter errorReporter(errors);
-	shared_ptr<Scanner> scanner = make_shared<Scanner>(CharStream(m_source), "");
+	shared_ptr<Scanner> scanner = make_shared<Scanner>(CharStream(m_source, ""));
 	m_ast = yul::Parser(errorReporter, flavour).parse(scanner, false);
 	if (!m_ast || !errorReporter.errors().empty())
 	{
diff --git a/test/tools/yulopti.cpp b/test/tools/yulopti.cpp
index 5a8a5106..5273bbb9 100644
--- a/test/tools/yulopti.cpp
+++ b/test/tools/yulopti.cpp
@@ -81,7 +81,7 @@ public:
 	bool parse(string const& _input)
 	{
 		ErrorReporter errorReporter(m_errors);
-		shared_ptr<Scanner> scanner = make_shared<Scanner>(CharStream(_input), "");
+		shared_ptr<Scanner> scanner = make_shared<Scanner>(CharStream(_input, ""));
 		m_ast = yul::Parser(errorReporter, yul::AsmFlavour::Strict).parse(scanner, false);
 		if (!m_ast || !errorReporter.errors().empty())
 		{