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

[1/3] SourceLocation related refactoring.

7 files changed, 79 insertions, 82 deletions

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(