Parse identifiers according to spec

If a unicode escape sequence decodes to a char that is
not allowed in the identifier we need to throw a parse
error. So decode before checking whether the char is
valid.

Also fix the set of accepted unicode characters for the
start and in the middle of an identifier to what the spec
demands.

Change-Id: I35075b0587ef4e4edb745750cec6d5c764631c0d
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

1 files changed, 94 insertions, 31 deletions

diff --git a/src/qml/qml/parser/qqmljslexer.cpp b/src/qml/qml/parser/qqmljslexer.cpp
index 0142e94db7..1270fdbc91 100644
--- a/src/qml/qml/parser/qqmljslexer.cpp
+++ b/src/qml/qml/parser/qqmljslexer.cpp
@@ -275,6 +275,59 @@ QChar Lexer::decodeUnicodeEscapeCharacter(bool *ok)
     return QChar();
 }
 
+static inline bool isIdentifierStart(QChar ch)
+{
+    // fast path for ascii
+    if ((ch.unicode() >= 'a' && ch.unicode() <= 'z') ||
+        (ch.unicode() >= 'A' && ch.unicode() <= 'Z') ||
+        ch == '$' || ch == '_')
+        return true;
+
+    switch (ch.category()) {
+    case QChar::Number_Letter:
+    case QChar::Letter_Uppercase:
+    case QChar::Letter_Lowercase:
+    case QChar::Letter_Titlecase:
+    case QChar::Letter_Modifier:
+    case QChar::Letter_Other:
+        return true;
+    default:
+        break;
+    }
+    return false;
+}
+
+static bool isIdentifierPart(QChar ch)
+{
+    // fast path for ascii
+    if ((ch.unicode() >= 'a' && ch.unicode() <= 'z') ||
+        (ch.unicode() >= 'A' && ch.unicode() <= 'Z') ||
+        (ch.unicode() >= '0' && ch.unicode() <= '9') ||
+        ch == '$' || ch == '_' ||
+        ch.unicode() == 0x200c /* ZWNJ */ || ch.unicode() == 0x200d /* ZWJ */)
+        return true;
+
+    switch (ch.category()) {
+    case QChar::Mark_NonSpacing:
+    case QChar::Mark_SpacingCombining:
+
+    case QChar::Number_DecimalDigit:
+    case QChar::Number_Letter:
+
+    case QChar::Letter_Uppercase:
+    case QChar::Letter_Lowercase:
+    case QChar::Letter_Titlecase:
+    case QChar::Letter_Modifier:
+    case QChar::Letter_Other:
+
+    case QChar::Punctuation_Connector:
+        return true;
+    default:
+        break;
+    }
+    return false;
+}
+
 int Lexer::scanToken()
 {
     if (_stackToken != -1) {
@@ -697,28 +750,28 @@ again:
     case '9':
         return scanNumber(ch);
 
-    default:
-        if (ch.isLetter() || ch == QLatin1Char('$') || ch == QLatin1Char('_') || (ch == QLatin1Char('\\') && _char == QLatin1Char('u'))) {
-            bool identifierWithEscapeChars = false;
-            if (ch == QLatin1Char('\\')) {
-                identifierWithEscapeChars = true;
+    default: {
+        QChar c = ch;
+        bool identifierWithEscapeChars = false;
+        if (c == QLatin1Char('\\') && _char == QLatin1Char('u')) {
+            identifierWithEscapeChars = true;
+            bool ok = false;
+            c = decodeUnicodeEscapeCharacter(&ok);
+            if (! ok) {
+                _errorCode = IllegalUnicodeEscapeSequence;
+                _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
+                return T_ERROR;
+            }
+        }
+        if (isIdentifierStart(c)) {
+            if (identifierWithEscapeChars) {
                 _tokenText.resize(0);
-                bool ok = false;
-                _tokenText += decodeUnicodeEscapeCharacter(&ok);
+                _tokenText += c;
                 _validTokenText = true;
-                if (! ok) {
-                    _errorCode = IllegalUnicodeEscapeSequence;
-                    _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
-                    return T_ERROR;
-                }
             }
             while (true) {
-                if (_char.isLetterOrNumber() || _char == QLatin1Char('$') || _char == QLatin1Char('_')) {
-                    if (identifierWithEscapeChars)
-                        _tokenText += _char;
-
-                    scanChar();
-                } else if (_char == QLatin1Char('\\') && _codePtr[0] == QLatin1Char('u')) {
+                c = _char;
+                if (_char == QLatin1Char('\\') && _codePtr[0] == QLatin1Char('u')) {
                     if (! identifierWithEscapeChars) {
                         identifierWithEscapeChars = true;
                         _tokenText.resize(0);
@@ -728,31 +781,41 @@ again:
 
                     scanChar(); // skip '\\'
                     bool ok = false;
-                    _tokenText += decodeUnicodeEscapeCharacter(&ok);
+                    c = decodeUnicodeEscapeCharacter(&ok);
                     if (! ok) {
                         _errorCode = IllegalUnicodeEscapeSequence;
                         _errorMessage = QCoreApplication::translate("QQmlParser", "Illegal unicode escape sequence");
                         return T_ERROR;
                     }
-                } else {
-                    _tokenLength = _codePtr - _tokenStartPtr - 1;
+                    if (isIdentifierPart(c))
+                        _tokenText += c;
+                    continue;
+                } else if (isIdentifierPart(c)) {
+                    if (identifierWithEscapeChars)
+                        _tokenText += c;
+
+                    scanChar();
+                    continue;
+                }
 
-                    int kind = T_IDENTIFIER;
+                _tokenLength = _codePtr - _tokenStartPtr - 1;
 
-                    if (! identifierWithEscapeChars)
-                        kind = classify(_tokenStartPtr, _tokenLength, _qmlMode);
+                int kind = T_IDENTIFIER;
 
-                    if (_engine) {
-                        if (kind == T_IDENTIFIER && identifierWithEscapeChars)
-                            _tokenSpell = _engine->newStringRef(_tokenText);
-                        else
-                            _tokenSpell = _engine->midRef(_tokenStartPtr - _code.unicode(), _tokenLength);
-                    }
+                if (! identifierWithEscapeChars)
+                    kind = classify(_tokenStartPtr, _tokenLength, _qmlMode);
 
-                    return kind;
+                if (_engine) {
+                    if (kind == T_IDENTIFIER && identifierWithEscapeChars)
+                        _tokenSpell = _engine->newStringRef(_tokenText);
+                    else
+                        _tokenSpell = _engine->midRef(_tokenStartPtr - _code.unicode(), _tokenLength);
                 }
+
+                return kind;
             }
         }
+        }
 
         break;
     }