undo Py3.3 surrogates support fixes - breaks too many special cases with strings

CHANGES.rst

@@ -26,13 +26,6 @@ Features added
 Bugs fixed
 ----------
 
-* Surrogate code points in Unicode string literals failed to compile and/or
-  load in CPython 3.3.  To work around this change introduced by CPython,
-  Cython switched from UTF-8 to Python Unicode escapes ('\u0101') internally
-  for storing literal Unicode strings in C code.  This may add a slight
-  initialisation overhead if a large number of non-Latin1 characters are
-  used in the code.
-
 Other changes
 -------------
 

Cython/Compiler/Code.py

@@ -991,7 +991,7 @@ class GlobalState(object):
     def get_string_const(self, text, py_version=None):
         # return a C string constant, creating a new one if necessary
         if text.is_unicode:
-            byte_string = text.escapeencode()
+            byte_string = text.utf8encode()
         else:
             byte_string = text.byteencode()
         try:
@@ -1006,7 +1006,7 @@ class GlobalState(object):
         # return a Python string constant, creating a new one if necessary
         py3str_cstring = None
         if is_str and unicode_value is not None \
-               and unicode_value.escapeencode() != text.byteencode():
+               and unicode_value.utf8encode() != text.byteencode():
             py3str_cstring = self.get_string_const(unicode_value, py_version=3)
             c_string = self.get_string_const(text, py_version=2)
         else:

Cython/Compiler/StringEncoding.py

@@ -12,8 +12,6 @@ else:
     _unicode, _str, _bytes = unicode, str, str
     IS_PYTHON3 = False
 
-IS_PYTHON24 = sys.version_info[:2] < (2,5)
-
 empty_bytes = _bytes()
 empty_unicode = _unicode()
 
@@ -128,13 +126,6 @@ class EncodedString(_unicode):
         assert self.encoding is None
         return self.encode("UTF-8")
 
-    def escapeencode(self):
-        assert self.encoding is None
-        if IS_PYTHON24:
-            # work around bug in Py24 encoder
-            return self.replace(u'\\', u'\\\\').encode('unicode_escape')
-        return self.encode('unicode_escape')
-
     def is_unicode(self):
         return self.encoding is None
     is_unicode = property(is_unicode)
@@ -156,9 +147,6 @@ class BytesLiteral(_bytes):
     def utf8encode(self):
         assert False, "this is not a unicode string: %r" % self
 
-    def escapeencode(self):
-        assert False, "this is not a unicode string: %r" % self
-
     def __str__(self):
         """Fake-decode the byte string to unicode to support %
         formatting of unicode strings.
@@ -177,8 +165,6 @@ char_from_escape_sequence = {
     r'\v' : u'\v',
     }.get
 
-_c_special = ('\\', '??', '"') + tuple(map(chr, range(32)))
-
 def _to_escape_sequence(s):
     if s in '\n\r\t':
         return repr(s)[1:-1]
@@ -190,22 +176,19 @@ def _to_escape_sequence(s):
         # within a character sequence, oct passes much better than hex
         return ''.join(['\\%03o' % ord(c) for c in s])
 
-def _build_specials_replacer():
+_c_special = ('\\', '??', '"') + tuple(map(chr, range(32)))
+_c_special_replacements = [(orig.encode('ASCII'),
+                            _to_escape_sequence(orig).encode('ASCII'))
+                           for orig in _c_special ]
+
+def _build_specials_test():
     subexps = []
-    replacements = {}
     for special in _c_special:
         regexp = ''.join(['[%s]' % c.replace('\\', '\\\\') for c in special])
         subexps.append(regexp)
-        replacements[special.encode('ASCII')] = _to_escape_sequence(special).encode('ASCII')
-
-    sub = re.compile(('(%s)' % '|'.join(subexps)).encode('ASCII')).sub
-    def replace_specials(m):
-        return replacements[m.group(1)]
-    def replace(s):
-        return sub(replace_specials, s)
-    return replace
+    return re.compile('|'.join(subexps).encode('ASCII')).search
 
-_replace_specials = _build_specials_replacer()
+_has_specials = _build_specials_test()
 
 def escape_char(c):
     if IS_PYTHON3:
@@ -227,7 +210,10 @@ def escape_byte_string(s):
     encoded as ISO-8859-1, will result in the correct byte sequence
     being written.
     """
-    s = _replace_specials(s)
+    if _has_specials(s):
+        for special, replacement in _c_special_replacements:
+            if special in s:
+                s = s.replace(special, replacement)
     try:
         return s.decode("ASCII") # trial decoding: plain ASCII => done
     except UnicodeDecodeError:

Cython/Utility/StringTools.c

@@ -17,7 +17,7 @@ static int __Pyx_InitStrings(__Pyx_StringTabEntry *t) {
     while (t->p) {
         #if PY_MAJOR_VERSION < 3
         if (t->is_unicode) {
-            *t->p = PyUnicode_DecodeUnicodeEscape(t->s, t->n - 1, NULL);
+            *t->p = PyUnicode_DecodeUTF8(t->s, t->n - 1, NULL);
         } else if (t->intern) {
             *t->p = PyString_InternFromString(t->s);
         } else {
@@ -25,13 +25,12 @@ static int __Pyx_InitStrings(__Pyx_StringTabEntry *t) {
         }
         #else  /* Python 3+ has unicode identifiers */
         if (t->is_unicode | t->is_str) {
-            if (unlikely(t->encoding)) {
+            if (t->intern) {
+                *t->p = PyUnicode_InternFromString(t->s);
+            } else if (t->encoding) {
                 *t->p = PyUnicode_Decode(t->s, t->n - 1, t->encoding, NULL);
             } else {
-                *t->p = PyUnicode_DecodeUnicodeEscape(t->s, t->n - 1, NULL);
-            }
-            if (t->intern && likely(*t->p)) {
-                PyUnicode_InternInPlace(t->p);
+                *t->p = PyUnicode_FromStringAndSize(t->s, t->n - 1);
             }
         } else {
             *t->p = PyBytes_FromStringAndSize(t->s, t->n - 1);

tests/run/unicodeliterals.pyx

@@ -17,10 +17,6 @@ __doc__ = br"""
     u'\x03g\xf8\uf8d2S\xf8k ik'
     >>> f
     u'\xf8'
-    >>> g
-    u'\udc00'
-    >>> h
-    u'\ud800'
     >>> add
     u'S\xf8k ik\xfc\xd6\xe4abc'
     >>> null
@@ -40,10 +36,6 @@ __doc__ = br"""
     10
     >>> len(f)
     1
-    >>> len(g)
-    1
-    >>> len(h)
-    1
     >>> len(add)
     12
     >>> len(null)
@@ -71,10 +63,6 @@ __doc__ = br"""
     True
     >>> f == u'\\xf8' # unescaped by Python
     True
-    >>> g == u'\\udc00' # unescaped by Python (required by doctest)
-    True
-    >>> h == u'\\ud800' # unescaped by Python (required by doctest)
-    True
     >>> k == u'\\N{SNOWMAN}' == u'\\u2603'
     True
     >>> add == u'Søk ik' + u'üÖä' + 'abc'
@@ -107,8 +95,6 @@ c = u'Søk ik'
 d = u'üÖä'
 e = u'\x03\x67\xf8\uf8d2Søk ik'
 f = u'\xf8'
-g = u'\udc00'   # lone trail surrogate
-h = u'\ud800'   # lone lead surrogate
 k = u'\N{SNOWMAN}'
 
 add = u'Søk ik' + u'üÖä' + u'abc'