fixes for escape sequences in unicode literals

Cython/Compiler/Lexicon.py

@@ -61,7 +61,9 @@ def make_lexicon():
     two_oct = octdigit + octdigit
     three_oct = octdigit + octdigit + octdigit
     two_hex = hexdigit + hexdigit
-    escapeseq = Str("\\") + (two_oct | three_oct | two_hex | AnyChar)
+    four_hex = two_hex + two_hex
+    escapeseq = Str("\\") + (two_oct | three_oct | two_hex |
+                             Str('u') + four_hex | Str('x') + two_hex | AnyChar)
     
     bra = Any("([{")
     ket = Any(")]}")

Cython/Compiler/Parsing.py

@@ -565,11 +565,18 @@ def p_string_literal(s):
                 c = systr[1]
                 if c in "'\"\\abfnrtv01234567":
                     chars.append(systr)
-                elif c == 'x':
-                    chars.append('\\x0' + systr[2:])
                 elif c == '\n':
                     pass
-                elif c == 'u':
+                elif c in 'ux':
+                    if kind == 'u':
+                        try:
+                            chars.append(systr.decode('unicode_escape'))
+                        except UnicodeDecodeError:
+                            s.error("Invalid unicode escape '%s'" % systr,
+                                    pos = pos)
+                    elif c == 'x':
+                        chars.append('\\x0' + systr[2:])
+                    else:
                         chars.append(systr)
                 else:
                     chars.append(r'\\' + systr[1:])
@@ -585,8 +592,6 @@ def p_string_literal(s):
                     (sy, s.systring))
     s.next()
     value = ''.join(chars)
-    if kind == 'u':
-        value = value.decode('raw_unicode_escape')
     #print "p_string_literal: value =", repr(value) ###
     return kind, value